CN113120782B

CN113120782B - Auxiliary arm, crane, auxiliary arm unfolding method and auxiliary arm retracting method

Info

Publication number: CN113120782B
Application number: CN202110475361.1A
Authority: CN
Inventors: 马善华; 张艳伟; 朱威; 李伟
Original assignee: Xuzhou Heavy Machinery Co Ltd
Current assignee: Xuzhou Heavy Machinery Co Ltd
Priority date: 2021-04-29
Filing date: 2021-04-29
Publication date: 2024-02-13
Anticipated expiration: 2041-04-29
Also published as: CN113120782A

Abstract

The invention discloses an auxiliary arm, a crane, an auxiliary arm unfolding method and an auxiliary arm retracting method, and relates to the field of engineering machinery. The secondary arm includes a secondary arm body and a jackscrew mechanism. The auxiliary arm body includes a connection frame having a first connection hole and a second connection hole, the first and second connection holes being coaxially arranged. The jackscrew mechanism comprises a first shaft, a second shaft and a driving mechanism; the first shaft and the second shaft are both disposed between the first connection hole and the second connection hole, and the first shaft and the second shaft are both coaxial with the first connection hole. The driving mechanism is in driving connection with the first shaft and the second shaft so as to drive the first shaft and the second shaft to extend and retract simultaneously. Wherein when the first shaft is in an extended state, the first shaft is inserted into the first connecting hole, and when the first shaft is in a retracted state, the first shaft is separated from the first connecting hole; the second shaft is inserted into the second connection hole when the second shaft is in the extended state, and the second shaft is separated from the second connection hole when the second shaft is in the retracted state.

Description

Auxiliary arm, crane, auxiliary arm unfolding method and auxiliary arm retracting method

Technical Field

The invention relates to the field of engineering machinery, in particular to an auxiliary arm, a crane, an auxiliary arm unfolding method and an auxiliary arm retracting method.

Background

In order to obtain a suitable lifting height and amplitude, the crane is designed with several telescopic lifting arms. But is limited by the structure and the weight, in the related art, the main arm is 3-7 sections; for medium and small tonnage cranes, the main arm is generally not more than 5 knots. In order to further extend the length of the boom to achieve a higher lifting height and amplitude, the crane is equipped with a secondary boom. When not in use, the auxiliary arm is arranged on one side of the basic arm of the main arm; when the auxiliary arm is required to be used, the auxiliary arm is mounted on the head of the tail section arm of the main arm, and the auxiliary arm is connected with the tail section arm through a pin shaft.

In the related art, when the auxiliary arm is unfolded, after the related connecting pin shaft is removed, the auxiliary arm is rotated around a rotating shaft of a front bracket arranged on the main arm, and the auxiliary arm is rotated to align with a connecting hole on one side of the arm head of the tail arm in the width direction; then two first connecting pin shafts are inserted; then, the front support pin shaft is pulled out, and the auxiliary arm is continuously pushed to rotate around the first connecting pin shaft until the mounting hole on the other side of the auxiliary arm is aligned with the hole on the other side of the arm head in the width direction; and then two second connecting pin shafts are inserted to finish the installation and fixation of the auxiliary arm. The recovery auxiliary arm is required to gradually pull out each connecting pin shaft.

The fixed auxiliary arm is arranged on two sides of the arm support in the width direction by pin shafts, and two pin shafts are coaxially arranged on each side in the width direction. During installation, the auxiliary arm is rotated to align the auxiliary arm installation hole with the main arm connection hole, and then the four connection pins are knocked into the holes sequentially by using a tool.

The inventors found that at least the following problems exist in the prior art: in the existing auxiliary arm pin shaft mounting mode, because the auxiliary arm mounting hole and the main arm connecting hole are difficult to accurately align due to the limitation of machining errors, pin shaft penetration and extraction are difficult. Copper hammer is usually required to be used for knocking, the position of the arm head is higher, particularly the position of the pin shaft above the arm head is high, and an operator needs to ascend to finish the disassembling and assembling operation of the pin shaft. The installation efficiency is low and the operation is inconvenient.

Disclosure of Invention

The invention provides an auxiliary arm, a crane, an auxiliary arm unfolding method and an auxiliary arm retracting method, which are used for simplifying the installation and the disassembly of the auxiliary arm.

The embodiment of the invention provides a secondary arm, which comprises the following components:

a sub-arm body including a connection frame having a first connection hole and a second connection hole coaxially arranged; and

the jackscrew mechanism comprises a first shaft, a second shaft and a driving mechanism; the first shaft and the second shaft are both disposed between the first connection hole and the second connection hole, and the first shaft and the second shaft are both coaxial with the first connection hole; the driving mechanism is in driving connection with the first shaft and the second shaft so as to drive the first shaft and the second shaft to extend and retract simultaneously;

wherein when the first shaft is in an extended state, the first shaft is inserted into the first connection hole, and when the first shaft is in a retracted state, the first shaft is separated from the first connection hole; and when the second shaft is in an extending state, the second shaft is inserted into the second connecting hole, and when the second shaft is in a retracting state, the second shaft is separated from the second connecting hole.

In some embodiments, the drive mechanism comprises:

the first connecting seat is fixedly connected with the connecting frame; the first connecting seat is provided with a first through hole allowing the first shaft to pass through;

the second connecting seat is also fixedly connected with the connecting frame; the second connecting seat is provided with a second through hole for allowing the second shaft to pass through; and

a drum disposed between the first and second connection seats, and rotatably connected to at least one of the first and second connection seats;

the first shaft is provided with a first thread towards one end of the rotary drum, the first end of the rotary drum is correspondingly provided with a first thread section, the first thread is in threaded fit with the first thread section, and the first shaft is positioned in the first through hole; the second shaft is provided with a second thread towards one end of the rotary drum, the second end of the rotary drum is correspondingly provided with a second thread section, the second thread and the second thread section form threaded fit, and the second shaft is positioned in the second through hole; the first thread and the second thread are of opposite hand.

In some embodiments, the drive mechanism further comprises:

the inner ring of the first bearing is sleeved on the rotary drum;

the first end cover is provided with a first inner concave part and is fixedly connected with the outer ring of the first bearing and the second connecting seat; and

the second end cover is provided with a second inner concave part and is fixedly connected with the outer ring of the first bearing and the second connecting seat;

wherein the first and second recesses mate to form a mounting cavity for receiving the first bearing.

In some embodiments, the outer wall of the second end of the drum is provided with engagement teeth; the drive mechanism further includes:

the gear is positioned outside the rotary drum and positioned in the second through hole of the second connecting seat; the gear is meshed with the meshing teeth; and

a gear shaft inserted into the through hole of the gear; the gear shaft is rotatably connected with the second connecting seat.

In some embodiments, the number of teeth of the gear is less than the number of teeth of the engagement teeth provided on the outer wall of the second end of the drum.

In some embodiments, one end of the gear shaft protrudes out of the second through hole of the second connection seat, and a portion of the gear shaft located outside the second through hole is configured to be non-circular.

In some embodiments, the jackscrew mechanism further comprises:

the guide mechanism comprises a first guide piece, a second guide piece and a first guide piece, wherein the first guide piece comprises a first mounting end and a first extending end; the first installation end is installed on the first connecting seat, and the first extending end extends into the first through hole;

the outer wall of the first shaft is provided with a first sliding groove, and the length direction of the first sliding groove is parallel to the axis direction of the first shaft; the first protruding end is inserted into the first chute.

In some embodiments, the guide mechanism further comprises:

a second guide member including a second mounting end and a second projecting end; the second installation end is installed on the second connecting seat, and the second extending end extends into the second through hole;

the outer wall of the second shaft is provided with a second sliding groove, and the length direction of the second sliding groove is parallel to the axis direction of the second shaft; the second protruding end is inserted into the second sliding groove.

In some embodiments, the first shaft has a dimension away from an end of the drum that is less than a dimension of the first shaft toward an end of the drum; and/or the dimension of the end of the second shaft away from the drum is smaller than the dimension of the end of the second shaft towards the drum.

In some embodiments, at least one set of the first connection hole and the second connection hole is provided on each side of the connection frame along the width direction of the sub-arm body; the jackscrew mechanism is arranged between each group of the first connecting holes and the second connecting holes.

The embodiment of the invention also provides a crane, which comprises the auxiliary arm provided by any technical scheme of the invention.

The embodiment of the invention also provides a method for expanding the auxiliary arm, wherein the auxiliary arm is provided by any technical scheme of the invention, and the method for expanding the auxiliary arm comprises the following steps:

the auxiliary arm is rotationally connected around the first bracket until the first connecting hole and the second connecting hole positioned at one side of the width direction of the auxiliary arm are aligned with the inserting holes of the main arms respectively; wherein, along the width direction of the main arm, each side of the main arm is provided with two coaxial plug holes; the first bracket is arranged on the main arm, and the auxiliary arm is rotatably connected with the first bracket; wherein the first bracket is fixed to the main arm;

the driving mechanism of the sub arm is driven such that the first shaft located at one side in the width direction of the sub arm is inserted into the first connection hole and one of the insertion holes, and the second shaft is inserted into the second connection hole and the other of the insertion holes.

In some embodiments, the method of forearm deployment further comprises the steps of:

continuing to rotate the auxiliary arm until the first connecting hole and the second connecting hole positioned on the other side of the width direction of the auxiliary arm are aligned with the inserting holes of the main arms respectively;

the driving mechanism of the sub arm is driven such that the first shaft located on the other side in the width direction of the sub arm is inserted into the first connection hole and one of the insertion holes, and the second shaft is inserted into the second connection hole and the other of the insertion holes.

The embodiment of the invention also provides a method for retracting the auxiliary arm, wherein the auxiliary arm is provided by any technical scheme of the invention, and the method for retracting the auxiliary arm comprises the following steps:

a driving mechanism for driving the jackscrew mechanism on one side of the auxiliary arm far away from the first bracket, so that the first shaft and the second shaft driven by the driving mechanism retract to disconnect the auxiliary arm and the main arm;

continuing to rotate the auxiliary arm until the auxiliary arm is close to the first bracket of the main arm;

connecting the auxiliary arm with the first bracket;

continuing to rotate the secondary arm so that the secondary arm is proximate to a second bracket mounted to the primary arm; wherein the second bracket and the first bracket are arranged at intervals;

a driving mechanism that drives the jack mechanism near one side of the first bracket so that the first shaft and the second shaft driven by the driving mechanism are retracted so that the sub-arm and the main arm are disconnected;

and connecting the auxiliary arm with the second bracket.

The auxiliary arm provided by the technical scheme has the auxiliary arm main body and the jackscrew mechanism, the connecting frame of the auxiliary arm main body is matched with the first shaft and the second shaft of the jackscrew mechanism, and the auxiliary arm is convenient to install and detach by extending and retracting the first shaft and the second shaft simultaneously. And the installation, the disassembly and the installation efficiency of the first shaft and the second shaft can be improved by at least one time by one operation.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:

FIG. 1 is a schematic diagram of a connection state between a secondary arm and a primary arm according to an embodiment of the present invention;

FIG. 2 is a schematic view of a sub-arm and a main arm in a connection state at a connection frame in an enlarged part according to an embodiment of the present invention;

FIG. 3 is an enlarged partial schematic view of a sub-arm at a connection frame according to an embodiment of the present invention;

fig. 4 is a schematic perspective view of a jackscrew mechanism of a secondary arm according to an embodiment of the present invention;

FIG. 5 is an exploded view of a screw mechanism of a secondary arm according to an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of a secondary arm jackscrew mechanism provided in an embodiment of the present invention in a retracted state;

FIG. 7 is a schematic cross-sectional view of a secondary arm jackscrew mechanism in an extended state provided by an embodiment of the present invention;

FIG. 8 is a schematic flow chart of a method for expanding a sub-arm according to other embodiments of the present invention;

fig. 9 is a flowchart of a method for retracting a sub-arm according to still other embodiments of the present invention.

Detailed Description

The technical scheme provided by the invention is described in more detail below with reference to fig. 1 to 9.

The terminology and terminology used herein are explained.

Main arm: also called the main boom. The main arm is a telescopic arm used for hoisting on a crane and consists of 3-7 sections of arms. The basic arm of the main arm is positioned at the outermost section of the main arm, and the main arm keeps the position motionless when stretching. The last section arm of the main arm is the innermost section of the main arm, and the main arm is positioned at the highest position when extending out and is connected with the lifting hook to carry out the hanging operation. One or more intermediate arms are provided between the base arm and the end arm of the main arm.

Auxiliary arm: also known as a secondary boom, may be mounted to the main boom finish arm head for extending the boom length to achieve a higher lifting height.

Referring to fig. 1, an embodiment of the present invention provides a sub-arm 100, which sub-arm 100 is used to extend the boom length of a crane. The sub-arm 100 is mounted to the head of the final arm of the main arm 200 of the crane, if necessary, so that the length of the entire boom increases. After use, the sub arm 100 is detached from the head of the last arm of the main arm 200 and attached to the side of the main arm 200. The auxiliary arm 100 provided by the embodiment of the invention is used for simplifying the mounting and dismounting actions between the auxiliary arm 100 and the main arm 200, so that the auxiliary arm of the crane is more convenient, reliable and efficient to mount and dismount.

Referring to fig. 1 to 3, the sub-arm 100 includes a sub-arm body 1 and a jack mechanism 2. The sub arm body 1 includes a link 11, the link 11 having a first link hole 111 and a second link hole 112, the first link hole 111 and the second link hole 112 being coaxially arranged. Referring to fig. 4 and 5, the jack mechanism 2 includes a first shaft 21, a second shaft 22, and a drive mechanism 23. The first shaft 21 and the second shaft 22 are both disposed between the first connection hole 111 and the second connection hole 112, and the first shaft 21 and the second shaft 22 are both coaxial with the first connection hole 111. The driving mechanism 23 is in driving connection with the first shaft 21 and the second shaft 22 to drive the first shaft 21 and the second shaft 22 to extend and retract simultaneously. Wherein, referring to fig. 7, when the first shaft 21 is in the extended state, the first shaft 21 is inserted into the first connection hole 111. Referring to fig. 6, when the first shaft 21 is in the retracted state, the first shaft 21 is separated from the first connection hole 111. Referring to fig. 7, when the second shaft 22 is in the extended state, the second shaft 22 is inserted into the second connection hole 112. Referring to fig. 6, when the second shaft 22 is in the retracted state, the second shaft 22 is away from the second connection hole 112.

The auxiliary arm body 1 comprises an arm support 12 and a connecting frame 11, and the length and the size of the arm support 12 are set according to requirements. The connecting frame 11 is located at the end of the arm support 12. The connection between the main arm 200 and the sub arm 100 is achieved by the connection frame 11. When the sub-arm 100 is required to operate, the main arm 200 and the sub-arm 100 are connected together. When the sub-arm 100 is not required to operate, the main arm 200 and the sub-arm 100 are disconnected, and then the sub-arm 100 is mounted to the side of the main arm 200.

Referring to fig. 2 and 3, in some embodiments, at least one set of first and second connection holes 111 and 112 are provided at both sides of the connection frame 11 in the width direction of the sub-arm body 1. A jack screw mechanism 2 is arranged between each set of the first connection hole 111 and the second connection hole 112.

Referring to fig. 2 and 3, the connection frame 11 is a substantially rectangular frame, and each corner of the rectangular frame is provided with a boss, each boss having one or two connection holes. Taking the direction in which the connection frame 11 is in use as an example, i.e. the direction illustrated in fig. 3, the connection hole at the top is the first connection hole 111, and the connection hole at the bottom is the second connection hole 112. The first connecting hole 111 corresponds to the plugging hole of the corresponding position of the main arm 200, namely, the first plugging hole 201; the first connection hole 111 also corresponds to the first shaft 21. The second connecting hole 112 corresponds to another plug hole at the corresponding position of the main arm 200, namely, the second plug hole 202; the second connecting hole 112 also corresponds to the second shaft 22.

The first shaft 21 and the second shaft 22 are simultaneously extended and simultaneously retracted. For convenience of description, both sides in the width direction of the sub arm 100 are denoted as a side and B side. Wherein the first shaft 21 and the second shaft 22 on the a side are simultaneously in the extended state and simultaneously in the retracted state. The first shaft 21 and the second shaft 22 on the B side are simultaneously in the extended state and simultaneously in the retracted state. The a side corresponds to a side of the main arm 200 near the first bracket, and the B side corresponds to a side of the main arm 200 far from the first bracket. When the sub-arm 100 is mounted, the first shaft 21 and the second shaft 22 on the a side are protruded first, and the first shaft 21 and the second shaft 22 on the B side are protruded first. When the sub-arm 100 is detached, the first shaft 21 and the second shaft 22 on the B side are retracted first, and the first shaft 21 and the second shaft 22 on the a side are retracted later.

Referring to fig. 2 and 3, one jack mechanism 2 is arranged on each of the a side and the B side in the width direction of the sub-arm 100. As described above, the connecting frame 11 is substantially rectangular. Between the two projections of the connecting frame 11 on the a side, a jackscrew mechanism 2 is arranged. A jackscrew mechanism 2 is also arranged between the two projections of the connecting frame 11 on the B side. The two jack mechanisms 2 may be implemented in the same way.

Referring to fig. 2, 4 and 5, the jack mechanism 2 includes a first shaft 21 and a second shaft 22 coaxially disposed. In the mounted state of the sub-arm 100, the axes of the first shaft 21 and the second shaft 22 of the jack mechanism 2 positioned on the a side are coaxial with the first connection hole 111, the second connection hole 112, and the first insertion hole 201 positioned on the a side. The axes of the first shaft 21 and the second shaft 22 of the plug screw mechanism 2 positioned on the side B are coaxial with the first connecting hole 111, the second connecting hole 112 and the second plug hole 202 positioned on the side B. The first shaft 21 and the second shaft 22 of each jack mechanism 2 are operated simultaneously, i.e., extend and retract simultaneously. A linkage mechanism may be employed to achieve synchronous motion of the first shaft 21 and the second shaft 22.

Referring to fig. 3 to 7, in particular, the drive mechanism 23 of the jack mechanism 2 adopts the implementation described below.

Referring to fig. 3-7, in some embodiments, the drive mechanism 23 includes a first coupling seat 231, a second coupling seat 232, and a drum 233.

The first connecting seat 231 is fixedly connected with the connecting frame 11; the first connection seat 231 has a first through hole 231a. The first connection seat 231 and the connection frame 11 are fixed together by welding with the protrusions located at the top as shown in fig. 3. The protrusion has a first connection hole 111. The first through hole 231a of the first coupling seat 231 and the first coupling hole 111 of the protrusion are coaxial at all times, i.e., coaxial regardless of whether the sub-arm 100 is in the use state or the standby state. The first shaft 21 is extended and retracted in the first through hole 231a. When the first shaft 21 is protruded outside the first through hole 231a, it is inserted into the first connection hole 111 with continued protrusion. When the first shaft 21 is retracted, it is retracted from the first connection hole 111 into the first through hole 231a.

The second connecting seat 232 is also fixedly connected with the connecting frame 11; the second connection base 232 has a second through hole 232a. The second connector base 232 and the connector frame 11 are welded together by a protrusion at the bottom as shown in fig. 3. The bottom protrusion has a second connection hole 112. The second through hole 232a of the second connecting seat 232 and the protruding second connecting hole 112 of the bottom are coaxial all the time, i.e. whether the sub-arm 100 is in the use state or in the standby state. The second shaft 22 extends and retracts within the second through hole 232a. When the second shaft 22 is extended to the outside of the second through hole 232a, it is inserted into the second connection hole 112 while being continued to be extended. The second shaft 22 is retracted from the second connecting hole 112 into the second through hole 232a when retracted.

The drum 233 is disposed between the first and second connection seats 231 and 232, and the drum 233 is rotatably connected with at least one of the first and second connection seats 231 and 232. Wherein the first shaft 21 is provided with a first thread 210 towards one end of the drum 233, and the first end of the drum 233 is correspondingly provided with a first thread segment 233b. The first thread 210 and the first thread segment 233b are threadedly engaged. The first shaft 21 is located in the first through hole 231a. The second shaft 22 is provided with a second thread 220 towards one end of the drum 233, and a second end of the drum 233 is correspondingly provided with a second thread segment 233c. The second thread 220 forms a threaded engagement with the second thread segment 233c. The first thread 210 and the second thread 220 are oppositely threaded.

Rotating the drum 233 in a first direction, the first shaft 21 and the second shaft 22 extend simultaneously. Rotating in the second direction, the first shaft 21 and the second shaft 22 retract simultaneously. The first direction and the second direction are opposite.

In the above technical solution, the drum 233 is rotated by an external force, and the drum 233 drives the first shaft 21 and the second shaft 22 to move up and down linearly. And through the rotatory promotion of screw thread, utilized the less screw thread lift angle of screw thread, can push first axle 21 and second axle 22 flexible with less power, make the installation steadily laborsaving, actuating mechanism 23 size is little, the action is firm reliable, and the operation is very convenient.

With continued reference to fig. 4-7, in some embodiments, the drive mechanism 23 further includes a first bearing 234, a first end cap 235, and a second end cap 236.

The inner ring of the first bearing 234 is sleeved on the drum 233.

The first end cap 235 has a first concave portion, and the first end cap 235 is fixedly connected to both the outer race of the first bearing 234 and the second connecting seat 232.

The second end cover 236 has a second concave portion, and the second end cover 236 is fixedly connected to the outer ring of the first bearing 234 and the second connecting seat 232. Wherein the first and second recesses mate to form a mounting cavity for receiving the first bearing 234. During rotation of the drum 233, neither the first end cap 235 nor the second end cap 236 rotates with the drum 233, but the first bearing 234 rotates with the drum 233. The first and second end caps 235 and 236 function to protect the first bearing 234 from foreign objects entering the first bearing 234 and also avoid danger to an operator due to the rotation of the first bearing 234.

The first end cover 235, the second end cover 236 and the second connecting seat 232 are fixedly connected through a plurality of connecting bolts 239. This makes the structure of the entire jack mechanism 2 more stable.

In the above technical solution, the rotatable connection between the drum 233 and the second connection base 232 is achieved by means of bearings. The rotatable connecting mechanism is not required to be arranged between the first connecting seat 231 and the rotary drum 233, and the whole jackscrew mechanism 2 is compact in structure and reliable in action.

With continued reference to fig. 4-7, a description will now be given of how the drum 233 can be easily rotated. In some embodiments, the outer wall of the second end of the drum 233 is provided with engagement teeth 233a; the drive mechanism 23 also includes a gear 237 and a gear shaft 238. The gear 237 is located outside the drum 233 and in the second through hole 232a of the second connection block 232; the gear 237 is meshed with the meshing teeth 233 a. The gear shaft 238 is inserted into the through hole of the gear 237; the gear shaft 238 is rotatably coupled to the second connector base 232. The number of teeth of the gear 237 is smaller than the number of teeth of the engaging teeth 233a provided on the outer wall of the second end of the drum 233, so that the input force is further reduced, and the difficulty in mounting and dismounting the auxiliary arm 100 is reduced. According to the technical scheme, the rotary drum 233 can be rotated by rotating the gear 237, so that the rotary drum 233 can be rotated more conveniently.

In some embodiments, one end of the gear shaft 238 protrudes out of the second through hole 232a of the second connection socket 232, and a portion of the gear shaft 238 located outside the second through hole 232a is configured to be non-circular. The gear shaft 238 may be rotated by a tool such as an electric wrench, and a portion of the gear shaft 238 located outside the second through hole 232a is configured to be non-circular, such that the gear shaft 238 is well stressed and is not easily slipped during the rotation. In addition, the gear shaft 238 is located at one end of the second connecting seat 232 away from the first connecting seat 231, and is relatively low, so that an operator does not need to ascend, and the installation operation of the auxiliary arm 100 can be completed from the ground, thereby avoiding the danger caused by ascending.

With continued reference to fig. 4-7, the first shaft 21, the second shaft 22, and the drum 233 are threadably engaged, and some rotation may occur during rotation of the first shaft 21 and the second shaft 22, in order to reduce this, such that the first shaft 21 is firmly moved linearly up and down, and in some embodiments, the jackscrew mechanism 2 further includes a guide mechanism 24. The guide mechanism 24 includes a first guide member 241, the first guide member 241 including a first mounting end 241a and a first protruding end 241b. The first mounting end 241a is, for example, a nut. The first protruding end 241b is, for example, a bolt. The first mounting end 241a is mounted to the first connection seat 231, and the first protruding end 241b protrudes into the first through hole 231a. Wherein, the outer wall of the first shaft 21 is provided with a first chute 211, and the length direction of the first chute 211 is parallel to the axis direction of the first shaft 21; the protruding end of the first guide 241 is inserted into the first sliding groove 211. The first guide 241 is, for example, a bolt fixedly mounted to the first coupling seat 231, and the bolt is fixed during the linear movement of the first shaft 21 to be extended and retracted. The extending end of the bolt is always positioned in the first sliding groove 211 of the first shaft 21 so as to ensure that the first shaft 21 extends linearly and retracts linearly.

Referring to fig. 5, in some embodiments, the guide mechanism 24 includes a second guide 242, the second guide 242 including a second mounting end 242a and a second protruding end 242b; the second mounting end 242a is mounted to the second connecting base 232, and the second protruding end 242b protrudes into the second through hole 232a. The outer wall of the second shaft 22 is provided with a second chute 221, and the length direction of the second chute 221 is parallel to the axis direction of the second shaft 22; the second protruding end 242b of the second guide 242 is inserted into the second chute 221. The second guide 242 is, for example, a bolt fixedly mounted to the second connecting base 232, and the bolt is stationary during the linear movement of the second shaft 22 for extension and retraction. The extending end of the bolt is always located in the second sliding groove 221 of the second shaft 22, so as to ensure that the second shaft 22 extends linearly and retracts linearly.

Referring to fig. 4-7, in some embodiments, the dimension of the end of the first shaft 21 remote from the drum 233 is less than the dimension of the end of the first shaft 21 toward the drum 233. The end of the first shaft 21 is pointed to facilitate insertion into the first connection hole 111.

With continued reference to fig. 4-7, the dimension of the end of the second shaft 22 remote from the drum 233 is less than the dimension of the end of the second shaft 22 toward the drum 233. The end of the second shaft 22 is pointed to facilitate insertion into the second connection hole 112.

The embodiment of the invention also provides a crane, which comprises the auxiliary arm 100 provided by any technical scheme of the invention.

Referring to fig. 8, an embodiment of the present invention further provides a method for expanding a sub-arm, where the sub-arm 100 is the sub-arm 100 provided in any of the embodiments of the present invention. The sub-arm 100 is used for a crane. The main arm 200 of the crane comprises a first bracket (not shown) and a second bracket (not shown). The first brackets and the second brackets are disposed apart in the length direction of the main arm 200 and are located at the side of the main arm 200. The auxiliary arm unfolding method comprises the following steps:

in step S110, the sub-arm 100 is rotatably connected around the first bracket until the first connection hole 111 and the second connection hole 112 located at one side of the sub-arm 100 in the width direction are aligned with the insertion holes of the respective main arms 200. Wherein, along the width direction of the main arm 200, two coaxial plug holes are arranged on each side of the main arm 200, namely, two first plug holes 201 on the A side and two second plug holes 202 on the A side are coaxial, and two first plug holes 201 on the B side and two second plug holes 202 on the B side are coaxial. The first bracket is mounted on the main arm 200, and the auxiliary arm 100 is rotatably connected with the first bracket;

step S120 of driving the driving mechanism 23 of the sub-arm 100 such that the first shaft 21 located at one side in the width direction of the sub-arm 100 is inserted into the first connection hole 111 and one of the insertion holes, and at the same time, the second shaft 22 is inserted into the second connection hole 112 and the other insertion hole. That is, the first shaft 21 and the second shaft 22 on the a side are simultaneously protruded such that the first shaft 21 is inserted into the first connection hole 111 and the first insertion hole 201 on the a side, and the second shaft 22 is inserted into the second connection hole 112 and the second insertion hole 202 on the a side.

The steps of inserting the first shaft 21 and the second shaft 22 are as follows: when the sub-arm 100 is mounted, the sub-arm 100 is turned into the first connection hole 111 of the sub-arm 100. After the connecting holes 112 are aligned with the first inserting holes of the main arm 200, the gear 237 is rotated by using a manual or automatic tool, the gear 237 drives the rotary drum 233 to rotate, the inner side threads of the rotary drum 233 push the first shaft 21 and the second shaft 22 to extend upwards and downwards simultaneously, and the inner side threads penetrate into the first connecting holes 111, the second connecting holes 112 and the first inserting holes, so that the locking of the side A auxiliary arm 100 is completed. Then, the sub arm 100 is pushed to rotate around the a-side screw shaft, and the first shaft 21 and the second shaft 22 of the other B-side screw mechanism 2 are mounted, thereby locking the sub arm 100.

With continued reference to fig. 8, in some embodiments, the forearm deployment method further includes the steps of:

step S130, the sub-arm 100 is continuously rotated until the first connection hole 111 and the second connection hole 112 on the other side, i.e., the B side, of the width direction of the sub-arm 100 are also aligned with the insertion holes of the respective main arms 200. That is, the first connection hole 111 on the B side is aligned with the first insertion hole 201 of the main arm 200 on the B side, and the second connection hole 112 on the B side is aligned with the second insertion hole 202 of the main arm 200 on the B side.

Step S140, driving the driving mechanism 23 of the sub-arm 100 such that the first shaft 21 located on the other side, i.e., the B-side, in the width direction of the sub-arm 100 is inserted into the first connection hole 111 and the first insertion hole 201, and the second shaft 22 is inserted into the second connection hole 112 and the second insertion hole 202.

The above technical solution realizes convenient installation of the main arm 200 and the auxiliary arm 100.

Referring to fig. 9, the embodiment of the present invention further provides a method for retracting a sub-arm, where the sub-arm 100 is the sub-arm 100 provided by any one of the embodiments of the present invention. The sub-arm 100 is used for a crane. The main arm 200 of the crane comprises a first bracket and a second bracket. The first brackets and the second brackets are disposed apart in the length direction of the main arm 200 and are located at the side of the main arm 200. The sub-arm retraction method is arranged in reverse to the sub-arm 100 installation method. The auxiliary arm retraction method comprises the following steps:

step S210, driving the driving mechanism 23 of the jack mechanism 2 on the side far from the first bracket so that the first shaft 21 and the second shaft 22 driven by the driving mechanism 23 are retracted to disconnect the sub arm 100 and the main arm 200. I.e., the first shaft 21 and the second shaft 22 on the B side are both retracted, thus disconnecting the main arm 200 and the sub arm 100 on the B side.

The specific operation steps are as follows: when the auxiliary arm 100 is detached, the gear 237 is rotated in the opposite direction to that when the auxiliary arm 100 is installed, the rotation of the gear 237 drives the rotary drum 233 to synchronously rotate, and the rotation of the rotary drum 233 drives the first shaft 21 and the second shaft 22 which are in threaded connection with the rotary drum 233 to retract, so that the retraction of the first shaft 21 and the second shaft 22 on the side B is realized.

Step S220, the auxiliary arm 100 is continuously turned until the auxiliary arm 100 approaches the first bracket of the main arm 200.

Step S230, connecting the sub-arm 100 to the first bracket.

Step S240, continuing to rotate the auxiliary arm 100 so that the auxiliary arm 100 approaches the second bracket, and the second bracket is mounted on the main arm 200. Wherein the second bracket and the first bracket are arranged at intervals.

Step S250, driving the driving mechanism 23 of the jack mechanism 2 near one side of the first bracket so that the first shaft 21 and the second shaft 22 driven by the driving mechanism 23 are retracted so that the sub arm 100 and the main arm 200 are disconnected. I.e., simultaneously retracting the first shaft 21 and the second shaft 22 on the a side, the connection of the main arm 200 and the sub arm 100 on the a side is disconnected.

Step S260, the sub-arm 100 is connected to the second bracket.

The above technical solution realizes convenient disassembly of the main arm 200 and the auxiliary arm 100.

In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the protection of the present invention.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be replaced with others, which may not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A secondary arm, comprising:

a sub-arm main body (1) including a connection frame (11), the connection frame (11) having a first connection hole (111) and a second connection hole (112), the first connection hole (111) and the second connection hole (112) being coaxially arranged; and

a jackscrew mechanism (2) comprising a first shaft (21), a second shaft (22) and a driving mechanism (23); -said first shaft (21) and said second shaft (22) are both arranged between said first connection hole (111) and said second connection hole (112), and-said first shaft (21) and said second shaft (22) are both coaxial with said first connection hole (111); the driving mechanism (23) is in driving connection with the first shaft (21) and the second shaft (22) so as to drive the first shaft (21) and the second shaft (22) to extend and retract simultaneously;

wherein, when the first shaft (21) is in an extended state, the first shaft (21) is inserted into the first connection hole (111); when the first shaft (21) is in a retracted state, the first shaft (21) is separated from the first connecting hole (111); when the second shaft (22) is in an extended state, the second shaft (22) is inserted into the second connection hole (112); when the second shaft (22) is in a retracted state, the second shaft (22) is separated from the second connecting hole (112);

wherein the driving mechanism (23) comprises:

the first connecting seat (231) is fixedly connected with the connecting frame (11); the first connection seat (231) has a first through hole (231 a) allowing the first shaft (21) to pass through;

the second connecting seat (232) is also fixedly connected with the connecting frame (11); the second connecting seat (232) is provided with a second through hole (232 a) allowing the second shaft (22) to pass through; and

a drum (233) arranged between the first connection seat (231) and the second connection seat (232), and the drum (233) is rotatably connected with at least one of the first connection seat (231) and the second connection seat (232);

wherein, one end of the first shaft (21) facing the rotary drum (233) is provided with a first thread (210), the first end of the rotary drum (233) is correspondingly provided with a first thread section (233 b), the first thread (210) and the first thread section (233 b) are in threaded fit, and the first shaft (21) is positioned in the first through hole (231 a); a second thread (220) is arranged at one end of the second shaft (22) facing the rotary drum (233), a second thread section (233 c) is correspondingly arranged at the second end of the rotary drum (233), the second thread (220) and the second thread section (233 c) form a threaded fit, and the second shaft (22) is positioned in the second through hole (232 a); the first thread (210) and the second thread (220) are of opposite hand.

2. The auxiliary arm according to claim 1, wherein the drive mechanism (23) further comprises:

the inner ring of the first bearing (234) is sleeved on the rotary drum (233);

a first end cover (235) having a first concave portion, the first end cover (235) being fixedly connected to both the outer race of the first bearing (234) and the second connection seat (232); and

the second end cover (236) is provided with a second inner concave part, and the second end cover (236) is fixedly connected with the outer ring of the first bearing (234) and the second connecting seat (232);

wherein the first and second recesses mate to form a mounting cavity for receiving the first bearing (234).

3. The auxiliary arm according to claim 1, characterized in that the outer wall of the second end of the drum (233) is provided with engagement teeth (233 a); the drive mechanism (23) further includes:

a gear (237) located outside the drum (233) and in a second through hole (232 a) of the second connection seat (232); the gear (237) is meshed with the meshing teeth (233 a); and

a gear shaft (238), the gear shaft (238) being inserted into the through hole of the gear (237); the gear shaft (238) is rotatably connected with the second connecting seat (232).

4. A secondary arm according to claim 3, characterized in that the number of teeth of the gear wheel (237) is smaller than the number of teeth of the engagement teeth (233 a) provided on the outer wall of the second end of the drum (233).

5. A secondary arm according to claim 3, wherein one end of the gear shaft (238) protrudes out of the second through hole (232 a) of the second connection seat (232), and a portion of the gear shaft (238) located outside the second through hole (232 a) is configured to be non-circular.

6. The auxiliary arm according to claim 1, wherein the jackscrew mechanism (2) further comprises:

a guide mechanism (24) comprising a first guide (241) comprising a first mounting end (241 a) and a first protruding end (241 b); the first mounting end (241 a) is mounted to the first connecting seat (231), and the first protruding end (241 b) protrudes into the first through hole (231 a);

wherein, the outer wall of the first shaft (21) is provided with a first chute (211), and the length direction of the first chute (211) is parallel to the axis direction of the first shaft (21); the first protruding end (241 b) is inserted into the first sliding groove (211).

7. The auxiliary arm according to claim 6, wherein the guide mechanism (24) further comprises:

a second guide (242) comprising a second mounting end (242 a) and a second protruding end (242 b); the second mounting end (242 a) is mounted to the second connecting seat (232), and the second protruding end (242 b) protrudes into the second through hole (232 a);

the outer wall of the second shaft (22) is provided with a second chute (221), and the length direction of the second chute (221) is parallel to the axis direction of the second shaft (22); the second protruding end (242 b) is inserted into the second chute (221).

8. The auxiliary arm according to claim 1, wherein the dimension of the end of the first shaft (21) remote from the drum (233) is smaller than the dimension of the end of the first shaft (21) facing the drum (233); and/or the dimension of the end of the second shaft (22) remote from the drum (233) is smaller than the dimension of the end of the second shaft (22) facing the drum (233).

9. The sub-arm according to claim 1, wherein at least one set of the first connection hole (111) and the second connection hole (112) is provided on each of both sides of the connection frame (11) along the width direction of the sub-arm main body (1); the jackscrew mechanism (2) is arranged between each group of the first connecting hole (111) and the second connecting hole (112).

10. A crane comprising a jib according to any one of claims 1-9.

11. A method of deploying a sub-arm, wherein the sub-arm is the sub-arm according to any one of claims 1 to 9, the method comprising the steps of:

the auxiliary arm is rotationally connected around the first bracket until the first connecting hole and the second connecting hole positioned at one side of the width direction of the auxiliary arm are aligned with the inserting holes of the main arms respectively; wherein, along the width direction of the main arm, each side of the main arm is provided with two coaxial plug holes; the first bracket is arranged on the main arm, and the auxiliary arm is rotatably connected with the first bracket;

12. The method of forearm deployment as in claim 11, further comprising the steps of:

13. A method of retracting a sub-arm, wherein the sub-arm is the sub-arm according to any one of claims 1 to 9, the method comprising the steps of:

a driving mechanism for driving the jackscrew mechanism on one side of the auxiliary arm far away from the first bracket, so that the first shaft and the second shaft driven by the driving mechanism retract to disconnect the auxiliary arm and the main arm; wherein the first bracket is fixed to the main arm;

connecting the auxiliary arm with the first bracket;

and connecting the auxiliary arm with the second bracket.