Mast type lifting system and aerial work platform

Abstract

The utility model discloses a mast type lifting system and an aerial work platform, the mast type lifting system comprises a lifting arm device, a traction device and a hydraulic control device, and a first tensioning wheel and a second tensioning wheel are arranged at the upper end and the lower end of a telescopic joint arm located on the inner side in the lifting arm device respectively. An extending traction piece in the traction device is wound on a first tensioning wheel, the two ends of the extending traction piece are connected with the knuckle arms on the two adjacent sides correspondingly, a retracting traction piece is wound on a second tensioning wheel, the two ends of the retracting traction piece are connected with the knuckle arms on the two adjacent sides correspondingly, and the hydraulic control device comprises a telescopic oil cylinder in driving connection with the telescopic knuckle arm located on the innermost side. The pressure stop valve is connected into a rodless cavity oil return oil way of the telescopic oil cylinder and is set to be conducted under the condition that the oil pressure of the rodless cavity oil return oil way reaches the preset load pressure, so that certain back pressure is always kept in a rodless cavity, and the phenomenon that a traction piece is loosened due to clamping stagnation of a telescopic knuckle arm is avoided; and after the clamping stagnation is eliminated, the phenomenon of rapid falling of the telescopic knuckle arm is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of aerial work platforms, and in particular relates to a mast-type lifting system and an aerial work platform. Background Art

[0002] Mast-type aerial work platforms are specialized equipment for aerial work with a wide range of uses. They can be used for indoor and outdoor mechanical installation, equipment repair, building maintenance, and cargo storage at stations, docks, bridges, halls, and factories. The mast-type aerial work platform consists of a chassis, a liftable mast, and a work platform. The mast is located above the chassis, and wheels are provided at the bottom of the chassis to move the entire device. However, when the work platform is lowered, if a telescopic arm in the mast becomes stuck, the telescopic arm will not be able to descend by gravity. Not only will the synchronous retraction of the telescopic arm be impossible, but the traction mechanism for synchronous extension will also become loose. If the descent button is not found and the operation of the descending button is continued, the rodless chamber of the telescopic cylinder will continue to leak oil, causing the telescopic arm to fall rapidly after the jam is eliminated. Utility Model Content

[0003] In view of the above-mentioned defects or shortcomings, the present invention provides a mast-type lifting system and an aerial work platform, which aim to solve the technical problem that the existing mast structure is prone to rapid falling of the telescopic arm after the telescopic arm is unstuck.

[0004] To achieve the above-mentioned objectives, the first aspect of the present invention provides a mast-type lifting system, wherein the mast-type lifting system includes a lifting arm device, a traction device and a hydraulic control device; the lifting arm device includes a fixed basic section arm and at least two telescopic section arms nested in sequence on the outside of the basic section arm, and the telescopic section arms located on the inner side are respectively provided with a first tensioning wheel and a second tensioning wheel at the upper and lower ends; the traction device includes an extending traction member and a retracting traction member, the extending traction member is wound around the first tensioning wheel and its two ends are respectively connected to the section arms on both sides of the adjacent two sides, and the retracting traction member is wound around the second tensioning wheel and its two ends are respectively connected to the section arms on both sides of the adjacent two sides; the hydraulic control device includes a telescopic oil cylinder provided on the basic section arm and drivingly connected to the telescopic section arm located on the innermost side, and a pressure cut-off valve in the rodless chamber return oil circuit connected to the telescopic oil cylinder, the pressure cut-off valve being set to be conductive when the oil pressure in the rodless chamber return oil circuit reaches a preset load pressure.

[0005] In one embodiment of the present invention, the rodless chamber return oil circuit includes a working oil port connected to the hydraulic reversing valve and an oil circuit behind the reversing valve of the rodless chamber of the telescopic oil cylinder. The pressure cut-off valve is arranged on the oil circuit behind the reversing valve, and the pressure cut-off valve includes two valve groups arranged in parallel, one of which includes a first one-way valve that conducts in the oil inlet direction of the telescopic oil cylinder, and the other valve group includes a second one-way valve that conducts in the oil outlet direction of the telescopic oil cylinder. The second one-way valve is set to conduct when the oil pressure in the oil circuit behind the reversing valve reaches a preset load pressure.

[0006] In one embodiment of the present invention, a descending valve group is provided between the rodless chamber of the telescopic cylinder and the hydraulic reversing valve, and the oil circuit behind the reversing valve includes an oil circuit in front of the descending valve connecting the hydraulic reversing valve and the descending valve group; wherein, the pressure cut-off valve is provided on the oil circuit in front of the descending valve and is provided as a two-way one-way valve including a first one-way valve and a second one-way valve, or, the one-way valve on the oil inlet circuit behind the descending valve in the descending valve group is provided as a first one-way valve, and the second one-way valve is provided on the oil return circuit behind the descending valve in the descending valve group.

[0007] In one embodiment of the present invention, the rodless chamber return oil circuit includes a first reversing valve front oil circuit connecting the oil tank and the return oil port of the hydraulic reversing valve, and a pressure cut-off valve is arranged on the first reversing valve front oil circuit, and the pressure cut-off valve is arranged as a third one-way valve or back pressure valve with adjustable opening pressure.

[0008] In one embodiment of the present invention, the first tensioning wheel and the second tensioning wheel on the same telescopic joint arm are arranged on the same side, and the traction device also includes a first connecting component and a second connecting component, the first connecting component is arranged at the upper end of the inner joint arm and the upper and lower ends are respectively connected to the inner ends of the extending traction member and the retracting traction member on the same telescopic joint arm in a one-to-one correspondence, the second connecting component is arranged at the lower end of the outer joint arm and the upper and lower ends are respectively connected to the outer ends of the extending traction member and the retracting traction member on the same telescopic joint arm in a one-to-one correspondence.

[0009] In one embodiment of the present invention, all traction devices are arranged on the same side of the lifting arm device.

[0010] In one embodiment of the present invention, notches are formed on the same side at both upper and lower ends of the telescopic arm, and an installation shaft for installing the first tensioning wheel or the second tensioning wheel is provided on the inner wall of the telescopic arm corresponding to the notch, and the tensioning wheel groups on different telescopic arms are staggered in sequence along the width direction of the lifting arm device.

[0011] In one embodiment of the present invention, the first connecting component includes a first connecting member and a second connecting member, and the first connecting member and the second connecting member are respectively connected one-to-one with the inner ends of the extending traction member and the retracting traction member on the same telescopic joint arm. The first connecting member is arranged on the inner wall of the inner joint arm, and the second connecting member is arranged on the outer wall of the inner joint arm and is located on the lower side of the first connecting member.

[0012] In one embodiment of the present invention, the second connecting assembly includes a third connecting member, the upper and lower ends of the third connecting member are respectively connected one-to-one with the outer ends of the extending traction member and the retracting traction member on the same telescopic joint arm, and the third connecting member is arranged on the inner wall of the outer joint arm.

[0013] In one embodiment of the present invention, the extending traction member is configured as a chain, and the first connecting member includes a fixed portion and a swinging portion. The fixed portion is provided on the inner section arm and a clamping space is formed at the upper end. The lower end of the swinging portion extends into the clamping space and is swingably provided on the fixed portion through a connecting pin shaft, and the upper end of the swinging portion is connected to the chain.

[0014] To achieve the above-mentioned objectives, a second aspect of the present invention provides an aerial work platform, wherein the aerial work platform includes the mast-type lifting system described above.

[0015] Through the above technical solution, the mast-type lifting system provided by the embodiment of the utility model has the following beneficial effects:

[0016] When the above-mentioned mast-type lifting system is used, since the telescopic arm located on the inner side is provided with a first tensioning wheel and a second tensioning wheel at the upper and lower ends, the traction device includes not only an extending traction member wound around the first tensioning wheel, but also a retracting traction member wound around the second tensioning wheel. Therefore, when the telescopic cylinder drives the innermost telescopic arm to extend, due to the effect of the first tensioning wheel on the extending traction member, it can drive the other telescopic arms to extend synchronously, and when the telescopic cylinder drives the innermost telescopic arm to retract, due to the effect of the second tensioning wheel on the retracting traction member, it can drive the other telescopic arms to retract synchronously. If a telescopic arm gets stuck during the descent of the working platform, Due to the upward pulling action of the retracting traction parts, all telescopic arms will stop synchronously and will no longer descend, thereby avoiding the phenomenon of slackness of the traction parts. At the same time, a pressure shut-off valve is added to the rodless chamber return oil circuit of the telescopic cylinder. Since the pressure shut-off valve will only conduct oil leakage when the oil pressure in the rodless chamber return oil circuit reaches the preset load pressure, and when all the aforementioned telescopic arms stop synchronously due to jamming, the oil pressure in the rodless chamber return oil circuit will drop, causing the pressure shut-off valve to respond as non-conducting, then the rodless chamber of the telescopic cylinder will not leak oil and maintain a certain back pressure. After the jam is eliminated, the rapid falling phenomenon caused by the oil in the rodless chamber running out can also be avoided, thereby achieving the purpose of improving safety performance.

[0017] Other features and advantages of the present invention will be described in detail in the subsequent detailed description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without inventive work. In the drawings:

[0019] Figure 1 This is a schematic structural diagram of an aerial work platform according to one embodiment of the present utility model;

[0020] Figure 2 It is a partial structural diagram of a mast-type lifting system according to one embodiment of the present utility model;

[0021] Figure 3 This is a schematic structural diagram of a first connecting assembly on a basic section arm according to an embodiment of the present utility model;

[0022] Figure 4 This is a schematic diagram of the hydraulic principle of the hydraulic control device according to the first embodiment of the present utility model;

[0023] Figure 5 This is a schematic diagram of the hydraulic principle of the hydraulic control device according to the second embodiment of the present utility model;

[0024] Figure 6 It is a schematic diagram of the hydraulic principle of the hydraulic control device in the third embodiment of the present utility model.

[0025] Description of Reference Numerals

[0026] 100 Lifting arm device 110 Basic section arm

[0027] 120 Telescopic boom 121 First tensioning wheel

[0028] 122 Second tension wheel 200 Traction device

[0029] 210 Extending the traction member 220 Retracting the traction member

[0030] 230 first connecting component 231 first connecting piece

[0031] 232 second connecting member 233 fixing portion

[0032] 234 Swinging portion 240 Second connecting component

[0033] 241 Third connecting member 300 Hydraulic control device

[0034] 310 Telescopic Cylinder 320 Pressure Shut-off Valve

[0035] 321 First one-way valve 322 Second one-way valve

[0036] 323 Third one-way valve

[0037] 330 hydraulic reversing valve 340 reversing valve rear oil circuit

[0038] 350 First reversing valve front oil circuit 360 Oil supply assembly

[0039] 370 oil circuit before descending valve 380 descending valve group

[0040] 381 descending valve body 382 descending valve rear oil inlet line

[0041] 383 oil return line after descending valve 384 damping DETAILED DESCRIPTION

[0042] The following is a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0043] The mast-type lifting system and the aerial work platform of the present invention will be described below with reference to the accompanying drawings.

[0044] like Figure 1 、 Figure 2 、 Figures 4 to 6 As shown, the utility model provides a mast-type lifting system, wherein the mast-type lifting system includes:

[0045] The lifting arm device 100 includes a fixed basic arm 110 and at least two telescopic arms 120 sequentially nested outside the basic arm 110. The telescopic arms 120 located inside are each provided with a first tensioning wheel 121 and a second tensioning wheel 122 at the upper and lower ends.

[0046] The traction device 200 includes an extending traction member 210 and a retracting traction member 220. The extending traction member 210 is wound around the first tensioning wheel 121 and its two ends are respectively connected to the adjacent two joint arms. The retracting traction member 220 is wound around the second tensioning wheel 122 and its two ends are respectively connected to the adjacent two joint arms.

[0047] The hydraulic control device 300 includes a telescopic cylinder 310 provided on the basic boom 110 and drivingly connected to the innermost telescopic boom 120, and a pressure cut-off valve 320 in the rodless chamber return oil circuit connected to the telescopic cylinder 310. The pressure cut-off valve 320 is set to be open when the oil pressure in the rodless chamber return oil circuit reaches a preset load pressure.

[0048] When the above-mentioned mast-type lifting system is used, since the telescopic boom 120 located on the inner side is provided with a first tensioning wheel 121 and a second tensioning wheel 122 at the upper and lower ends, the traction device 200 not only includes an extension traction member 210 wound around the first tensioning wheel 121, but also includes a retraction traction member 220 wound around the second tensioning wheel 122. Therefore, when the telescopic cylinder 310 drives the innermost telescopic boom 120 to extend, due to the action of the first tensioning wheel 121 on the extension traction member 210, it can drive the other telescopic booms 120 to extend synchronously, and when the telescopic cylinder 310 drives the innermost telescopic boom 120 to retract, due to the action of the second tensioning wheel 122 on the retraction traction member 220, it can drive the other telescopic booms 120 to retract synchronously. If a telescopic arm 120 is stuck, due to the upward pulling action of the retracting traction member 220, all the telescopic arms 120 will stop synchronously and no longer descend, thereby avoiding the phenomenon of loosening of the traction member. At the same time, a pressure cut-off valve 320 is added to the rodless chamber return oil circuit of the telescopic cylinder 310. Since the pressure cut-off valve 320 is only conductive to prevent oil leakage when the oil pressure in the rodless chamber return oil circuit reaches the preset load pressure, and when all the aforementioned telescopic arms 120 are kept stopped synchronously due to the jam, the oil pressure in the rodless chamber return oil circuit will drop, causing the pressure cut-off valve 320 to respond as non-conductive, and the rodless chamber of the telescopic cylinder 310 will not leak oil and maintain a certain back pressure. After the jam is eliminated, the rapid falling phenomenon caused by the oil in the rodless chamber running out can also be avoided, thereby achieving the purpose of improving safety performance.

[0049] Specifically, there may be at least two telescopic booms 120, and the inner telescopic booms 120 refer to all telescopic booms 120 between the base boom 110 and the outermost telescopic boom 120. It should be noted that the adjacent booms refer to the booms on the inner and outer sides of the telescopic boom 120 where the tensioning pulley is currently installed.

[0050] The present invention will be explained by taking an example of a lifting arm device 100 having four telescopic joint arms 120, that is, the lifting arm device 100 has a total of five joint arms, which are, from the inside to the outside: the basic joint arm 110, the first telescopic joint arm, the second telescopic joint arm, the third telescopic joint arm and the fourth telescopic joint arm. The number of the telescopic joint arms 120 located on the inner side is three, namely the first telescopic joint arm, the second telescopic joint arm and the third telescopic joint arm, and the telescopic oil cylinder 310 is drivingly connected to the first telescopic joint arm. In order to achieve the synchronous extension and retraction of the remaining telescopic joint arms 120 following the first telescopic joint arm, the upper and lower ends of the first telescopic joint arm, the second telescopic joint arm and the third telescopic joint arm are respectively provided with a first tensioning wheel 121 and a second tensioning wheel 122, and the two ends of the extended traction member 210 wound on the first tensioning wheel 121 of the first telescopic joint arm are both set downward and are respectively connected to the basic joint arm 110 and the second telescopic joint arm, the two ends of the extended traction member 210 wound on the first tensioning wheel 121 of the second telescopic joint arm are both set downward and are respectively connected to the first telescopic joint arm and the third telescopic joint arm, the two ends of the extended traction member 210 wound on the first tensioning wheel 121 of the third telescopic joint arm are both set downward and are respectively connected to the second telescopic joint arm and the fourth telescopic joint arm, the two ends of the extended traction member 210 wound on the first tensioning wheel 121 of the fourth telescopic joint arm are both set downward and are respectively connected to the third telescopic joint arm and the fifth telescopic joint arm 120, so as to achieve the synchronous extension and retraction of the remaining telescopic joint arms 120 The second telescopic arm, the third telescopic arm and the fourth telescopic arm are synchronously extended following the first telescopic arm; both ends of the retraction traction piece 220 wound on the second tensioning wheel 122 of the first telescopic arm are set upward and are respectively connected to the basic arm 110 and the second telescopic arm, the two ends of the retraction traction piece 220 wound on the second tensioning wheel 122 of the second telescopic arm are set upward and are respectively connected to the first telescopic arm and the third telescopic arm, the two ends of the retraction traction piece 220 wound on the second tensioning wheel 122 of the third telescopic arm are set upward and are respectively connected to the second telescopic arm and the fourth telescopic arm, the two ends of the retraction traction piece 220 wound on the second tensioning wheel 122 of the fourth telescopic arm are set upward and are respectively connected to the third telescopic arm and the fifth telescopic arm 120, so as to realize the synchronous retraction of the second telescopic arm, the third telescopic arm and the fourth telescopic arm following the first telescopic arm.

[0051] like Figure 4 and Figure 5As shown, in the first and second embodiments of the present invention, the rodless chamber return oil circuit includes a post-reversing valve oil circuit 340 connecting the working oil port of the hydraulic reversing valve 330 and the rodless chamber of the telescopic cylinder 310. A pressure cutoff valve 320 is disposed on the post-reversing valve oil circuit 340, that is, the pressure cutoff valve 320 can be disposed in the oil circuit between the telescopic cylinder 310 and the working oil port of the hydraulic reversing valve 330. The pressure cutoff valve 320 includes two valve groups arranged in parallel. One valve group includes a first check valve 321 that conducts oil inlet to the telescopic cylinder 310, and the other valve group includes a second check valve 322 that conducts oil outlet from the telescopic cylinder 310. The second check valve 322 is configured to open when the oil pressure in the post-reversing valve oil circuit 340 reaches a preset load pressure. Placing the pressure cutoff valve 320 in the post-reversing valve oil circuit 340 places it closer to the rodless chamber, further reducing oil leakage. In addition, since the oil circuit 340 behind the reversing valve also needs to meet the demand for oil inlet to the rodless chamber, the pressure cut-off valve 320 can be set to include two valve groups, one of which can be conducted in the oil inlet direction through the first one-way valve 321, and the other valve group can be conducted in the oil return direction through the second one-way valve 322, and the second one-way valve 322 can be set to cut off and maintain oil when the oil pressure does not reach the preset load pressure, thereby meeting the above requirements.

[0052] Furthermore, when the telescopic arm 120 needs to be extended synchronously, the hydraulic reversing valve 330 is switched to connect the working oil port with the oil inlet of the hydraulic reversing valve 330, and the oil supply assembly 360 of the hydraulic control device 300 can supply oil to the rodless chamber from the valve group provided with the first one-way valve 321; when the telescopic arm 120 needs to be retracted synchronously, the hydraulic reversing valve 330 is switched to connect the working oil port with the return oil port of the hydraulic reversing valve 330, so that the oil in the rodless chamber can flow from the valve group provided with the second one-way valve 322 to the return oil port of the hydraulic reversing valve 330, and finally flow back to the oil tank.

[0053] like Figure 4As shown, in the first embodiment of the present invention, a descending valve assembly 380 is provided between the rodless chamber of the telescopic cylinder 310 and the hydraulic reversing valve 330. The reversing valve rear oil circuit 340 includes a descending valve front oil circuit 370 connecting the hydraulic reversing valve 330 and the descending valve assembly 380. The pressure cutoff valve 320 can be provided on the descending valve front oil circuit 370 and configured as a bidirectional check valve comprising a first check valve 321 and a second check valve 322. Using an existing bidirectional check valve as the pressure cutoff valve 320 provided on the reversing valve rear oil circuit 340 can reduce the number of in-house design and production steps. Specifically, in the two valve groups of the two-way one-way valve, not only the second one-way valve 322 but also the first one-way valve 321 can set the opening pressure. However, in order to ensure the conduction in the oil inlet direction, the first one-way valve 321 can be set to open at a smaller oil pressure, while the second one-way valve 322 is set to be conductive only when the oil pressure reaches a preset load pressure. The preset load pressure can be set to be greater than or equal to half of the total gravity of all telescopic arms 120, and less than the total gravity of all telescopic arms 120.

[0054] like Figure 5 As shown, in the second embodiment of the present invention, a descending valve assembly 380 is provided between the rodless chamber of the telescopic cylinder 310 and the hydraulic reversing valve 330. The reversing valve rear oil circuit 340 includes a descending valve front oil circuit 370 connecting the hydraulic reversing valve 330 and the descending valve assembly 380. The one-way valve on the descending valve rear oil inlet circuit 382 in the descending valve assembly 380 is a first one-way valve 321, and the second one-way valve 322 is provided on the descending valve rear oil return circuit 383 in the descending valve assembly 380. Therefore, the descending valve assembly 380 can be improved to meet the requirement of shutting off and maintaining oil pressure when the oil pressure does not reach the preset load pressure.

[0055] Specifically, the existing structure of the descending valve group 380 includes a descending valve body 381, a descending valve rear oil inlet circuit 382 and a descending valve rear oil return circuit 383. The descending valve rear oil inlet circuit 382 and the descending valve rear oil return circuit 383 are arranged in parallel, and one of the junction ends of the two is connected to the valve rear end of the descending valve body 381, and the other junction end is connected to the rodless chamber of the telescopic cylinder 310. The valve front end of the descending valve body 381 is connected to the hydraulic reversing valve 330 through the descending valve front oil circuit 370. The one-way valve on the descending valve rear oil inlet circuit 382 is set as a first one-way valve 321. The descending valve rear oil return circuit 383 originally only has a damper 384, so it can be obtained by adding a second one-way valve 322 to the descending valve rear oil return circuit 383.

[0056] like Figure 6As shown, in the third embodiment of the present invention, the rodless chamber return oil circuit includes a first reversing valve front oil circuit 350 connecting the oil tank and the return oil port of the hydraulic reversing valve 330, and the pressure cut-off valve 320 is arranged on the first reversing valve front oil circuit 350. The pressure cut-off valve 320 is configured as a third one-way valve 323 or a back pressure valve with adjustable opening pressure. By arranging the pressure cut-off valve 320 in the first reversing valve front oil circuit 350, there is no need to consider meeting the requirements of the rodless chamber oil supply, and the structure is simpler and the cost is lower. Specifically, the hydraulic control device 300 also includes a second reversing valve front oil circuit arranged between the oil supply component 360 and the oil inlet of the hydraulic reversing valve 330. The oil supply component 360 includes an oil pump and a drive component that drives the oil pump to rotate.

[0057] In one embodiment of the present invention, the first tensioning wheel 121 and the second tensioning wheel 122 on the same telescopic boom 120 are arranged on the same side, and the traction device 200 further includes a first connecting assembly 230 and a second connecting assembly 240. The first connecting assembly 230 is arranged at the upper end of the inner boom, and its upper and lower ends are respectively connected to the inner ends of the extension traction member 210 and the retraction traction member 220 on the same telescopic boom 120 in a one-to-one correspondence. The second connecting assembly 240 is arranged at the lower end of the outer boom, and its upper and lower ends are respectively connected to the outer ends of the extension traction member 210 and the retraction traction member 220 on the same telescopic boom 120 in a one-to-one correspondence. By adding the first connecting assembly 230 and the second connecting assembly 240, a traction module with both extension and retraction traction functions is arranged in a ring shape on one side of the telescopic boom 120. Compared with a solution in which the extension traction member 210 and the retraction traction member 220 are provided on both sides, the arrangement of the connecting assemblies can be reduced. It should be noted in particular that the joint arm located on the inner side of the telescopic joint arm 120 where the tensioning wheel corresponding to the current traction member is located and is adjacent to it is the inner joint arm, and the joint arm located on the outer side of the telescopic joint arm 120 where the tensioning wheel corresponding to the current traction member is located and is adjacent to it is the outer joint arm. Of the two ends of the extended traction member 210 and the retracted traction member 220, the inner end is set as the inner end of the extended traction member 210 and the retracted traction member 220, and the outer end is set as the outer end of the extended traction member 210 and the retracted traction member 220.

[0058] In one embodiment of the present invention, all traction devices 200 are arranged on the same side of the lifting arm assembly 100. That is, the first tensioning pulley 121 and the second tensioning pulley 122 on all telescopic arms 120 are also arranged on the same side. This eliminates the need to reserve space on the other side of the lifting arm assembly 100 for the tensioning pulley, thereby reducing the size of the lifting arm assembly 100 and lowering production costs.

[0059] In one embodiment of the present invention, notches are formed on the same side at both the upper and lower ends of the telescopic boom 120. Mounting shafts for mounting the first tensioning wheel 121 or the second tensioning wheel 122 are provided on the inner wall of the telescopic boom 120 corresponding to the notches. The tensioning wheel assemblies on different telescopic booms 120 are staggered along the width of the lifting arm assembly 100. The addition of the notches not only prevents the tensioning wheels from extending beyond the corresponding telescopic boom 120 in height, providing a certain degree of protection, but also facilitates the placement of the mounting shafts. The ends of the mounting shafts can be directly connected to the adjacent side of the telescopic boom 120 that does not have a notch. It should be noted that the tensioning wheel group on the telescopic joint arm 120 is composed of a first tensioning wheel 121 and a second tensioning wheel 122 on the telescopic joint arm 120, and the first tensioning wheel 121 and the second tensioning wheel 122 in the tensioning wheel group should be set to be in the same vertical direction. In addition, since the outermost telescopic joint arm 120 does not need to be provided with the first tensioning wheel 121 and the second tensioning wheel 122, there is no need to form a notch.

[0060] See also Figure 2 and Figure 3 In one embodiment of the present invention, the first connecting assembly 230 includes a first connecting member 231 and a second connecting member 232. The first connecting member 231 and the second connecting member 232 are respectively connected to the inner ends of the extension traction member 210 and the retraction traction member 220 on the same telescopic boom 120. The first connecting member 231 is provided on the inner wall of the inner boom, and the second connecting member 232 is provided on the outer wall of the inner boom and is located below the first connecting member 231. That is, the first connecting assembly 230 is provided as a separate body, and the first connecting member 231 for connecting with the extension traction member 210 is provided on the inner wall of the inner boom, while the second connecting member 232 for connecting with the retraction traction member 220 is provided on the outer wall of the inner boom, which can facilitate disassembly and assembly. Specifically, when assembling the traction member, since the first connecting assembly 230 is arranged near the upper end of the telescopic joint arm 120, it is more convenient to extend the traction member 210 from the upper end of the inner joint arm into the joint arm inner cavity to connect with it. In order to play a protective role, the first connecting member 231 can be arranged on the inner wall of the inner joint arm; while it is more time-consuming and labor-intensive to extend the retracting traction member 220 from the lower end of the inner joint arm into the joint arm inner cavity to connect with it. In order to facilitate the connection of the retracting traction member 220, the second connecting member 232 can be arranged on the outer wall of the inner joint arm. Specifically, the first connecting member 231 can be fixed to the inner joint arm by driving a fastener from the outer side of the inner joint arm, and the second connecting member 232 can be fixed to the outer wall of the inner joint arm by welding.

[0061] In one embodiment of the present invention, the second connecting assembly 240 includes a third connecting member 241. The upper and lower ends of the third connecting member 241 are respectively connected to the outer ends of the extension traction member 210 and the retraction traction member 220 on the same telescopic boom 120. The third connecting member 241 is located on the inner wall of the outer boom. Because the second connecting assembly 240 is located near the lower end of the telescopic boom 120, it is convenient for the retraction traction member 220 to extend from the lower end of the inner boom into the inner cavity of the boom and connect therewith. The addition of a notch also facilitates the installation of the second connecting assembly 240 or the extension traction member 210 within the inner cavity of the outer boom. Therefore, the second connecting assembly 240 can be configured as an integrated third connecting member 241 and located on the inner wall of the outer boom, thereby reducing production costs and improving production efficiency. Specifically, the third connecting member 241 can be secured to the outer boom by driving fasteners from the outside of the outer boom.

[0062] Specifically, the installation method of the traction member can be: first connect the two ends of the extended traction member 210 with the first connecting member 231 and the third connecting member 241 respectively; then install the first connecting member 231 on the inner section arm and connect one end of the retracted traction member 220 with the second connecting member 232; after the outer section arm is sleeved on the outside of the inner section arm, install the third connecting member 241 on the outer section arm and connect the other end of the retracted traction member 220 with the third connecting member 241.

[0063] In one embodiment of the present invention, the extending traction member 210 is configured as a chain. Compared to a wire rope, a chain provides greater stability during the lifting process. The first connecting member 231 includes a fixed portion 233 and a swinging portion 234. The fixed portion 233 is disposed on the inner arm and has a clamping space formed at its upper end. The lower end of the swinging portion 234 extends into the clamping space and is pivotally mounted on the fixed portion 233 via a connecting pin. The upper end of the swinging portion 234 is connected to the chain. By adding the swinging portion 234 to the first connecting member 231 and connecting it to the chain, an automatic return function is achieved. Specifically, the upper end of the swinging portion 234 is detachably connected to the chain, and the retracting traction member 220 can be configured as a wire rope.

[0064] Furthermore, the third connecting member 241 can also be configured to include a fixed portion 233 and a swinging portion 234. The fixed portion 233 of the third connecting member 241 is arranged on the outer segment arm and a clamping space is formed at the upper end. The lower end of the swinging portion 234 extends into the clamping space and is swingably arranged on the fixed portion 233 through a connecting pin shaft. The upper end of the swinging portion 234 is connected to the chain, and the lower end of the fixed portion 233 of the third connecting member 241 is provided with a structure that can be connected to the retraction traction member 220.

[0065] The present invention also provides an aerial work platform, wherein the aerial work platform includes the mast-type lifting system described above. Because the aerial work platform utilizes all of the technical solutions of the aforementioned embodiments, it possesses at least all of the beneficial effects brought about by the technical solutions of the aforementioned embodiments, and thus will not be further elaborated here. The aerial work platform may specifically be a mast-type aerial work platform.

[0066] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0067] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0069] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A mast-type lifting system, characterized in that: The mast-type lifting system comprises: A lifting arm device (100) comprises a fixed basic arm (110) and at least two telescopic arms (120) sequentially nested outside the basic arm (110), wherein the telescopic arms (120) located inside are each provided with a first tensioning wheel (121) and a second tensioning wheel (122) at the upper and lower ends thereof; The traction device (200) comprises an extending traction member (210) and a retracting traction member (220), wherein the extending traction member (210) is wound around the first tensioning wheel (121) and its two ends are respectively connected to the joint arms on two adjacent sides, and the retracting traction member (220) is wound around the second tensioning wheel (122) and its two ends are respectively connected to the joint arms on two adjacent sides; The hydraulic control device (300) comprises a telescopic oil cylinder (310) provided on the basic joint arm (110) and drivingly connected to the telescopic joint arm (120) located at the innermost side, and a pressure cut-off valve (320) in a rodless chamber return oil circuit connected to the telescopic oil cylinder (310), wherein the pressure cut-off valve (320) is set to be conductive when the oil pressure in the rodless chamber return oil circuit reaches a preset load pressure.

2. The mast-type lifting system according to claim 1, characterized in that: The rodless chamber oil return oil circuit includes a working oil port connected to a hydraulic reversing valve (330) and a reversing valve rear oil circuit (340) of the rodless chamber of the telescopic oil cylinder (310). The pressure cut-off valve (320) is provided on the reversing valve rear oil circuit (340), and the pressure cut-off valve (320) includes two valve groups arranged in parallel, one of which includes a first one-way valve (321) conducting in the oil inlet direction of the telescopic oil cylinder (310), and the other includes a second one-way valve (322) conducting in the oil outlet direction of the telescopic oil cylinder (310). The second one-way valve (322) is set to conduct when the oil pressure in the reversing valve rear oil circuit (340) reaches a preset load pressure.

3. The mast-type lifting system according to claim 2, characterized in that: A descending valve group (380) is provided between the rodless chamber of the telescopic oil cylinder (310) and the hydraulic reversing valve (330), and the reversing valve rear oil circuit (340) includes a descending valve front oil circuit (370) connecting the hydraulic reversing valve (330) and the descending valve group (380); The pressure cut-off valve (320) is provided on the oil circuit (370) before the descending valve and is configured as a two-way one-way valve including the first one-way valve (321) and the second one-way valve (322); or the one-way valve on the oil inlet circuit (382) after the descending valve in the descending valve group (380) is configured as the first one-way valve (321), and the second one-way valve (322) is provided on the oil return circuit (383) after the descending valve in the descending valve group (380).

4. The mast-type lifting system according to claim 1, characterized in that: The rodless chamber oil return oil circuit includes a first reversing valve front oil circuit (350) connected to an oil tank and an oil return port of a hydraulic reversing valve (330); the pressure cut-off valve (320) is arranged on the first reversing valve front oil circuit (350); and the pressure cut-off valve (320) is configured as a third one-way valve (323) or a back pressure valve with adjustable opening pressure.

5. The mast-type lifting system according to any one of claims 1 to 4, characterized in that: The first tensioning wheel (121) and the second tensioning wheel (122) on the same telescopic joint arm (120) are arranged on the same side, and the traction device (200) further includes a first connecting component (230) and a second connecting component (240), wherein the first connecting component (230) is arranged at the upper end of the inner joint arm, and the upper and lower ends are respectively connected to the inner ends of the extending traction member (210) and the retracting traction member (220) on the same telescopic joint arm (120) in a one-to-one correspondence, and the second connecting component (240) is arranged at the lower end of the outer joint arm, and the upper and lower ends are respectively connected to the outer ends of the extending traction member (210) and the retracting traction member (220) on the same telescopic joint arm (120) in a one-to-one correspondence.

6. The mast-type lifting system according to claim 5, characterized in that: All traction devices (200) are arranged on the same side of the lifting arm device (100).

7. The mast-type lifting system according to claim 6, characterized in that: Notches are formed at both upper and lower ends of the telescopic arm (120) on the same side, and an installation shaft for installing the first tensioning wheel (121) or the second tensioning wheel (122) is provided on the inner wall of the telescopic arm (120) corresponding to the notch, and the tensioning wheel groups on different telescopic arms (120) are staggered in sequence along the width direction of the lifting arm device (100).

8. The mast-type lifting system according to claim 5, characterized in that: The first connecting assembly (230) comprises a first connecting member (231) and a second connecting member (232), wherein the first connecting member (231) and the second connecting member (232) are respectively connected to the inner ends of the extending traction member (210) and the retracting traction member (220) on the same telescopic joint arm (120) in a one-to-one correspondence, the first connecting member (231) being arranged on the inner wall of the inner joint arm, and the second connecting member (232) being arranged on the outer wall of the inner joint arm and located below the first connecting member (231); The second connecting assembly (240) includes a third connecting member (241), the upper and lower ends of the third connecting member (241) are respectively connected to the outer ends of the extending traction member (210) and the retracting traction member (220) on the same telescopic joint arm (120) in a one-to-one correspondence, and the third connecting member (241) is arranged on the inner wall of the outer joint arm.

9. The mast-type lifting system according to claim 8, characterized in that: The extending traction member (210) is configured as a chain. The first connecting member (231) includes a fixed portion (233) and a swing portion (234). The fixed portion (233) is provided on the inner section arm and has a clamping space formed at its upper end. The lower end of the swing portion (234) extends into the clamping space and is swingably provided on the fixed portion (233) via a connecting pin. The upper end of the swing portion (234) is connected to the chain.

10. An aerial work platform, characterized in that: The aerial work platform comprises a mast-type lifting system according to any one of claims 1 to 9.

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