A power-off protection device and method for the top section of a tower crane

Abstract

The invention discloses a power-off protection device and a protection method for the top section of a tower crane, belonging to the field of construction machinery. When the lifting oil cylinder on the top section jacks up the top section and power is cut off, the hydraulic oil in the lifting oil cylinder is controlled by a pressure relief valve to flow back into the fuel tank, and the output shaft of the lifting oil cylinder contracts, causing the top section to descend until it docks with the top of the standard section. By controlling the pressure relief of the lifting oil cylinder, the top section can fall, reducing the clearance between the standard section and the top section, enabling the standard section and the top section to dock with each other, increasing the clampable range between the standard section and the top section, and thus ensuring the stability between the standard section and the top section to improve the safety of the entire tower crane.

Description

Technical Field

[0001] The present invention belongs to the field of construction machinery, and particularly relates to a power-off protection device and a protection method for the top section of a tower crane. Background Art

[0002] Tower cranes are commonly used construction equipment in construction projects. Currently, all tower cranes have the function of automatic lifting, so they are widely used on construction sites.

[0003] The lifting of a tower crane increases with the height of the building under construction. When the tower crane increases in height, generally one unit section height is increased each time. After the standard sections 10 made of each unit section are accumulated, the entire tower crane can be lifted to the required height; the lifting of the tower crane is inseparable from the top section 11 and the standard section 10. The top section 11 is a workbench that can move up and down and is arranged at the top of the highest standard section 10. Its length is generally longer than that of the standard section. When lifting upward (reference can be made to the attached drawings of this application Figure 1 、 2 ), the telescopic oil cylinder 12 on the top section 10 is controlled to work. The output shaft end of the telescopic oil cylinder 12 abuts against the standard section 10. When the output shaft continuously extends, it can drive the top section 11 to rise. The height vacated between the top section 11 and the standard section 10 is filled by other standard sections 10, and the height of the entire tower crane is increased.

[0004] Although the length of the top section is longer than that of the standard section and generally no accidents such as collapse will occur, each time the height of the tower crane is increased, it is still necessary to operate in accordance with the specifications. In fact, the tower crane is most prone to problems when lifting and lowering in height. In actual use, it is found that when a power failure occurs during the upward climbing process of the top section, all the electrical equipment on the tower crane stops working, especially the oil cylinder on the top section cannot achieve normal telescoping, resulting in an embarrassing situation where the entire top section can neither go up nor down. Since the top section and the standard section are not fixed properly at this time, accidents are very likely to occur. Moreover, the tower crane is an aerial work equipment. For tower cranes with relatively high heights, there are often strong winds at high altitudes. When the strong wind blows, the top section is very easy to shake. Therefore, the entire tower crane is in an unstable state. Currently, some measures are to increase the number of fastening bolts between the top section and the standard section to achieve stable connection between the top section and the standard section. However, due to the upward movement of the top section, the clampable area between the standard section and the top section decreases, creating a void in the middle, and the entire tower crane is in a very unstable state. Therefore, this method is not suitable for tower cranes used in aerial work. Therefore, other methods need to be found to solve this problem. Summary of the Invention

[0005] The object of the present invention is to address the above problems and provide a power-off protection device and method for the top section of a tower crane, which relieves the pressure of the oil cylinder, allows the top section to descend and dock with the standard section, reduces the gap between the top section and the standard section, and improves the safety of the tower crane.

[0006] To achieve the above object, the technical solution adopted by the present invention is: when the lifting oil cylinder on the top section tops up the top section and loses power, the hydraulic oil in the lifting oil cylinder is controlled by a pressure relief valve to flow back into the fuel tank, and the output shaft of the lifting oil cylinder contracts, causing the top section to descend until it docks with the top of the standard section.

[0007] A protection device adopting the power-off protection method for the top section of a tower crane, the protection device includes a first pipeline and a second pipeline that are connected to the lifting oil cylinder, a first branch pipe is connected to the first pipeline, and a pressure relief valve assembly for relieving pressure on the lifting oil cylinder is provided on the first branch pipe;

[0008] A second branch pipe is connected to the second pipeline, and an energy storage element and a first valve element are sequentially connected to the second branch pipe.

[0009] As a further improvement of the above technical solution, the valve core of the first valve element is connected to a sliding rod, and a driving source for driving its movement is provided at one end of the sliding rod;

[0010] A buffer device for controlling the slow movement of the sliding rod is connected to the outside of the sliding rod.

[0011] As a further improvement of the above technical solution, the buffer device includes a receiving box, the sliding rod passes through the receiving box, a damping plate located inside the receiving box is fixedly provided on the sliding rod, and a buffer fluid is filled in the receiving box.

[0012] As a further improvement of the above technical solution, the outlet end of the first valve element is connected to a third branch pipe that communicates with the second pipeline, a fourth branch pipe is provided on the third branch pipe, and a second valve element is provided on the fourth branch pipe;

[0013] A guiding device is provided between the standard section and the top section, the guiding device includes a top pressing member fixedly provided on the top section, and the top pressing member is connected to the second valve element through a pipeline.

[0014] As a further improvement of the above technical solution, the guiding device further includes a connecting bracket hinged to the end of the output shaft of the top pressing member;

[0015] A guiding strip is fixedly provided on the side of the standard section, and a guiding wheel and a guiding block that can cooperate with the guiding strip respectively are connected to the connecting bracket.

[0016] As a further improvement of the above technical solution, when power is off, the pressure relief valve assembly opens to relieve pressure in the lifting oil cylinder;

[0017] The first valve member opens slowly, allowing the pressure inside the first valve member to enter the lifting oil cylinder, causing the output shaft of the lifting oil cylinder to contract, driving the top section to descend, and protecting the tower crane.

[0018] Advantages of the present invention:

[0019] 1. The present invention provides a tower crane top section power-off protection device and a protection method. By controlling the pressure relief of the lifting oil cylinder, the top section can fall, reducing the gap between the standard section and the top section, enabling the standard section and the top section to be mutually docked, increasing the clampable range between the standard section and the top section, and thus ensuring the stability between the standard section and the top section to improve the safety of the entire tower crane.

[0020] 2. By arranging 12 lifting oil cylinders on the first pipeline, the hydraulic oil in the lifting oil cylinder can be discharged to achieve pressure relief of the lifting oil cylinder. By connecting and arranging an energy storage member on the second pipeline, the energy stored in the energy storage member can be used. After a power failure, under the action of the self-weight of the tower crane boom and the top section, the output shaft of the lifting oil cylinder can still be driven to retract, playing a protective role for the tower crane.

[0021] 3. By arranging a first valve member at the outlet end of the energy storage member, it can control the release of the pressure in the energy storage member. The opening and closing of the first valve member are controlled by the movement of a sliding rod. The buffer fluid filled in the accommodating box can form a blocking effect on the damping plate on the sliding rod, allowing the sliding rod to move slowly. On the one hand, it can delay the release of the pressure in the energy storage member to prevent the situation of power coming back immediately after a power failure. On the other hand, it can allow the pressure in the energy storage member to slowly enter the lifting oil cylinder, reducing the rapid impact of the pressure in the energy storage member on the lifting oil cylinder, enabling the lifting oil cylinder to gradually descend from slow to fast, and thus playing a protective role for the entire hydraulic pipeline and the tower crane.

[0022] 4. After a power failure, the pressure released from the energy storage member can push the pressing member to move, driving the contact between the guiding wheel and the standard section, and making the guiding block and the conducting strip contact each other, playing a role in guiding and stabilizing the descent of the top section. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the overall layout of the present invention;

[0024] Figure 2 It is a schematic diagram of the working state of the present invention when installing the standard section with the top section rising;

[0025] Figure 3 For Figure 1 It is a schematic cross-sectional structure diagram in the A-A direction in

[0026] Figure 4 For Figure 2Schematic diagram of the partial enlarged structure at position B in [the figure];

[0027] Figure 5 is Figure 2 Schematic diagram of the sectional structure in the C-C direction in [the figure];

[0028] Figure 6 is Figure 3 Schematic diagram of the partial enlarged structure at position D in [the figure];

[0029] Figure 7 It is the hydraulic schematic diagram of the protection device.

[0030] The text markings in the figure are indicated as follows: 10, standard section; 11, top section; 12, lifting cylinder; 121, first pipeline; 1211, first branch pipe; 1212, pressure relief valve assembly; 122, second pipeline; 1221, second branch pipe; 1222, energy storage component; 1223, first valve component; 1224, sliding rod; 1225, accommodating box; 1226, damping plate; 1227, buffer fluid; 13, third branch pipe; 131, fourth branch pipe; 14, second valve component; 15, top pressing component; 151, connecting bracket; 152, guide wheel; 153, guide block; 16, conducting wire section. Specific implementation manners

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not have any restrictive effect on the protection scope of the present invention.

[0032] A tower crane top section power-off protection method includes a standard section 10 and a top section 11 arranged outside the standard section 10. Specifically, the top section 11 is arranged at the top of the standard section 10. The top of the top section 11 is connected to the operation room, the cross arm, and the slewing platform that supports the rotation of the cross arm of the tower crane. The end of the output shaft of the lifting cylinder 12 on the top section 11 is fixed to the standard section 10. When increasing the height of the top section, control the lifting cylinder 12 to extend, jack up the top section 11 upward, so that there is a space for accommodating the standard section 10 between the top section 11 and the uppermost standard section 10; when the lifting cylinder 12 on the top section 11 jacks up the top section 11 and cuts off the power, control the hydraulic oil in the lifting cylinder 12 to flow back into the fuel tank through the pressure relief valve, and the output shaft of the lifting cylinder 12 contracts, so that the top section 11 descends until it docks with the top of the standard section 10. After the standard section 10 and the top section 11 are docked with each other, the space between the topmost standard section 10 and the top section 11 is eliminated, so that there is more clamping space between the standard section 10 and the top section 11, improving the safety of the entire tower crane.

[0033] As shown in the attached specification Figures 1-7As shown, as a specific embodiment of the present invention, the specific structure of the present invention is: a protection device for power-off protection of the tower crane top section. The protection device includes a first pipeline 121 and a second pipeline 122 that are connected to the lifting oil cylinder 12. Both the first pipeline 121 and the second pipeline 122 are the original hydraulic system pipelines of the lifting oil cylinder 12. A first branch pipe 1211 is connected to the first pipeline 121, and a pressure relief valve assembly 1212 for relieving pressure on the lifting oil cylinder 12 is provided on the first branch pipe 1211. In this embodiment, the pressure relief valve assembly 1212 is a combined valve of two valves, specifically including a manual valve and an electromagnetically controlled valve that is normally closed when energized. The manual valve is controlled manually. Specifically, when controlling the tower crane to rise, the manual valve is opened. The electromagnetically controlled valve is normally closed when energized and will not relieve pressure on the lifting oil cylinder 12. When a power failure occurs, the electromagnetically controlled valve de-energizes and switches its state, causing the entire pressure relief valve assembly 1212 to open, and the lifting oil cylinder 12 can be relieved of pressure;

[0034] A second branch pipe 1221 is connected to the second pipeline 122. An energy storage member 1222 and a first valve member 1223 are sequentially connected to the second branch pipe 1221. In this embodiment, the energy storage member 1222 is an energy storage tank; specifically, reference can be made to the attached drawings of the specification Figure 3 、 6 As shown, the first valve member 1223 is a control valve that is manually controlled to be opened and closed. A check valve is also connected between the energy storage member 1222 and the first pipeline 121. The flow direction of the check valve is towards the energy storage member 1222, that is, when the entire hydraulic system is working normally, the pressure oil enters the energy storage member 1222 through the check valve for energy storage; when a power failure occurs, the first valve member 1223 is controlled to be opened, allowing the pressure oil in the energy storage member 1222 to enter the lifting oil cylinder 12 and push the output shaft to retract upward, causing the top section 11 to descend and protecting the entire tower crane.

[0035] As shown in the attached drawings of the specification Figure 3 、 6As shown in the figure, on the basis of the above-mentioned embodiments, further optimization is carried out: the valve core of the first valve member 1223 is connected to a slide rod 1224, and a driving source for driving its movement is provided at one end of the slide rod 1224. In this embodiment, the driving source is an electromagnet provided at one end of the slide rod 1224. When the electromagnet is energized, it adsorbs the slide rod 1224, driving the first valve member 1223 to close. The end of the slide rod 1224 is made of a magnetically adsorbable material. In order to protect the energy storage member 1222 and the first valve member 1223, a protective box is provided outside the energy storage member 1222 and the first valve member 1223. Specifically, the protective box is fixedly arranged with the top section 11, and the protective box is fixedly arranged with the energy storage member 1222 and the first valve member 1223. A blocking plate for preventing the movement of the slide rod 1224 is hinged on the protective box. When there is no need to increase the height of the tower crane, the blocking plate is turned down to block the slide rod 1224, preventing the slide rod 1224 from retracting, so that the entire first valve member 1223 can be in a normally closed state. When it is necessary to increase the height of the tower crane, the blocking plate is opened, so that the blocking plate loses its blocking effect on the slide rod 1224. After the power is cut off, the electromagnet loses its adsorption effect on the slide rod 1224; the slide rod 1224 will automatically retract, opening the first valve member 1223. A buffer device for controlling the slow movement of the slide rod 1224 is connected to the outside of the slide rod 1224.

[0036] The buffer device includes a receiving box 1225. The slide rod 1224 passes through the receiving box 1225. A damping plate 1226 located inside the receiving box 1225 is fixedly arranged on the slide rod 1224. A spring for pushing the damping plate 1226 to move downward is arranged between the upper surface of the damping plate 1226 and the receiving box 1225. The receiving box 1225 is filled with a buffer fluid 1227. In this embodiment, the buffer fluid 1227 can be selected as oil with high viscosity or a non-Newtonian fluid. In this embodiment, a non-Newtonian fluid is used. After the electromagnet is powered off and loses its adsorption effect on the slide rod 1224, under the action of the spring and the self-gravity of the slide rod 1224, the slide rod 1224 moves downward. Under the block of the buffer fluid 1227, the slide rod 1224 can slowly fall, that is, the first valve member 1223 can be slowly opened, playing a buffering role. When the first valve member 1223 is slowly opened, on the one hand, it can play a delaying role to prevent the power from coming on again immediately after the power is cut off for a while, so that the operation can continue at the height where the original top section 11 has risen. On the other hand, in the case of continuous power failure, the pressure in the energy storage member 1222 can be slowly released into the lifting oil cylinder 12, so that the lifting oil cylinder 12 first slowly falls and then quickly falls as the first valve member 1223 is opened, which can reduce the instantaneous impact of the pressure in the energy storage member 1222 on the lifting oil cylinder 12 when the first valve member 1223 is opened, playing a protective role.

[0037] As described in the specification appendix Figure 3, 4 , 5, 6, and 7, further optimized on the basis of the above embodiment: one end of the outlet of the first valve component 1223 is connected to the third branch pipe 13 connected to the second pipeline 122, the third branch pipe 13 is provided with a fourth branch pipe 131, and the fourth branch pipe 131 is provided with a second valve component 14. In this embodiment, the second valve component 14 is a solenoid valve that is normally closed when powered on. When the power is off, the second valve component 14 opens to allow the hydraulic oil in the energy storage component 1222 to pass through the second valve component 14;

[0038] A guide device is provided between the standard section 10 and the top section 11, and the guide device includes a top pressure piece 15 fixedly provided on the top section 11, and the top pressure piece 15 is specifically a top pressure oil cylinder, and has only one oil inlet and outlet, and the top pressure piece 15 is connected to the second valve member 14 through a pipeline; when the hydraulic oil passes through the second valve member 14, it can enter the top pressure piece 15, so that the output shaft of the top pressure piece 15 is pushed forward, and the guide device also includes a connecting bracket 151 hingedly provided at the end of the output shaft of the top pressure piece 15;

[0039] The side of the standard section 10 is fixedly provided with a conductor bar 16, and the connecting bracket 151 is connected with a guide wheel 152 and a guide block 153 which can respectively cooperate with the conductor bar 16, wherein the connecting bracket 151, the guide wheel 152 and the conductor bar 16 are provided with mating surfaces which can cooperate with each other, and the mating surfaces can be referred to in the appendix of the specification. Figure 5 As shown, the mating surface is "V" shaped. When hydraulic oil is injected into the top pressure piece 15, the output shaft of the top pressure piece 15 can be pushed outward, thereby driving the guide wheel 152 and the connecting bracket 151 to be closer to the conductor bar 16, thereby reducing the gap between the standard section 10 and the top section 11, preventing large shaking between the standard section 10 and the top section 11, and maintaining the stability of the top section 11 during the descent process.

[0040] The specific method of the protection device is: when adding a standard section 10 to the tower crane, first manually open the manual control valve in the pressure relief valve assembly 1212, flip open the blocking plate in the protection box, so that it loses the blocking effect with the slide rod 1224, and then normally perform the lifting and lowering operation of the top section 11 to add the standard section 10;

[0041] When power is cut off, the solenoid valve in the pressure relief valve assembly 1212 is de-energized and opened, connecting the first pipeline 121 and the first branch pipe 1211 to the fuel tank. The electromagnet at one end of the sliding rod 1224 is de-energized, losing its adsorption effect on the sliding rod 1224. Under the action of the spring and its own weight, the sliding rod 1224 can be pushed to move downward. The buffer fluid 1227 buffers the movement of the sliding rod 1224, causing the sliding rod 1224 to move downward slowly. As a result, the first valve member 1223 is slowly opened, allowing the pressure inside the first valve member 1223 to enter the lifting cylinder 12, causing the output shaft of the lifting cylinder 12 to contract. The hydraulic oil in the lifting cylinder 12 flows directly into the fuel tank through the first pipeline 121, the first branch pipe 1211, and the pressure relief valve assembly 1212, relieving the pressure in the lifting cylinder 12; and driving the top section 11 to descend, protecting the tower crane.

[0042] The second valve member 14 is connected after power is cut off. After the first valve member 1223 is opened, it allows hydraulic oil to flow into the pressing member 15, pushing the output shaft of the pressing member 15 to extend forward, reducing the gap between the connecting bracket 151, the guide wheel 152, and the conducting wire strip 16, thereby ensuring that the top section 11 descends stably when descending.

[0043] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such a process, method, article or device.

[0044] In this article, specific examples are used to elaborate on the principles and implementation manners of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that due to the limitation of literal expression and the objectively infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements, retouches or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, retouches, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, should all be regarded as the protection scope of the present invention.

Claims

1. A power-off protection device for the top section of a tower crane, characterized in that: When the lifting cylinder (12) on the top section (11) powers off after lifting the top section (11), the hydraulic oil in the lifting cylinder (12) is controlled by a pressure relief valve to flow back into the fuel tank, and the output shaft of the lifting cylinder (12) contracts, causing the top section (11) to descend until it docks with the top of the standard section (10). It includes a first pipeline (121) and a second pipeline (122) that are connected to the lifting cylinder (12). A first branch pipe (1211) is connected to the first pipeline (121), and a pressure relief valve assembly (1212) for relieving pressure on the lifting cylinder (12) is provided on the first branch pipe (1211). A second branch pipe (1221) is connected to the second pipeline (122). An energy storage member (1222) and a first valve member (1223) are sequentially connected to the second branch pipe (1221). The valve core of the first valve member (1223) is connected to a sliding rod (1224), and a driving source for driving its movement is provided at one end of the sliding rod (1224). A buffer device for controlling the slow movement of the sliding rod (1224) is connected to the outside of the sliding rod (1224). The buffer device includes a receiving box (1225). The sliding rod (1224) passes through the receiving box (1225), and a damping plate (1226) located inside the receiving box (1225) is fixedly provided on the sliding rod (1224). The receiving box (1225) is filled with a buffer fluid (1227).

2. The power-off protection device for the top section of a tower crane according to claim 1, characterized in that: One end of the outlet of the first valve member (1223) is connected to a third branch pipe (13) that communicates with the second pipeline (122). A fourth branch pipe (131) is provided on the third branch pipe (13), and a second valve member (14) is provided on the fourth branch pipe (131). A guiding device is provided between the standard section (10) and the top section (11). The guiding device includes a pressing member (15) fixedly provided on the top section (11), and the pressing member (15) is connected to the second valve member (14) through a pipeline.

3. The power-off protection device for the top section of a tower crane according to claim 2, characterized in that: The guiding device further includes a connecting bracket (151) hinged to the end of the output shaft of the pressing member (15). A guiding strip (16) is fixedly provided on the side of the standard section (10). A guiding wheel (152) and a guiding block (153) that can cooperate with the guiding strip (16) respectively are connected to the connecting bracket (151).

4. The method for the power-off protection device for the top section of a tower crane according to any one of claims 2-3, characterized in that: When power is off, the pressure relief valve assembly (1212) opens to relieve pressure in the lifting cylinder (12). The first valve member (1223) slowly opens, allowing the pressure inside the first valve member (1223) to enter the lifting cylinder (12), causing the output shaft of the lifting cylinder (12) to contract and driving the top section (11) to descend to protect the tower crane.

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