A tower crane

Abstract

The present invention provides a tower crane, and particularly relates to a super heavy tower crane, which is characterized in that a boom comprises a balanced arm and a lifting arm that are connected, and the balanced arm and the lifting arm are respectively located on both sides of a tower frame; a track is provided on the lifting arm, and the track is arranged along the length direction of the lifting arm; a fixed counterweight device is fixedly connected to the balanced arm, and a movable counterweight device is connected to the track arranged on the lifting arm, and a driving device is used to drive the movable counterweight device to move along the track to maintain the balance of the tower body; the movable counterweight device is connected to the hoisting load through a safety rope; under normal working conditions, the effective length of the safety rope can change with the lateral and vertical movement of the load without affecting the movement of the movable counterweight; under the accident condition of load loss, the safety rope quickly drives the counterweight block to move toward the outside direction of the lifting arm to prevent the tower body from overturning.

Description

Technical Field

[0001] The invention relates to a lifting device, in particular to a tower crane. Background Art

[0002] There are many types of tower cranes available today, but their main structure is largely the same: a vertical tower composed of several stacked tower units. A slewing mechanism is located at the top of the tower, corresponding to the slewing mechanism at the lower end of the slewing tower. A tower crane arm is vertically connected to the slewing tower. The long arm, located on one side of the tower and equipped with a lifting trolley, is the boom, while the short arm, located on the other side of the tower and equipped with a counterweight, is the balance arm. The ends of the boom and balance arm are respectively connected to the top of the slewing tower by boom and balance arm cables. An operator's cabin is also located on the slewing tower. A disadvantage of this type of crane is that the counterweight is fixed to the end of the balance arm, resulting in a fixed counterweight torque. When the boom is unloaded or lightly loaded, the boom torque is less than the balance arm torque, causing the tower to tilt toward the balance arm. When the boom is heavily loaded, the boom torque exceeds the balance arm torque, causing the tower to tilt toward the boom again. This poses significant safety risks, and for heavy tower cranes in particular, the structure requires a bulky structure, making costs difficult to control. Data shows that Denmark's K10000 heavy-duty tower crane uses a case where a movable counterweight is arranged on the balance arm. However, firstly, there are many devices on the balance arm, making the arrangement difficult; secondly, in order to reduce the weight of the movable counterweight, the balance arm is set too long, which is inconvenient to operate a small crane on the same tower; thirdly, arranging the movable counterweight on the balance arm is not easy to solve the problem of tower overturning in the accident condition of sudden loss of lifting load. Summary of the Invention

[0003] The main technical problem to be solved by the present invention is to provide a tower crane which can adjust the moment of the lifting arm in real time.

[0004] In order to solve the above technical problems, the present invention provides a tower crane, comprising: a tower frame, a boom, a fixed counterweight, a movable counterweight, and a driving device;

[0005] The boom includes a balancing arm and a lifting arm, and the balancing arm and the lifting arm are respectively located on both sides of the tower;

[0006] The boom is provided with a track, and the track is arranged along the length direction of the boom;

[0007] The fixed counterweight device is fixedly connected to the balance arm, the movable counterweight device is connected to the track provided on the lifting arm, and the driving device is used to drive the movable counterweight device to move along the track.

[0008] In a preferred embodiment, it includes a hoisting load sensor, a hoisting load position sensor, a movable counterweight position sensor, and a controller. The hoisting load sensor, the load position sensor, and the movable counterweight position sensor are respectively used to obtain hoisting load data, the position information of the hoisting trolley, and the position information of the movable counterweight, and send the above data and position information to the controller;

[0009] The controller calculates the sum M1 of the hoisting load moment and the center of gravity moment of the boom according to the data of the hoisting load sensor and the hoisting load position sensor, and then compares the difference with the sum M2 of the center of gravity moment of the balance arm and the fixed counterweight moment to obtain the expected value M3 of the movable counterweight moment;

[0010] The controller calculates the actual value M4 of the moment of the movable counterweight according to the data of the movable counterweight position sensor. When M4 > M3, the driving device drives the movable counterweight to move towards the tower; when M4 < M3, the driving device drives the movable counterweight to move in the opposite direction of the tower.

[0011] In a preferred embodiment, when the balance arm side of the tower is subjected to tensile stress and the boom side of the tower is subjected to compressive stress, the movable counterweight moves towards the tower; when the balance arm side of the tower is subjected to compressive stress and the boom side of the tower is subjected to tensile stress, the movable counterweight moves away from the tower.

[0012] In a preferred embodiment, the driving device includes a hydraulic piston system; wherein the piston is fixedly connected to the boom and remains stationary, and the piston cylinder is connected to the movable counterweight and can move relative to the piston;

[0013] A cavity is formed between the side of the piston and the piston cylinder, and a partition is provided on the piston rod to divide the cavity into two parts, namely the tower side cavity A and the non-tower side cavity B. Each cavity is provided with a hydraulic medium outlet and an inlet;

[0014] When M4 < M3, the hydraulic medium flows out of cavity A and into cavity B;

[0015] When M4 > M3, the hydraulic medium flows out of cavity B and into cavity A.

[0016] In a preferred embodiment, the boom is a truss structure, and the structural members forming the truss include pipes with a circular inner cross-section, and the pipes are filled with liquid, and the liquid is connected to the hydraulic piston system.

[0017] In a preferred embodiment, the pipe includes a pipe section that is arc-shaped along the length direction, and the center of the arc faces downward; the liquid pressure in the pipe section is adjusted by a hydraulic device according to the magnitude of the load moment. When the moment increases, the pressure increases, and when the moment decreases, the pressure decreases to adjust the deformation amount of the boom.

[0018] In a preferred embodiment, the movable counterweight device is connected to the hoisted load via a safety rope;

[0019] Under normal working conditions, the effective length of the safety rope can change with the lateral and vertical movement of the load without affecting the movement of the movable counterweight;

[0020] In the event of a load shedding accident, the safety rope drives the movable counterweight to move rapidly toward the outside of the boom. After reaching the set limit position or speed, the safety rope breaks, falls off, or other conditions occur that do not affect the position of the movable counterweight.

[0021] In a preferred embodiment, it further comprises a traveling device, wherein wheels are installed on both sides of the traveling direction, and space is left at the bottom for a heavy-load axle vehicle to be inserted.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0023] The present invention provides a tower crane, in which a movable counterweight is arranged on a lifting arm. Firstly, the torque of the movable counterweight can be adjusted in real time, so that the torque of the movable configuration can adapt to the difference between the sum M1 of the lifting load torque and the lifting arm center of gravity torque and the sum M2 of the balance arm center of gravity torque and the fixed counterweight torque, and the tower body is always in a balanced state; secondly, the tight arrangement space on the balance arm is not occupied, and the movable counterweight is arranged in the spacious space on the lifting arm, so the weight of the movable counterweight can be set to be smaller, which is convenient for the operation of the driving mechanism; thirdly, a shorter balance arm is retained, which is conducive to the daily operation of a small crane arranged on the same tower above the heavy lifting arm; fourthly, the movable counterweight is arranged on the lifting arm and connected to the load through a safety rope, which can prevent the lifting from overturning. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of a tower crane in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "set / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] refer to Figure 1 The present invention provides a tower crane, comprising: a tower frame 1, a boom 2, a fixed counterweight 3, a movable counterweight 4, a driving device, a hoisting load sensor, a hoisting load position sensor, a movable counterweight position sensor, and a controller;

[0029] The tower 1 is vertically connected to the boom 2 via a turntable; the boom 2 includes a balancing arm 21 and a lifting arm 22 connected thereto, and the balancing arm 21 and the lifting arm 22 are respectively located on either side of the tower 1; a track 221 is provided on the lifting arm 22, and the track 221 is arranged along the length direction of the lifting arm 22; the fixed counterweight 3 device is fixedly connected to the balancing arm 21, and the movable counterweight 4 device is connected to the track 221 provided on the lifting arm 22, and the driving device is used to drive the movable counterweight 4 device to move along the track 221;

[0030] The hoisting load sensor, load position sensor and movable counterweight position sensor are used to obtain hoisting load data, position information of the hoisting trolley and position information of the movable counterweight 4 respectively, and send the above data and position information to the controller.

[0031] During use, the controller calculates the sum M1 of the hoisting load torque and the center-of-gravity torque of the boom 22 based on the data from the hoisting load sensor and the hoisting load position sensor, and then compares the difference with the sum M2 of the center-of-gravity torque of the counter-jib 21 and the torque of the fixed counterweight 3 to obtain the expected value M3 of the torque of the movable counterweight 4. Then, the controller calculates the actual value M4 of the torque of the movable counterweight 4 according to the data from the movable counterweight position sensor. When M4 > M3, the drive device drives the movable counterweight 4 to move towards the tower 1; when M4 < M3, the drive device drives the movable counterweight 4 to move in the opposite direction of the tower 1. Thus, it can be achieved that the torque of the movable configuration can adapt to the difference between the sum M1 of the hoisting load torque and the center-of-gravity torque of the boom 22 and the sum M2 of the center-of-gravity torque of the counter-jib 21 and the torque of the fixed counterweight 3.

[0032] In this embodiment, before the actual use of the tower crane, it further includes a step of checking the tower crane. Specifically, it is checked according to the strain display signal set on the tower 1:

[0033] When the tower 1 is under tensile stress on the counter-jib 21 side and compressive stress on the boom 22 side of the tower 1, the movable counterweight 4 moves towards the tower 1; when the tower 1 is under compressive stress on the counter-jib 21 side and tensile stress on the boom 22 side of the tower 1, the movable counterweight 4 moves in the direction away from the tower 1.

[0034] In this embodiment, the drive device includes a hydraulic piston system; wherein the piston is fixedly connected to the boom 22 and remains stationary, and the piston cylinder is connected to the movable counterweight 4 and can move relative to the piston; a cavity is formed between the side of the piston and the piston cylinder, and a partition is provided on the piston rod to divide the cavity into two parts, namely the cavity A on the tower 1 side and the cavity B on the side away from the tower 1, and each cavity is provided with a hydraulic medium outlet and an inlet;

[0035] When M4 < M?3, the hydraulic medium flows out of the cavity A and flows into the cavity B; when M4 > M3, the hydraulic medium flows out of the cavity B and flows into the cavity A.

[0036] Specifically, control valves are correspondingly provided at the outlets and inlets of the cavity A and the cavity B. The control system is connected to the control valves. When the torque of the movable counterweight 4 is greater than the set value, the inlet valve of the cavity A is closed, the outlet valve is opened, the inlet valve of the cavity B is opened, and the outlet valve is closed, and the hydraulic medium pushes the piston cylinder and the movable counterweight 4 to move towards the tower 1 side. On the contrary, when the torque of the movable counterweight 4 is less than the set value, the inlet valve of the cavity A is opened, the outlet valve is closed, the inlet valve of the cavity B is closed, and the outlet valve is opened, and the hydraulic medium pushes the piston cylinder and the movable counterweight 4 to move in the direction away from the tower 1 side.

[0037] In this embodiment, to facilitate the flow of hydraulic fluid, boom 2 is constructed as a truss structure. The truss' components include tubing with a circular inner cross-section, filled with liquid that communicates with the hydraulic piston system. Specifically, the tubing includes curved segments along its length, with the center of the arc facing downward. The fluid pressure within these segments is adjusted by a hydraulic device based on the load torque. Increasing torque increases the pressure, while decreasing torque decreases the pressure, thereby adjusting the deformation of boom 22.

[0038] To ensure safety, the movable counterweight 4 device is connected to the hoisted load 6 through a safety rope 5; under normal working conditions, the effective length of the safety rope 5 can change with the lateral and vertical movement of the load 6 without affecting the movement of the movable counterweight 4; under the accident condition of the load 6 falling off, the safety rope 5 drives the movable counterweight 4 to move rapidly toward the outside of the crane arm 22. After reaching the set extreme position, the safety rope 5 breaks, falls off or other conditions occur that do not affect the position of the movable counterweight 4.

[0039] Finally, the tower crane further comprises a traveling device, which is provided with wheels on both sides along the traveling direction, and has space at the bottom for a heavy-load axle vehicle to be inserted.

[0040] The above is only a preferred specific embodiment of the present invention, but the design concept of the present invention is not limited to this. Any technician familiar with this technical field who uses this concept to make non-substantial changes to the present invention within the technical scope disclosed by the present invention shall be deemed to infringe the scope of protection of the present invention.

Claims

1. A tower crane, characterized in that Comprising: Tower, boom, fixed counterweight, movable counterweight, drive device; The tower is vertically connected to the boom through a turntable; The boom includes a connected balance arm and a lifting arm, and the balance arm and the lifting arm are respectively located on both sides of the tower; A track is provided on the lifting arm, and the track is arranged along the length direction of the lifting arm; The fixed counterweight is fixedly connected to the balance arm, the movable counterweight is connected to the track provided on the lifting arm, and the drive device is used to drive the movable counterweight to move along the track; The movable counterweight is connected to the lifting load by a safety rope; Under normal working conditions, the effective length of the safety rope can change with the horizontal and vertical movement of the load without affecting the movement of the movable counterweight; In the accident condition of load shedding, the safety rope drives the movable counterweight to move outward in the direction of the lifting arm. After reaching the set limit position, the safety rope breaks or falls off.

2. A tower crane according to claim 1, characterized in that: Comprising a lifting load sensor, a lifting load position sensor, a movable counterweight position sensor, and a controller; the lifting load sensor, the load position sensor, and the movable counterweight position sensor are respectively used to obtain the lifting load data, the position information of the lifting trolley, and the position information of the movable counterweight, and send the above data and position information to the controller; The controller calculates the sum M1 of the lifting load moment and the center of gravity moment of the lifting arm according to the data of the lifting load sensor and the lifting load position sensor, and then compares the difference with the sum M2 of the center of gravity moment of the balance arm and the fixed counterweight moment to obtain the expected value M3 of the movable counterweight moment; The controller calculates the actual value M4 of the moment of the movable counterweight according to the data of the movable counterweight position sensor. When M4 > M3, the drive device drives the movable counterweight to move in the direction of the tower; when M4 < M3, the drive device drives the movable counterweight to move in the opposite direction of the tower.

3. A tower crane according to claim 1, characterized in that: When the tower's balance arm side bears tensile stress and the tower's lifting arm side bears compressive stress, the movable counterweight moves in the direction of the tower; when the tower's balance arm side bears compressive stress and the tower's lifting arm side bears tensile stress, the movable counterweight moves in the direction away from the tower.

4. A tower crane according to claim 2, characterized in that: The drive device includes a hydraulic piston system; wherein the piston is fixedly connected to the lifting arm and remains stationary, and the piston cylinder is connected to the movable counterweight and can move relative to the piston; A cavity is formed between the side of the piston and the piston cylinder. A partition is provided on the piston rod, dividing the cavity into two parts, namely the tower side cavity A and the tower-back side cavity B. Each cavity is provided with a hydraulic medium outlet and an inlet; When M4 < M3, the hydraulic medium flows out of cavity A and into cavity B; When M4 > M3, the hydraulic medium flows out of cavity B and into cavity A.

5. A tower crane according to claim 4, characterized in that: The boom is a truss structure. The structural members forming the truss include pipes with a circular inner cross-section, and the pipes are filled with liquid, and the liquid is connected to the hydraulic piston system.

6. A tower crane according to claim 5, characterized in that: The pipe includes a pipe section that is arc-shaped along the length direction, and the center of the arc faces downward; the liquid pressure in the pipe section is adjusted by a hydraulic device according to the magnitude of the load moment. The moment increases and the pressure increases, and the moment decreases and the pressure decreases to adjust the deformation amount of the lifting arm.

7. A tower crane according to claim 1, characterized in that: The utility model also comprises a traveling device, wherein wheels are installed on both sides of the traveling device along the traveling direction, and space is reserved at the bottom for a heavy-load axle vehicle to be inserted.

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