Heavy hoisting equipment

Abstract

The invention relates to the technical field of heavy cranes, and discloses heavy hoisting equipment which comprises a hoisting motor and a block brake, the block brake comprises a pull rod, a brake tile, a brake wheel, a lever and a pusher, and the pusher is started in a delayed mode based on the hoisting motor. The hoisting motor provides torque firstly, and then the pusher releases the clamping braking state of the brake tile and the brake wheel. The hoisting motor and the pusher are started in a staggered mode, and the situation that when the hoisting motor does not reach the hoisting torque in the starting stage, a heavy object slides to a hook can be prevented; by arranging the damping mechanism, time-staggered starting is achieved, the system precision requirement for controlling a timestamp can be lowered, smooth starting transition of the hoisting motor and the brake wheel can be achieved, and guarantee is provided for starting smoothness of a hovering heavy object; the damping structure is combined with a brake tile abrasion condition verification method, the inspection window period of technicians is compensated, and the possible excessive abrasion condition in the window period is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy cranes, and particularly to a heavy lifting device. Background Art

[0002] A crane refers to a multi-action lifting machine that vertically lifts and horizontally transports heavy objects within a certain range. According to the structural form, cranes are mainly divided into light and small lifting equipment, bridge type (bridge crane, gantry crane), boom type (self-propelled, tower type, portal type, railway type, floating ship type, mast type crane), and cable type.

[0003] For a bridge crane, it refers to a bridge-type crane with a bridge running on elevated tracks, also known as an overhead crane. The bridge of the bridge crane runs longitudinally along the tracks laid on both sides of the elevated structure, and the hoisting trolley runs transversely along the tracks laid on the bridge, forming a rectangular working range, so that the space under the bridge can be fully utilized to lift materials without being hindered by ground equipment. This kind of crane is widely used in indoor and outdoor warehouses, factories, docks, open storage yards, etc.

[0004] The brakes of bridge cranes are mostly electro-hydraulic block brakes, which mainly consist of a brake wheel, brake shoes, brake springs, tie rods, levers, electro-hydraulic thrusters, etc. They are installed between the output shaft of the hoisting motor and the input shaft of the gearbox. When the crane needs to stop or decelerate, the brake shoes are pressed tightly against the brake wheel under the action of the brake spring, and the crane stops moving through friction. It should be noted in the bridge crane control system that regarding the control of preventing hook slipping, after the heavy object hovers in mid-air and moves horizontally, and immediately after the brake is released, it is extremely easy for the heavy object to slide down due to the stop state and cause hook slipping, which can generate a large instantaneous tension and affect the hoisting safety; and due to the frequent braking during the hoisting process, the brake shoes are easily worn, and technicians need to regularly inspect and replace them. If the inspection is derelict or the wear critical value occurs during a non-inspection period, it is easy to have abnormal braking and affect the hoisting safety. This application aims to solve the above technical problems. Summary of the Invention

[0005] Aiming at the deficiencies existing in the use of the existing electro-hydraulic block brakes of bridge cranes in the background art, the present invention provides a heavy lifting device, which has the advantages of preventing the hook from slipping when the heavy object hovers and starts, smooth start, and wear detection of the brake tiles, and solves the technical problems proposed in the above background art.

[0006] The present invention provides the following technical solution: A heavy lifting device includes a hoisting motor and a block brake. The block brake includes a tie rod, brake tiles, a brake wheel, a lever, and a thruster. The thruster is delayed in starting based on the hoisting motor, so that the hoisting motor first provides torque and the thruster then releases the clamping and braking state between the brake tiles and the brake wheel.

[0007] Preferably, an interval period is set for the power-on time points of the hoisting motor and the pusher. The hoisting motor is powered on first, and the pusher is powered on after the hoisting motor. When the pusher is powered on, the braking state of the brake tiles and the brake wheel is released.

[0008] Preferably, a damping mechanism is hinged in the middle of the lever. The damping mechanism is located between the hinge points of the pull rod and the pusher. The damping mechanism includes a damping cylinder. A damping piston is slidably connected inside the damping cylinder. The top of the damping piston is fixedly connected with a damping rod. A damping hole is penetrated through the damping piston. A hydraulic pipe is arranged outside the damping cylinder. The two ends of the hydraulic pipe are respectively communicated with the upper part and the lower part of the damping cylinder. A one-way valve is arranged at the connection of the hydraulic pipe and the lower part of the damping cylinder. The one-way valve is used to limit the single-way conduction of the hydraulic pipe to the lower part of the damping cylinder. The upper part, the lower part of the damping cylinder and the hydraulic pipe are all filled with hydraulic oil.

[0009] Preferably, the time for the hydraulic oil volume to pass through the damping hole under the rated stroke of the damping piston is about 1-2 s.

[0010] A method for verifying the wear condition of the brake tiles of a heavy hoisting device, which is applied to the heavy hoisting device, includes the following steps: S1. Enter the rated time difference ΔT; S2. Start the hoisting motor and record the time point T1; S3. Obtain the real-time speed of the hoisting motor, and when the rated speed is reached, record the time T2; S4. Calculate the time difference (T2 - T1); S5. Compare (T2 - T1) with ΔT; S6. When the calculated time difference is the same as or close to the rated time difference, it is determined that the wear condition of the brake tiles is within the controllable range and can be used normally; otherwise, it is determined that the wear condition of the brake tiles is serious, and the technician is reminded to conduct a timely inspection and debugging to compensate for the wear, or the pushing stroke is abnormal and needs to be adjusted for compensation.

[0011] Preferably, in step S5, for the comparison method, the precision digit of the timing accuracy is adopted, and after rounding, the values of the two are compared to see if they are the same.

[0012] Preferably, in step S5, for the comparison method, the change rate is calculated by ((T2 - T1) - ΔT) / ΔT, and it is set that the change rate is normal within the rated range and abnormal if it exceeds.

[0013] The present invention has the following beneficial effects: 1. By starting the hoisting motor and the pusher at different times, the present invention can prevent the heavy object from slipping off the hook when the hoisting motor fails to reach the lifting torque during the starting stage.

[0014] 2. The present invention realizes staggered start by setting a damping mechanism, which can reduce the system accuracy requirements for controlling timestamps and enable smooth start-up transition between the hoisting motor and the brake wheel, providing guarantee for the smooth start-up of the suspended heavy object.

[0015] 3. The verification method based on the damping mechanism in the present invention can detect the wear condition of the brake tiles in real time through the electronic control system, making up for the inspection window period of technicians, avoiding excessive wear that may occur during the window period, and effectively implementing automated safe hoisting operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a layout schematic diagram of the hoisting trolley of the present invention; Figure 2 is a top view of the structure of the block brake of the present invention; Figure 3 is of the present invention Figure 2 front view of the structure; Figure 4 is a schematic diagram of the structure of the damping mechanism of the present invention; Figure 5 is a block diagram of the wear verification method of the present invention.

[0017] In the figure: 1, crossbeam; 2, hoisting trolley; 3, hoisting motor; 4, block brake; 5, gearbox; 6, roller; 41, base; 42, bracket; 43, pull rod; 45, brake tile; 46, brake wheel; 47, lever; 48, pusher; 49, damping mechanism; 441, brake frame; 442, ejector rod; 443, stop block; 444, brake spring; 491, damping cylinder; 492, damping rod; 493, damping piston; 494, damping hole; 495, hydraulic pipe; 496, check valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a 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 those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] Please refer to Figures 1-3, a heavy lifting device. Since the main improvement of this application lies in the trolley brake part of the bridge crane, the introduction of the trolley part is omitted in the specification of this application. This application specifically includes a crossbeam 1. There are two groups of crossbeams 1, which are arranged in parallel on the trolley tracks of the bridge crane. The crossbeam 1 is provided with tracks for supporting the sliding of the lifting trolley 2. At the top of the lifting trolley 2, a hoisting motor 3, a block brake 4, a gearbox 5, and a roller 6 are fixedly installed. The output shaft of the hoisting motor 3 is fixedly connected to the input shaft of the block brake 4 through a coupling. The output shaft of the block brake 4 is fixedly connected to the input shaft of the gearbox 5. The output shaft of the gearbox 5 is fixedly connected to the input end of the roller 6. The roller 6 is used for winding the steel wire rope to realize the lifting and lowering of heavy objects.

[0020] Among them, the block brake 4 includes a base 41. The base 41 is fixedly installed at the top of the lifting trolley 2, generally fixed by bolts and anti-slip gaskets. Four brackets 42 are arranged in a rectangular column at the top of the base 41. The brackets 42 are vertically arranged flat steel plates. Refer to Figure 3 , the brackets 42 are successively provided with a pull rod 43, a braking mechanism, and a brake shoe 45 from top to bottom. The left and right ends of the pull rod 43 are provided with threads in opposite directions. One end of the pull rod 43 is threadedly connected to the top shaft between the two brackets 42, and the other end of the pull rod 43 is threadedly connected to a lever 47; the braking mechanism includes a brake frame 441, a push rod 442, a stop block 443, and a brake spring 444. The brake frame 441 is a concave groove frame arranged horizontally. The open end of the groove of the brake frame 441 is hinged to the middle shaft between the other two brackets 42. A stop block 443 and a brake spring 444 are arranged in the groove of the brake frame 441. One end of the brake spring 444 contacts the inner end surface of the groove of the brake frame 441, and the other end of the brake spring 444 contacts the stop block 443. One end of the push rod 442 is threadedly connected to the middle shaft between the two brackets 42, and the other end of the push rod 442 penetrates the end surface of the groove of the brake frame 441 and extends into the brake spring 444 and is threadedly connected to the stop block 443. The brake spring 444 is in an initial compressed state due to the extrusion between the stop block 443 and the end surface of the groove of the brake frame 441; the brake shoe 45 is hinged to the bottom shaft between the two brackets 42. There are two brake shoes 45 and they are symmetrically arranged. A brake wheel 46 is arranged between the two brake shoes 45. One end of the brake wheel 46 is fixedly connected to the output shaft of the hoisting motor 3, and the other end of the brake wheel 46 is fixedly connected to the input shaft of the gearbox 5. The two brake shoes 45 move towards each other to clamp the brake wheel 46 to complete the braking.

[0021] Refer to Figure 3The lever 47 is hinged on the top axis between the other two brackets 42, and the hinge axis is not the same axis as the hinge axis of the pull rod 43 and the lever 47. The hinge axis of the pull rod 43 and the lever 47 is on the axis center of the lever 47, and the hinge axis of the lever 47 and the bracket 42 are eccentrically arranged. A pusher 48 is hinged on one end of the lever 47, and the output shaft of the pusher 48 is hinged to one end of the lever 47, and the bottom end of the pusher 48 is hinged to the top end of the base 41.

[0022] Thus, the structure of the complete electric hydraulic block brake is formed. By cutting off the power, the pusher 48 is not powered and the output is pushed. Figure 3 For example, the output shaft at the top of the pusher 48 drops and retracts, and under the action of the eccentric lever of the lever 47 and the pulling force of the pull rod 43, the left and right groups of brackets 42 rotate toward each other with their bottom hinge axes as the center, so that the brake spring 444 is compressed, and the two brake shoes 45 clamp the brake wheel 46 to complete the braking; conversely, after power is turned on, the reverse action is performed to release the brake.

[0023] The above-mentioned action process, in the process of hoisting, is to brake by power off, and lift or lower by power on. After the heavy object is suspended in mid-air and braked, it is moved horizontally. When it is in place, it is powered on to continue lifting or lowering. At the moment of power on, the pusher 48 is instantly lifted, and the brake spring 444 is instantly released, resulting in the instantaneous clamping and unlocking of the two brake shoes 45. However, at this time, the torque of the hoisting motor 3 has not yet reached the rated maximum value. In this short moment, the heavy object is prone to slip due to inertia.

[0024] In this regard, an implementation method of system logic circuit control can be provided, in which an interval period is set between the power-on time points of the hoisting motor 3 and the pusher 48, that is, the hoisting motor 3 is powered on first, and the pusher 48 is powered on after the hoisting motor 3, and the length of the interval time is strictly controlled to ensure that the hoisting motor 3 will not overheat due to braking.

[0025] Another control implementation method of mechanical setting is provided. A damping mechanism 49 is hinged in the middle of the lever 47. The damping mechanism 49 is located between the hinge points of the pull rod 43 and the actuator 48. The bottom end of the damping mechanism 49 is hinged to the top end of the base 41. The damping mechanism 49 includes a damping cylinder 491. A damping piston 493 is slidably connected inside the damping cylinder 491. The top end of the damping piston 493 is fixedly connected to a damping rod 492. The damping rod 492 is hinged to the middle of the lever 47. A damping hole 494 is formed through the damping piston 493. A hydraulic pipe 495 is arranged outside the damping cylinder 491. The two ends of the hydraulic pipe 495 are respectively communicated with the upper part and the lower part of the damping cylinder 491. The upper part and the lower part of the damping cylinder 491 are bounded by the damping piston 493. Among them, a one-way valve 496 is arranged at the connection of the hydraulic pipe 495 and the lower part of the damping cylinder 491. The one-way valve 496 is used to limit the one-way conduction of the hydraulic pipe 495 to the lower part of the damping cylinder 491, that is, the one-way valve 496 only allows the lower part of the damping cylinder 491 to conduct unidirectionally to one end of the hydraulic pipe 495. The upper part, the lower part of the damping cylinder 491 and the hydraulic pipe 495 are all filled with hydraulic oil.

[0026] Thus, a cooperation is formed. When releasing the brake, the actuator 48 jacks up one end of the lever 47. At the same time, the damping rod 492 also extends out of the damping cylinder 491. The damping cylinder 491 drives the damping piston 493 to move upward. Due to the one-way conduction property of the one-way valve 496, it prevents the hydraulic oil in the upper part of the damping cylinder 491 from entering the lower part of the damping cylinder 491 through the hydraulic pipe 495. It can only make the hydraulic oil in the upper part of the damping cylinder 491 enter the lower part of the damping cylinder 491 through the damping hole 494. And because the damping hole 494 has a small hole damping effect, hysteresis is generated. Furthermore, when the hoisting motor 3 and the actuator 48 are energized at the same time, the hoisting motor 3 will also generate a pre-moving storage torque first, and the brake tile 45 will move later to release the brake, ensuring that the heavy object has enough lifting torque immediately after releasing the hover and is not prone to slipping hooks. On the contrary, when braking is required, the damping piston 493 moves downward. The hydraulic oil in the lower part of the damping cylinder 491 can quickly enter the upper part of the damping cylinder 491 through the one-way valve 496 via the hydraulic pipe 495, so as to stop in time.

[0027] For the optimization of implementation parameters, generally, the pushing stroke of the actuator 48 is adjusted to 1 cm, and the stroke of the damping mechanism 49 is close to 0.5 cm. Under this stroke, the total amount of hydraulic oil activity is controlled at 5-10 mL, and the time for the damping hole 494 to pass through the hydraulic oil volume is about 1-2 s.

[0028] Regarding the wear problem of the brake tile 45, in addition to the regular inspection by technical personnel, a systematic detection of the wear condition is adopted. Specifically, it is a method for verifying the wear condition of the brake tile of a heavy lifting equipment. The specific steps are as follows: S1. Input the rated time difference ΔT; The rated time difference refers to the time when the hoisting motor 3 and the pusher 48 start at different times (or adopt the control implementation method set by the above-mentioned mechanism) when the brake shoe 45 and the brake wheel 46 are normally clamped, and the speed of the hoisting motor 3 reaches the normal operating speed. Due to the delayed start of the pusher 48, that is, after the hoisting motor 3 starts, affected by the clamping of the brake shoe 45 and the brake wheel 46, the output shaft of the hoisting motor 3 is still in the braking state. After the braking is completely released, the output speed of the hoisting motor 3 will gradually increase to the normal speed. During this period, if the brake shoe 45 is severely worn and may affect the braking effect, when the hoisting motor 3 starts, even if the pusher 48 starts delayed, the output shaft speed of the hoisting motor 3 will reach the rated speed earlier than the normal state. According to the abnormality of this time difference, the wear condition can be systematically verified.

[0029] S2. Start the hoisting motor 3 and record the time point T1; S3. Obtain the real-time speed of the hoisting motor 3 and record the time T2 when it reaches the rated speed; S4. Calculate the time difference (T2 - T1); This time difference can be calculated by taking the difference between the point time stamps of two parameters recorded successively; or the system can start timing from the T1 moment as the starting segment and end timing when reaching the T2 moment to obtain the time difference.

[0030] S5. Compare (T2 - T1) with ΔT; For the comparison method, the precise number of digits of the timing accuracy can be used, and after rounding, compare whether the two values are the same; or ((T2 - T1) - ΔT) / ΔT can be used to calculate the change rate, and it is set that the change rate is normal within the rated range, and it is abnormal if it exceeds.

[0031] S6. When it is calculated that the time difference is the same as or close to the rated time difference, it is determined that the wear condition of the brake shoe 45 is within the controllable range and can be used normally; otherwise, it is determined that the wear condition of the brake shoe 45 is serious, and the technical personnel are reminded to conduct inspections and debug to compensate for the wear in a timely manner, or the pushing stroke is abnormal and needs to be adjusted and compensated.

[0032] The above verification method is preferably used in the control implementation method set by the mechanism, that is, based on the use of the damping mechanism 49, the wear condition can be verified in more detail. Because of the delayed release, the premise for the hoisting motor 3 to drive the brake wheel 46 to rotate and accelerate in advance is only near the braking and non-braking critical point. And based on the damping mechanism 49, if the wear is large but does not affect a single braking, within the stroke range of the damping rod 492, it can be gradually released and there is a situation of advancing rotation, so that the abnormality can also be detected.

Claims

1. A heavy lifting device, comprising a hoisting motor (3) and a block brake (4), wherein the block brake (4) comprises a pull rod (43), brake linings (45), a brake wheel (46), a lever (47), and a pusher (48), and is characterized in that: The pusher (48) is delayed in starting based on the hoisting motor (3), so that the hoisting motor (3) first provides torque, and then the pusher (48) releases the clamping and braking state between the brake tile (45) and the brake wheel (46).

2. The heavy lifting equipment according to claim 1, characterized in that: An interval period is set for the power-on time points of the hoisting motor (3) and the pusher (48). The hoisting motor (3) is powered on first, and the pusher (48) is powered on after the hoisting motor (3). When the pusher (48) is powered on, the braking state between the brake tile (45) and the brake wheel (46) is released.

3. A heavy lifting device according to claim 1, characterized in that: A damping mechanism (49) is hinged in the middle of the lever (47). The damping mechanism (49) is located between the hinge points of the pull rod (43) and the pusher (48). The damping mechanism (49) includes a damping cylinder (491). A damping piston (493) is slidably connected inside the damping cylinder (491). The top of the damping piston (493) is fixedly connected to a damping rod (492). A damping hole (494) is formed through the damping piston (493). A hydraulic pipe (495) is arranged outside the damping cylinder (491). The two ends of the hydraulic pipe (495) are respectively communicated with the upper part and the lower part of the damping cylinder (491). A one-way valve (496) is arranged at the connection between the hydraulic pipe (495) and the lower part of the damping cylinder (491). The one-way valve (496) is used to limit the one-way conduction of the hydraulic pipe (495) to the lower part of the damping cylinder (491). The upper part, the lower part of the damping cylinder (491) and the hydraulic pipe (495) are all filled with hydraulic oil.

4. A heavy lifting device according to claim 3, characterized in that: The time for the damping hole (494) to pass through the hydraulic oil volume under the rated stroke of the damping piston (493) is about 1-2 s.

5. A method for verifying the wear condition of the brake tiles of a heavy lifting device, which is applied to the heavy lifting device according to any one of claims 1-3, and is characterized in that, It includes the following steps: S1. Input the rated time difference ΔT; S2. Start the hoisting motor (3) and record the time point T1; S3. Obtain the real-time speed of the hoisting motor (3), and when it reaches the rated speed, record the time T2; S4. Calculate the time difference (T2 - T1); S5. Compare (T2 - T1) with ΔT; S6. When the calculated time difference is the same as or close to the rated time difference, it is determined that the wear condition of the brake tile (45) is within the controllable range and can be used normally; Otherwise, it is determined that the wear condition of the brake tile (45) is serious, and the technician is reminded to conduct timely inspection and commissioning to compensate for the wear, or the pushing stroke is abnormal and needs to be adjusted and compensated.

6. A method for calibrating the wear condition of the brake tiles of a heavy lifting device according to claim 5, characterized in that: In step S5, for the comparison method, the accurate number of digits of the timing accuracy is adopted, and after rounding, the values of the two are compared.

7. A method for calibrating the wear condition of the brake tiles of a heavy lifting device according to claim 5, characterized in that: In step S5, for the comparison method, the change rate is calculated by ((T2 - T1) - ΔT) / ΔT. It is set that the change rate is normal within the rated range, and it is abnormal if it exceeds.

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