Method for measuring braking torque of hoisting winch by utilizing static tension difference

Abstract

The invention discloses a method for measuring the braking torque of a hoisting winch by using a static tension difference, which comprises the following steps of: (1) setting hoisting containers on two sides to be no-load and heavy-load respectively, placing the hoisting containers at safe and appropriate positions convenient to operate in a shaft, and ensuring that the static tension difference of hoisting first ropes on two sides is the actual load capacity Q of the heavy-load hoisting containers; (2) enabling all the brakes to be in a full-braking state, and closing n pairs of auxiliary brake ball valves needing to be tested; (3) working oil pressure is established through a hydraulic station, the rest of unclosed brakes are manually and slowly opened, and whether the winding drum has the rotation tendency or not is observed; (4) if the winding drum does not rotate, it is indicated that the tested brake set meets the safety requirement; and (5) calculating the measured value of the number n of the to-be-tested brakes. The brake torque detection device has the beneficial effects that the brake torque can be rapidly detected during daily maintenance of the brake and installation and debugging of the elevator, and the requirement for safe operation of the elevator is met.

Description

Technical Field

[0001] The invention relates to the technical field of hoists, and in particular to a method for measuring the braking torque of a hoisting winch by utilizing static tension difference. Background Art

[0002] The braking system of the hoist is a key link to ensure the safe operation of the hoist (winch). The braking torque is an important parameter of the hoist braking system. If the braking torque is insufficient, it is very likely to cause a major accident in the hoisting link. In order to truly ensure the safe and reliable operation of the hoist, it is particularly important to do a good job in the detection and inspection of the braking torque. The "Safety Regulations for Metal and Non-metal Mines" requires that the ratio of the maximum braking torque of the hoist and the rotational torque generated by the difference in the maximum static tension between the hoisting system and the hoisting system shall not be less than 3 times during normal production hoisting to ensure the safety of the equipment under extreme conditions. The comparison value in the regulations does not require precise measurement, and it only needs to be not less than 3 times to meet the hoisting safety requirements. In fact, when the hoist is braked, the ratio of the braking torque generated by the friction between the brake and the brake disc to the minimum torque actually required for the hoisting system to stop is the safety factor of the braking system. Although the current conventional method for detecting the maximum braking torque of the mine hoist can quantitatively determine the braking torque value of each brake, its operation is complicated, the detection time is long, and the impact on production is large. At present, the detection of the braking torque of the mine hoist conventionally adopts the direct tension sensor measurement method, such as Figure 1 As shown, the device includes a steel beam 1, a hand chain hoist 2, a connecting device 3, a tension sensor 4, a dynamometer 5 and a hoist 6. The braking torque detection method is: put the hoist in a braking state at a balanced position, connect the tension sensor in series to the drum and the steel beam, and slowly pull the hand chain hoist under braking conditions until the drum has a rotation direction, and measure its drum braking force P. The braking torque Mz is calculated, Mz = FR, where: Mz is the braking torque, Nm; F is the tangential braking force measured by the tension sensor, N; R is the braking radius of the tension, m. Although this method can accurately measure the braking torque, it has the following obvious limitations:

[0003] (1) Long detection time: The conventional method of measuring the braking torque requires the hoist to be in a balanced position, and then use a hand chain hoist to adjust the drum rotation. This process is complicated and time-consuming. Especially in the mine production process, long shutdown detection will affect normal production operations.

[0004] (2) High operational complexity: This method requires multiple operating steps, including installing the tension sensor, adjusting the tension, etc., which requires a high level of technical skills of the operator. This not only increases the difficulty of detection, but may also lead to safety problems caused by improper operation.

[0005] (3) High dependence on equipment: Conventional testing methods rely on a variety of equipment, such as tension sensors, force gauges, connection devices, etc. These devices require regular calibration and maintenance, further increasing the cost and complexity of testing.

[0006] (4) Data limitations: Although the direct test method can provide quantitative data of the braking torque, these data may be affected by factors such as the test environment and equipment accuracy, and there is a certain degree of uncertainty.

[0007] (5) Great impact on production: Long-term shutdown inspection not only reduces production efficiency, but may also cause delays in production tasks. In the mine production process, the hoist is a key equipment, and frequent shutdown inspection is obviously not conducive to the continuity and stability of production.

[0008] Chinese invention patent publication number CN109060225A discloses a method and device for measuring the braking torque of a hoist. The operation process is as follows: select a wire rope with a length of 22 times the diameter of the drum, then fold it in half, fix the two ends of the rope in the bolt holes of the drum, wrap the wire rope around the drum of the hoist for 3 turns, connect the folding point of the wire rope to the dynamometer of the measuring device, and connect the dynamometer to the hand chain hoist; when the drum is fully braked, pull the hand chain of the hand chain hoist, and measure and calculate the braking torque at the moment when the wire rope pulls the drum of the hoist to rotate. This patent still uses the direct tension sensor measurement method. Summary of the invention

[0009] The technical problem to be solved by the present invention is that the existing method for lifting winch braking torque has many drawbacks, and for this purpose, a method for measuring the lifting winch braking torque by utilizing static tension difference is provided.

[0010] The technical solution of the present invention is: a method for measuring the braking torque of a hoisting winch by using a static tension difference, comprising the following steps: (1) adjusting the position of the hoisting container: setting the hoisting containers on both sides to empty load and heavy load respectively, placing the hoisting containers in a safe and suitable position in the wellbore for convenient operation, and ensuring that the static tension difference of the hoisting head ropes on both sides is the actual load Q of the heavy load hoisting container; (2) setting the brake state: setting all brakes to a full braking state, closing the n to be tested 测 Auxiliary brake ball valve; (3) Oil pressure establishment and observation: Establish working oil pressure through the hydraulic station, manually slowly open the remaining brakes that are not closed, and observe whether the drum has a tendency to rotate; (4) Judgment standard: If the drum does not rotate, it indicates that the test brake group meets the safety requirements. If there is a rotation phenomenon, the brake should be braked immediately, and the brake and brake shoe should be further inspected and processed, and then tested again. The brakes should be tested in groups one by one in the same way; (5) The number of brake pairs required to be tested n 测 Value calculation

[0011]

[0012] Where n is the number of brake pairs tested, K is the ratio of the actual static tension difference during the test to the maximum static tension difference of the lifting system. By calculating the combination of different brake groups, it is possible to quickly evaluate whether the braking torque meets the safety standards.

[0013] In the above scheme, before step (1), check that all brakes are in good working condition, ensure that there is no oil stain, and that the brake clearance and oil pressure meet the requirements.

[0014] The beneficial effects of the present invention are that the braking torque can be quickly detected during daily maintenance of the brake and installation and commissioning of the hoist, meeting the requirements for safe operation of the hoist, and the operation is convenient, the detection time is short, and the impact on production is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the existing mine hoist torque detection device;

[0016] Figure 2 It is the brake arrangement diagram of the present invention;

[0017] In the figure, 1. steel beam, 2. hand hoist, 3. connecting device, 4. tension sensor, 5. dynamometer, 6. lifting winch, 7. brake, 8. brake ball valve. DETAILED DESCRIPTION

[0018] The technical scheme of the present invention is described clearly and completely below in conjunction with the embodiments. 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 by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0019] Considering the conventional method of measuring braking torque, which is to calculate the braking torque by measuring the tension of the pull rod, the detection process is time-consuming, labor-intensive and affects production. The safety regulations only require that the ratio of the maximum braking torque to the rotational torque generated by the maximum static tension difference be no less than 3 times, and do not require accurate measurement of the ratio. Therefore, this paper proposes a new method for quickly testing the braking torque of the hoist using the static tension difference. The core idea of ​​this method is to achieve rapid qualitative detection through the relationship between the static tension difference and the braking torque generated by the brake of the hoist, so as to determine whether the hoist torque meets the requirements of the safety regulations.

[0020] Relationship between static tension difference and braking torque: According to the principle of torque balance, when the hoist is in braking state, the static tension difference of the hoist ropes on both sides will generate a rotational torque. The braking torque of the hoist can be calculated by measuring the static tension difference when one side of the hoist container is empty and the other side is heavily loaded.

[0021] The specific steps of the test are as follows:

[0022] Preliminary preparation: Check that all brakes 7 are in good working condition, ensure that there is no oil stain, and that the brake clearance and oil pressure meet the requirements.

[0023] Adjust the position of the lifting container: set the lifting containers on both sides to empty and heavy load respectively, and place the lifting container in a safe and suitable position in the wellbore for convenient operation (equal weight tail rope), ensuring that the static tension difference of the lifting head ropes on both sides is the actual load capacity Q of the heavy-load lifting container.

[0024] Brake status setting: Figure 2 As shown, put all brakes in full braking state and close the n to be tested. 测 Auxiliary brake ball valve 8.

[0025] Oil pressure establishment and observation: Establish working oil pressure through the hydraulic station, manually and slowly open the remaining brakes that are not closed, and observe whether the reel has a tendency to rotate.

[0026] Judgment criteria: If the drum does not rotate, it indicates that the tested brake group meets the safety requirements. If there is rotation, brake immediately, further check and handle the brake and brake shoe, and then test again. Test each brake in groups one by one in the same way.

[0027] Number of brake pairs required for testing n 测 Value calculation

[0028] The maximum braking torque required by the safety regulations and the rotational torque generated by the difference between the maximum static tension of the lifting system should not be less than 3 times the requirement.

[0029]

[0030] Where: Mz is the braking torque, Nm; ΔFjmax is the maximum static tension difference of the lifting system, N; D j is the nominal diameter of the hoist drum, m.

[0031] The hoisting machine torque is generated by the brake configured on the hoist.

[0032]

[0033] Where: n is the number of brakes configured for the hoist; P is the braking force generated by one brake on the brake disc, N; D m _ is the average friction diameter of the brake disc, m.

[0034] The average friction diameter of the brake disc is D m The difference between the diameter of the hoist drum and D m ≈Dj.

[0035]

[0036] nP ≥ 3ΔF j max

[0037]

[0038] According to the above formula, when the hoisting system is under the maximum static tension, one third of the configured brake pairs are applied, and the hoist drum does not slip. This can meet the safety regulations.

[0039]

[0040] Take into account that in actual testing, the static tension difference is different from the maximum static tension difference of the lifting system.

[0041]

[0042] Where: K is the ratio of the actual static tension difference during the test to the maximum static tension difference of the lifting system. The recommended value of K is Q is the measured static tension difference (actual load of the lifting container), N.

[0043] The number of brake pairs required to be tested is the number of hoist brake pairs n 测 for

[0044]

[0045] Where: n 测 Number of brake pairs to be tested.

[0046] n 测 It is the number of brake pairs that need to be tested. By calculating the combination of different brake groups, it is quickly evaluated whether the braking torque meets the safety standards.

[0047] In actual testing, the number of brake pairs n may not be divisible. and There is a large difference, so the static tension difference in the actual test (the actual load of the lifting container) is adjusted to take a reasonable K value to minimize the difference between the two.

Claims

1. A method for measuring the braking torque of a lifting winch using static tension difference, characterized in that: The following steps are involved: (1) Adjustment of the position of the lifting container: Set the lifting containers on both sides to empty and heavy load respectively, and place the lifting containers in a safe and suitable position in the shaft for convenient operation, ensuring that the static tension difference of the lifting ropes on both sides is the actual load Q of the heavy load lifting container; (2) Brake state setting: Set all brakes to full braking state, close the n to be tested 测 Auxiliary brake ball valve; (3) Oil pressure establishment and observation: Establish working oil pressure through the hydraulic station, manually slowly open the remaining brakes that are not closed, and observe whether the drum has a tendency to rotate; (4) Judgment standard: If the drum does not rotate, it indicates that the test brake group meets the safety requirements. If there is a rotation phenomenon, the brake should be braked immediately, and the brake and brake shoe should be further inspected and processed, and then tested again. The brakes should be tested in groups one by one in the same way; (5) The number of brake pairs required to be tested n 测 Value calculation Where n is the number of brake pairs tested, K is the ratio of the actual static tension difference during the test to the maximum static tension difference of the lifting system. By calculating the combination of different brake groups, it is possible to quickly evaluate whether the braking torque meets the safety standards.

2. The method for measuring the braking torque of a lifting winch by using static tension difference as claimed in claim 1, characterized in that: Before the step (1), check that all brakes are in good working condition, ensure that there is no oil stain, and that the brake clearance and oil pressure meet the requirements.

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