Mine hoist braking system and method for preventing braking thermal failure

Abstract

The invention discloses a mine hoist braking system and method for preventing braking thermal failure, the system comprises a hoist braking disc liquid cooling mechanical structure, a liquid cooling circulation pipeline, a braking hydraulic loop, a state detection feedback system and a closed-loop control loop, the braking disc liquid cooling structure adopts an annular liquid cooling cavity design and is arranged on the outer edge of a braking disc; the double flow channels of the winding drum main shaft and the rotary sealing joint are connected with a liquid cooling circulation pipeline, so that efficient cooling liquid circulation is realized; the liquid cooling circulation system can achieve accurate control over the flow of cooling liquid, and the braking hydraulic loop can adjust braking torque output in real time. According to the closed-loop control loop, collaborative optimization of braking friction heat management and braking force adjustment is achieved, compared with a traditional braking system, the problem that temperature rise is too fast due to friction between a brake shoe and a brake disc can be effectively solved, the braking heat failure risk is remarkably reduced, and the braking efficiency is improved. Therefore, the continuous braking reliability and the operation safety of the mine hoist are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mine hoist braking, and in particular to a mine hoist braking system and method for preventing brake thermal failure. Background Art

[0002] Thermal failure prevention in mine hoist braking systems is a core challenge in mine safety. Traditional braking technology relies on the principle of mechanical friction, resulting in a high degree of coupling between braking force generation and frictional heat generation. This leads to a sharp rise in temperature at the contact area between the brake disc and friction pad during emergency braking, heavy load lowering, or frequent starting and stopping. When the temperature exceeds the material tolerance threshold, thermal decay occurs at the friction interface, causing a sharp drop in the friction coefficient, unstable braking torque, and even causing brake disc cracking or friction pad erosion, seriously threatening hoist operation safety. While existing technologies have attempted to mitigate this issue through structural optimization, material upgrades, and improved control strategies, they still suffer from significant drawbacks under the complex operating conditions of high dust, confined environments, and dynamic loads in mines. In structural design, multi-disc brakes distribute the heat load by increasing the number of friction pairs. However, in actual operation, mine dust intrudes into the gaps between the discs, forming an insulating layer that causes localized heat accumulation and significantly reduces heat dissipation efficiency. Some solutions employ the addition of cooling fins or diversion grooves on the brake disc surface to enhance passive heat dissipation. However, continuous dust deposition causes these structures to rapidly fail, exacerbating heat accumulation. Research in the materials field focuses on improving high-temperature resistance, such as using ceramic-based composites or high-thermal-conductivity alloys. However, the brittle nature of ceramic materials makes them difficult to withstand high-frequency thermal shocks, and the hardness mismatch between alloy materials and friction plates leads to abnormal wear. In addition, the high cost restricts large-scale application. Traditional control logic can only release the braking force or shut down the equipment after the temperature exceeds the limit, and lacks the ability to dynamically intervene in the heat generation process. For example, in heavy load lowering or continuous braking scenarios, the system cannot adjust the braking force distribution ratio according to the real-time temperature field distribution and load, resulting in uncontrolled accumulation of heat, which eventually exceeds the tolerance limit of the material. The high temperature generated by the friction between the brake disc and the brake shoe can easily cause thermal failure, resulting in a decrease in braking torque or even failure. Summary of the Invention

[0003] In view of the above-mentioned technical deficiencies, the object of the present invention is to provide a mine hoist braking system and method that can prevent brake thermal failure.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a mine hoist braking system for preventing brake thermal failure, including a hoist brake disc liquid cooling mechanical structure, a liquid cooling circulation pipeline, a brake hydraulic circuit, a state detection feedback system, and a closed-loop control circuit. The hoist brake disc liquid cooling mechanical structure includes a brake disc, a reel main shaft, and a rotary sealing joint. The rotary sealing joint is sealed with the reel main shaft, and a liquid cooling pipe inlet joint and a liquid cooling pipe outlet joint are provided on the rotary sealing joint. The brake disc is an outer annular cavity structure, and a circumferentially staggered turbulent flow is provided inside the brake disc. The column, the reel main shaft is provided with an inlet flow channel and an outlet flow channel connected to the rotary sealing joint. The coolant flows in through the liquid cooling pipe inlet joint, then enters the liquid inlet flow channel of the reel main shaft through the rotary sealing joint, and then flows through the brake disc annular cavity and then flows out from the liquid outlet flow channel of the reel main shaft through the rotary sealing joint and the liquid cooling pipe outlet joint; the liquid cooling circulation pipeline includes a liquid storage tank, a cooling water pump, an electromagnetic proportional flow valve, a cooler, a temperature sensor, a pressure sensor, and a flow sensor. The coolant flowing out of the return liquid flow channel is cooled by the cooler and then flows into the liquid storage tank. The cooling water pump is used to transport the coolant in the liquid storage tank to the liquid cooling pipe inlet joint through the electromagnetic proportional flow valve. The temperature sensor, pressure sensor, and flow sensor are used to detect the coolant inlet and outlet temperatures, pressure, and flow rate of the liquid cooling circulation pipeline, respectively. The state detection feedback system includes an infrared temperature sensor, a rotary encoder, a displacement sensor, and an oil pressure sensor. The infrared temperature sensor, rotary encoder, and brake shoe displacement sensor are used to detect the temperature of the brake disc, the rotation speed of the drum, and the displacement of the brake shoe, respectively. The oil pressure sensor is used to detect the pressure in the brake return chamber. The brake hydraulic circuit includes a fuel tank, a hydraulic pump, an accumulator, a three-position four-way proportional reversing valve, and a brake. The hydraulic pump is used to transport the hydraulic oil in the fuel tank to the brake control cylinder through the three-position four-way proportional reversing valve. The accumulator is used to provide brake oil pressure for the brake in an emergency. The closed-loop control circuit is used to dynamically adjust the electromagnetic proportional flow valve and the three-position four-way proportional reversing valve based on the feedback signal of the state detection feedback system to achieve coordinated control of brake friction heat management and braking force regulation. Preferably, the turbulent columns are arranged in a diamond-shaped array, with a height equal to the height of the brake disc cavity, and a diameter-to-pitch ratio of 1:1.5-2. Preferably, the liquid cooling circulation pipeline also includes redundant safety components, including a one-way valve and a relief valve arranged in series at the cooling water pump outlet; manual valves 1 and 2, and two-position, two-way solenoid valves 1 and 2, arranged in parallel in the main loop of the liquid cooling circulation pipeline.

[0006] Preferably, a manual valve three and a filter one are sequentially provided on the pipeline between the liquid storage tank and the liquid inlet of the cooling water pump; and a filter two is provided on the pipeline between the two-position two-way solenoid valve two and the cooling machine.

[0007] Preferably, the accumulator switches the oil supply path via a two-position three-way electromagnetic reversing valve.

[0008] Preferably, the pipeline between the two-position three-way solenoid directional reversing valve and the three-position four-way proportional directional reversing valve is provided with a hydraulic oil filter and a three-position four-way solenoid directional reversing valve in sequence.

[0009] Preferably, a second two-position three-way solenoid directional valve is provided between the two-position three-way solenoid directional valve and the hydraulic oil filter, and a second overflow valve is provided between the three-position four-way proportional directional valve and the three-position four-way solenoid directional valve.

[0010] Preferably, the oil outlet of the hydraulic pump is provided with a high-pressure filter and a manual valve four in sequence, a one-way valve two is provided between the manual valve four and the accumulator, the pipeline between the high-pressure filter and the manual valve four is connected to the oil tank through a proportional overflow valve, and the hydraulic pump is connected to a motor.

[0011] The present invention also provides a control method for the above-mentioned mine hoist braking system for preventing brake thermal failure, comprising the following steps:

[0012] 1. The temperature of the brake disc during braking is divided into levels: Level I: Brake disc temperature T p <T1, Level II: Brake disc temperature T1≤T p <T2, Level III: Brake disc temperature T p ≥T2, T p is the brake disc temperature detected by the infrared temperature sensor 4), T1 and T2 are the set temperature dividing lines, the value range of T1 is 45~55℃, and the value range of T2 is 95~105℃;

[0013] 2. After the brake command is issued, the cooling water pump starts, and the two-position two-way solenoid valve 1 and the two-position two-way solenoid valve 2 are in the left position; after the accumulator is charged, the three-position four-way solenoid reversing valve is in the left position, and the two-position three-way solenoid reversing valve 2 is in the left position;

[0014] 3. According to the temperature level of the brake disc, control the valve opening U of the electromagnetic proportional flow valve in the liquid cooling circulation system y for:

[0015]

[0016] Where U max It is the control input value when the electromagnetic proportional flow valve port is fully open, that is, the maximum control input value;

[0017] 4. Consider the effect of brake disc temperature on the brake friction coefficient f during braking. uThe control input U of the three-position four-way proportional reversing valve 28) in the hydraulic brake system is controlled according to the brake disc temperature, drum angle feedback, brake shoe displacement and brake oil return chamber pressure. z for:

[0018]

[0019] Where k z is the brake pressure control closed loop proportional parameter, k s is the closed-loop proportional parameter of the reel speed control, θ 1d is the desired braking speed curve of the drum, θ1 is the drum speed measured by the rotary encoder, k g is the stiffness coefficient of the brake disc spring, x0 is the initial compression of the brake disc spring, x p is the brake shoe displacement measured by the displacement sensor, A z is the effective area of the brake oil return chamber, p z is the brake oil return chamber pressure detected by the oil pressure sensor, Rz is the brake friction radius, f μ (T p ) is the brake disc temperature T p The relevant braking friction coefficient is calculated as follows:

[0020]

[0021] Where T0 is the initial temperature, f μ1 is the friction coefficient at T0 temperature, k1 is the growth rate of the friction coefficient in the low temperature section as the temperature changes; f μ2 is the friction coefficient at temperature T1, k2 is the slope of the friction coefficient in the medium temperature section changing with temperature; f μ3 is the friction coefficient at temperature T2, k3 is the attenuation rate of the friction coefficient in the high temperature section as the temperature changes;

[0022] 5. After the braking task is completed and the brake command is issued, the coolant pump is closed, the two-position two-way solenoid valve 1, the two-position two-way solenoid valve 2, the three-position four-way solenoid reversing valve are in the middle position, and the two-position three-way solenoid reversing valve 2 is in the right position. When the next braking operation is required, the above steps are repeated. During emergency braking, the accumulator switches the oil supply path via the two-position three-way solenoid reversing valve. The present invention also provides a mine hoist equipped with the above-described mine hoist braking system that prevents brake thermal failure.

[0023] The beneficial effects of the present invention are:

[0024] The brake disc of this invention incorporates a liquid cooling circulation structure. An annular cavity with a higher heat exchange coefficient is located on the outer circumference of the disc, along with a liquid cooling circulation piping system. This circulating coolant effectively removes brake friction heat, preventing the potential for brake thermal failure due to overheating. Unlike conventional brake discs, this disc utilizes a hollow design, allowing the coolant to cover a large area of the disc surface, thereby enhancing heat exchange. Furthermore, the annular cavity is designed with circumferentially staggered turbulent columns. These columns effectively reduce the heat transfer boundary layer, enhance coolant turbulence, promote coolant mixing, and significantly improve heat dissipation efficiency. The height of the columns matches the height of the disc's hollow core, significantly enhancing the disc's structural rigidity and effectively improving its resistance to thermomechanical deformation.

[0025] 2. The present invention enables coordinated control of brake friction heat and braking torque. It utilizes an infrared temperature sensor to monitor brake disc temperature in real time and dynamically evaluates it based on preset temperature grading standards. The control system precisely adjusts the opening of the electromagnetic proportional flow valve in the liquid cooling circulation system according to different temperature levels, achieving refined control of coolant flow. This hierarchical control mechanism effectively addresses the problem of brake thermal failure caused by frictional heat accumulation and avoids energy waste in the cooling system by optimizing flow. Furthermore, to address the significant impact of brake disc temperature on the friction coefficient, the present invention establishes a quantitative relationship model between the friction coefficient and brake disc temperature and integrates it into the hydraulic brake system controller. Through this compensatory control strategy, the system dynamically adjusts the braking torque output based on temperature changes, ensuring that the actual braking torque more accurately tracks the target value, significantly improving the stability and reliability of braking performance.

[0026] 3. The liquid cooling system of the present invention can reduce the peak temperature of the brake disc, avoid thermal degradation of the friction material, and adopt temperature graded control to extend the service life of the brake disc and reduce the probability of thermal cracks.

[0027] 4. The accumulator of the present invention ensures full-pressure braking after power failure, which can better ensure the emergency braking effect.

[0028] 5. The present invention can adjust the cooling flow and braking force as needed, and can better save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1This is a schematic diagram of the mine hoist braking system for preventing brake thermal failure proposed by the present invention;

[0031] Figure 2 This is a flow chart of the control method proposed by the present invention;

[0032] Figure 3 This is a closed-loop control principle diagram of the control method proposed in the present invention;

[0033] Figure 4 This is a schematic diagram of the liquid cooling mechanical structure of the hoist brake disc;

[0034] Figure 5 This is a schematic diagram of the liquid cooling system;

[0035] Figure 6 Schematic diagram of the mine hoist braking system.

[0036] Among them: 1. Brake disc; 2. Reel; 3.1, 3.2, 3.3, 3.4, Brake; 4. Infrared temperature sensor; 5. Reel spindle; 6. Bearing seat; 7. Rotary seal joint; 8. Liquid cooling pipe joint; 9. Cooling machine; 10. Liquid storage tank; 11.1. Manual valve 3; 11.2. Manual valve 1; 11.3. Manual valve 2; 12.1. Filter 1; 12.2. Filter 2; 13. Cooling water pump; 14.1. Check valve; 15. Overflow valve; 16.1. Two-position two-way solenoid valve 1; 16.2. Two-position two-way solenoid valve 2; 17.1, 17.2. Temperature sensor; 1 8.1, 18.2, pressure sensor; 19.1, 19.2, flow sensor; 20, electromagnetic proportional flow valve; 21, oil tank; 22, motor; 23, hydraulic pump; 24, high-pressure filter; 25, proportional relief valve; 26.1, manual valve four; 26.2, one-way valve two; 27, accumulator; 28, three-position four-way proportional directional valve; 29, three-position four-way directional valve; 30, relief valve two; 31, hydraulic oil filter; 32, two-position three-way electromagnetic directional valve; 33, turbulence column; 34, oil pressure sensor; 35, rotary encoder; 36, displacement sensor; 37, two-position three-way electromagnetic directional valve two. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] like Figure 1-6 As shown, this embodiment provides a mine hoist braking system and method for preventing brake thermal failure.

[0039] The present embodiment provides a mine hoist braking system for preventing brake thermal failure, including a liquid-cooling mechanical structure for a hoist brake disc, a liquid-cooling circulation pipeline, a brake hydraulic circuit, a state detection feedback system, and a closed-loop control circuit. The brake disc liquid-cooling structure adopts an annular liquid-cooling cavity design, which is arranged at the outer edge of the brake disc and is connected to the liquid-cooling circulation pipeline through the double flow channels and rotary sealing joints of the reel main shaft to achieve efficient coolant circulation; the liquid-cooling mechanical structure for the hoist brake disc includes a brake disc 1, a reel main shaft 5, and a rotary sealing joint 7. The rotary sealing joint is sealed with the reel main shaft 5, and a liquid cooling pipe inlet joint 8.1 and a liquid cooling pipe outlet joint 8.2 are provided on the rotary sealing joint 7. The brake disc 1 is an outer circular cavity structure. The inside of the moving disc 1 is provided with circumferentially staggered turbulent columns 33, and the reel main shaft 5 is provided with an inlet flow channel and an outlet flow channel connected to the rotary sealing joint 7. The coolant flows in through the liquid cooling pipe inlet joint 8.1, and then enters the liquid inlet flow channel of the reel main shaft 5 through the rotary sealing joint 7. After flowing through the annular cavity of the brake disc 1, it flows out from the outlet flow channel of the reel main shaft 5 through the rotary sealing joint 7 and the liquid cooling pipe outlet joint 8.2; the liquid cooling circulation pipeline includes a liquid storage tank 10, a cooling water pump 13, an electromagnetic proportional flow valve 20, a cooler 9, a temperature sensor 18, a pressure sensor 17, and a flow sensor 19. The coolant flowing out of the return flow channel is cooled by the cooler 9 and then flows into the liquid storage tank 10. The cooling water pump 13 is used to transfer the coolant in the liquid storage tank 10 to the liquid storage tank 10. The coolant is delivered to the liquid cooling pipe inlet connector 8.1 via the electromagnetic proportional flow valve 20. The temperature sensors 17.1 and 17.2, pressure sensors 18.1 and 18.2, and flow sensors 19.1 and 19.2 are used to detect the coolant inlet and outlet temperatures, pressures, and flow rates of the liquid cooling circulation pipeline, respectively. The state detection feedback system includes an infrared temperature sensor 4, a rotary encoder 35, a displacement sensor 36, and an oil pressure sensor 34. The infrared temperature sensor 4, rotary encoder 35, and brake shoe displacement sensor 36 are used to detect the temperature of the brake disc 1, the rotation speed of the drum 2, and the brake shoe displacements of the brakes 3.1, 3.2, 3.3, and 3.4, respectively. The oil pressure sensor 34 is used to detect the pressure of the brakes 3.1 and 3.4. 2, 3.3, 3.4 return oil chamber pressure; the brake hydraulic circuit includes a fuel tank 21, a hydraulic pump 23, an accumulator 27, a three-position four-way proportional directional valve 28, and brakes 3.1, 3.2, 3.3, and 3.4. The hydraulic pump 23 is used to deliver the hydraulic oil in the fuel tank 21 to the control cylinders of brakes 3.1, 3.2, 3.3, and 3.4 via the three-position four-way proportional directional valve 28. The accumulator 27 is used to provide brake oil pressure to brakes 3.1, 3.2, 3.3, and 3.4 in an emergency; the closed-loop control circuit is used to dynamically adjust the electromagnetic proportional flow valve 20 and the three-position four-way proportional directional valve 28 according to the feedback signal of the state detection feedback system, so as to achieve coordinated control of brake friction heat management and braking force regulation.

[0040] The rotary sealing joint 7 can ensure sealing performance in a rotating state.

[0041] The turbulence columns 33 are distributed in a diamond array, with a height the same as the cavity height of the brake disc 1, and a diameter-to-pitch ratio of 1:1.5-2, which significantly enhances the structural rigidity of the brake disc and effectively improves its ability to resist thermal mechanical deformation.

[0042] The liquid cooling circulation pipeline also includes redundant safety components, which include a one-way valve 14.1 and a relief valve 15 arranged in series at the liquid outlet of the cooling water pump 13; manual valve 1 11.2 and manual valve 2 11.3, as well as a two-position, two-way solenoid valve 1 16.1 and a two-position, two-way solenoid valve 2 16.2 arranged in parallel in the main loop of the liquid cooling circulation pipeline.

[0043] A manual valve 3 11.1 and a filter 12.1 are sequentially provided on the pipeline between the liquid storage tank 10 and the liquid inlet of the cooling water pump 13; a filter 2 12.2 is provided on the pipeline between the two-position two-way solenoid valve 2 16.2 and the cooling machine 9.

[0044] The accumulator 27 switches the oil supply path through a two-position three-way electromagnetic reversing valve 32 , and the specific switching method adopts an existing method well known to those skilled in the art.

[0045] The pipeline between the two-position three-way electromagnetic reversing valve 32 and the three-position four-way proportional reversing valve 28 is provided with a hydraulic oil filter 31 and a three-position four-way electromagnetic reversing valve 29 in sequence.

[0046] A second two-position three-way electromagnetic reversing valve 37 is provided between the two-position three-way electromagnetic reversing valve 32 and the hydraulic oil filter 31 , and a second overflow valve 30 is provided between the three-position four-way proportional reversing valve 28 and the three-position four-way electromagnetic reversing valve 29 .

[0047] The oil outlet of the hydraulic pump 23 is sequentially provided with a high-pressure filter 24 and a manual valve 26.1. A one-way valve 26.2 is provided between the manual valve 26.1 and the accumulator 27. The pipeline between the high-pressure filter 24 and the manual valve 26.1 is connected to the oil tank 21 through a proportional relief valve 25. The hydraulic pump 23 is connected to the motor 22.

[0048] The brake disc 1 of this embodiment, the drum 2, the brake 3.1, 3.2, 3.3, 3.4, the infrared temperature sensor 4, the drum spindle 5, the bearing seat 6, the rotary sealing joint 7, the liquid cooling pipe joint 8, the cooler 9, the liquid storage tank 10, the manual valve 3 11.1, the manual valve 1 11.2, the manual valve 2 11.3, the filter 1 12.1, the filter 2 12.2, the cooling water pump 13, the one-way valve 14.1, the overflow valve 15, the two-position two-way solenoid valve 1 16.1, the two-position two-way solenoid valve 2 16.2, the temperature sensors 17.1, 17.2, the pressure sensors 18.1, 18.2, the flow sensor 19.1, 19.2, electromagnetic proportional flow valve 20, oil tank 21, motor 22, hydraulic pump 23, high-pressure filter 24, proportional relief valve 25, manual valve four 26.1, check valve two 26.2, accumulator 27, three-position four-way proportional directional valve 28, three-position four-way directional valve 29, relief valve two 30, hydraulic oil filter 31, two-position three-way electromagnetic directional valve 32, turbulence column 33, oil pressure sensor 34, rotary encoder 35, displacement sensor 36, and two-position three-way electromagnetic directional valve two 37 employ existing products or structures well known to those skilled in the art, and their mutual connections also employ existing products or structures well known to those skilled in the art.

[0049] The closed-loop control circuit of this embodiment is an existing closed-loop control circuit well known to those skilled in the art, and is controlled by an existing controller well known to those skilled in the art, which will be described in detail herein.

[0050] This embodiment also provides a control method for a mine hoist braking system to prevent brake thermal failure, comprising the following steps:

[0051] 1. The temperature of the brake disc during braking is divided into levels: Level I: Brake disc temperature T p <T1, Level II: Brake disc temperature T1≤T p <T2, Level III: Brake disc temperature T p ≥T2, T p is the brake disc temperature detected by the infrared temperature sensor 4, T1 and T2 are the set temperature dividing lines, the value range of T1 is 45-55°C, and the value range of T2 is 95-105°C;

[0052] 2. After the brake command is issued, the cooling water pump 13 starts, and the two-position two-way solenoid valve 1 16.1 and the two-position two-way solenoid valve 2 16.2 are in the left position. After the accumulator 27 is charged, the three-position four-way solenoid reversing valve 29 is in the left position, and the two-position three-way solenoid reversing valve 2 37 is in the left position.

[0053] 3. The closed-loop control circuit controls the valve opening U of the electromagnetic proportional flow valve 20 in the liquid cooling circulation system according to the temperature level of the brake disc. y for:

[0054]

[0055] Where U max It is the control input value when the valve port of the electromagnetic proportional flow valve 20 is fully open, that is, the maximum control input value;

[0056] 4. Consider the effect of brake disc temperature on the brake friction coefficient f during braking. u The closed-loop control circuit controls the control input U of the three-position four-way proportional reversing valve 28 in the hydraulic brake system according to the brake disc temperature, drum angle feedback, brake shoe displacement and brake oil return chamber pressure. z for:

[0057]

[0058] Where k z k is the pressure control closed loop proportional parameter of brakes 3.1, 3.2, 3.3, and 3.4, s is the closed-loop proportional parameter of the speed control of reel 2, θ 1d is the desired braking speed curve of the reel 2, θ1 is the reel speed measured by the rotary encoder 35, k g is the stiffness coefficient of the disc springs of brakes 3.1, 3.2, 3.3, and 3.4, x0 is the initial compression of the disc springs of brakes 3.1, 3.2, 3.3, and 3.4, and x p is the brake shoe displacement measured by the displacement sensor 37, A z The effective area of the oil return chamber of brakes 3.1, 3.2, 3.3, and 3.4, p z is the brake oil return chamber pressure detected by the oil pressure sensor 34, Rz is the brake friction radius, and f μ (T p ) is the brake disc temperature T p The relevant braking friction coefficient is calculated as follows:

[0059]

[0060] Where T0 is the initial temperature, f μ1 is the friction coefficient at T0 temperature, k1 is the growth rate of the friction coefficient in the low temperature section as the temperature changes; f μ2 is the friction coefficient at temperature T1, k2 is the slope of the friction coefficient in the medium temperature section changing with temperature; f μ3 is the friction coefficient at temperature T2, k3 is the attenuation rate of the friction coefficient in the high temperature section as the temperature changes;

[0061] 5. After completing the braking task, after the braking command is issued, the coolant pump 13 is closed, the two-position two-way solenoid valve 1 16.1, the two-position two-way solenoid valve 2 16.2, the three-position four-way solenoid reversing valve 29 are in the middle position, and the two-position three-way solenoid reversing valve 2 37 is in the right position. When the next braking operation is required, the above steps are repeated; during emergency braking, the accumulator 27 switches the oil supply path through the two-position three-way solenoid reversing valve 32, and the specific switching method adopts the existing method well known to those skilled in the art.

[0062] The liquid cooling system of this embodiment can reduce the peak temperature of the brake disc, preventing thermal degradation of the friction material. Its temperature-graded control can extend the life of the brake disc and reduce the probability of thermal cracking. The accumulator of this embodiment ensures full-pressure braking after power failure, ensuring better emergency braking performance. This embodiment can adjust the cooling flow rate and braking force on demand, achieving better energy conservation. This embodiment can achieve coordinated control of brake friction heat and braking torque. It uses an infrared temperature sensor to monitor the brake disc temperature in real time and dynamically evaluates it according to preset temperature classification standards. The control system precisely adjusts the opening of the electromagnetic proportional flow valve in the liquid cooling circulation system based on different temperature levels, achieving refined control of the coolant flow rate. This graded control mechanism effectively addresses the problem of brake thermal failure caused by frictional heat accumulation and avoids energy waste in the cooling system by optimizing the flow rate. Furthermore, to address the significant impact of brake disc temperature on the friction coefficient, this embodiment establishes a quantitative relationship model between the friction coefficient and brake disc temperature and integrates it into the hydraulic brake system controller. Through this compensation control strategy, the system can dynamically adjust the braking torque output based on temperature changes, ensuring that the actual braking torque more accurately tracks the target value, significantly improving the stability and reliability of braking performance.

[0063] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A mine hoist braking system for preventing brake thermal failure, characterized in that: The invention comprises a liquid cooling mechanical structure of a lifting machine brake disc, a liquid cooling circulation pipeline, a brake hydraulic circuit, a state detection feedback system, and a closed-loop control circuit. The liquid cooling mechanical structure of the lifting machine brake disc comprises a brake disc (1), a reel main shaft (5), and a rotary sealing joint (7). The rotary sealing joint is sealed with the reel main shaft (5). The rotary sealing joint (7) is provided with a liquid cooling pipe inlet joint (8.1) and a liquid cooling pipe outlet joint (8.2). The brake disc (1) is an outer annular cavity structure. The brake disc (1) is provided with circumferentially staggered turbulent columns (33). The reel main shaft (5) is provided with a liquid inlet flow channel and a liquid outlet flow channel connected to the rotary sealing joint (7). The liquid flows in through the liquid cooling pipe inlet joint (8.1), then enters the liquid inlet flow channel of the reel main shaft (5) through the rotary sealing joint (7), then flows through the annular cavity of the brake disc (1), and then flows out from the liquid outlet flow channel of the reel main shaft (5) through the rotary sealing joint (7) and the liquid cooling pipe outlet joint (8.2); the liquid cooling circulation pipeline includes a liquid storage tank (10), a cooling water pump (13), an electromagnetic proportional flow valve (20), a cooling machine (9), a temperature sensor (18), a pressure sensor (17), and a flow sensor (19); the cooling liquid flowing out of the return flow channel is cooled by the cooling machine (9) and then flows into the liquid storage tank (10); the cooling water pump (13) is used to cool the cooling liquid in the liquid storage tank (10) The liquid is delivered to the liquid cooling pipe inlet joint (8.1) through the electromagnetic proportional flow valve (20), and the temperature sensors (17.1, 17.2), pressure sensors (18.1, 18.2), and flow sensors (19.1, 19.2) are used to detect the inlet and outlet temperatures, pressures, and flows of the coolant in the liquid cooling circulation pipeline, respectively. The state detection feedback system includes an infrared temperature sensor (4), a rotary encoder (35), a displacement sensor (36), and an oil pressure sensor (34). The infrared temperature sensor (4), the rotary encoder (35), and the brake shoe displacement sensor (36) are used to detect the temperature of the brake disc (1), the rotation speed of the drum (2), and the speed of the brake (3.1). , 3.2, 3.3, 3.4); the oil pressure sensor (34) is used to detect the return oil chamber pressure of the brakes (3.1, 3.2, 3.3, 3.4); the brake hydraulic circuit includes an oil tank (21), a hydraulic pump (23), an accumulator (27), a three-position four-way proportional reversing valve (28), and brakes (3.1, 3.2, 3.3, 3.4); the hydraulic pump (23) is used to deliver the hydraulic oil in the oil tank (21) to the control oil cylinders of the brakes (3.1, 3.2, 3.3, 3.4) through the three-position four-way proportional reversing valve (28); the accumulator (27) is used to apply pressure to the brakes (3.1, 3.2, 3.3, 3.4) in an emergency.4) providing brake oil pressure; the closed-loop control circuit is used to dynamically adjust the electromagnetic proportional flow valve (20) and the three-position four-way proportional reversing valve (28) according to the feedback signal of the state detection feedback system, so as to realize the coordinated control of brake friction heat management and brake force regulation.

2. A mine hoist braking system for preventing brake thermal failure according to claim 1, characterized in that: The turbulent columns (33) are distributed in a diamond array, with a height the same as the cavity height of the brake disc (1), and a diameter-to-spacing ratio of 1:1.5-2.

3. The mine hoist braking system for preventing brake thermal failure according to claim 1, characterized in that: The liquid cooling circulation pipeline further includes a redundant safety component, which includes a one-way valve (14.1) and a relief valve (15) arranged in series at the liquid outlet of the cooling water pump (13); a manual valve 1 (11.2) and a manual valve 2 (11.3) and a two-position, two-way solenoid valve 1 (16.1) and a two-position, two-way solenoid valve 2 (16.2) arranged in parallel in the main loop of the liquid cooling circulation pipeline.

4. A mine hoist braking system for preventing brake thermal failure according to claim 3, characterized in that: Manual valve three (11.1) and filter one (12.1) are sequentially provided on the pipeline between the liquid storage tank (10) and the liquid inlet of the cooling water pump (13); filter two (12.2) is provided on the pipeline between the two-position two-way solenoid valve two (16.2) and the cooling machine (9).

5. The mine hoist braking system for preventing brake thermal failure according to claim 1, characterized in that: The accumulator (27) switches the oil supply path via a two-position three-way electromagnetic reversing valve (32).

6. A mine hoist braking system for preventing brake thermal failure according to claim 5, characterized in that: The pipeline between the two-position three-way electromagnetic reversing valve (32) and the three-position four-way proportional reversing valve (28) is provided with a hydraulic oil filter (31) and a three-position four-way electromagnetic reversing valve (29) in sequence.

7. A mine hoist braking system for preventing brake thermal failure according to claim 6, characterized in that: A second two-position three-way electromagnetic reversing valve (37) is provided between the two-position three-way electromagnetic reversing valve (32) and the hydraulic oil filter (31), and a second overflow valve (30) is provided between the three-position four-way proportional reversing valve (28) and the three-position four-way electromagnetic reversing valve (29).

8. The mine hoist braking system for preventing brake thermal failure according to claim 1, characterized in that: The oil outlet of the hydraulic pump (23) is sequentially provided with a high-pressure filter (24) and a manual valve (26.1). A one-way valve (26.2) is provided between the manual valve (26.1) and the accumulator (27). The pipeline between the high-pressure filter (24) and the manual valve (26.1) is connected to the oil tank (21) through a proportional relief valve (25). The hydraulic pump (23) is connected to a motor (22).

9. A method for controlling a mine hoist braking system to prevent brake thermal failure according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) The temperature of the brake disc during braking is divided into levels: Level I: Brake disc temperature T p <T1, Level II: Brake disc temperature T1≤T p <T2, Level III: Brake disc temperature T p ≥T2, T p is the brake disc temperature detected by the infrared temperature sensor (4), T1 and T2 are set temperature dividing lines, the value range of T1 is 45-55°C, and the value range of T2 is 95-105°C; (2) After the brake command is issued, the cooling water pump (13) starts, and the two-position two-way solenoid valve 1 (16.1) and the two-position two-way solenoid valve 2 (16.2) are in the left position; after the accumulator (27) is charged, the three-position four-way solenoid reversing valve (29) is in the left position, and the two-position three-way solenoid reversing valve 2 (37) is in the left position; (3) According to the temperature level of the brake disc, the valve opening U of the electromagnetic proportional flow valve (20) in the liquid cooling circulation system is controlled. y for: Where U max It is the control input value when the valve port of the electromagnetic proportional flow valve 20 is fully open, that is, the maximum control input value; (4) Consider the effect of brake disc temperature on the braking friction coefficient f during braking u The control input U of the three-position four-way proportional reversing valve (28) in the hydraulic brake system is controlled according to the influence of the brake disc temperature, the drum angle feedback, the brake shoe displacement and the brake oil return chamber pressure. z for: Where k z is the pressure control closed loop proportional parameter of the brake (3.1, 3.2, 3.3, 3.4), k s is the closed-loop proportional parameter of the speed control of the reel (2), θ 1d is the desired braking speed curve of the drum (2), θ1 is the drum speed measured by the rotary encoder (35), k g is the stiffness coefficient of the disc spring of the brake (3.1, 3.2, 3.3, 3.4), x0 is the initial compression of the disc spring of the brake (3.1, 3.2, 3.3, 3.4), x p is the brake shoe displacement measured by the displacement sensor (37), A z is the effective area of the oil return chamber of the brake (3.1, 3.2, 3.3, 3.4), p z is the brake oil return chamber pressure detected by the oil pressure sensor (34), Rz is the brake friction radius, f μ (T p ) is the brake disc temperature T p The relevant braking friction coefficient is calculated as follows: Where T0 is the initial temperature, f μ1 is the friction coefficient at T0 temperature, k1 is the growth rate of the friction coefficient in the low temperature section as the temperature changes; f μ2 is the friction coefficient at temperature T1, k2 is the slope of the friction coefficient in the medium temperature section changing with temperature; f μ3 is the friction coefficient at temperature T2, k3 is the attenuation rate of the friction coefficient in the high temperature section as the temperature changes; (5) After the braking task is completed, the cooling liquid pump (13) is closed after the braking command is issued, the two-position two-way solenoid valve 1 (16.1), the two-position two-way solenoid valve 2 (16.2), the three-position four-way solenoid reversing valve (29) are in the middle position, and the two-position three-way solenoid reversing valve 2 (37) is in the right position. When the next braking operation is required, the above steps are repeated; during emergency braking, the accumulator (27) switches the oil supply path through the two-position three-way solenoid reversing valve (32).

10. A mine hoist, characterized in that: A mine hoist braking system equipped with a brake thermal failure prevention system as described in any one of claims 1 to 8.

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