Temperature rise monitoring system and method for hoisting mechanism brake of a hoisting machine

Abstract

One technical solution of the present invention is to provide a method for monitoring the temperature rise of the hoisting mechanism brake of a hoisting machine. Another technical solution of the present invention is to provide a temperature rise monitoring system for the hoisting mechanism brake of a hoisting machine, which is characterized by including: a weight monitoring module; a rotational speed monitoring module; a temperature monitoring module; a braking state monitoring module; a data processing module, which gives a judgment result by using the above-mentioned temperature rise monitoring method based on the received weight monitoring data, motor rotational speed monitoring data, temperature monitoring data, and braking state monitoring data. The present invention realizes the real-time monitoring and early warning of the temperature rise of the brake through monitoring modules such as weight, rotational speed, temperature, and braking state. The method is economical, easy to implement, and has strong engineering practicability.

Description

Technical Field

[0001] The present invention relates to a temperature rise monitoring system and a temperature rise monitoring method for a hoisting mechanism brake of a hoisting machine, belonging to the field of hoisting machine safety. Background Art

[0002] The brake is an important safety device for hoisting machines. The hoisting mechanism of hoisting machines often uses electro-hydraulic brakes. The electro-hydraulic brake generates a braking torque by tightly fitting the friction plate and the brake wheel through the spring force of the braking mechanism, and consumes the kinetic energy of the operating mechanism in the form of frictional heat energy. The heat generated by braking causes the temperature of the brake to rise. If the temperature exceeds a certain limit, it will affect the braking performance, and even cause the high-temperature failure of the braking components, resulting in accidents. The existing brake temperature rise monitoring systems and methods are realized by presetting temperature sensors in the friction plate or the brake wheel, or by using a thermal imager for non-contact temperature measurement. The former can only measure the temperature at certain points, and the latter has high requirements for the measurement environment. The implementation costs of both are high and the technical difficulties are great. Summary of the Invention

[0003] The technical problem to be solved by the present invention is that the existing brake temperature rise monitoring systems and methods have certain limitations, and the implementation costs are high and the technical difficulties are great.

[0004] To solve the above technical problem, a technical solution of the present invention is to provide a temperature rise monitoring method for a hoisting mechanism brake of a hoisting machine, which is characterized by including the following steps:

[0005] Step 1: Set the initial value of the braking times variable k to 0, and enter Step 2;

[0006] Step 2: Continuously obtain the braking state monitoring data. When the hoisting mechanism brakes, the braking state monitoring data changes, and the brake state switches from open to closed, and enter Step 3;

[0007] Step 3: k = k + 1;

[0008] Record the moment when the braking state monitoring data changes, denoted as moment t;

[0009] Record the weight monitoring data, the motor speed monitoring data, and the temperature monitoring data at moment t. Denote the weight monitoring data at moment t as G, the motor speed monitoring data at moment t as n, and the temperature monitoring data at moment t as T 0 ;

[0010] Step 4: Calculate the braking energy E of the hoisting mechanism

[0011]

[0012] Wherein, J represents the moment of inertia of the transmission mechanism of the hoisting mechanism converted to the motor shaft, g represents the acceleration due to gravity, and i represents the ratio of the hoisting speed of the hoisting mechanism to the motor speed;

[0013] Step 5, calculate the instantaneous maximum temperature T k ' of the brake during the k-th braking process, then there is:

[0014]

[0015] Wherein, E k is the braking energy of the hoisting mechanism during the k-th braking process calculated in Step 4; λ is the energy-temperature rise coefficient; T k-1 is the temperature of the brake after the (k - 1)-th braking and before the k-th braking, T 0(k-1) is the temperature monitoring data during the (k - 1)-th braking, β is the temperature reduction coefficient, and t k is the moment when the braking state monitoring data changes during the k-th braking;

[0016] Calculate the temperature T k of the brake after the k-th braking and before the (k + 1)-th braking;

[0017] Step 6, based on the temperature T k of the brake, judge the working state of the brake; based on the instantaneous maximum temperature T k ' of the brake, judge the risk of brake thermal degradation.

[0018] Preferably, in the said Step 6, based on the temperature T k of the brake, judge the working state of the brake according to the following conditions:

[0019] If T k ≤0.85T max , judge that the brake is in a low-load working state, and T max is the preset allowable long-term working temperature of the brake;

[0020] If 0.85T max <T k ≤0.92T max , judge that the brake is in a medium-load working state;

[0021] If 0.92T max <T k ≤T max , judge that the brake is in a high-load working state;

[0022] If T k >T max , judge that the brake is in an overloaded working state.

[0023] Preferably, in step 5, based on the instantaneous maximum temperature T of the brake k ', the risk of brake thermal degradation is judged according to the following conditions:

[0024] If T k '≤0.9T max ', it is judged that the risk of brake thermal degradation is low, and T max ' is the preset allowable instantaneous maximum temperature of the brake;

[0025] If 0.9T max '<T k '≤T max ', it is judged that the risk of brake thermal degradation is relatively high;

[0026] If T k '>T max ', it is judged that the risk of brake thermal degradation is high.

[0027] Preferably, after step 5 and before step 6, the following steps are further included:

[0028] Compare the instantaneous maximum temperature T k ' and the temperature T k obtained in the k-th braking process with the instantaneous maximum temperature and temperature obtained in at least two previous braking processes. Judge whether the brake enters the thermal equilibrium state according to the change range. If so, enter step 6. If the brake does not enter the thermal equilibrium state, return to step 2.

[0029] Another technical solution of the present invention is to provide a temperature rise monitoring system for the hoisting mechanism brake of a hoisting machine, which is characterized by including:

[0030] A weight monitoring module for monitoring the weight of the heavy object lifted by the hoisting mechanism and sending the obtained weight monitoring data to the data processing module in real time;

[0031] A rotational speed monitoring module for monitoring the motor rotational speed of the hoisting mechanism and sending the obtained motor rotational speed monitoring data to the data processing module in real time;

[0032] A temperature monitoring module for monitoring the ambient temperature and sending the obtained temperature monitoring data to the data processing module in real time;

[0033] A brake state monitoring module for monitoring the state of the hoisting mechanism brake and sending the obtained brake state monitoring data to the data processing module in real time;

[0034] A data processing module, based on the received weight monitoring data, motor rotational speed monitoring data, temperature monitoring data, and brake state monitoring data, gives a judgment result by using the above temperature rise monitoring method.

[0035] Preferably, it further includes a human-computer interaction module, which is used to display the determination result output by the data processing module to remind relevant personnel.

[0036] Through monitoring modules such as weight, rotational speed, temperature, and braking state, the present invention realizes real-time monitoring and early warning of the temperature rise of the brake, with an economical method, easy to implement, and strong engineering practicability. Description of the Drawings

[0037] Figure 1 is a schematic structural diagram of the system of the present invention;

[0038] Figure 2 is a flowchart of the method of the present invention. Detailed Embodiments

[0039] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0040] As Figure 1 shown, a temperature rise monitoring system for a hoisting mechanism brake of a hoisting machinery disclosed by the present invention includes:

[0041] A weight monitoring module, which is used to monitor the weight of the heavy object lifted by the hoisting mechanism and send the obtained weight monitoring data to the data processing module in real time. In this embodiment, the weight monitoring module is a weight sensor arranged on the base of the hoisting mechanism drum.

[0042] A rotational speed monitoring module, which is used to monitor the rotational speed of the motor of the hoisting mechanism and send the obtained motor rotational speed monitoring data to the data processing module in real time. In this embodiment, the rotational speed monitoring module is a rotary encoder arranged on the motor shaft of the hoisting mechanism.

[0043] A temperature monitoring module, which is used to monitor the ambient temperature and send the obtained temperature monitoring data to the data processing module in real time. In this embodiment, the temperature monitoring module is a temperature sensor.

[0044] A braking state monitoring module, which is used to monitor the state of the hoisting mechanism brake (the state of the brake includes open or closed) and send the obtained braking state monitoring data to the data processing module in real time. In this embodiment, the braking state monitoring module is a limit switch, a travel switch or a proximity switch arranged on the brake, or a current sensor arranged on the brake control circuit or the power circuit.

[0045] The data processing module gives a judgment result based on the received weight monitoring data, motor speed monitoring data, temperature monitoring data, and braking state monitoring data, and sends the judgment result to the human-machine interaction module.

[0046] The human-machine interaction module is used to display the judgment result output by the data processing module to remind relevant personnel.

[0047] The above data processing module gives the foregoing judgment result by using a temperature rise monitoring method for the brake of the hoisting mechanism of a hoisting machine. The temperature rise monitoring method includes the following steps:

[0048] Step 1: Set the initial value of the brake count variable k to 0, and go to Step 2;

[0049] Step 2: Continuously obtain the braking state monitoring data. When the hoisting mechanism brakes, the braking state monitoring data changes from "open" to "closed", and go to Step 3;

[0050] Step 3: k = k + 1;

[0051] Record the moment when the braking state monitoring data changes, denoted as moment t;

[0052] Record the weight monitoring data, motor speed monitoring data, and temperature monitoring data at moment t. Denote the weight monitoring data at moment t as G, the motor speed monitoring data at moment t as n, and the temperature monitoring data at moment t as T 0 ;

[0053] Step 4: Calculate the braking energy E of the hoisting mechanism

[0054]

[0055] where v represents the hoisting speed of the hoisting mechanism, m represents the mass of the heavy object hoisted by the hoisting mechanism, J represents the moment of inertia of the transmission mechanism of the hoisting mechanism reduced to the motor shaft, ω represents the angular velocity of the motor rotation, g represents the acceleration due to gravity, and i represents the ratio of the hoisting speed of the hoisting mechanism to the motor speed;

[0056] Step 5: Calculate the instantaneous maximum temperature T k ' of the brake during the k-th braking process, then there is:

[0057]

[0058] where E k is the braking energy of the hoisting mechanism during the k-th braking process calculated in Step 4; λ is the energy-temperature rise coefficient; T k-1 is the temperature of the brake after the (k - 1)-th braking and before the k-th braking, T 0(k-1)is the temperature monitoring data at the (k - 1)-th braking, β is the temperature reduction coefficient, and t k is the moment when the braking state monitoring data changes at the k-th braking;

[0059] Calculate the temperature T of the brake after the k-th braking and before the (k + 1)-th braking k ;

[0060] Step 6: Compare the instantaneous maximum temperature T k ' and the temperature T k obtained during the k-th braking process with the instantaneous maximum temperature and temperature obtained during the previous braking processes. Determine whether the brake has entered the thermal equilibrium state based on the change amplitude. If so, proceed to Step 7. If the brake has not entered the thermal equilibrium state, return to Step 2;

[0061] Step 7: Based on the temperature T of the brake k judge the working state of the brake, and there are:

[0062] If T k ≤0.85T max , it is judged that the brake is in a low-load working state, and T max is the preset allowable long-term working temperature of the brake;

[0063] If 0.85T max <T k ≤0.92T max , it is judged that the brake is in a medium-load working state;

[0064] If 0.92T max <T k ≤T max , it is judged that the brake is in a high-load working state;

[0065] If T k >T max , it is judged that the brake is in an overloaded working state.

[0066] Based on the instantaneous maximum temperature T of the brake k ' judge the risk of brake thermal degradation, and there are:

[0067] If T k '≤0.9T max ', it is judged that the risk of brake thermal degradation is low, and T max ' is the preset allowable instantaneous maximum temperature of the brake;

[0068] If 0.9T max '<T k '≤T max ' at this time, it is judged that the risk of brake thermal degradation is relatively high;

[0069] If T k '> T max ', it is determined that the risk of brake thermal degradation is high.

[0070] Taking a general bridge crane as an example, the hoisting speed to motor speed ratio i = 0.003 m / r, the moment of inertia J of the transmission mechanism referred to the motor shaft is 10 kg·m 2 , the energy-temperature rise coefficient λ = 6 kJ / °C, the temperature drop coefficient β = -0.0116 s -1 , the room temperature is maintained at T 0 = 20°C, the allowable long-term working temperature T of the brake max = 200°C, the allowable instantaneous maximum temperature T' of the brake max = 500°C, the gravitational acceleration g = 10 m / s 2 .

[0071] (1) If the motor speed n = 2000 r / min, G = 200 kN, the braking time interval, i.e., t 2 -t 1 = t 3 -t 2 =... = 60 s, the braking energy E 1 = E 2 =... = 579 kJ

[0072]

[0073]

[0074]

[0075]

[0076] ······

[0077]

[0078]

[0079]

[0080]

[0081] T' 9 = T' 10 = T' 11 =... = 193°C

[0082] T 9 = T 10 = T 11 =... = 96°C

[0083] The brake enters the thermal equilibrium state.

[0084] Further judgment:

[0085] 96 °C < 0.85T max , the brake is in a low-load working state;

[0086] 193 °C < 0.9T′ max , the risk of thermal degradation of the brake is low.

[0087] (2) If the motor speed n = 2000 r / min, G = 200 kN, the braking time interval, i.e., t 2 -t 1 = t 3 -t 2 =... = 30 s, the braking energy E 1 = E 2 =... = 579 kJ

[0088]

[0089]

[0090]

[0091]

[0092] ······

[0093]

[0094]

[0095]

[0096]

[0097] T′ 13 = T′ 14 = T′ 15 =... = 331 °C

[0098] T 13 = T 14 = T 15 =... = 234 °C

[0099] The brake enters the thermal equilibrium state.

[0100] Further judgment:

[0101] 234 °C > T max , the brake is in an overloaded working state;

[0102] 331℃ < 0.9T′ max , the risk of brake thermal degradation is low.

[0103] (3) If the motor speed n = 2000 r / min and G = 1200 kN, the braking time interval, i.e., t 2 -t 1 = t 3 -t 2 =... = 120 s, the braking energy E 1 = E 2 =... = 2379 kJ

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114] T′ 5 = T′ 6 = T′ 7 =... = 529℃

[0115] T 5 = T 6 = T 7 =... = 132℃

[0116] The brake enters the thermal equilibrium state.

[0117] Further judgment:

[0118] 132℃ < 0.85T max , the brake is in a low-load working state;

[0119] 529 > T′ max , the risk of brake thermal degradation is high.

Claims

1. A method for monitoring the temperature rise of the hoisting mechanism brake of a hoisting machine, characterized in that, it includes the following steps: Step 1: Set the initial value of the braking frequency variable k to 0, and enter Step 2; Step 2: Continuously obtain the braking state monitoring data. When the hoisting mechanism brakes, the braking state monitoring data changes, and the brake state switches from open to closed, then enter Step 3; Step 3: k = k + 1; Record the moment when the braking state monitoring data changes, denoted as moment t; Record the weight monitoring data, motor speed monitoring data, and temperature monitoring data at time t. Denote the weight monitoring data at time t as G, the motor speed monitoring data at time t as n, and the temperature monitoring data at time t as T 0 ; Step 4: Calculate the braking energy E of the hoisting mechanism In the formula, J represents the moment of inertia of the transmission mechanism of the hoisting mechanism referred to the motor shaft, g represents the acceleration due to gravity, and i represents the ratio of the hoisting speed to the motor speed of the hoisting mechanism; Step 5, calculate the instantaneous maximum temperature T of the brake during the k-th braking process k ', then there is: where, E k is the hoisting mechanism braking energy in the k-th braking process calculated in step 4; λ is the energy-temperature rise coefficient; T k-1 is the temperature of the brake after the (k - 1)-th braking and before the k-th braking, T 0(k-1) is the temperature monitoring data during the (k - 1)-th braking, β is the temperature drop coefficient, t k is the moment when the braking state monitoring data changes during the k-th braking; Calculate the temperature T of the brake after the k-th braking and before the (k + 1)-th braking k ; Step 6. Based on the temperature T of the brake k Determine the working state of the brake; based on the instantaneous maximum temperature T of the brake k Judge the risk of thermal degradation of the brake.

2. The method for monitoring the temperature rise of the hoisting mechanism brake of a hoisting machine according to claim 1, characterized in that, In step 6, based on the temperature T of the brake k , determine the working state of the brake according to the following conditions: If T k ≤ 0.85T max , it is determined that the brake is in a low-load working state, and T max is the preset allowable long-time working temperature of the brake; If 0.85T max <T k ≤0.92T max , it is determined that the brake is in the medium load working state; If 0.92T max <T k ≤T max , it is determined that the brake is in a high-load working state; If T k >T max , it is determined that the brake is in an overloaded working state.

3. The method for monitoring the temperature rise of the hoisting mechanism brake of a hoisting machine according to claim 1, characterized in that, In the said step 6, based on the instantaneous maximum temperature T k ' of the brake, judge the risk of brake thermal degradation according to the following conditions: If T k '≤0.9T max ', it is determined that the risk of brake thermal degradation is low, and T max ' is the preset maximum allowable instantaneous temperature of the brake; If 0.9T max '<T k '≤T max ', it is determined that the risk of brake thermal degradation is relatively high; If T k '> T max ', it is determined that the risk of brake thermal degradation is high.

4. The method for monitoring the temperature rise of the hoisting mechanism brake of a hoisting machine according to claim 1, characterized in that, After the said Step 5 and before the said Step 6, the following steps are further included: The instantaneous maximum temperature T obtained during the k-th braking process k ' and the temperature T k are compared with the instantaneous maximum temperatures and temperatures obtained during at least two previous braking processes. According to the change range, it is judged whether the brake enters the thermal equilibrium state. If so, go to step 6. If the brake does not enter the thermal equilibrium state, return to step 2.

5. A temperature rise monitoring system for the hoisting mechanism brake of a hoisting machine, characterized in that, it includes: A weight monitoring module, which is used to monitor the weight of the heavy object hoisted by the hoisting mechanism and send the obtained weight monitoring data to the data processing module in real time; A rotational speed monitoring module, which is used to monitor the rotational speed of the motor of the hoisting mechanism and send the obtained motor rotational speed monitoring data to the data processing module in real time; A temperature monitoring module, which is used to monitor the ambient temperature and send the obtained temperature monitoring data to the data processing module in real time; A braking state monitoring module, which is used to monitor the state of the hoisting mechanism brake and send the obtained braking state monitoring data to the data processing module in real time; A data processing module, which gives a judgment result by using the temperature rise monitoring method described in claim 1 based on the received weight monitoring data, motor rotational speed monitoring data, temperature monitoring data, and braking state monitoring data.

6. The temperature rise monitoring system for the hoisting mechanism brake of a hoisting machine according to claim 5, characterized in that, It further includes a human - machine interaction module, which is used to display the judgment result output by the data processing module to remind relevant personnel.

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