Method for judging actual working conditions and set working conditions of lifting hook and grab bucket

Abstract

The invention discloses a method for judging actual working conditions and set working conditions of a lifting hook and a grab bucket, which belongs to the technical field of hoisting equipment and comprises the following steps: step 1, data acquisition: acquiring data near the lifting hook and the grab bucket by using a data acquisition module, the data acquisition module reads real-time numerical values such as current voltage, current and frequency of the motor by controlling a frequency converter of the motor; 2, data processing: when selection work is carried out according to the lifting hook and the grab bucket, judgment is carried out through a data processing module according to the actual working condition and the set working condition, and the data processing module can obtain the weight value of the current lifted object through formula conversion calculation according to the value acquired by a data acquisition module and some known values; and 3, data display: displaying the data, and processing the data to obtain a result. The method for judging the actual working conditions and the set working conditions of the lifting hook and the grab bucket has real-time performance, accuracy and reliability, and the safety and the working efficiency of the crane can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lifting equipment, and in particular to a method for distinguishing actual working conditions and set working conditions of a hook and a grab bucket. Background Art

[0002] In the field of cranes, hooks and grabs are commonly used to pick up objects. Hooks and grabs are directly connected by wire ropes, and electrical feedback cannot form a closed loop. At the beginning of the operation, the corresponding operation mode is selected according to the actual situation. If the current operation is a hook operation, the driver needs to select the hook operation mode on the linkage table. If the current operation is a grab operation, the driver needs to select the grab operation mode on the linkage table.

[0003] However, in actual operation, due to operator negligence or equipment failure, if the operation mode selected by the driver is different from the current actual operation mode, these situations will not only affect the service life of the crane, but may also cause harm to the operator and the surrounding environment. Therefore, it is of great significance to judge whether the working mode of the hook and grab is consistent with the actual situation. Summary of the invention

[0004] The object of the present invention is to provide a method for distinguishing the actual working condition and the set working condition of a hook and a grab bucket, so as to solve the problems raised in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for distinguishing the actual working condition and the set working condition of a hook and a grab bucket, comprising the following steps:

[0006] Step 1: Data collection: Use the data collection module to collect data near the hook and grab. The data collection module reads the real-time values ​​of the motor's current voltage, current, frequency, etc. by controlling the motor's frequency converter;

[0007] Step 2, data processing: When selecting work according to the hook and grab, the data processing module is used to determine the actual working conditions and the set working conditions. The data processing module uses the values ​​collected by the data acquisition module and some known values, and calculates through formula conversion to obtain the weight value of the current hanging object;

[0008] Step 3: Data display: used to display data and display the results of data processing on the data display module;

[0009] Step 4: Alarm reminder: It is used for alarm reminder. When the hook working condition is selected, if the weight of the hanging object processed by the data processing module is inconsistent with the set weight of the hanging object, the system will judge that the working condition selection is wrong and use the alarm reminder module to issue an alarm reminder. The alarm will not be eliminated until the operator selects the corresponding correct working condition.

[0010] As a preferred embodiment, the data processing module processes data.

[0011] When the hook working condition is selected, the actual weight t1 of the hook is set in the data processing module;

[0012] When the grab bucket working condition is selected, the actual weight t2 of the grab bucket is set in the data processing module;

[0013] In the operating state, in the no-load state, the weight converted from the real-time value of the motor collected by the lifting inverter at each gear of the grab bucket or hook is recorded as a comparison value.

[0014] As a preferred implementation scheme, when the hook working condition is selected, if the weight of the hanging object obtained by the data processing module is inconsistent with the set weight of the hanging object, the system will determine that the working condition selection is wrong and issue an alarm. When the operator selects the corresponding correct working condition, the alarm will be eliminated. If the weight of the hanging object obtained by the data processing module is consistent with the set weight of the hanging object, normal operation will be performed.

[0015] As a preferred implementation scheme, when the grab bucket working condition is selected, if the weight of the hanging object obtained by the data processing module is inconsistent with the set weight of the hanging object, the system will determine that the working condition selection is wrong and issue an alarm. When the operator selects the corresponding correct working condition, the alarm will be eliminated. If the weight of the hanging object obtained by the data processing module is consistent with the set weight of the hanging object, normal operation will be carried out.

[0016] As a preferred implementation scheme, the conversion formula between current and hanging weight is:

[0017] The current frequency, voltage and current of the motor can all be read out through the frequency converter. The drum diameter, speed ratio of the reducer, wire rope diameter and pulley multiple are all known fixed values, and the weight of the object currently hoisted by the crane can be calculated.

[0018] Calculate the motor power:

[0019] The motor power P can be calculated by the formula

[0020] Calculate, where V is the motor line voltage (V), I is the motor line current (A), and cosφ is the power factor (for general industrial motors, this value is usually between 0.8 and 0.9);

[0021] Calculate the lifting speed:

[0022] The lifting speed V can be calculated by the motor speed, reducer ratio and drum diameter, the formula is as follows:

[0023]

[0024] The motor speed can be determined by the frequency and the number of poles. Usually, the relationship between the motor speed n, frequency f and the number of poles P is:

[0025] Calculate the static load power of the lifting mechanism:

[0026] Using the formula Calculate the static load power of the lifting mechanism, where Q is the lifting weight, G is the hook weight, V is the lifting speed (m / s), and θ is the overall efficiency;

[0027] Calculate lifting weight:

[0028] The lifting weight Q can be calculated by the formula Calculate, where P is the motor power (W), θ is the transmission efficiency (usually taken as 0.85), V is the lifting speed (m / s), and g is the acceleration due to gravity (9.81m / s2).

[0029] Compared with the prior art, the technical effects and advantages of the present invention are as follows:

[0030] The method for distinguishing the actual working condition of the hook and grab bucket from the set working condition is to judge whether the weight of the hook and grab bucket is normal by real-time monitoring the current change of the inverter during operation. In the no-load state, the stable output current value of the inverter of each gear of the grab bucket or hook is recorded as a comparison value. When the value read by the PLC is different from the preset value under the selected hook or spreader working condition, the system will judge that the working condition selection is wrong and prompt an alarm. The alarm can only be eliminated after the corresponding correct working condition is selected.

[0031] The method for distinguishing the actual working condition and the set working condition of the hook and grab bucket is real-time, accurate and reliable, and can improve the safety and working efficiency of the crane. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a process framework diagram of the present invention. DETAILED DESCRIPTION

[0033] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0034] See also Figure 1 , a method for distinguishing the actual working condition and the setting working condition of the hook and grab, this embodiment, comprises the following steps:

[0035] Step 1: Data collection: Use the data collection module to collect data near the hook and grab. The data collection module reads the real-time values ​​of the motor's current voltage, current, frequency, etc. by controlling the motor's frequency converter;

[0036] Step 2, data processing: When selecting work according to the hook and grab, the data processing module is used to determine the actual working conditions and the set working conditions. The data processing module uses the values ​​collected by the data acquisition module and some known values, and calculates through formula conversion to obtain the weight value of the current hanging object;

[0037] Step 3: Data display: used to display data and display the results of data processing on the data display module;

[0038] Step 4: Alarm reminder: It is used for alarm reminder. When the hook working condition is selected, if the weight of the hanging object processed by the data processing module is inconsistent with the set weight of the hanging object, the system will judge that the working condition selection is wrong and use the alarm reminder module to issue an alarm reminder. The alarm will not be eliminated until the operator selects the corresponding correct working condition.

[0039] In actual use, in the field of cranes, hooks and grabs are commonly used to pick up objects. Hooks and grabs are directly connected by wire ropes, and electrical feedback cannot form a closed loop. At the beginning of the operation, select the corresponding operation mode according to the actual situation. If the current operation is a hook operation, the driver needs to select the hook operation mode on the linkage table. If the current operation is a grab operation, the driver needs to select the grab operation mode on the linkage table.

[0040] When the data processing module processes data,

[0041] When the hook working condition is selected, the actual weight t1 of the hook is set in the data processing module;

[0042] When the grab bucket working condition is selected, the actual weight t2 of the grab bucket is set in the data processing module;

[0043] In the operating state, in the no-load state, the weight converted from the real-time value of the motor collected by the lifting inverter at each gear of the grab bucket or hook is recorded as a comparison value.

[0044] When the hook working condition is selected, if the weight of the hanging object processed by the data processing module is inconsistent with the set weight of the hanging object, the system will determine that the working condition selection is wrong and issue an alarm. When the operator selects the corresponding correct working condition, the alarm will be eliminated. If the weight of the hanging object processed by the data processing module is consistent with the set weight of the hanging object, normal operation will be carried out.

[0045] When the grab bucket working condition is selected, if the weight of the hanging object obtained by the data processing module is inconsistent with the set weight of the hanging object, the system will determine that the working condition selection is wrong and issue an alarm. When the operator selects the corresponding correct working condition, the alarm will be eliminated. If the weight of the hanging object obtained by the data processing module is consistent with the set weight of the hanging object, normal operation will be carried out.

[0046] In the no-load state, the stable output current value of the inverter at each gear of the grab or hook is recorded as the comparison value. When the hook or spreader working condition is selected, if the value read by the PLC is different from the preset value, the system will judge that the working condition selection is wrong and prompt an alarm. The alarm can only be eliminated after the corresponding correct working condition is selected.

[0047] The conversion formula between current and hanging weight is:

[0048] The current frequency, voltage and current of the motor can all be read out through the frequency converter. The drum diameter, speed ratio of the reducer, wire rope diameter and pulley multiple are all known fixed values, and the weight of the object currently hoisted by the crane can be calculated.

[0049] Calculate the motor power:

[0050] The motor power P can be calculated by the formula

[0051] Calculate, where V is the motor line voltage (V), I is the motor line current (A), and cosφ is the power factor (for general industrial motors, this value is usually between 0.8 and 0.9);

[0052] Calculate the lifting speed:

[0053] The lifting speed V can be calculated by the motor speed, reducer ratio and drum diameter, the formula is as follows:

[0054] The motor speed can be determined by the frequency and the number of poles. Usually, the relationship between the motor speed n, frequency f and the number of poles P is:

[0055] Calculate the static load power of the lifting mechanism:

[0056] Using the formula Calculate the static load power of the lifting mechanism, where Q is the lifting weight, G is the hook weight, V is the lifting speed (m / s), and θ is the overall efficiency;

[0057] Calculate lifting weight:

[0058] The lifting weight Q can be calculated by the formula Calculate, where P is the motor power (W), θ is the transmission efficiency (usually taken as 0.85), V is the lifting speed (m / s), and g is the acceleration due to gravity (9.81m / s2).

[0059] It should be noted that, in this document, relational terms such as one and two are merely used to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for distinguishing the actual working condition and the set working condition of a hook and a grab bucket, characterized in that: The following steps are involved: Step 1: Data collection: Use the data collection module to collect data near the hook and grab. The data collection module reads the real-time values ​​of the motor's current voltage, current, frequency, etc. by controlling the motor's frequency converter; Step 2, data processing: When selecting work according to the hook and grab, the data processing module is used to determine the actual working conditions and the set working conditions. The data processing module uses the values ​​collected by the data acquisition module and some known values, and calculates through formula conversion to obtain the weight value of the current hanging object; Step 3: Data display: used to display data and display the results of data processing on the data display module; Step 4: Alarm reminder: It is used for alarm reminder. When the hook working condition is selected, if the weight of the hanging object processed by the data processing module is inconsistent with the set weight of the hanging object, the system will judge that the working condition selection is wrong and use the alarm reminder module to issue an alarm reminder. The alarm will not be eliminated until the operator selects the corresponding correct working condition.

2. A method for distinguishing the actual working condition and the set working condition of a hook and a grab bucket according to claim 1, characterized in that: When the data processing module processes data, When the hook working condition is selected, the actual weight t1 of the hook is set in the data processing module; When the grab bucket working condition is selected, the actual weight t2 of the grab bucket is set in the data processing module; In the operating state, in the no-load state, the weight converted from the real-time value of the motor collected by the lifting inverter at each gear of the grab bucket or hook is recorded as a comparison value.

3. A method for distinguishing the actual working condition and the set working condition of a hook and a grab bucket according to claim 2, characterized in that: When the hook working condition is selected, if the weight of the hanging object processed by the data processing module is inconsistent with the set weight of the hanging object, the system will determine that the working condition selection is wrong and issue an alarm. When the operator selects the corresponding correct working condition, the alarm will be eliminated. If the weight of the hanging object processed by the data processing module is consistent with the set weight of the hanging object, normal operation will be carried out.

4. A method for distinguishing the actual working condition and the set working condition of a hook and a grab bucket according to claim 2, characterized in that: When the grab bucket working condition is selected, if the weight of the hanging object obtained by the data processing module is inconsistent with the set weight of the hanging object, the system will determine that the working condition selection is wrong and issue an alarm. When the operator selects the corresponding correct working condition, the alarm will be eliminated. If the weight of the hanging object obtained by the data processing module is consistent with the set weight of the hanging object, normal operation will be carried out.

5. A method for distinguishing the actual working condition and the setting working condition of a hook and a grab bucket according to claim 1, characterized in that: The conversion formula between the current and the weight of the suspended object is: The current frequency, voltage and current of the motor can all be read out through the frequency converter. The drum diameter, speed ratio of the reducer, wire rope diameter and pulley multiple are all known fixed values, and the weight of the object currently hoisted by the crane can be calculated. Calculate the motor power: The motor power P can be calculated by the formula Calculate, where V is the motor line voltage (V), I is the motor line current (A), and cosφ is the power factor (for general industrial motors, this value is usually between 0.8 and 0.9); Calculate the lifting speed: The lifting speed V can be calculated by the motor speed, reducer ratio and drum diameter, the formula is as follows: The motor speed can be determined by the frequency and the number of poles. Usually, the relationship between the motor speed n, frequency f and the number of poles P is: Calculate the static load power of the lifting mechanism: Using the formula Calculate the static load power of the lifting mechanism, where Q is the lifting weight, G is the hook weight, V is the lifting speed (m / s), and θ is the overall efficiency; Calculate lifting weight: The lifting weight Q can be calculated by the formula Calculate, where P is the motor power (W), θ is the transmission efficiency (usually taken as 0.85), V is the lifting speed (m / s), and g is the acceleration due to gravity (9.81m / s2).

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