Lightweight hoisting machinery weight limiting device

Abstract

The invention discloses a light hoisting machinery weight limiting device which is a safety protection device special for a light crane and is small in size, light in weight, convenient to install and low in cost. The device is mainly used for electric hoist cranes of various models and specifications. The device realizes weight control by controlling the magnitude of current through the current transformer and the hoisting capacity limiter, has the functions of overweight alarm and cutting off a crane overweight loop power supply, and can avoid equipment and human injury accidents caused by overload of hoisting equipment. The device is simple and reliable in structure, and can be transformed on the basis of the existing light hoisting machinery, so that the existing light hoisting machinery meets the requirement that the national hoisting machinery must be provided with a limited weight, and the cost is effectively saved for enterprises.

Description

Technical Field

[0001] The invention relates to a safety protection device for light lifting machinery, in particular to a weight limiting device for light lifting machinery, which is suitable for electric hoist cranes of various models and specifications. Background Art

[0002] Light lifting machinery, such as electric hoist cranes, are widely used in various industries and fields, especially in the occasions of lifting, transporting and installing heavy objects. This type of machinery is usually composed of motors, motor control components, chains, control lines, etc., and has the characteristics of simple structure and easy operation. However, due to the lack of effective weight limiting devices, once overweight occurs during the lifting process, it is easy to cause equipment damage and even cause personal safety accidents. Therefore, light lifting machinery often faces safety issues in practical applications.

[0003] Although the existing light lifting machinery has basic functions, it has obvious deficiencies in safety. This is mainly reflected in the following aspects: First, there is a lack of effective overload protection mechanism. When the lifting load exceeds the rated load capacity of the equipment, the equipment cannot stop running in time, which is easy to cause equipment damage and safety accidents; second, the existing protection measures usually rely on the experience and judgment of the operator, with many subjective factors and low reliability; finally, the national and industry standards have put forward clear requirements for the weight limit function of lifting machinery. Equipment without weight limit function will face the risk of elimination, and enterprises need to spend a high cost to update or transform equipment.

[0004] In order to solve the above problems, the present invention designs and invents a simple, practical, sensitive and reliable light lifting machinery weight limiter. The device is mainly composed of a current transformer, a lifting weight limiter, a control line and a conduction line. By installing a current transformer at the input end of the motor, the working current of the motor is monitored, and the current signal is transmitted to the lifting weight limiter through the signal line. A current threshold corresponding to the limited weight is set on the lifting weight limiter. When the detected current exceeds the set value, the lifting weight limiter will immediately cut off the power supply of the motor and stop the motor from rotating, thereby effectively preventing the occurrence of overload and protecting the safety of equipment and personnel.

[0005] The present invention adds a current transformer and a lifting weight limiter to the existing light lifting machinery, and realizes the weight limit function by controlling the magnitude of the motor input current. This transformation not only solves the problem that light lifting machinery lacks a weight limit function, making it meet the requirements of national and industry standards, but also saves the cost of updating equipment for enterprises, and has important practical application value. It can be said that this transformation is an economical, efficient, safe and reliable solution. Summary of the invention

[0006] In view of the deficiencies that existing light lifting machinery lacks a weight limit function and that weight limit devices in the prior art are large in size, heavy in weight, complex in installation, and high in cost, the present invention adopts the following technical solutions:

[0007] The present invention provides a weight limit device for light lifting machinery, which includes a current transformer, a load limiter, a control wire, and a transmission wire. The current transformer is used to monitor the current change at the input end of the motor in real time and transmit the detection signal to the load limiter through the transmission wire. Further, the load limiter includes a display screen and a plurality of function buttons, which are used to set weight limit parameters and respond to overloading conditions. Among them, when the detected current value exceeds the preset limit value, the load limiter automatically cuts off the power supply of the motor to prevent overloading operation.

[0008] Further, the current transformer is installed at a specific position of the wire at the input end of the motor and is signal-connected to the load limiter through the transmission wire. In particular, the design of the current transformer ensures that it can accurately detect current changes and maintain the stability of signal transmission. The load limiter is installed inside the control box housing and is connected to external devices through the control wire, thereby realizing the functions of remote monitoring and operation. The control box housing protects the internal components and ensures the reliable operation of the device under complex working conditions.

[0009] The beneficial effects of the present invention are as follows. By adopting a current transformer and a load limiter with a compact design, the volume and weight of the device are significantly reduced, making it easy to install and maintain. Further, the device has a simple structure and low manufacturing cost, and is suitable for wide application in various light lifting machinery. In particular, by monitoring the current change in real time and combining with the preset weight limit parameters, the device can cut off the power supply of the motor in a timely manner under overloading conditions, effectively avoiding equipment damage and personal safety accidents caused by overloading, thereby improving the safety and reliability of light lifting machinery. Description of the Drawings

[0010] Figure 1 Schematic diagram of the ordinary light lifting machinery of the present invention;

[0011] Figure 2 Schematic diagram of the current transformer of the present invention;

[0012] Figure 3 Schematic diagram of the load limiter of the present invention;

[0013] Figure 4 Installation structure diagram of the current transformer of the present invention;

[0014] Figure 5 Installation structure diagram of the lifting limiter of the present invention;

[0015] Figure 6This is the overall installation schematic diagram of the present invention.

[0016] The reference numerals are as follows:

[0017] 1. Electric hoist traveling guide rail; 2. Electric hoist; 3. Electric hoist control component; 4. Electric hoist motor; 5. Conductive wire; 6. Current transformer; 7. Display screen; 8. Button; 9. Brand logo; 10. Electric wire; 11. Lifting weight limiter; 12. Control box housing; 13. Control wire. Detailed implementation manners

[0018] The present invention provides a weight limiting device for light lifting machinery. Through the combination of a current transformer and a lifting weight limiter, the device realizes overload protection for light lifting machinery (such as an electric hoist). The following will detail the specific implementation manners of the present invention with reference to the accompanying drawings.

[0019] Figure 1 Shows the basic structure of a common light lifting machinery (electric hoist), including an electric hoist traveling guide rail 1, an electric hoist 2, an electric hoist control component 3, and an electric hoist motor 4. In the case without installing a weight limiting device, the electric hoist drives the sprocket to rotate through the motor 4 to complete the lifting operation. However, due to the lack of a weight limiting function, once an overweight phenomenon occurs during the lifting process, the motor 4 may be damaged due to overload, and in severe cases, it may even cause personal safety accidents.

[0020] To solve the above problems, the present invention designs a weight limiting device for light lifting machinery, and its main components include a current transformer 6, a lifting weight limiter 11, a control wire 13, and a conductive wire 5. Figure 2 Is the schematic diagram of the current transformer 6, Figure 3 Is the schematic diagram of the lifting weight limiter 11, Figure 4 Is the installation structure diagram of the current transformer 6, Figure 5 Is the installation structure diagram of the lifting weight limiter 11, Figure 6 This is the overall installation schematic diagram of the present invention.

[0021] First, the current transformer 6 is installed on the input electric wire of the electric hoist motor 4. The specific installation position is as Figure 4 shown. The current transformer 6 is fixed on the electric wire 10 through a clamping member to ensure that it can accurately detect the input current of the motor 4. The output end of the current transformer 6 is connected to the lifting weight limiter 11 through the conductive wire 5 to transmit the real-time detected current signal to the lifting weight limiter 11. The design of the current transformer 6 ensures its stability and reliability under complex working conditions, and can accurately and timely detect the change of the current.

[0022] The lifting weight limiter 11 is installed inside the control box housing 12, and the control box housing 12 protects the internal components from the influence of the external environment. The structure of the lifting weight limiter 11 is as shown in Figure 3 Figure Figure 3 , which includes a display screen 7, multiple function buttons 8, and a brand logo 9. The display screen 7 is used to display the input current value of the current motor 4 and the set weight limit parameters, and the function buttons 8 are used to set and adjust the weight limit parameters. The lifting weight limiter 11 is connected to the electric hoist control component 3 through a control line 13, so as to realize the control of the motor 4. The installation position of the control box housing 12 is as shown in Figure 5 Figure Figure 5 , and it is fixed at an appropriate position of the electric hoist 2 through bolts or other fixing parts to ensure its stability during operation.

[0023] In the specific implementation process, first, install the current transformer 6 on the input wire of the electric hoist motor 4. During installation, pass the wire 10 through the central hole of the current transformer 6, and then fix the current transformer 6 on the wire 10 through a clamping part. Ensure good contact between the wire 10 and the current transformer 6 to ensure the accuracy of current detection. Then, connect the output end of the current transformer 6 to the input end of the lifting weight limiter 11 through a transmission wire 5. The connection of the transmission wire 5 should ensure the stability of signal transmission and avoid signal loss or interference.

[0024] The installation steps of the lifting weight limiter 11 are as follows: First, place the lifting weight limiter 11 inside the control box housing 12, and fix the lifting weight limiter 11 inside the control box housing 12 through bolts or other fixing parts. Then, fix the control box housing 12 at an appropriate position of the electric hoist 2, usually near the electric hoist control component 3 for easy operation and monitoring. The fixing of the control box housing 12 should ensure its stability during operation and avoid loosening of the device due to vibration or other external forces.

[0025] Set the weight limit parameters on the lifting weight limiter 11. Through the function buttons 8, the operator can set the current value corresponding to the maximum allowable lifting weight of the electric hoist. For example, if the maximum allowable lifting weight of the electric hoist is 1 ton, the operator can view and set the corresponding current value through the display screen 7 of the lifting weight limiter 11. After setting, the lifting weight limiter 11 will continuously monitor the current signal transmitted by the current transformer 6. When the detected current value exceeds the preset limit, the lifting weight limiter 11 will immediately cut off the power supply of the motor 4, causing the motor 4 to stop rotating, thereby avoiding overloading operation.

[0026] The internal circuit design of the lifting weight limiter 11 includes a signal processing module, a control module, and a power supply module. The signal processing module is used to receive and process the current signal transmitted by the current transformer 6, convert it into an electrical signal, and perform amplification and filtering processing. The control module compares the processed electrical signal with the preset weight limit parameter. When it detects that the current value exceeds the preset limit, the control module issues an instruction to cut off the power supply of the motor 4 through the power supply module. The power supply module is responsible for providing stable power for the entire device to ensure its normal operation under various working conditions.

[0027] The specific operation principle is as follows: When the electric hoist 2 starts to work, the motor 4 obtains current from the power supply through the wire 10. The current transformer 6 monitors the input current of the motor 4 in real time and transmits the detected current signal to the lifting weight limiter 11 through the transmission wire 5. The signal processing module of the lifting weight limiter 11 processes the received current signal, converts it into an electrical signal, and performs amplification and filtering. Then, the control module compares the processed electrical signal with the preset weight limit parameter. If the detected current value is less than or equal to the preset limit, the electric hoist 2 will continue to work normally. If the detected current value exceeds the preset limit, the control module will immediately issue an instruction to cut off the power supply of the motor 4 through the power supply module, causing the motor 4 to stop rotating. At the same time, the display screen 7 of the lifting weight limiter 11 will display an alarm message to remind the operator that the current device is in an overloaded state and immediate measures need to be taken to handle it.

[0028] To verify the reliability and practicability of the present invention, multiple experiments and optimizations were carried out. During the experiment, first, the current transformer 6 was installed at the input end of the motor 4 of the electric hoist 2, and the lifting weight limiter 11 was fixed inside the control box housing 12. Then, different weight limit parameters were set through the function button 8 to conduct lifting experiments with different weights. The experimental results showed that when the lifting weight exceeded the preset limit, the lifting weight limiter 11 could quickly and accurately cut off the power supply of the motor 4, and the motor 4 immediately stopped rotating, effectively avoiding equipment damage and personal safety accidents. In addition, by optimizing the parameter settings of the current transformer 6 and the lifting weight limiter 11, the stability and reliability of the device under various working conditions were ensured.

[0029] In practical applications, the weight limit device of the present invention can be widely applied to electric hoist cranes of various models and specifications. For example, in the production workshop of a factory, by installing the weight limit device of the present invention, it can be ensured that the electric hoist will not be damaged due to overloading when handling heavy objects, improving the safety and efficiency of production. In a construction site, the weight limit device of the present invention can prevent the electric hoist from being overloaded when hoisting building materials, ensuring construction safety. In the warehousing and logistics industry, the weight limit device of the present invention can ensure that the electric hoist will not have an accident due to overloading when handling goods, improving the safety and reliability of logistics.

[0030] The weight limit device of the present invention is not only small in size and light in weight, but also convenient to install and low in cost. Through simple installation steps, this device can be quickly installed on existing light lifting machinery to achieve the weight limit function. In particular, the weight limit device of the present invention fully considers the use environment and working conditions of light lifting machinery in its design, ensuring its stability and reliability in various complex environments. By real-time monitoring of current changes and combining with preset weight limit parameters, the weight limit device of the present invention can cut off the motor power supply in a timely manner under overloading conditions, effectively avoiding equipment damage and personal safety accidents caused by overloading, thereby improving the safety and reliability of light lifting machinery.

[0031] In the specific implementation process, the parameters of the load limiter 11 can be further optimized according to different application scenarios and requirements. For example, in some occasions with high precision requirements, the sensitivity and reliability of the device can be improved by increasing the precision of the current transformer 6 and the response speed of the load limiter 11. In some occasions with relatively harsh environments, the normal operation of the device in complex environments such as high temperature, humidity, and dust can be ensured by increasing the protection level of the control box housing 12.

[0032] The weight limit device for light lifting machinery of the present invention realizes the overload protection function of light lifting machinery through the compactly designed current transformer 6 and load limiter 11. This device has a simple structure and low manufacturing cost, and is suitable for wide application in various light lifting machinery. By real-time monitoring of current changes and combining with preset weight limit parameters, the weight limit device of the present invention can cut off the motor power supply in a timely manner under overloading conditions, effectively avoiding equipment damage and personal safety accidents caused by overloading, thereby improving the safety and reliability of light lifting machinery.

[0033] The above description shows and describes several preferred embodiments of the present invention. However, as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be changed within the scope of the inventive concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A light lifting machinery weight limiting device, characterized in that: include: A current transformer (6) is used to monitor the current change at the input end of the motor (4) in real time, and transmit the detection signal to the lifting weight limiter (11) through the transmission line (5); A weight limiter (11) comprises a display screen (7) and a plurality of function buttons (8) for setting weight limit parameters and responding to an overload state; The lifting weight limiter (11) is installed in the control box housing (12) and connected to the external device through the control line (13); When it is detected that the current value exceeds a preset limit, the lifting weight limiter (11) automatically cuts off the power supply of the motor (4) to prevent overload operation.

2. The light lifting machinery weight limiting device according to claim 1, characterized in that: The current transformer (6) is installed at a specific position of the electric wire (10) at the input end of the motor (4), and realizes signal connection with the lifting weight limiter (11) through the conductive wire (5).

3. The light lifting machinery weight limiting device according to claim 2, characterized in that: The current transformer (6) is fixed to the electric wire (10) by means of a clamping piece, thereby ensuring that it can accurately detect current changes and maintain the stability of signal transmission.

4. The light lifting machinery weight limiting device according to claim 1, characterized in that: The display screen (7) of the weight limiter (11) is used to display the current input current value of the motor (4) and the set weight limit parameters, and the function button (8) is used to set and adjust the weight limit parameters.

5. The light lifting machinery weight limiting device according to claim 4, characterized in that: The control line (13) of the lifting weight limiter (11) is connected to the electric hoist control component (3) to realize the control of the motor (4).

6. The light lifting machinery weight limiting device according to claim 1, characterized in that: The control box housing (12) protects the internal components of the lifting weight limiter (11) and prevents the external environment from affecting the device.

7. The light lifting machinery weight limiting device according to claim 1, characterized in that: The lifting weight limiter (11) includes a signal processing module, a control module and a power supply module, wherein the signal processing module is used to receive and process the current signal transmitted by the current transformer (6), and the control module compares the processed electrical signal with the preset weight limit parameter. When the detected current value exceeds the preset limit, the control module issues an instruction to cut off the power supply of the motor (4) through the power supply module.

8. The light lifting machinery weight limiting device according to claim 1, characterized in that: The display screen (7) of the lifting weight limiter (11) displays an alarm message to remind the operator that the equipment is currently in an overload state and that immediate measures need to be taken to deal with it.

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