Electric limit structure for preventing top collision of electric endless chain hoist
By combining photoelectric limit switches with reflectors, the position of the hook is monitored in real time and the power is cut off, which solves the problem of anti-collision when the electric chain hoist is running at high speed. It achieves a simple structure and stable anti-collision effect, which is convenient for equipment modification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI DELIC LIGHT CRANE
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-02
AI Technical Summary
The existing anti-impact structure of electric chain hoists is prone to damage during high-speed operation. The mechanical limit device has high strength requirements and strict installation accuracy requirements under high-speed inertial impact, which is not conducive to modification.
The design adopts a photoelectric limit switch. By working with a reflector, the position of the hook is monitored in real time and the power is cut off to achieve the anti-overhead collision function.
It achieves anti-impact performance during high-speed operation, has a simple structure, stable function, strong adaptability, and is easy to install and modify existing equipment.
Smart Images
Figure CN224313158U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an anti-collision structure for an electric chain hoist, and in particular discloses an electric limit structure for anti-collision of an electric chain hoist. Background Technology
[0002] The current anti-overhead structure of electric chain hoists primarily uses an electrical limit mechanism where the upper end of the hook fixing assembly contacts a pressure plate with a return spring to compress the electrical limit contacts, thereby cutting off the power and stopping the hook's ascent. This achieves the anti-overhead function. However, its biggest drawback is that at high speeds, the hook's inertial upward movement during power cut-off can cause excessive compression of the electrical limit contacts, leading to damage and disabling the anti-overhead function. Therefore, current anti-overhead electrical limit mechanisms have a high failure rate when used in high-speed electric chain hoists. Furthermore, existing purely mechanical anti-overhead limit devices must withstand significant inertial impacts at high speeds, requiring high strength and precise installation, which is detrimental to the structural modification of existing electric chain hoists. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings of existing technologies by designing an anti-overshoot electrical limit structure for electric chain hoists. Employing a photoelectric limit switch design, it boasts high sensitivity and can promptly cut off the power supply to the electric chain hoist when the hook reaches the set position, thus achieving the anti-overshoot function. This invention is not only simple in structure and has a wide adjustable range, but also small in size and stable in function.
[0004] This utility model is implemented as follows: an electric chain hoist anti-overshoot electrical limit structure includes a photoelectric limit switch fixed to the bottom of the electric chain hoist housing via a switch mounting base and a reflector correspondingly disposed on the hook fixing assembly of the electric chain hoist. The installation position of the photoelectric limit switch corresponds to the running path of the electric chain hoist hook and is connected to the circuit of the electric chain hoist control system.
[0005] The reflector is located on the outer surface of the hook fixing assembly opposite to the photoelectric limit switch, and its top edge is lower than or equal to the top of the hook fixing assembly of the electric chain hoist.
[0006] The photoelectric limit switch determines the rising position of the hook of the electric chain hoist by first emitting a light wave and then receiving the reflected light wave reflected back by the reflector.
[0007] The switch mounting base includes a mounting bracket and a mounting platform. The mounting bracket is fixedly connected to the bottom of the electric chain hoist housing. The photoelectric limit switch is fixed to the mounting platform and kept horizontal to ensure the monitoring sensitivity of the photoelectric limit switch. The relative position of the mounting bracket and the mounting platform of the switch mounting base is adjustable to match the needs of different electric chain hoists.
[0008] The beneficial effects of this utility model are as follows: The application principle of this utility model is simple and easy to understand. It fully utilizes the high sensitivity of the photoelectric limit switch to promptly trigger the circuit switching of the electric chain hoist when the hook rises to the set position, cutting off the power supply for rising and thus stopping the electric chain hoist from rising, achieving anti-overhead performance. Because this utility model has a large adjustable range, stable function, and a simple structure and small size, it is easy to install and facilitates the direct modification of existing electric chain hoists, enabling existing electric chain hoists to also have anti-overhead function. Attached Figure Description
[0009] Figure 1 This is a schematic diagram showing the installation position relationship of the anti-collision electrical limiting structure described in this utility model.
[0010] Figure 2 yes Figure 1 Side view.
[0011] Figure 3 This is a partially enlarged schematic diagram of the reflector mounting position in this utility model.
[0012] In the diagram: 1. Photoelectric limit switch; 2. Switch mounting base; 3. Reflector; 4. Hook fixing assembly; 5. Electric chain hoist housing; 6. Lifting chain. Detailed Implementation
[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0014] According to the appendix Figure 1 ~Attached Figure 3This utility model relates to an anti-overshoot electrical limit structure for an electric chain hoist, comprising a photoelectric limit switch 1 fixed to the bottom of the electric chain hoist housing 5 via a switch mounting base 2, and a reflector 3 correspondingly mounted on the hook fixing assembly 4 of the electric chain hoist. The photoelectric limit switch 1 is installed in a position corresponding to the running path of the electric chain hoist hook and is connected to the electric chain hoist control system circuit. The reflector 3 is located on the outer surface of the hook fixing assembly 4 on the side opposite to the photoelectric limit switch 1, and its top edge height does not exceed the top of the hook fixing assembly of the electric chain hoist. The photoelectric limit switch 1 determines that the hook of the electric chain hoist has risen to the set position by first emitting a light wave and then receiving the reflected light wave reflected back from the reflector 3.
[0015] The switch mounting base 2 includes a mounting bracket and a mounting platform. The mounting bracket is fixedly connected to the bottom of the electric chain hoist housing 5. The photoelectric limit switch 1 is fixed to the mounting platform and kept horizontal to ensure the monitoring sensitivity of the photoelectric limit switch 1. To increase the applicable adjustment range of this utility model, the mounting bracket and mounting platform of the switch mounting base 2 are designed to be height adjustable, and their relative positions are adjustable to match the needs of different electric chain hoists.
[0016] The working principle and process of this utility model are as follows: The electric chain hoist hook moves in an ascending and descending manner under the drive of the lifting chain 6. Since the photoelectric limit switch 1 corresponds to the running path of the electric chain hoist hook, the reflector 3 set on the hook fixing component 4 of the electric chain hoist rises or falls synchronously with the lifting chain 6. When it rises to the set position, it reflects the light wave emitted by the photoelectric limit switch 1 back to the photoelectric limit switch 1. When the photoelectric limit switch 1 receives the reflected light wave reflected back by the reflector 3, it immediately triggers the cutting off of the rising power supply circuit of the electric chain hoist, so that the electric chain hoist stops the rising action of the lifting chain 6, thereby realizing the function of preventing the hook fixing component from hitting the top.
Claims
1. An anti-collision electrical limit structure for an electric chain hoist, characterized in that: The aforementioned anti-collision electrical limit structure includes a photoelectric limit switch fixed to the bottom of the electric chain hoist housing via a switch mounting base and a reflector correspondingly installed on the hook fixing assembly of the electric chain hoist. The installation position of the photoelectric limit switch corresponds to the running path of the electric chain hoist hook and is connected to the circuit of the electric chain hoist control system.
2. The electric chain hoist anti-impact electrical limiting structure according to claim 1, characterized in that: The reflector is located on the outer surface of the hook fixing assembly opposite to the photoelectric limit switch, and its top edge is lower than or equal to the top of the hook fixing assembly of the electric chain hoist.
3. The electric limit structure for preventing top impact of an electric chain hoist according to claim 1, characterized in that: The photoelectric limit switch determines the rising position of the hook of the electric chain hoist by first emitting a light wave and then receiving the reflected light wave reflected back by the reflector.
4. The electric limit structure for preventing top impact of an electric chain hoist according to claim 1, characterized in that: The switch mounting base includes a mounting bracket and a mounting platform, and the mounting bracket is fixedly connected to the bottom of the electric chain hoist housing.
5. The electric limit structure for preventing top impact of an electric chain hoist according to claim 1 or 4, characterized in that: The photoelectric limit switch is fixed on the mounting platform and kept horizontal.
6. The electric limit structure for preventing top impact of an electric chain hoist according to claim 1 or 4, characterized in that: The relative position of the mounting bracket and the mounting platform of the switch mounting base is adjustable.