Limit switch of mine hoist
By introducing a Hall sensor and connecting it in parallel with a contact switch into the limit switch of the mine hoist, and combining it with a self-testing circuit and indicator lights, the problem of corrosion of mechanical limit switches in high humidity environments was solved, and reliability and safety were achieved in harsh environments.
Patent Information
- Application Number
- CN202423096328.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-12-16
AI Technical Summary
Mechanical limit switches in mine hoists are susceptible to the high humidity environment underground, which can lead to contact corrosion, poor contact, and affect safe operation.
The system uses a Hall sensor connected in parallel with a contact switch. Through the meshing of gears and racks, the movement of the push rod is detected by a magnet and the Hall sensor, and a signal is output. It is also equipped with a self-test circuit and indicator lights for self-testing.
It improves the reliability of limit switches, ensures normal operation in harsh environments, enables self-testing of contact switches, and guarantees the safe operation of the hoist.
Smart Images
Figure CN223496056U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mining equipment technology, and in particular to a limit switch for a mine hoist. Background Technology
[0002] The 2JTP-1.6 single-rope winding hoist used in the mine has many mechanical limit switches, which are crucial for the safe operation of the hoist. The current problem is that the mechanical limit switches, mainly composed of a housing, push rod, spring, moving contact, and stationary contact, are susceptible to corrosion in the high-humidity underground environment, despite the protection of the housing. This corrosion leads to poor contact and ultimately, failure of the limit switches. Utility Model Content
[0003] To overcome the shortcomings of the prior art, this utility model discloses a limit switch for a mine hoist, adopting the following technical solution:
[0004] A limit switch for a mine hoist includes a housing, a push rod, a spring, a moving contact, and a stationary contact. The moving contact and the stationary contact constitute a contact switch. A gear and a Hall sensor are installed inside the housing. A rack is provided on the push rod, and the gear and the rack are meshed together. Multiple magnets are fixed circumferentially on the end face of the gear. The Hall sensor is positioned opposite to the magnets. When the push rod moves, the Hall sensor outputs a signal.
[0005] To further improve the technical solution, the Hall sensor is a Hall switch sensor, which outputs a switching signal, and the Hall switch sensor is connected in parallel with a contact switch.
[0006] In a further improved technical solution, the Hall sensor outputs a self-test signal, and the limit switch also includes a self-test circuit connected to the Hall sensor to detect whether the contact switch has failed.
[0007] To further improve the technical solution, an indicator light A is installed on the housing. Indicator light A is connected to a Hall sensor, and indicator light A lights up when the Hall sensor outputs a signal.
[0008] To further improve the technical solution, an indicator light B is installed on the housing. The indicator light B is connected to a contact switch, and when the contact switch is closed, the indicator light B lights up.
[0009] After implementing the above technical solution, the beneficial effects of this utility model compared to the prior art are:
[0010] The limit switch of this mine hoist has a Hall sensor that is linked to the push rod. The Hall sensor can be connected in parallel with the contact switch as a redundant switch, which greatly improves the reliability of the limit switch. The Hall sensor can also be connected with the self-testing circuit as a self-testing element, which can realize the self-testing of the contact switch and ensure the safe operation of the mine hoist. Attached Figure Description
[0011] Appendix Figure 1 The diagram shown is a structural schematic of the mine hoist when the limit switch is not triggered.
[0012] Appendix Figure 2 The diagram shown is a schematic of the structure when the limit switch of the hoist in this mine is triggered.
[0013] Appendix Figure 3 The diagram shows a Hall sensor connected in parallel with a contact switch.
[0014] Appendix Figure 4 The diagram shows the connection between the Hall sensor and the self-test circuit.
[0015] In the attached diagram: 1. Housing; 2. Push rod; 3. Spring; 4. Moving contact; 5. Stationary contact; 6. Gear; 7. Magnet; 8. Hall sensor; 9. Self-test circuit; 10. Indicator light A; 11. Indicator light B. Detailed Implementation
[0016] The preferred embodiments of this utility model are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of this utility model and are not intended to limit the scope of protection of this utility model. It should be noted that in the description of this utility model, terms such as "front," "rear," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of this utility model. It should also be noted that in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0017] Example 1: Refer to Appendix Figure 1A limit switch for a mine hoist includes a housing 1. Inside the housing 1, a push rod 2, a spring 3, a set of moving contacts 4, and two sets of stationary contacts 5 are installed. The moving contacts 4 and stationary contacts 5 constitute a contact switch. A roller is installed at the head end of the push rod 2. Because the push rod 2 needs to extend and retract, moisture inevitably enters the housing 1 through gaps, causing the moving contacts 4 and stationary contacts 5 to corrode.
[0018] To address the problems in the background art, a gear 6 and a Hall sensor 8 are installed inside the housing 1. A rack is machined onto the push rod 2, and the gear 6 meshes with the rack. Six magnets 7 are fixed circumferentially on the end face of the gear 6, and the Hall sensor 8 is positioned opposite to the magnets 7.
[0019] See attached document Figure 2 When the moving parts of the hoist touch the rollers, the push rod 2 moves to the right and drives the gear 6 to rotate clockwise via the rack. A magnet 7 is fixed on the end face of the gear 6. The rotation of the magnet 7 causes a change in the magnetic field, which in turn causes the Hall sensor 8 to output a signal.
[0020] See attached document Figure 3 In this embodiment, the Hall sensor 8 is a Hall switch sensor, which outputs a switching signal and is connected in parallel with a contact switch.
[0021] A Hall effect switch sensor is an active magnetoelectric conversion device based on the Hall effect, capable of converting magnetic induction signals into electrical signals for practical applications. When the magnetic field changes to a certain extent, the trigger inside the Hall switch flips, and the output level also flips accordingly, exhibiting switching characteristics. Hall effect switch sensors are characterized by small size, light weight, low power consumption, fast response speed, and stable signal transmission, making them suitable for long-term operation. More importantly, Hall effect switch sensors are unaffected by high humidity and corrosive environments, making them suitable for operation in harsh environments.
[0022] Because the Hall effect sensor and the contact switch are connected in parallel, the Hall effect sensor can still ensure the limit switch closes normally even if the contact switch fails due to contact corrosion. Therefore, the Hall effect sensor is a redundant design for the contact switch.
[0023] For ease of maintenance, indicator lights A10 and B11 are installed on housing 1. Indicator light A10 is connected to Hall sensor 8; when Hall sensor 8 outputs a signal, indicator light A10 illuminates. Indicator light B11 is connected to a contact switch; when the contact switch is closed, indicator light B11 illuminates. Maintenance personnel can determine whether there is a problem with the contact switch or Hall sensor 8 by observing the on / off status of indicator lights A10 and B11.
[0024] Example 2: Refer to Appendix Figure 4In this embodiment, the limit switch also includes a self-test circuit 9. The Hall sensor 8 outputs a self-test signal. The self-test circuit 9 is connected to the Hall sensor 8. The self-test circuit 9 is existing technology and can detect whether the contact switch has failed.
[0025] If, during operation, the Hall sensor 8 detects that the push rod 2 has started to move, but the contact switch does not conduct, it indicates that there is a problem with the contact switch.
[0026] The parts not detailed herein are prior art. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of protection of which is defined by the appended claims and their equivalents.
Claims
1. A limit switch for a mine hoist, comprising a housing, a push rod, a spring, a moving contact, and a stationary contact, wherein the moving contact and the stationary contact constitute a contact switch, characterized in that: Gears and Hall sensors are installed inside the housing. A rack is provided on the push rod, and the gears and racks are meshed together. Multiple magnets are fixed circumferentially on the end face of the gears. The Hall sensors are positioned opposite the magnets. When the push rod moves, the Hall sensors output signals.
2. The limit switch for a mine hoist as described in claim 1, characterized in that: The Hall sensor is a Hall switch sensor, which outputs a switching signal and is connected in parallel with a contact switch.
3. A limit switch for a mine hoist as described in claim 1, characterized in that: The Hall sensor outputs a self-test signal, and the limit switch also includes a self-test circuit connected to the Hall sensor to detect whether the contact switch has failed.
4. A limit switch for a mine hoist as described in claim 1, characterized in that: An indicator light A is installed on the housing. Indicator light A is connected to a Hall sensor. When the Hall sensor outputs a signal, indicator light A lights up.
5. A limit switch for a mine hoist as described in claim 1 or 4, characterized in that: An indicator light B is installed on the housing. Indicator light B is connected to a contact switch. When the contact switch is closed, indicator light B lights up.