Push-pull type secondary lifting limiting device of electric hoist
By introducing a push-pull secondary lifting limit device into the electric hoist, the combination of the touch switch and telescopic rod and the electromagnet is used to automatically cut off the motor power when the limit fails, solving the safety hazards caused by the single limit structure of the traditional electric hoist, and improving the safety and reliability of the equipment.
Patent Information
- Application Number
- CN202421657819.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-07-12
AI Technical Summary
Traditional electric hoists only have a primary limit structure, and there are safety hazards after failure. When the secondary limit structure fails, the operator cannot know in time and can continue to operate and rise, which poses a risk of top rushing.
A push-pull secondary lifting limiting device for electric hoist is designed, and the limiting function is achieved through the touch switch and telescopic rod and the electromagnet, and the motor power is cut off under the action of the main lifting force to ensure the reliability of the limiting function.
It improves the safety of the electric hoist, avoids top-flooding accidents caused by limit failure, and enhances the reliability and safety of operation.
Smart Images
Figure CN223073823U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of electric hoists, and relates to a push-pull type secondary lifting limit device for an electric hoist. Background Art
[0002] The steel wire rope of a traditional electric hoist has only a primary limit structure, which is a height limiter installed at the head of the drum. Through this limit structure, the limit in the lifting direction can be realized when lifting objects. In actual use, once this limit structure fails, the wire rope hoist will have no limit device, thus creating a safety hazard. The lifted object below is likely to hit the motor due to excessive rising, causing damage to the electric hoist.
[0003] In order to increase the safety of the electric hoist, some electric hoists have added a secondary limit structure. However, when the secondary limit structure is damaged, since there is no detection device for the secondary limit structure, the operator cannot know that the limit has failed and can continue to operate the up button, and the electric hoist can still continue to rise. Therefore, there are safety hazards such as overtravel. Summary of the Utility Model
[0004] Aiming at the deficiencies of the prior art, the utility model provides a push-pull type secondary lifting limit device for an electric hoist, which can further improve the safety of the electric hoist.
[0005] To solve the above technical problems, the purpose of the utility model is achieved through the following technical solutions:
[0006] A push-pull type secondary lifting limit device for an electric hoist, including a touch switch electrically connected to the main lifting motor. A telescopic rod penetrating up and down is slidably arranged in the touch switch. A first electromagnet is sleeved on the telescopic rod above the touch switch, and the first electromagnet is fixedly connected to the telescopic rod. A driving mechanism for driving the first electromagnet to move upward is arranged above the first electromagnet. A second electromagnet is sleeved on the telescopic rod below the touch switch, and the second electromagnet is fixedly connected to the touch switch and slidably matched with the telescopic rod. A contact cooperating with the touch switch is arranged on the telescopic rod in the touch switch. After the first electromagnet and the second electromagnet are energized, an attractive force is generated. After the telescopic rod moves downward, the contact closes the touch switch, and after moving upward, the contact disconnects the touch switch.
[0007] In the above push-pull type secondary lifting limit device for an electric hoist, a fixing device is arranged on one side of the touch switch, and the fixing device is fixedly connected to the upper end of the main lifting chain or the electric hoist. The lower end of the telescopic rod forms a secondary lifting limit point. Preferably, the fixing device is a horizontally arranged fixing rod or fixing bracket.
[0008] In the above-mentioned push-pull type secondary hoisting limit device of an electric hoist, a primary hoisting limit device is provided inside the electric hoist, and the primary hoisting limit point of the primary hoisting limit device is lower than the secondary hoisting limit point.
[0009] In the above-mentioned push-pull type secondary hoisting limit device of an electric hoist, an outer shell is provided for the first electromagnet, the driving mechanism is arranged inside the outer shell, and a through hole for the telescopic rod to extend out is provided at the top of the outer shell.
[0010] In the above-mentioned push-pull type secondary hoisting limit device of an electric hoist, the driving mechanism is a spring, the spring is sleeved on the telescopic rod, one end of which is fixedly connected to the upper side of the first electromagnet, and the other end is fixedly connected to the upper side inside the outer shell. Other mechanisms can also be used for the driving mechanism, such as metal shrapnel or damping telescopic devices, etc.
[0011] In the above-mentioned push-pull type secondary hoisting limit device of an electric hoist, an upper limit block is fixed at the upper end of the telescopic rod, and a lower limit block is fixed at the lower end. When the upper limit block abuts against the outer shell, it forms a lower displacement stroke limit for the telescopic rod, and when the lower limit block abuts against the second electromagnet, it forms an upper displacement stroke limit for the telescopic rod. Preferably, both the upper limit block and the lower limit block are coaxial annular blocks fixed on the telescopic rod.
[0012] In the above-mentioned push-pull type secondary hoisting limit device of an electric hoist, the starting power supplies of the first electromagnet and the second electromagnet are electrically connected to the start-stop button of the starting handle.
[0013] Compared with the prior art, the present invention has the following beneficial effects:
[0014] The present invention provides a push-pull type secondary hoisting limit device for an electric hoist, which realizes the limit function through the cooperation of a telescopic rod with a contact and a touch switch. At the same time, when the electromagnet does not act or the driving mechanism fails, the telescopic rod can still be pushed open by the upward lifting force of the main hoisting to play a limiting role, so accidents such as overtop will not occur. Therefore, the push-pull type secondary hoisting limit device for an electric hoist provided by the present invention can further improve the safety of the electric hoist. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is a schematic structural diagram of the present invention;
[0016] Reference numerals: 1, touch switch; 2, telescopic rod; 3, first electromagnet; 4, driving mechanism; 5, second electromagnet; 6, contact; 7, fixing device; 8, outer shell; 9, upper limit block; 10, lower limit block. DETAILED DESCRIPTION OF THE INVENTION
[0017] The present utility model will be further described below with specific embodiments in conjunction with the accompanying drawings. Refer to Figure 1 :
[0018] A push-pull type secondary lifting limit device for an electric hoist, comprising a touch switch 1. A telescopic rod 2 penetrating up and down is slidably arranged in the touch switch 1. A first electromagnet 3 is sleeved on the telescopic rod 2 above the touch switch 1. The first electromagnet 3 is fixedly connected to the telescopic rod 2. A driving mechanism 4 for driving the first electromagnet 3 to move upward is arranged above the first electromagnet 3. A second electromagnet 5 is sleeved on the telescopic rod 2 below the touch switch 1. The second electromagnet 5 is fixedly connected to the touch switch 1 and slidably matched with the telescopic rod 2. A contact 6 cooperating with the touch switch 1 is arranged on the telescopic rod 2 in the touch switch 1. The first electromagnet 3, the second electromagnet 5 and the main lifting motor are all electrically connected to the touch switch 1. After the first electromagnet 3 and the second electromagnet 5 are powered on, they generate an attractive force. After the telescopic rod 2 moves downward, the contact 6 closes the touch switch 1. After moving upward, the contact 6 disconnects the touch switch 1.
[0019] During operation, the power supplies of the first electromagnet 3 and the second electromagnet 5 are turned on. The attractive forces of the first electromagnet 3 and the second electromagnet 5 drive the telescopic rod 2 and the first electromagnet 3 to move downward, and at the same time stretch the driving mechanism 4. The contact 6 of the telescopic rod 2 moves to the lower side in the touch switch 1 and connects the contact 6 switch to make it in the normally open state. The lifting motor normally performs the lifting operation. The power supplies of the first electromagnet 3 and the second electromagnet 5 are turned off. The attractive forces of the first electromagnet 3 and the second electromagnet 5 disappear. The driving mechanism 4 drives the first electromagnet 3 to move upward, and the telescopic rod 2 moves upward accordingly. After the contact 6 on the telescopic rod 2 moves upward, it no longer connects the contact 6 switch, and the contact 6 switch disconnects, cutting off the power supply of the lifting motor. When the contact 6 switch fails and the power supplies of the first electromagnet 3 and the second electromagnet 5 are turned off, the power supply of the lifting motor is still not cut off. Therefore, the operator can timely judge the state of the lifting limit device.
[0020] A fixing device 7 is arranged on one side of the above-mentioned touch switch 1. The fixing device 7 is fixedly connected to the upper end of the main lifting chain or the electric hoist. The lower end of the telescopic rod 2 forms a secondary lifting limit point. Preferably, the fixing device 7 is a horizontally arranged fixing rod or fixing bracket.
[0021] The above-mentioned electric hoist is provided with a primary lifting limit device, and the primary lifting limit point of the primary lifting limit device is lower than the secondary lifting limit point. For example, the primary lifting limit point is 1 meter away from the limit lifting position, and the secondary lifting limit point is 0.8 meter away from the limit lifting position.
[0022] During operation, when the hoisting height reaches the first hoisting limit point, the first hoisting limit device comes into effect and further hoisting is stopped; when the first hoisting limit device fails, the electric hoist will continue to hoist beyond the first hoisting limit point and reach the second hoisting limit point. At this time, the telescopic rod 2 is pushed open by the upward force of the main hoist, the touch switch 1 is cut off, and then the power supply of the main hoist motor is cut off to stop the hoisting. When the electromagnet does not act or the driving mechanism 4 fails, the telescopic rod 2 is pushed open by the upward force of the main hoist, and it still does not affect the function of the limit device.
[0023] In this embodiment, the structure of the driving mechanism 4 is as follows: an outer shell is provided outside the first electromagnet 3, the driving mechanism 4 is arranged inside the outer shell 8, and a through hole for the telescopic rod 2 to extend out is provided at the top of the outer shell 8.
[0024] Further, the driving mechanism 4 is a spring, the spring is sleeved on the telescopic rod 2, one end of which is fixedly connected to the upper side of the first electromagnet 3, and the other end is fixedly connected to the upper side inside the outer shell 8. The driving mechanism 4 can also use other mechanisms, such as metal shrapnel or damping telescopic devices, etc.
[0025] In order to limit the moving stroke of the telescopic rod 2, an upper limit block 9 is fixed to the upper end of the telescopic rod 2, and a lower limit block 10 is fixed to the lower end. When the upper limit block 9 abuts against the outer shell 8, it forms a lower displacement stroke limit for the telescopic rod 2, and when the lower limit block 10 abuts against the second electromagnet 5, it forms an upper displacement stroke limit for the telescopic rod 2. Preferably, both the upper limit block 9 and the lower limit block 10 are coaxial annular blocks fixed on the telescopic rod 2.
[0026] The starting power supplies of the above-mentioned first electromagnet 3 and second electromagnet 5 are electrically connected to the start-stop button of the starting handle. Through the start-stop button of the starting handle, the starting power supplies of the first electromagnet 3 and the second electromagnet 5 can be conveniently controlled.
[0027] The above embodiments are only the preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.
Claims
1. A push-pull type secondary lifting limit device for an electric hoist, characterized in that, It includes a touch switch (1) electrically connected to the main hoist motor. A telescopic rod (2) that penetrates up and down is slidably arranged in the touch switch (1). A first electromagnet (3) is sleeved on the telescopic rod (2) above the touch switch (1). The first electromagnet (3) is fixedly connected to the telescopic rod (2). A driving mechanism (4) for driving the first electromagnet (3) to move upward is arranged above the first electromagnet (3). A second electromagnet (5) is sleeved on the telescopic rod (2) below the touch switch (1). The second electromagnet (5) is fixedly connected to the touch switch (1) and slidably matched with the telescopic rod (2). A contact (6) that cooperates with the touch switch (1) is arranged on the telescopic rod (2) in the touch switch (1). After the first electromagnet (3) and the second electromagnet (5) are energized, they generate an attractive force. After the telescopic rod (2) moves downward, the contact (6) closes the touch switch (1). After moving upward, the contact (6) disconnects the touch switch (1).
2. The push-pull type secondary lifting limit device for an electric hoist according to claim 1, characterized in that, A fixing device (7) is arranged on one side of the touch switch (1). The fixing device (7) is fixedly connected to the upper end of the main hoist chain or the electric hoist. The lower end of the telescopic rod (2) forms a secondary hoisting limit point.
3. The push-pull type secondary lifting limit device of an electric hoist according to claim 2, characterized in that, An electric hoist is provided with a primary hoisting limit device. The primary hoisting limit point of the primary hoisting limit device is lower than the secondary hoisting limit point.
4. The push-pull type secondary lifting limit device for an electric hoist according to claim 1, wherein, An outer cover shell (8) is arranged outside the first electromagnet (3). The driving mechanism (4) is arranged inside the outer cover shell (8). A through hole for the telescopic rod (2) to extend out is arranged at the top of the outer cover shell (8).
5. The push-pull type secondary lifting limit device for an electric hoist according to claim 4, characterized in that, The driving mechanism (4) is a spring. The spring is sleeved on the telescopic rod (2). One end of the spring is fixedly connected to the upper side of the first electromagnet (3), and the other end is fixedly connected to the upper side inside the outer cover shell (8).
6. The push-pull type secondary hoisting limit device of an electric hoist according to claim 4, characterized in that, An upper limit block (9) is fixed to the upper end of the telescopic rod (2), and a lower limit block (10) is fixed to the lower end. When the upper limit block (9) abuts against the outer cover shell (8), it forms a lower displacement stroke limit for the telescopic rod (2). When the lower limit block (10) abuts against the second electromagnet (5), it forms an upper displacement stroke limit for the telescopic rod (2).
7. The push-pull type secondary lifting limit device of an electric hoist according to claim 1, characterized in that, The starting power supplies of the first electromagnet (3) and the second electromagnet (5) are electrically connected to the start-stop button of the starting handle.