A wire rope lowering method for a lower positioner

Abstract

The application provides a wire discharging method of a lower limit position device of a steel wire rope, and the specific steps comprise: (1) when winding a layer of steel wire rope on a winding drum, a press roller is lifted by the steel wire rope and separated from the surface of the winding drum, and it is identified that the steel wire rope does not reach the lower limit position, and the winding drum normally performs a lowering action; (2) the winding drum starts to rotate and performs a lowering action, until the steel wire rope on the winding drum is left with n turns, the steel wire rope is separated from the lower side of the press roller, and the press roller is tightly pressed on the surface of the winding drum, at this time, it is identified that the steel wire rope reaches the lower limit position; (3) after winding a layer of steel wire rope on the winding drum, the steel wire rope is separated from the surface of the winding drum, and a travel switch does not work, when the steel wire rope reaches the preset lower limit position of the steel wire rope, the steel wire rope is discharged along the direction of the inclined part of the press roller, after the discharge, the press roller is attached to the surface of the winding drum, so that the press roller is pressed downward, and the spring of the spring device is restored to the natural state, the discharging action is completed, and the lowering rope action is more smooth.

Description

Technical Field

[0001] This invention relates to the field of crane lifting equipment technology, and specifically to a method for releasing a wire rope from a lower limit device. Background Technology

[0002] Currently, in actual crane lifting operations, the crane lifting equipment is used to lift or lower goods and is a crucial mechanism within the crane. Its performance directly affects the overall performance of the crane. When the crane lifting equipment reaches its lifting or lowering limit position, it should automatically cut off the power source and stop moving, thereby achieving the lifting and lowering limit function of the lifting mechanism and preventing damage to the lifted goods and the crane itself. For example, Chinese patent application number CN202022547910.5, published on July 20, 2021, discloses a lifting mechanism for a crane, relating to the technical field of crane lifting mechanisms. It includes a drum wrapped with wire rope and a wall frame for supporting the drum, as well as a spring. One end of the spring is fixed to the wall frame, and the other end is fixed to a pressure roller shaft. One end of the pressure roller shaft is rotatably connected to a pressure roller. The spring provides initial preload tension, ensuring the pressure roller always presses against the wire rope on the drum. A connecting rod is connected to the middle of the pressure roller shaft, and the other end of the connecting rod is connected to a connecting rod shaft and a detection rod. The two photoelectric proximity switches in this hoisting mechanism are used to detect when the hoisting wire rope reaches its upper and lower limits. Compared with mechanical limit switches, photoelectric proximity switches offer superior positioning accuracy, operating frequency, service life, ease of installation and adjustment, and adaptability to harsh environments. However, this mechanism pre-sets the lower limit position to the third loop of the first layer. During the descent of the wire rope, the wire rope moves the pressure roller downward by the diameter of one wire rope. The pressure roller rotates the connecting rod, and the center of the detection rod's head coincides with the center of the first proximity switch during rotation, thus achieving descent control. In other words, the lower limit control is achieved by the pressure roller driving the connecting rod to rotate. Furthermore, because the pressure roller has a step, it affects the descent and exit of the wire rope after it has descended, thereby impacting the equipment's operating efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a method for releasing the lower limit device of a wire rope, which enables the detection of the lower limit position of the wire rope during the descent process, making the rope release action smoother.

[0004] To achieve the above objectives, a method for discharging wire rope using a lower limit device is provided. This method involves detecting the lower limit of a layer of wire rope on a drum using the lower limit device. The method includes a support, a pressure roller, a spring device, and a limit switch. The support is installed on both sides of the pressure roller, and the spring device is located on both sides of the pressure roller. One end of the spring device is connected to the support, and the other end is connected to one end of the pressure roller. The support is connected to both ends of the pressure roller via the spring device. The limit switch is located on the support on one side of the pressure roller. The spring device is movably positioned between the limit switch and both ends of the pressure roller. The spring device includes a spring. When the spring is in its natural state, the pressure roller is in contact with the drum, and the limit switch is activated. When the spring is compressed, one end of the limit switch is connected to the spring device, triggering the limit switch to deactivate. The pressure roller has inclined portions on both sides, tilted upwards and inwards. The angle between the inclined surface of the inclined portion and the surface of the pressure roller is 15°-20°. The specific steps include: (1) When a layer of wire rope is wound on the drum, the pressure roller is lifted by the wire rope and separated from the surface of the drum. This is identified as the wire rope not reaching the lower limit position, and the drum proceeds to lower normally. (2) The drum starts to rotate and lowers until there are n turns of wire rope remaining on the drum. The wire rope then leaves the bottom of the pressure roller, causing the pressure roller to press tightly against the surface of the drum. At this time, the wire rope is preset to reach the lower limit position. (3) After a layer of wire rope is wound on the drum, the wire rope separates from the drum surface and the limit switch does not work. When the wire rope reaches the preset lower limit position of the wire rope, the wire rope exits along the inclined part of the pressure roller. After exiting the rope, the pressure roller is in contact with the drum surface, which causes the pressure roller to press down, thereby driving the spring of the spring device to return to its natural state. The spring device moves down and does not contact the limit switch, thereby triggering the limit switch to work and controlling the drum not to perform the rope exit action.

[0005] The above setup utilizes spring devices on both sides of the pressure roller. When the pressure roller is pressed against the drum surface, the limit switch activates, indicating that the wire rope has reached its lower limit position. A limit switch is also installed on a bracket on one side of the pressure roller. When the wire rope is being wound up, it enters the corresponding groove on the drum from the inclined section, causing the pressure roller to lift. This lift compresses the springs in the spring device, deactivating the limit switch and allowing the winding process to continue. When the wire rope is being released, it slides out of the groove on the drum from the inclined section. With no wire rope remaining between the pressure roller and the drum, they return to their original contact state, thus identifying the wire rope. The lower limit position is detected when no wire rope is wound on the drum and the limit switch is triggered, causing the drum to stop working and thus preventing further rope release. The lower limit position of the wire rope is detected by lifting and pressing the pressure roller using only one pressure roller and two spring devices. The structure is simple, and the inclined parts on both sides of the pressure roller facilitate the wire rope to enter or slide out of the groove on the drum, improving work efficiency and preventing inaccurate limit position detection due to untimely wire rope winding and unwinding. By setting the above angle, it is convenient for the winding and unwinding of the wire rope, and the pressure roller skin can be made thinner, reducing the weight of the pressure roller.

[0006] Furthermore, there are two or more supports, including support one and support two. Support one and support two are respectively arranged on both sides of the pressure roller, and support one and support two are arranged parallel to each other. Support one and support two are fixedly installed on the steel plate by bolts.

[0007] The above configuration, by mounting brackets on both sides of the pressure roller, allows for the installation of connecting spring devices and limit switches.

[0008] Furthermore, the pressure roller includes a pressure roller body and a pressure roller skin. Bearings are provided at both ends of the pressure roller body. A rotating shaft passes through the interior of the pressure roller body through the bearings. Both ends of the rotating shaft are rotatably connected to one end of the spring device. The pressure roller skin is fixed to the surface of the pressure roller body by screws.

[0009] The above configuration involves installing bearings at both ends of the pressure roller body, allowing the rotating shaft to pass through the interior of the pressure roller body and thus enabling the pressure roller to rotate. By connecting one end of the rotating shaft to the spring device, the pressure roller can be pressed tightly against the surface of the drum when the drum is not wound with wire rope.

[0010] Furthermore, the pressure roller skin includes a pressure roller skin body, with inclined portions disposed on both sides of the pressure roller skin body. The cross-section of the pressure roller skin is circular, and the cross-section of the pressure roller body is circular. One end of the inclined portion is connected to the surface of the pressure roller body, and the other end of the inclined portion is connected to the surface of the pressure roller skin. The cross-sectional radius of the pressure roller skin body is larger than the cross-sectional radius of the pressure roller body.

[0011] The above configuration, with inclined sections at both ends of the pressure roller skin, facilitates the wire rope to smoothly enter the area below the pressure roller from both ends during the upward movement of the wire rope, lifting the pressure roller and separating it from the drum. This prevents the wire rope from getting stuck on the steps of the pressure roller and thus improves the efficiency of the lifting operation.

[0012] Furthermore, there are two or more spring devices arranged parallel to both sides of the pressure roller. Each spring device includes a guide seat, a spacer, a support rod, a spring, and a support rod seat. The guide seat is fixed to the bracket by bolts. A through hole is provided at the end of the guide seat away from the bracket. The spacer is provided at both ends of the through hole on the guide seat. The support rod passes through the through hole on the guide seat. One end of the support rod is fixedly connected to the support rod seat. The other end of the support rod is fixedly connected to one end of the limit switch through a steel plate. The spring is sleeved on the end of the support rod connected to the bearing end of the pressure roller. One end of the spring is connected to the guide seat, and the other end of the spring is connected to the support rod seat. Step (2) specifically includes the following: when the drum starts to rotate and performs the lowering action, the wire rope on the drum gradually detaches from the drum until there are n turns of wire rope remaining. At this time, the wire rope completely detaches from the bottom of the pressure roller, so that the pressure roller presses tightly against the surface of the drum, triggering the lower limit device of the wire rope. The control system recognizes that the wire rope has reached the lower limit position.

[0013] The above setup, by connecting the support rod to the support rod seat and installing a spring sleeve on the end of the support rod connected to the support rod seat, allows the pressure roller to reset when the drum is not wound with wire rope, so that the pressure roller presses tightly against the drum surface, recognizing that the wire rope has reached the lower limit position.

[0014] Furthermore, one end of the limit switch is connected to the support rod of the spring device via a steel plate, and the other end of the limit switch is fixed to the bracket by bolts; Step (1) specifically includes the following: when a layer of wire rope is wound on the drum, the pressure roller is lifted by the wire rope by at least 2mm, thereby separating from the surface of the drum. At this time, the lower limit device of the wire rope is not triggered, and the control system recognizes that the wire rope has not reached the lower limit position, and the drum normally performs the lowering action.

[0015] The above configuration, by connecting the limit switch to the support rod of the spring device, allows the signal of the wire rope reaching the lower limit position to be transmitted to the control system, thereby preventing the drum from lowering. Furthermore, the support rod seat includes a first fixed plate and a second fixed plate, which are vertically arranged. The first fixed plate has a support rod mounting hole corresponding to the position of the support rod, with one end of the support rod fixedly installed in the mounting hole and a limit bolt at the other end. The second fixed plate has a shaft mounting hole, with a limit post on one side of the shaft mounting hole.

[0016] The above configuration, by fixing one end of the support rod to the support rod seat and then fixing one end of the rotating shaft to the support rod seat through a limiting post, prevents the rotating shaft from rotating. A bearing is installed between the rotating shaft and the pressure roller, allowing the pressure roller to rotate, thereby reducing friction between the drum and the pressure roller. In addition, when the pressure roller is lifted, the support rod seat is lifted, and then the support rod moves upward to contact the limit switch. The limiting bolt on the other end of the support rod prevents the support rod from disengaging from the guide seat when it moves downward, resulting in good structural stability. Attached Figure Description

[0017] Figure 1 This is the front view of the present invention.

[0018] Figure 2 This is a side view of the present invention.

[0019] Figure 3 This is an enlarged view of point A in the present invention.

[0020] Figure 4 This is a flowchart of the process of the present invention.

[0021] Reference numerals in the attached drawings: 1. Bracket 1; 2. Roller skin; 3. Roller body; 4. Shaft; 5. Guide seat; 6. Spacer; 7. Support rod; 8. Steel plate; 9. Bracket 2; 10. Pad plate; 11. Bearing; 12. Spring; 13. Support rod seat; 14. Inclined surface; 15. Roller body surface; 16. Roller skin surface; 17. Limit switch; 131. First fixing plate; 132. Second fixing plate; 1321. Shaft mounting hole; 1322. Limit post. Detailed Implementation

[0022] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation details.

[0023] like Figure 1-3As shown, this embodiment of the invention provides a lower limit device for a wire rope, used for detecting the lower limit of a wire rope wound on a drum. The device includes a bracket, a pressure roller, a spring device, and a limit switch 17. The bracket includes a first bracket 1 and a second bracket 9, which are arranged parallel to each other on both sides of the pressure roller. One end of the first bracket 1 and one end of the second bracket 9 are respectively fixed to a pad 10 by bolts. The other end of the first bracket 1 is used to install a connecting spring device, and the other end of the second bracket 9 is used to install a connecting spring device and the limit switch 17.

[0024] In this embodiment, as Figure 1 As shown, two spring devices are provided, arranged parallel to both sides of the pressure roller. Each spring device includes a guide seat 5, a spacer 6, a support rod 7, a spring 12, and a support rod seat 13. The guide seat 5 is bolted to bracket 1 and bracket 2 9 respectively. A through hole is provided at the end of the guide seat 5 away from the bracket. Spacers 6, matching the through hole, are installed at both ends of the through hole. The support rod 7 of the spring device, mounted on bracket 2 9, passes through the through hole in the guide seat 5. One end of the support rod 7 passes through the spring 12 and is fixedly connected to the support rod seat 13. The other end of the support rod 7 is fixedly connected to the lower surface of the steel plate 8. The spring device installed on bracket 1 has one end of the support rod 7 passing through the hole on the guide seat 5, and then through the spring 12 directly slidingly connected to the support rod seat 13 along the length of the support rod 7; one end of the limit switch is connected to the upper surface of the steel plate 8, and the other end of the limit switch 17 is fixedly installed on the bracket 9 by bolts, which enables the signal of the wire rope reaching the lower limit position to be transmitted to the control system, and then the control system controls the drum to prevent it from lowering. The working principle of the control system controlling the drum to prevent it from lowering after receiving the signal is the prior art, and will not be described in detail here.

[0025] like Figure 3 As shown, the strut base 13 includes a first fixing plate 131 and a second fixing plate 132. The first fixing plate 131 and the second fixing plate 132 are arranged vertically. The first fixing plate 131 has a mounting hole that matches the position of the strut 7. One end of the strut 7 is fixedly installed in the mounting hole. In this embodiment, the strut 7 is interference-fitted into the mounting hole to achieve a fixed connection between the strut 7 and the strut base 13. A limit bolt is provided at the end connected to the lower surface of the steel plate 8. The second fixing plate 132 has a shaft mounting hole 1321. A limit post 1322 is provided on the left side of the shaft mounting hole 1321. During the installation process, the shaft is placed into the shaft mounting hole 1321 and then limited by the limit post 1322 to achieve a fixed installation of the shaft in the shaft mounting hole 1321.

[0026] In this embodiment, as Figure 1 and Figure 3As shown, the pressure roller includes a pressure roller body 3 and a pressure roller skin 2. Bearings 11 are provided at both ends of the pressure roller body 3. A rotating shaft 4 passes through the interior of the pressure roller body 3 via the bearings 11. Both ends of the rotating shaft 4 are connected to the rotating shaft mounting holes of the second fixing plate 132 of the support rod seat 13. The pressure roller skin 2 includes a pressure roller skin body. The pressure roller skin 2 is fixed to the outer surface of the pressure roller body 3 by screws, thus facilitating the replacement of the pressure roller skin 2. Inclined portions are provided at both ends of the pressure roller skin body. One end of the inclined surface 14 of the inclined portion is connected to the surface 15 of the pressure roller body. The other end of the inclined surface 14 of the inclined part is connected to the surface 16 of the pressure roller skin. The cross-section of the pressure roller skin 2 is circular, and the cross-section of the pressure roller body 3 is also circular. The radius of the cross-section of the pressure roller skin 2 is larger than the radius of the cross-section of the pressure roller body 3. Since the two ends of the pressure roller skin 2 are respectively provided with inclined parts, during the process of the wire rope rising, it is convenient for the wire rope to enter the pressure roller from both ends and lift the pressure roller, so that the pressure roller is separated from the drum. This avoids the wire rope getting stuck on the step of the pressure roller and being unable to lift the pressure roller, thereby improving the work efficiency.

[0027] like Figure 4 As shown, the working method of the lower limit device of the above-mentioned wire rope includes the following specific steps: (1) When a layer of wire rope is wound on the drum, the pressure roller is lifted by the wire rope by at least 2mm, thereby separating from the surface of the drum. At this time, the lower limit device of the wire rope is not triggered. The control system is preset to the wire rope not reaching the lower limit position, and the drum normally performs the lowering action.

[0028] (2) When the drum starts to rotate and lowers, the wire rope on the drum gradually detaches from the drum until n turns of the wire rope remain. In this embodiment, n turns are set to 5 turns. At this time, the wire rope completely detaches from the pressure roller, so that the pressure roller presses tightly against the surface of the drum, triggering the lower limit device of the wire rope. The control system recognizes that the wire rope has reached the lower limit position.

[0029] (3) After a layer of wire rope is wound on the drum, the wire rope separates from the drum surface and the limit switch does not work. When the wire rope reaches the preset lower limit position of the wire rope, the wire rope exits along the inclined part of the pressure roller. After exiting the rope, the pressure roller is in contact with the drum surface, which causes the pressure roller to press down, thereby driving the spring of the spring device to return to its natural state. The spring device moves down and does not contact the limit switch, thereby triggering the limit switch to work and controlling the drum not to perform the rope exit action.

Claims

1. A method for discharging a wire rope from a lower positioner of a wire rope, the method comprising: detecting a layer of the wire rope on a drum by a lower positioner of the wire rope; and discharging the wire rope from the lower positioner. The lower limit device for the wire rope includes a bracket, a pressure roller, a spring device, and a limit switch. The bracket is installed on both sides of the pressure roller, and the spring device is located on both sides of the pressure roller. One end of the spring device is connected to the bracket, and the other end of the spring device is connected to one end of the pressure roller. The bracket is connected to both ends of the pressure roller through the spring device. The limit switch is located on the bracket on one side of the pressure roller, and the spring device is movable between the limit switch and both ends of the pressure roller. The spring device includes a spring. When the spring is in its natural state, the pressure roller is in contact with the drum, and the limit switch is activated. When the spring is compressed, one end of the limit switch is connected to the spring device, triggering the limit switch to deactivate. The pressure roller has inclined portions on both sides that are inclined upward and inward. The pressure roller includes a pressure roller body and a pressure roller skin, and one end of the inclined surface of the inclined portion is connected to the surface of the pressure roller body. The other end of the inclined surface of the inclined part is connected to the surface of the pressure roller skin. The cross-sectional radius of the pressure roller skin is larger than the cross-sectional radius of the pressure roller body. During the upward movement of the wire rope, the wire rope enters the pressure roller from both ends and lifts the pressure roller, thus separating the pressure roller from the drum. The angle between the inclined surface of the inclined part and the surface of the pressure roller body is 15°-20°. The spring device includes a guide seat, a spacer, a support rod, and a support rod seat. The support rod of the spring device installed on the second bracket passes through the through hole on the guide seat. One end of the support rod passes through the spring and is fixedly connected to the support rod seat. The other end of the support rod is fixedly connected to the lower surface of the steel plate. The support rod of the spring device installed on the first bracket passes through the hole on the guide seat and then passes through the spring and is directly slidably connected to the support rod seat along the length of the support rod. One end of the limit switch is connected to the upper surface of the steel plate, and the other end of the limit switch is fixedly installed on the bracket by bolts. The specific steps include: (1) When a layer of wire rope is wound on the drum, the pressure roller is lifted by the wire rope and separated from the surface of the drum. This is identified as the wire rope not reaching the lower limit position, and the drum proceeds to lower normally. (2) The drum starts to rotate and lowers until there are n turns of wire rope remaining on the drum. The wire rope then leaves the bottom of the pressure roller, causing the pressure roller to press tightly against the surface of the drum. At this time, the wire rope is preset to reach the lower limit position. (3) After a layer of wire rope is wound on the drum, the wire rope separates from the drum surface and the limit switch does not work. When the wire rope reaches the preset lower limit position of the wire rope, the wire rope exits along the inclined part of the pressure roller. After exiting the rope, the pressure roller is in contact with the drum surface, which causes the pressure roller to press down, thereby driving the spring of the spring device to return to its natural state. The spring device moves down and does not contact the limit switch, thereby triggering the limit switch to work and controlling the drum not to perform the rope exit action.

2. The rope discharge method of the lower limit device for a steel wire rope according to claim 1, characterized in that: It includes a support first and a support second, which are respectively arranged on both sides of the pressure roller, and the support first and the support second are arranged in parallel. The support first and the support second are fixedly installed on the steel plate by bolts.

3. The rope discharge method of the lower limit device for a steel wire rope according to claim 1, characterized in that: Bearings are provided at both ends of the pressure roller body. The rotating shaft passes through the interior of the pressure roller body through the bearings. The two ends of the rotating shaft are rotatably connected to one end of the spring device. The pressure roller skin is fixed to the surface of the pressure roller body by screws.

4. The rope discharge method of the lower limit device for a steel wire rope according to claim 3, characterized in that: The pressure roller skin includes a pressure roller skin body, with inclined portions disposed on both sides of the pressure roller skin body. The cross-section of the pressure roller skin is circular, and the cross-section of the pressure roller body is circular. One end of the inclined portion is connected to the surface of the pressure roller body, and the other end of the inclined portion is connected to the surface of the pressure roller skin. The cross-sectional radius of the pressure roller skin body is larger than the cross-sectional radius of the pressure roller body.

5. The rope discharge method of the lower limit device for a steel wire rope according to claim 3, characterized in that: Step (2) specifically includes the following: when the drum starts to rotate and performs the lowering action, the wire rope on the drum gradually detaches from the drum until there are n turns of wire rope remaining. At this time, the wire rope completely detaches from the bottom of the pressure roller, so that the pressure roller presses tightly against the surface of the drum, triggering the lower limit device of the wire rope. The control system recognizes that the wire rope has reached the lower limit position.

6. The rope discharge method of the lower limit device for a steel wire rope according to claim 1, characterized in that: One end of the limit switch is connected to the support rod of the spring device via a steel plate, and the other end of the limit switch is fixed to the bracket by bolts; Step (1) specifically includes the following: when a layer of wire rope is wound on the drum, the pressure roller is lifted by the wire rope by at least 2mm, thereby separating from the surface of the drum. At this time, the lower limit device of the wire rope is not triggered, and the control system recognizes that the wire rope has not reached the lower limit position, and the drum normally performs the lowering action.

7. The rope discharge method of the lower limit device for a steel wire rope according to claim 1, characterized in that: n laps is 5 laps.

8. The rope discharge method of the lower limit device for a steel wire rope according to claim 5, characterized in that: The strut support includes a first fixing plate and a second fixing plate, which are arranged vertically. The first fixing plate has a strut mounting hole corresponding to the position of the strut. One end of the strut is fixedly installed in the strut mounting hole, and the other end of the strut is provided with a limit bolt. The second fixing plate has a shaft mounting hole, and a limit post is provided on one side of the shaft mounting hole.

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