Limiting device for preventing extreme position pressure building of variable-amplitude oil cylinder for crane

Abstract

The utility model discloses a limiting device for preventing extreme position pressure building of a variable-amplitude oil cylinder for a crane, which relates to the technical field of cranes and comprises a rotary table support, a variable-amplitude arm mounting frame is mounted on the rotary table support, the top of the variable-amplitude arm mounting frame is movably connected with the left end of a variable-amplitude arm, and the rotary table support is movably connected with one end of the variable-amplitude oil cylinder. The other end of the variable-amplitude oil cylinder is movably connected with the variable-amplitude arm; a limiting stopper support is installed at the position, located on the upper left portion of the arm shaft, of the top of the variable-amplitude arm installation frame, a variable-amplitude limiting stopper is installed on the limiting stopper support, and a trigger inclined face is arranged on the upper side of the left end of the variable-amplitude arm. During use, the variable-amplitude oil cylinder extends to push the right end of the variable-amplitude arm to be lifted, when the variable-amplitude oil cylinder extends to the longest working state, the trigger inclined plane on the variable-amplitude arm is in contact with the variable-amplitude limiter, and the variable-amplitude limiter sends a signal to limit continuous extension of the variable-amplitude oil cylinder, so that the condition of pressure building caused by the fact that the variable-amplitude oil cylinder runs to the limit position where the variable-amplitude oil cylinder extends completely is prevented, and the service life of the variable-amplitude oil cylinder is prolonged. And false triggering alarm of the moment limiting system is avoided.

Description

Technical Field

[0001] This utility model relates to the field of crane technology, specifically to a limiting device for preventing the limiting position of a boom cylinder used in cranes from being squeezed. Background Technology

[0002] The torque limiting system used on modern articulated boom cranes requires a pressure sensor to measure the pressure in the rodless chamber of the luffing cylinder, and then calculates the current torque value and the actual lifting weight using geometric relationships. When the cylinder is at its limit position (i.e., the cylinder has completed its full stroke), pressure buildup can occur, causing the pressure sensor to register an excessively high pressure, thus falsely triggering the torque alarm. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the existing defects and provide a limiting device for preventing the luffing cylinder of a crane from being stuck at the limit position. This device prevents the luffing cylinder from running to the limit position and stops the movement before the luffing cylinder reaches the limit position, thereby avoiding false triggering of the torque limit alarm. This can effectively solve the problems in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a limiting device for preventing the luffing cylinder of a crane from being pressed at its extreme position, comprising a turntable bracket, on which a luffing boom mounting bracket is mounted, the top of the luffing boom mounting bracket being movably connected to the left end of the luffing boom via a boom shaft, the turntable bracket being movably connected to one end of the luffing cylinder, and the other end of the luffing cylinder being movably connected to the right end of the luffing boom;

[0005] A limiter bracket is installed on the top of the luffing boom mounting bracket at the upper left position of the boom shaft. A luffing limiter is installed on the limiter bracket, and a trigger ramp is provided on the upper left side of the luffing boom.

[0006] When the luffing cylinder extends, it pushes the right end of the luffing arm to lift. When the luffing cylinder extends to its longest working state, the trigger ramp on the luffing arm contacts the luffing limit switch. The luffing limit switch sends a signal to limit the luffing cylinder from extending further, preventing the luffing cylinder from running to its fully extended limit position and causing pressure buildup, thereby avoiding false alarms triggered by the torque limiting system.

[0007] Furthermore, the amplitude limiter includes a limit mounting plate, a displacement adjustment assembly, and a proximity switch. The limit mounting plate is installed on the top of the limiter bracket, and the proximity switch is mounted on the limit mounting plate through the displacement adjustment assembly. The rear end of the proximity switch is located to the left of the trigger ramp.

[0008] Furthermore, the displacement adjustment assembly includes an adjustment groove and an adjustment nut. The adjustment groove is provided on the limiting mounting plate. The adjustment groove is inclined with the left side lower than the right side. The front end of the proximity switch passes through the adjustment groove, and the proximity switch is threaded with adjustment nuts at the front and rear sides of the limiting mounting plate.

[0009] Loosening the adjusting nut on the proximity switch allows you to adjust its position within the adjusting groove. Then, tightening the adjusting nut repositions the proximity switch to the appropriate position on the limit mounting plate. This allows you to adjust the limiting position of the luffing boom, which in turn allows you to adjust the maximum limit on the extension distance of the luffing cylinder.

[0010] Furthermore, the system also includes an alarm mounting assembly and an alarm, with the alarm mounted on the side of the limiter bracket via the alarm mounting assembly. When the inclined contact proximity switch is triggered, the alarm will sound, alerting the crane operator.

[0011] Furthermore, the alarm mounting assembly includes screws and an alarm bracket. The alarm bracket is fixedly connected to the side of the limiter bracket by screws, and the alarm is mounted on the top of the alarm bracket. The screws are used to securely mount the alarm bracket, and the alarm bracket is used to support the alarm mounted on the side of the limiter bracket.

[0012] Furthermore, it also includes a mounting box and a controller. The mounting box is provided on the side of the luffing boom mounting bracket, and the controller is installed inside the mounting box. The mounting box is used to protect the controller, and the controller is used to receive the trigger signal of the proximity switch and then stop the luffing cylinder from extending further. It can also control the alarm to work after receiving the trigger signal of the proximity switch.

[0013] Compared with existing technologies, the beneficial effects of the limiting device for preventing overpressure at extreme positions of the luffing cylinder in this crane are:

[0014] 1. When the luffing cylinder extends, it pushes the right end of the luffing arm to lift. When the luffing cylinder extends to its longest working state, the trigger ramp on the luffing arm contacts the luffing limit switch. The luffing limit switch sends a signal to limit the luffing cylinder from extending further, preventing the luffing cylinder from running to its fully extended limit position and causing pressure buildup, thereby avoiding false alarms triggered by the torque limiting system.

[0015] 2. Prevent the luffing cylinder from reaching its limit position by stopping its movement before it reaches the limit position, thereby avoiding false triggering of the torque limit alarm. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model when it is not triggered;

[0017] Figure 2This utility model Figure 1 A magnified view of the structure at point A in the middle;

[0018] Figure 3 This is a schematic diagram of the structure of the present invention when it is triggered;

[0019] Figure 4 This utility model Figure 3 A magnified schematic diagram of the structure at point B in the middle;

[0020] In the diagram: 1 Turntable, 2 Turntable bracket, 3 Arm shaft, 4 Luffing boom, 5 Cylinder mounting shaft one, 6 Luffing cylinder, 7 Cylinder mounting shaft two, 8 Trigger ramp, 9 Cylinder end mounting seat, 10 Luffing boom mounting bracket, 11 Limiter bracket, 12 Limiter mounting plate, 13 Adjusting groove, 14 Adjusting nut, 15 Proximity switch, 16 Screw, 17 Alarm support, 18 Alarm, 19 Mounting box, 20 Controller. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figures 1 to 4 This utility model provides a technical solution: a limiting device for preventing the luffing cylinder of a crane from being squeezed at the extreme position, including a turntable bracket 2, the turntable bracket 2 is installed on a turntable 1, a luffing boom mounting bracket 10 is installed on the turntable bracket 2, the top of the luffing boom mounting bracket 10 is movably connected to the left end of the luffing boom 4 through a boom shaft 3, one end of the luffing cylinder 6 is movably connected to the turntable bracket 2, and the other end of the luffing cylinder 6 is movably connected to the right end of the luffing boom 4;

[0023] It also includes cylinder mounting shaft 1 5, cylinder mounting shaft 2 7 and cylinder end mounting seat 9. The turntable bracket 2 is movably connected to one end of the luffing cylinder 6 through cylinder mounting shaft 1 5. The right end of the luffing arm 4 is fixedly connected to the cylinder end mounting seat 9. The cylinder end mounting seat 9 is movably connected to the other end of the luffing cylinder 6 through cylinder mounting shaft 2 7.

[0024] A limiter bracket 11 is installed on the top of the luffing boom mounting bracket 10 at the position above the left of the boom shaft 3. A luffing limiter is installed on the limiter bracket 11. A trigger ramp 8 is provided on the upper left side of the luffing boom 4.

[0025] When the luffing cylinder 6 extends, it pushes the right end of the luffing arm 4 to lift. When the luffing cylinder 6 extends to its longest working state, the trigger ramp 8 on the luffing arm 4 contacts the luffing limit switch. The luffing limit switch sends a signal to limit the luffing cylinder 6 from extending further, preventing the luffing cylinder 6 from running to its fully extended limit position and causing pressure buildup, thereby avoiding false alarms triggered by the torque limiting system.

[0026] The amplitude limit switch includes a limit mounting plate 12, a displacement adjustment assembly, and a proximity switch 15. The limit mounting plate 12 is mounted on the top of the limit switch bracket 11. The proximity switch 15 is mounted on the limit mounting plate 12 via the displacement adjustment assembly. The rear end of the proximity switch 15 is located to the left of the trigger ramp 8.

[0027] The displacement adjustment assembly includes an adjustment groove 13 and an adjustment nut 14. The adjustment groove 13 is provided on the limit mounting plate 12. The adjustment groove 13 is inclined with the left side lower and the right side higher. The front end of the proximity switch 15 passes through the adjustment groove 13, and the adjustment nut 14 is threadedly connected to the position of the proximity switch 15 at the front and rear sides of the limit mounting plate 12 respectively.

[0028] Loosening the adjusting nut 14 on the proximity switch 15 allows adjustment of the position of the proximity switch 15 within the adjusting groove 13. Then, tightening the adjusting nut 14 re-fixes the proximity switch 15 to a suitable position on the limit mounting plate 12. This allows adjustment of the limiting position of the luffing arm 4, which in turn allows adjustment of the maximum limit on the extension distance of the luffing cylinder 6, thus achieving the purpose of adjustable sensing distance of the proximity switch 15.

[0029] It also includes an alarm mounting assembly and an alarm 18, with the alarm 18 mounted on the side of the limiter bracket 11 via the alarm mounting assembly. When the inclined plane 8 contacts the proximity switch 15, the alarm 18 can sound an alarm to alert the crane operator.

[0030] The alarm mounting assembly includes screws 16 and an alarm bracket 17. The alarm bracket 17 is fixedly connected to the side of the limiter bracket 11 by screws 16, and an alarm 18 is mounted on the top of the alarm bracket 17. Screws 16 are used to fix the alarm bracket 17 in place, and the alarm bracket 17 is used to support the alarm 18 on the side of the limiter bracket 11.

[0031] It also includes a mounting box 19 and a controller 20. The mounting box 19 is provided on the side of the luffing boom mounting bracket 10, and the controller 20 is installed inside the mounting box 19. The mounting box 19 is used to protect the controller 20. The controller 20 is used to receive the trigger signal of the proximity switch 15 and then stop the luffing cylinder 6 from extending further. It can also control the alarm 18 to work after receiving the trigger signal of the proximity switch 15.

[0032] When the luffing cylinder 6 extends to its longest working state, the inclined plane 8 contacts the rear end of the proximity switch 15 in the luffing limiter. The proximity switch 15 is in the triggered state and outputs a high-level or low-level trigger signal, which is sent to the controller 20. The controller 20 controls the alarm 18 to work, and at the same time, the controller 20 controls the luffing cylinder 6 to stop extending further. That is, the controller 20 limits the luffing cylinder 6's starting action to prevent the luffing cylinder 6 from running to its fully extended limit position and causing a pressure build-up situation (if pressure build-up occurs, it will cause the torque limiting system to falsely trigger the alarm). After the limit device is triggered, the luffing arm 4 can only move in the retracting direction.

[0033] It is worth noting that the controller 20 disclosed in the above embodiments is a PLC controller. The output terminal of the controller 20 is electrically connected to the input terminal of the alarm 18. The alarm 18 is an audible and visual alarm. The controller 20 controls the operation of the luffing cylinder 6 and the alarm 18 using methods commonly used in the prior art.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] 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 which is defined by the appended claims and their equivalents.

Claims

1. A limiting device for preventing overpressure at extreme positions of a luffing cylinder for a crane, comprising a turntable support (2), wherein a luffing boom mounting bracket (10) is mounted on the turntable support (2), and the top of the luffing boom mounting bracket (10) is movably connected to the left end of a luffing boom (4) via a boom shaft (3), characterized in that, The turntable support (2) is movably connected to one end of the luffing cylinder (6), and the other end of the luffing cylinder (6) is movably connected to the right end of the luffing arm (4); The top of the luffing arm mounting bracket (10) is located at the upper left of the arm shaft (3) and a limiter bracket (11) is installed. A luffing limiter is installed on the limiter bracket (11) and a trigger ramp (8) is provided on the upper left side of the luffing arm (4).

2. The limiting device for preventing overpressure at extreme positions of a crane luffing cylinder according to claim 1, characterized in that: The amplitude limiter includes a limit mounting plate (12), a displacement adjustment component and a proximity switch (15). The limit mounting plate (12) is mounted on the top of the limiter bracket (11). The proximity switch (15) is mounted on the limit mounting plate (12) through the displacement adjustment component. The rear end of the proximity switch (15) is located to the left of the trigger ramp (8).

3. A limiting device for preventing overpressure at extreme positions in a crane luffing cylinder according to claim 2, characterized in that: The displacement adjustment assembly includes an adjustment groove (13) and an adjustment nut (14). The adjustment groove (13) is provided on the limiting mounting plate (12). The adjustment groove (13) is inclined with the left side lower and the right side higher. The front end of the proximity switch (15) passes through the adjustment groove (13), and the proximity switch (15) is threaded with the adjustment nut (14) at the front and rear sides of the limiting mounting plate (12).

4. A limiting device for preventing overpressure at extreme positions in a crane luffing cylinder according to claim 1, characterized in that: It also includes an alarm mounting assembly and an alarm (18), with the alarm (18) mounted on the side of the limiter bracket (11) via the alarm mounting assembly.

5. A limiting device for preventing overpressure at extreme positions in a crane luffing cylinder according to claim 4, characterized in that: The alarm mounting assembly includes screws (16) and an alarm bracket (17). The side of the limiter bracket (11) is fixedly connected to the alarm bracket (17) by screws (16), and an alarm (18) is mounted on the top of the alarm bracket (17).

6. A limiting device for preventing overpressure at extreme positions in a crane luffing cylinder according to claim 1, characterized in that: It also includes a mounting box (19) and a controller (20). The mounting box (19) is provided on the side of the luffing boom mounting frame (10), and the controller (20) is installed inside the mounting box (19).

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