Torque protection system of miniature crawler crane

Abstract

The invention relates to the technical field of special equipment, in particular to a miniature crawler crane torque protection system which comprises a measuring system, a height limiting system, a steel wire rope online detection system and an emergency braking system. The measuring system is used for measuring torque, the height limiting system is used for limiting the lifting height of a hook, the steel wire rope online detection system is used for online detection of steel wire rope abrasion, and the emergency braking system comprises a three-pulley sensor, a transmission mechanism and a brake. The brake is driven to act through the transmission mechanism, and the steel wire rope is clamped. By measuring the torque, it is guaranteed that the torque is within a proper range, the use safety is further guaranteed through height limiting and steel wire rope online detection, an emergency braking system is finally guaranteed through a mechanical means, the positive effect on limiting the running speed and equipment faults is achieved, and the safety and reliability of the device are improved. And the use safety is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of special equipment, and in particular to a torque protection system for a mini crawler crane. Background Art

[0002] The mini crawler crane is also called spider crane or spider crane because its appearance after the four legs are stretched out resembles a spider. Compared with other large cranes, the mini crawler crane has a compact structure and can be moved by itself on the construction site, or enter a small space for indoor lifting operations. It has high work efficiency and makes construction more convenient. The mini crawler crane has good stability, large load capacity, good anti-slip performance, and a wide range of applications. It is often suitable for large-scale material storage, large-scale production and manufacturing and other industries. It is operated by a wireless remote control or a fuselage switch, has a fast operating speed, a miniature design, a small size, and a strong lifting capacity. It bids farewell to the era when work in narrow spaces could only rely solely on manpower, which not only improves work efficiency but also ensures work safety.

[0003] Due to its compact structure, the mini crawler crane generally has a load capacity of 3 to 5 tons. Objects that are too heavy are not suitable for its use. Overloading may occur if the crane is not handled with care, which may easily lead to safety accidents. Therefore, existing mini crawler cranes are generally equipped with a torque protection system, which limits the torque to avoid overloading and ensure safety in use.

[0004] Torque is a physical concept, that is, the product of force and lever arm. Therefore, existing mini crawler cranes are generally equipped with rope sensors and tension sensors. Existing rope sensors generally have angle measurement functions, which can realize the measurement of arm elongation and arm inclination. Tension sensors can measure the tension of wire ropes. They have various specifications and models, including side pressure weight sensors, three-pulley tension sensors, and plate ring tension sensors. By measuring the rope tension, arm elongation, and inclination, the torque at this time can be calculated and compared with the set torque. When the limit is exceeded, an alarm will be triggered to warn the operator and ensure operation safety.

[0005] However, the above is only the most basic protection for torque. In actual operation, the on-site environment of the equipment is complex and changeable. On the one hand, the hook may easily touch the top due to viewing angle problems. At this time, the torque will not increase, but the weight may indeed fall off. At the same time, local tension may change due to wire rope wear, etc., causing fluctuations in torque detection and even serious safety hazards. In addition, the change in torque is also related to the speed change during operation. For example, when a weight drops rapidly and then stops suddenly, it is easy to cause torque overload due to inertia, causing safety accidents. Moreover, it is not uncommon for heavy objects to fall directly due to equipment damage.

[0006] It can be seen that the existing torque protection system alone does not adequately protect the torque of the crawler crane, and there are still many potential safety hazards in the process, which seriously affect the safety of life and property of the operators. Therefore, a torque protection system that can more comprehensively protect the torque of the micro crawler crane is an issue that needs to be urgently resolved. Summary of the invention

[0007] The purpose of the present invention is to provide a mini crawler crane torque protection system to solve the problem that the existing torque protection system still has great potential safety hazards and seriously affects the safety of life and property of operators.

[0008] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a mini crawler crane torque protection system, including a measuring system, a height limit system, an online wire rope detection system and an emergency braking system; the measuring system includes a tension measurement system, an arm extension measurement system and an angle measurement system; the emergency braking system cooperates with the tension measurement system; the measuring system, the height limit system and the online wire rope detection system are connected to a data processing system, and the data processing system is respectively connected to an alarm system and a display system.

[0009] Furthermore, the tension measurement system includes a three-pulley tension sensor; the arm extension measurement system includes a wire displacement sensor; the angle measurement system includes an inclination sensor; the wire rope online detection system includes a wire rope online detection device; the emergency braking system includes a brake; and the three-pulley tension sensor cooperates with the brake.

[0010] Furthermore, the three-pulley tension sensor includes a force-bearing wheel located in the middle and guide wheels located on both sides, the force-bearing wheel is connected to the axle pin type sensor, and the guide wheel on one side cooperates with the brake through a transmission mechanism.

[0011] Furthermore, the brake comprises a clamping plate and an eccentric clamping wheel, the rotating shaft of the eccentric clamping wheel cooperates with the transmission mechanism, clamping teeth are arranged on the outer periphery of the eccentric clamping wheel, a matching plate is arranged in the clamping plate, and the clamping teeth cooperate with the matching plate.

[0012] Furthermore, a fixing plate is provided in the clamping plate, the fixing plate is fixedly connected to the boom of the mini crawler crane, the matching plate is connected to the fixing plate, and rope guide holes are provided on both sides of the fixing plate.

[0013] Furthermore, the eccentric clamping wheel has its rotation axis at the farthest point from the periphery as a reference point, and the clamping teeth are arranged within an angle range of [0, 60-90°] on both sides of the reference point, and the angle range is established with the center of the circle where the eccentric clamping wheel is located as the center point.

[0014] Furthermore, when the reference point is closest to the matching plate, the distance between the reference point and the matching plate is 1 / 2 to 2 / 3 of the diameter of the wire rope.

[0015] Furthermore, the transmission mechanism includes a power generation device, which cooperates with the rotating shaft of the guide wheel on one side, the power generation device is connected to the electromagnet, the electromagnet cooperates with the suction part, and the suction part is connected to the rotating shaft of the eccentric clamping wheel.

[0016] Furthermore, the rotating shaft of the eccentric clamping wheel is connected to the first hinged rod, the first hinged rod is hinged to the second hinged rod, the suction part is located at the front end of the second hinged rod and connected to the second hinged rod, the first hinged rod is connected to the spring, and the other end of the spring is connected to the fixed rod.

[0017] Beneficial effects of the present invention:

[0018] 1. It can measure the torque and limit the hook height, and perform online detection of wire rope wear, ensuring the safe and stable use of the mini crawler crane;

[0019] 2. The three-pulley tension sensor is linked to the brake and a mechanical braking mechanism is used. When the pulley rotates too fast, it can drive the generator to generate current, so that the electromagnet can act on the eccentric pulley. When the magnetic force of the electromagnet reaches a certain level, the eccentric pulley and the wire rope fit closely together, which can mechanically lock the wire rope to prevent the heavy object from continuing to fall, thereby further improving the safety of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the system architecture of the present invention;

[0021] Figure 2 It is a schematic diagram of the installation of the system of the present invention;

[0022] Figure 3 It is a schematic diagram of the overall structure of the detection brake device of the present invention;

[0023] Figure 4 It is a schematic diagram of the external structure of the brake of the present invention;

[0024] Figure 5 It is a schematic diagram of the structure when the eccentric clamping wheel and the clamping plate in the brake of the present invention cooperate;

[0025] Figure 6 It is a schematic diagram of the transmission mechanism structure of the present invention (unmatched state);

[0026] Figure 7 It is a schematic diagram of the transmission mechanism structure of the present invention (matching state).

[0027] The names corresponding to the marks in the figure are:

[0028] 1. Pull-wire displacement sensor; 2. Detection brake device; 21. Mounting plate; 22. Mounting box; 23. Three-pulley tension sensor; 231. Guide wheel; 232. Force wheel; 2321. Axle pin sensor; 24. Brake; 241. Clamping plate; 2411. Fixed plate; 2412. Matching plate; 2413. Rope guide hole; 242. Eccentric clamping wheel; 2421. Clamping teeth; 3. Online detection device for wire rope; 4. Height limit switch; 5. Winch; 6. Transmission mechanism; 61. Power generation device; 62. Electromagnet; 63. Fixed rod; 64. Spring; 65. First hinged rod; 66. Second hinged rod; 67. Suction part. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] like Figure 1 As shown, the torque protection system of the present invention involves torque measurement, height protection, wire rope status detection and mechanical emergency braking, wherein for torque measurement, it includes a tension measurement system, an angle measurement system and an arm elongation measurement system, the height protection includes a height limit system, the wire rope status detection includes a wire rope online detection system, the tension measurement system, the angle measurement system, the arm elongation measurement system, the height limit system and the wire rope online detection system are respectively connected to the data processing system, and the data processing system is respectively connected to the alarm system and the display system.

[0031] like Figure 2-7 As shown, a winch 5 connected to a wire rope is arranged on the boom of the mini crawler crane, wherein a pull-wire displacement sensor 1, a detection brake device 2 and a wire rope online monitoring device 3 are respectively installed on the boom in conjunction with the wire rope, and a height limit switch 4 is arranged above the hook.

[0032] The detection brake device 2 includes a mounting plate 21, which is fixedly connected to the boom of the mini crawler crane. A mounting box 22 is arranged on the mounting plate 21, wherein a three-pulley tension sensor 23 is arranged in the mounting box 22. The three-pulley tension sensor 23 includes a force-bearing wheel 232 in the middle and guide wheels 231 on both sides. The force-bearing wheel 232 is connected to the axle pin sensor 2321, and the guide wheel 231 on one side is connected to the brake device 24 through a transmission mechanism 6.

[0033] A generator 61 is provided in the transmission mechanism 6, and the generator 61 cooperates with the guide wheel 231 on one side, wherein the rotating shaft of the guide wheel 231 is connected to the rotor of the generator 61, and the stator of the generator 61 is sleeved on the outside of the rotor, the generator 61 is connected to the electromagnet 62, and the electromagnet 62 cooperates with the suction part 67, wherein a fixed rod 63 is provided in the transmission mechanism 6, the fixed rod 63 is connected to the first hinged rod 65, the first hinged rod 65 is hinged to the second hinged rod 66, the suction part 67 is connected to the second hinged rod 66, and the first hinged rod 65 is provided to be connected to the transmission shaft of the eccentric clamping wheel 242 in the braking device 24.

[0034] The eccentric clamping wheel 242 is provided with clamping teeth 2421 on its outer periphery, and the eccentric clamping wheel 242 is matched with the clamping plate 241, wherein the eccentric clamping wheel 242 takes the farthest point of its rotation axis from the periphery as the reference point, and the clamping teeth 2421 are arranged within the angle range of [0, 60~90°] on both sides of the reference point, and the angle range is established with the center of the circle where the eccentric clamping wheel 242 is located as the center point.

[0035] A fixing plate 2411 is provided in the clamping plate 241, the fixing plate 2411 is connected to the boom of the mini crawler crane, the fixing plate 2411 is connected to the matching plate 2412, the matching plate 2412 matches with the eccentric clamping wheel 242, when the reference point is closest to the matching plate 2412, the distance between the reference point and the matching plate 2412 is 1 / 2 to 2 / 3 of the diameter of the wire rope, and rope guide holes 2413 are provided on both sides of the fixing plate 2411.

[0036] The principle of the present invention is:

[0037] When the present invention is in use, a detection brake device 2 and a wire rope online detection device 3 are installed on the boom of the mini crawler crane, and a height limit switch 4 is installed above the hook. During the process, since the wire displacement sensor 1 is generally existing, it can be directly used, and the existing wire displacement sensor 1 generally has an inclination sensor, therefore, the arm extension and inclination can be directly measured. When the wire displacement sensor 1 does not have an inclination sensor, it is necessary to install an inclination sensor separately. The wire displacement sensor 1 and the inclination sensor are both existing mature equipment, and their structural principles are not repeated here.

[0038] At the same time, the above-mentioned online detection device 3 for the wire rope and the height limit switch 4 are also existing. The online detection device 3 for the wire rope utilizes weak magnetic detection technology and the height limit switch 4 utilizes a tension sensor, etc. Since they are existing mature equipment technologies, their structural principles are not difficult to understand for those skilled in the art and will not be repeated here.

[0039] The three-pulley tension sensor 23 is used to detect the tension of the wire rope. The detection principle of the three-pulley tension sensor 23 is based on the axle pin type sensor 2321. Since it is already available, it will not be described in detail. In the process, the torque M when hoisting the heavy object can be obtained according to the detection data:

[0040] M=FL cosθ

[0041] Where: F is the tension of the wire rope;

[0042] L is the length of the boom extension;

[0043] θ is the inclination angle of the boom.

[0044] Compare the torque M with the set torque. For the set torque, generally take 80% of the maximum value of the torque. The maximum torque M max That is, it is measured when the arm is extended to the longest state and in a horizontal state, that is:

[0045] M max =0.8F max L max

[0046] Where: F max is the maximum tension of the wire rope;

[0047] L max It is the maximum length of the boom extension.

[0048] Since the arm extension is generally in a short state at the beginning of lifting, the actual control logic is to calculate the weight of the heavy object through the tension of the wire rope during the initial lifting, and then bring it into the calculation formula of the maximum torque to determine whether it is overloaded during lifting. According to the above formula, it can be seen that due to the setting of a certain design margin, the torque protection system of the mini crawler crane can protect the operation safety well in actual work.

[0049] However, in actual operations, due to the complex and changeable on-site operating conditions, many factors need to be considered. The tension of the wire rope will decrease when the hook touches the top. At this time, the torque detection will not trigger an alarm, and the weight is at risk of falling off due to the hook touching the top. When the wire rope is locally worn or broken, the local tension will increase, which may easily lead to breakage accidents. At the same time, due to equipment failure, the weight falls quickly, and when the weight drops quickly and then stops suddenly during operation, inertia may also cause torque overload in an instant, thereby causing safety accidents.

[0050] It can be seen that due to the complex and changeable situations in the actual operation process, the protection of torque through the basic torque protection system still has a greater risk. For example, if the mass of the heavy object is m, it is quickly lowered at a speed v, but it stops suddenly at a certain moment t. At this time, the acceleration of the heavy object is (with the downward vector as positive):

[0051]

[0052] The negative sign in the above formula only indicates the direction. The direction of acceleration a is upward at this time, and the tension of the wire rope is (with the upward vector as positive):

[0053] F=mg+ma

[0054] Then the moment M is:

[0055] M=(mg+ma)L cosθ

[0056] If at this time:

[0057] M=(mg+ma)Lcosθ>M max / 0.8=F max L max

[0058] The instantaneous torque will be greater than the maximum torque of the mini crawler crane, and there will be a risk of overload.

[0059] Therefore, in the technical solution of the present invention, the height of the hook is limited by the height limit switch 4 to prevent the heavy object from touching the top, and the state of the wire rope is detected in real time to avoid safety accidents caused by wear and breakage of the wire rope due to long-term use. At the same time, the brake 24 is used to brake the wire rope when the descending speed is too fast, which can effectively avoid the safety hazards caused by wire rope breakage and the rapid descent and subsequent sudden stop of the heavy object.

[0060] During the process, when the heavy object descends rapidly, the wire rope will drive the guide wheel 231 to rotate, and the rotation of the guide wheel 231 will cause the generator 61 to generate electricity, and the generated electricity will act on the electromagnet 62. The faster the guide wheel 231 rotates, the greater the electricity generated at this time, and the stronger the magnetic force of the electromagnet 62. When the magnetic force of the electromagnet 62 exceeds the elastic force of the spring when it is stretched, the eccentric clamping wheel 242 will move to contact the wire rope, and then driven by the wire rope, the eccentric clamping wheel 242 will rotate instantly to clamp the wire rope, thereby preventing the heavy object from continuing to fall off, thereby ensuring the safety of the operation.

[0061] During the process, the power generation device 61 can be a rectangular coil cutting the magnetic flux lines. If the length of the coil is l and the width is w, where the length direction is the direction of cutting the magnetic flux lines, and the magnetic field strength is B, the limit speed of the wire rope falling is set to v, that is, at this speed, the electromagnet 62 can drive the eccentric card wheel 242 to move, and the rotation speed of the guide wheel 231 is:

[0062]

[0063] Where: n is the speed of the guide wheel rotation, r / s;

[0064] D is the diameter of the eccentric pulley, m.

[0065] The speed of the guide wheel 231 is consistent with the speed of the coil, so the speed v at which the coil cuts the magnetic flux lines is 切割 for:

[0066] v 切割 =nw

[0067] The induced current I at this time is:

[0068]

[0069] Where R is the resistance of the coil.

[0070] It can be seen that only the speed v is a variable in the formula, and they are all constants. That is, as the maximum speed V of the wire rope increases, the induced current will also become larger and larger.

[0071] At this time, the magnetic field generated by the electromagnet 62 will also increase with the increase of current. When it is at the limit speed v, the electromagnet 62 can attract the suction part 67 to move, thereby driving the eccentric clamping wheel 242 to contact the wire rope, thereby achieving the jamming of the wire rope. It should be noted that as long as the guide wheel 231 rotates, a magnetic field will be generated in the electromagnet 62, and the suction part 67 will move at this time. However, when the magnetic field is small, the suction part 367 is restrained by the tension of the spring 64 and cannot move significantly. Therefore, the eccentric clamping wheel 242 only rotates slightly and does not contact the wire rope, thereby not triggering locking. When the suction force is greater than the tension of the spring 64 after deformation, the suction part 67 will move significantly (the suction part 67 does not have to contact the electromagnet 62), thereby driving the eccentric clamping wheel 242 to contact the wire rope, thereby triggering locking.

[0072] When the locking is triggered, the latching teeth 2421 are tightly engaged with the wire rope. Since the mass of the heavy object provides a downward pulling force, the wire rope tends to drive the eccentric clamping wheel 242 to rotate. Even if the electromagnet 62 has lost its magnetic field, this downward pulling force will make the eccentric clamping wheel 242 more stably fixed, thereby ensuring greater safety in use. When the fault is eliminated, you only need to lift the heavy object. At this time, the wire rope moves upward to drive the eccentric clamping wheel 242 to rotate. Since there is no magnetic field, the spring 64 drives the suction part 67 to reset. At this time, the eccentric clamping wheel 242 will also return to its original position, thereby releasing the locking. At this time, normal operation can continue. However, it should be noted that if the latching teeth of the eccentric clamping wheel 242 cause damage to the wire rope, it needs to be replaced at the end of the operation to ensure operation safety.

[0073] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A mini crawler crane torque protection system, characterized in that: It includes a measuring system, a height limit system, an online wire rope detection system and an emergency braking system; the measuring system includes a tension measuring system, an arm extension measuring system and an angle measuring system; the emergency braking system cooperates with the tension measuring system; the measuring system, the height limit system and the online wire rope detection system are connected to the data processing system, and the data processing system is respectively connected to the alarm system and the display system.

2. A mini crawler crane torque protection system according to claim 1, characterized in that: The tension measurement system comprises a three-pulley tension sensor (23); the arm extension measurement system comprises a wire displacement sensor (1); the angle measurement system comprises an inclination sensor; the wire rope online detection system comprises a wire rope online detection device (3); the emergency braking system comprises a brake (24), and the three-pulley tension sensor (23) cooperates with the brake (24).

3. The mini crawler crane torque protection system according to claim 2, characterized in that: The three-pulley tension sensor (23) includes a force-bearing wheel (232) located in the middle and guide wheels (231) located on both sides. The force-bearing wheel (232) is connected to the axle pin type sensor (2321), and the guide wheel (231) on one side cooperates with the brake (24) through a transmission mechanism (6).

4. The mini crawler crane torque protection system according to claim 3, characterized in that: The brake (24) comprises a clamping plate (241) and an eccentric clamping wheel (242); the rotating shaft of the eccentric clamping wheel (242) cooperates with the transmission mechanism (6); a clamping tooth (2421) is arranged on the outer periphery of the eccentric clamping wheel (242); a matching plate (2412) is arranged in the clamping plate (241); and the clamping tooth (2421) cooperates with the matching plate (2412).

5. The mini crawler crane torque protection system according to claim 4, characterized in that: The clamping plate (241) is provided with a fixing plate (2411), the fixing plate (2411) is fixedly connected to the boom of the mini crawler crane, the matching plate (2412) is connected to the fixing plate (2411), and rope guide holes (2413) are provided on both sides of the fixing plate (2411).

6. The mini crawler crane torque protection system according to claim 4, characterized in that: The eccentric clamping wheel (242) takes the farthest point of its rotation axis from the periphery as a reference point, and the clamping teeth (2421) are arranged within an angle range of [0, 60-90°] on both sides of the reference point, and the angle range is established with the center of the circle where the eccentric clamping wheel (242) is located as the center point.

7. A mini crawler crane torque protection system according to claim 6, characterized in that: When the reference point is closest to the matching plate (2412), the distance between the reference point and the matching plate (2412) is 1 / 2 to 2 / 3 of the diameter of the wire rope.

8. The mini crawler crane torque protection system according to claim 4, characterized in that: The transmission mechanism (6) includes a power generation device (61), the power generation device (61) cooperates with the rotating shaft of the guide wheel (231) on one side, the power generation device (61) is connected to the electromagnet (62), the electromagnet (62) cooperates with the suction part (67), and the suction part (67) is connected to the rotating shaft of the eccentric clamping wheel (242).

9. A mini crawler crane torque protection system according to claim 8, characterized in that: The rotating shaft of the eccentric clamping wheel (242) is connected to the first hinge rod (65), the first hinge rod (65) is hinged to the second hinge rod (66), the suction part (67) is located at the front end of the second hinge rod (66) and is connected to the second hinge rod (66), the first hinge rod (65) is connected to the spring (64), and the other end of the spring (64) is connected to the fixed rod (63).

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