Grab bucket lifting system and lifting machinery

Abstract

The present invention discloses a grab bucket lifting system and lifting machinery, the grab bucket lifting system includes a grab bucket device, a main lifting device and an auxiliary lifting device, the lifting connecting piece of the grab bucket device is fixedly arranged at the upper end of the grab bucket body, the opening and closing rope can drive the grab bucket body to switch between an unloading open state and a grabbing closed state, the main lifting rope of the main lifting device is connected to the lifting connecting piece through a main lifting pulley group, and the auxiliary lifting rope of the auxiliary lifting device is connected to the opening and closing rope through the auxiliary lifting pulley group. When the grab bucket body is in the unloading open state, the auxiliary lifting pulley group is located above the main lifting pulley group, and the first releasing length of the opening and closing rope is set to make the lateral spacing between the auxiliary lifting pulley group and the main lifting rope greater than or equal to the maximum offset distance of the main lifting rope under the action of the lateral deflection force, thereby making it possible to avoid the phenomenon of the pulley hook wearing the lifting rope while lifting the lifting weight of the grab bucket body.

Description

Technical Field

[0001] The present invention belongs to the technical field of lifting machinery, and in particular relates to a grab bucket lifting system and a lifting machinery. Background Art

[0002] Cranes are often used for lifting, transporting, loading and unloading, and installing large-tonnage materials at construction sites. However, with the expansion and extension of operating scenarios, the functions of cranes have also been further expanded, and they are used for loading and unloading and transporting materials by connecting grabs and other grabbing devices.

[0003] Currently, crane grabs can be categorized by drive type into mechanically driven grabs, electric grabs, and electro-hydraulic grabs. Mechanically driven grabs use opening and closing wire ropes to control the opening and closing of the bucket. Because they do not require external power, they are widely used in cranes. However, due to the small distance between the main and auxiliary lifting wire ropes of a mechanical grab, when connecting the grab, the auxiliary lifting wire rope connecting the opening and closing wire ropes is typically set to a single ratio to prevent the pulley hook on one lifting wire rope from abrading the other. However, this results in the crane's maximum lifting weight being determined by the single-rope tension of the auxiliary lifting wire rope, resulting in a low grab lifting capacity. Summary of the Invention

[0004] In response to the above-mentioned defects or shortcomings, the present invention provides a grab bucket lifting system and lifting machinery, which aims to solve the technical problem that the auxiliary lifting wire rope is set to a single ratio to prevent the lifting wire rope from being worn by the pulley hook on the other lifting wire rope, thereby resulting in a small grab bucket lifting weight.

[0005] To achieve the above-mentioned objectives, the first aspect of the present invention provides a grab bucket lifting system, wherein the grab bucket lifting system includes a grab bucket device, a main lifting device and an auxiliary lifting device; the grab bucket device includes a grab bucket body, a lifting connecting piece and an opening and closing rope, the lifting connecting piece is fixedly arranged at the upper end of the grab bucket body, and the opening and closing rope can drive the grab bucket body to switch between an unloading open state and a grabbing closed state; the main lifting device is arranged on the lifting machinery body, and the main lifting rope of the main lifting device is connected to the lifting connecting piece through a main lifting pulley group; the auxiliary lifting device is arranged on the lifting machinery body, and the auxiliary lifting rope of the auxiliary lifting device is connected to the opening and closing rope through the auxiliary lifting pulley group; when the grab bucket body is in the unloading open state, the auxiliary lifting pulley group is located above the main lifting pulley group, and the first release length of the opening and closing rope is set to make the lateral spacing between the auxiliary lifting pulley group and the main lifting rope greater than or equal to the maximum deflection distance of the main lifting rope under the action of the lateral deflection external force.

[0006] In one embodiment of the present invention, the calculation formula for the maximum deflection distance Lp is set as:

[0007] Lp=H' / tanθ;

[0008] Where H' represents the height from the grab bucket to the boom head, and θ represents the maximum deflection angle of the main hoist rope under the action of the lateral deflection external force;

[0009] The calculation formula for the maximum deflection angle θ is set as:

[0010] θ=arctan[(mω 2 (La+L'×cosɑ)+F' max ) / mg];

[0011] Where m is the weight of the grab bucket and the object being grabbed, ω is the angular velocity of the crane, La is the lateral distance between the boom hinge point and the center of rotation of the crane, L' is the length of the boom, ɑ is the horizontal angle of the boom, and F' is the horizontal angle of the boom. max It is expressed as the maximum value of the wind load on the grab body, and g is expressed as the acceleration due to gravity.

[0012] In one embodiment of the present invention, the maximum value F' of the wind load on the grab bucket body max Set as:

[0013] F' max =n×(mω 2 (La+L'×cosɑ));

[0014] Where m is the weight of the grab bucket and the grabbed object, ω is the angular velocity of the crane, La is the lateral distance between the boom hinge point and the center of rotation of the crane, L' is the length of the boom, ɑ is the horizontal angle of the boom, and n is set between 0.1 and 0.3.

[0015] In one embodiment of the present invention, the first release length L1 is set to satisfy:

[0016]

[0017] Where, H' represents the height from the grab body to the boom head, Lc represents the pulley center distance between the first fixed pulley on the boom head and the second fixed pulley on the goose head frame, ɑ represents the horizontal angle of the boom, β represents the angle between the pulley center line of the first fixed pulley and the second fixed pulley and the boom axis, Hh1 represents the total width of the auxiliary lifting pulley group, It represents the width of the pulley body of the main hoisting pulley group, and θ represents the maximum deflection angle of the main hoisting rope under the action of the lateral deflection external force.

[0018] In one embodiment of the present invention, the height H' from the grab body to the boom head is set to be equal to the vertical height of the boom, and the first release length L1 is further set to satisfy:

[0019]

[0020] Where, L' is the arm length of the boom, Lc is the pulley center distance between the first fixed pulley on the boom head and the second fixed pulley on the goose head frame, ɑ is the horizontal angle of the boom, β is the angle between the pulley center line of the first fixed pulley and the second fixed pulley and the boom axis, Hh1 is the total width of the auxiliary lifting pulley group, It represents the width of the pulley body of the main hoisting pulley group, and θ represents the maximum deflection angle of the main hoisting rope under the action of the lateral deflection external force.

[0021] In one embodiment of the present invention, the length L* of the lifting connection is set to satisfy:

[0022] L*≥max[(Hh2×arctan(ɑ-β) / 2), (Hh2×arcsin(ɑ-β) / 2)];

[0023] Where Hh2 is the total width of the main hoist pulley group, ɑ is the horizontal angle of the boom, and β is the angle between the center line of the first and second fixed pulleys and the boom axis.

[0024] In one embodiment of the present invention, the opening and closing rope includes a base section and an extension section. The base section can drive the grab bucket to switch between an unloading open state and a grabbing closed state. The extension section is detachably arranged between the base section and the auxiliary lifting pulley group to extend the release length of the opening and closing rope, and the number of extension sections used is determined according to the arm length of the lifting arm on the lifting machinery body.

[0025] In one embodiment of the present invention, a wear-resistant roller is provided on a side of the main lifting pulley block and / or the auxiliary lifting pulley block close to the other lifting device.

[0026] In one embodiment of the present invention, the main lifting pulley block and / or the auxiliary lifting pulley block are both configured as multi-rate pulley blocks.

[0027] In one embodiment of the present invention, the grab bucket lifting system further includes a control device, which is communicatively connected to the lifting drive components of the main lifting device and the auxiliary lifting device and is configured to:

[0028] When it is determined that the grab body is switched to the grab closed state, if a first control instruction for increasing the pulley height difference is received, the lifting drive component is controlled to prohibit execution of the first control instruction, wherein the pulley height difference is set to the height difference between the main lifting pulley group and the auxiliary lifting pulley group;

[0029] When it is determined that the grab body is switched to the unloading open state, if a second control instruction for reducing the pulley height difference is received, the lifting drive component is controlled to prohibit execution of the second control instruction.

[0030] In one embodiment of the present invention, the control device is further configured to:

[0031] When it is determined that the grab body is switched to the grab closed state, if a third control instruction for reducing the pulley height difference is received, the lifting drive component is controlled to execute the third control instruction;

[0032] When it is determined that the grab bucket body is switched to the unloading open state, if a fourth control instruction for increasing the pulley height difference is received, the lifting drive component is controlled to execute the fourth control instruction.

[0033] In one embodiment of the present invention, the control device includes a controller, a first detector, and a second detector. The first detector and the second detector are used to determine the positions of the main lifting pulley assembly and the auxiliary lifting pulley assembly in a one-to-one correspondence. The controller is communicatively connected to the first detector, the second detector, and the lifting drive components of the main lifting device and the auxiliary lifting device, respectively, and is configured as follows:

[0034] receiving detection data from the first detector and the second detector respectively;

[0035] Determine the pulley height difference based on the test data;

[0036] When the height difference of the pulleys reaches a preset maximum height difference, the grab body is determined to switch to a grab closed state;

[0037] When the pulley height difference reaches a preset minimum height difference, the grab body is determined to be switched to the unloading open state.

[0038] In one embodiment of the present invention, the first detector is configured as a first encoder installed on the lifting drive member of the main lifting device; and / or, the second detector is configured as a second encoder installed on the lifting drive member of the auxiliary lifting device.

[0039] To achieve the above object, a second aspect of the present invention provides a lifting machinery, wherein the lifting machinery includes the grab bucket hoisting system described above.

[0040] Through the above technical solution, the grab bucket lifting system provided by the present invention has the following beneficial effects:

[0041] When the grab bucket hoisting system is used, the main hoisting rope of the main hoisting device is connected to the hoisting connector on the grab bucket device via the main hoisting pulley block, and the auxiliary hoisting rope of the auxiliary hoisting device is connected to the opening and closing rope on the grab bucket device via the auxiliary hoisting pulley block. This allows both the main hoisting rope and the auxiliary hoisting rope to be set to a ratio of more than two, thereby achieving the purpose of lifting the weight of the grab bucket. At the same time, the length of the opening and closing rope released from the grab bucket is limited to ensure that the auxiliary hoisting pulley block does not rub against the main hoisting rope. Specifically, when the grab bucket is in the unloaded open state, the first length of the opening and closing rope released from the grab bucket is limited. At this time, the lateral spacing between the auxiliary hoisting pulley block and the main hoisting rope is minimized. If the auxiliary hoisting pulley block can be guaranteed to not rub against the main hoisting rope at this time, the main hoisting rope will not be rubbed during the lifting stroke of the auxiliary hoisting pulley block. More specifically, when the grab bucket is in the unloaded open state, the position of the auxiliary hoisting pulley block is first adjusted. Limiting it on the main lifting pulley block is equivalent to setting the first pay-out length limit of the opening and closing rope extending from the grab bucket body to be greater than the length of the lifting connector, and further directly limiting the first pay-out length can make the lateral spacing between the auxiliary lifting pulley block and the main lifting rope greater than or equal to the maximum deflection distance of the main lifting rope under the action of the lateral deflection external force. In this way, even if the main lifting rope deflects, the auxiliary lifting pulley block will not wear against the main lifting rope. In this way, while lifting the lifting weight of the grab bucket body, the pulley hook will not wear against the lifting rope.

[0042] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without inventive work. In the accompanying drawings:

[0044] Figure 1 is a structural diagram of a lifting machine according to an embodiment of the present invention;

[0045] Figure 2 yes Figure 1 Schematic diagram of the enlarged structure at A in the middle;

[0046] Figure 3 yes Figure 1 Schematic diagram of the enlarged structure at B in the middle;

[0047] Figure 4 2. It is a structural schematic diagram of a grab bucket body in an unloading open state according to an embodiment of the present invention;

[0048] Figure 5 is a structural schematic diagram of a grab bucket body in a grabbing closed state according to an embodiment of the present invention;

[0049] Figure 6 2 is a schematic structural diagram of a main lifting pulley assembly or an auxiliary lifting pulley assembly according to an embodiment of the present invention;

[0050] Figure 7 2 is a schematic structural diagram of an opening and closing rope according to an embodiment of the present invention;

[0051] Figure 8 is a first dimensioned view of an embodiment of the present invention in which the grab bucket is in an unloading open state and the main hoisting pulley assembly is located on a center perpendicular line of the first fixed pulley;

[0052] Figure 9 is a first dimensioned view of an embodiment of the present invention in which the grab bucket is in an unloading open state and the auxiliary lifting pulley assembly is located on a center perpendicular line of the second fixed pulley;

[0053] Figure 10 is a schematic diagram showing a grab bucket in an unloading open state and a main lifting device deflecting due to a lateral deflection external force according to an embodiment of the present invention;

[0054] Figure 11 is a second dimensioned view of an embodiment of the present invention in which the grab bucket is in an unloading open state and the main hoisting pulley assembly is located on a center perpendicular line of the first fixed pulley;

[0055] Figure 12 This is a second dimensioned drawing showing the grab bucket in an unloading open state and the auxiliary lifting pulley assembly located on a center perpendicular line of the second fixed pulley according to an embodiment of the present invention.

[0056] Description of reference numerals:

[0057] 100 Grab device 110 Grab body

[0058] 120 Lifting connector 130 Opening and closing rope

[0059] 131 Basic section 132 Extension section

[0060] 133 Shackle 200 Main lifting device

[0061] 210 Main hoisting rope 220 Main hoisting pulley block

[0062] 300 Auxiliary lifting device 310 Auxiliary lifting rope

[0063] 320 auxiliary lifting pulley set 400 wear-resistant roller

[0064] 500 turntable 600 crane arm

[0065] 610 Goose head frame 611 First fixed pulley

[0066] 612 Second fixed pulley DETAILED DESCRIPTION

[0067] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0068] The grab bucket hoisting system and the lifting machinery of the present invention will be described below with reference to the accompanying drawings.

[0069] like Figures 1 to 4 As shown, the present invention provides a grab bucket lifting system, wherein the grab bucket lifting system includes:

[0070] The grab device 100 includes a grab body 110, a lifting connector 120, and an opening and closing rope 130. The lifting connector 120 is fixed to the upper end of the grab body 110. The opening and closing rope 130 can drive the grab body 110 to switch between an unloading open state and a grabbing closed state.

[0071] The main hoisting device 200 is provided on the main body of the hoisting machine, and the main hoisting rope 210 of the main hoisting device 200 is connected to the hoisting connector 120 through the main hoisting pulley block 220;

[0072] The auxiliary lifting device 300 is provided on the main body of the hoisting machine, and the auxiliary lifting rope 310 of the auxiliary lifting device 300 is connected to the opening and closing rope 130 through the auxiliary lifting pulley block 320;

[0073] In which, when the grab body 110 is in the unloading open state, the auxiliary lifting pulley group 320 is located above the main lifting pulley group 220, and the first release length L1 of the opening and closing rope 130 is set to make the lateral distance W1 between the auxiliary lifting pulley group 320 and the main lifting rope 210 greater than or equal to the maximum deflection distance of the main lifting rope 210 under the action of the lateral deflection external force.

[0074] When the above-mentioned grab bucket lifting system is used, since the main lifting rope 210 of the main lifting device 200 is connected to the lifting connector 120 on the grab bucket device 100 through the main lifting pulley group 220, the auxiliary lifting rope 310 of the auxiliary lifting device 300 is connected to the opening and closing rope 130 on the grab bucket device 100 through the auxiliary lifting pulley group 320, so that both the main lifting rope 210 and the auxiliary lifting rope 310 are set to a double rate or above, thereby playing the role of lifting the lifting weight of the grab bucket body 110. At the same time, the length of the release of the opening and closing rope 130 from the grab bucket 110 is limited to ensure that the auxiliary lifting pulley group 320 will not grind the main lifting rope 210. Specifically, when the grab bucket 110 is in the unloading open state, the first release length of the opening and closing rope 130 from the grab bucket 110 is limited. At this time, the lateral distance between the auxiliary lifting pulley group 320 and the main lifting rope 210 is the smallest. If it can be ensured that the auxiliary lifting pulley group 320 will not grind the main lifting rope 210 at this time, the phenomenon of grinding the main lifting rope 210 will not occur during the lifting stroke of the auxiliary lifting pulley group 320. More specifically, when the grab bucket 110 is in the unloading open state, the auxiliary lifting pulley group 320 is firstly released. The position of 320 is limited above the main lifting pulley group 220, which is equivalent to setting the first release length limit of the opening and closing rope 130 extending from the grab body 110 to be greater than the length of the lifting connector 120, and further directly limiting the first release length can make the lateral distance between the auxiliary lifting pulley group 320 and the main lifting rope 210 greater than or equal to the maximum swing distance of the main lifting rope 210 under the action of the lateral swing external force. Even if the main lifting rope 210 swings, the auxiliary lifting pulley group 320 will not wear against the main lifting rope 210. In this way, while lifting the lifting weight of the grab body 110, the pulley hook will not wear the lifting rope.

[0075] Specifically, the lifting connection 120 can be set as a lifting chain, and the main lifting device 200 and the auxiliary lifting device 300 both include a lifting drive, a drum and a lifting rope. The lifting drive includes a hydraulic motor and a reducer. Its working principle is that the hydraulic motor drives the drum to rotate through the reducer via a coupling, so that the lifting rope wound on the drum drives the corresponding lifting pulley on the lifting machine body to move up and down, thereby achieving the lifting or lowering of the heavy object. In addition, the lifting drive and drum of the main lifting device 200 and the auxiliary lifting device 300 are both arranged on the turntable 500 of the lifting machine body, and the main lifting rope 210 of the main lifting device 200 and the auxiliary lifting rope 310 of the auxiliary lifting device 300 are wound on the corresponding drums, and the main lifting rope 210 and the auxiliary lifting rope 310 are extended from the corresponding drums at one end and guided to the boom 600 arm head along the arm length direction of the lifting arm 600 of the lifting machine body. At the arm head of the boom 600, not only a first fixed pulley 611 but also a goose head frame 610 is provided. A second fixed pulley 612 is provided at the end of the goose head frame 610 away from the boom 600. The main lifting rope 210 passes around the first fixed pulley 611 and the main lifting pulley group 220 in sequence and is fixedly connected to the boom 600. The auxiliary lifting rope 310 passes around the second fixed pulley 612 and the auxiliary lifting pulley group 320 in sequence and is fixedly connected to the goose head frame 610.

[0076] See also Figures 8 to 10 In one embodiment of the present invention, the calculation formula of the maximum deflection distance Lp is set as:

[0077] Lp=H' / tanθ;

[0078] Wherein, H' represents the height from the grab bucket 110 to the boom 600, and θ represents the maximum deflection angle of the main hoist rope 210 under the action of the lateral deflection external force;

[0079] The calculation formula for the maximum deflection angle θ is set as:

[0080] θ=arctan[(mω 2 (La+L'×cosɑ)+F' max ) / mg];

[0081] Where m is the weight of the grab bucket 110 and the grabbed object, ω is the angular velocity of the lifting machine, La is the lateral distance between the arm root hinge point of the lifting arm 600 and the center of rotation of the lifting machine, L' is the arm length of the lifting arm 600, ɑ is the horizontal angle of the lifting arm 600, and F' is the horizontal angle of the lifting arm 600. max It represents the maximum value of the wind load on the grab bucket body 110, and g represents the acceleration due to gravity.

[0082] Through the above-mentioned calculation formula of the maximum swing distance Lp and the maximum swing angle θ, the maximum swing distance Lp of the main lifting rope 210 under the action of the lateral swing external force can be calculated. Therefore, when designing the first release length of the opening and closing rope 130, it is sufficient to ensure that the lateral spacing between the auxiliary lifting pulley group 320 and the main lifting rope 210 is greater than or equal to the calculated maximum swing distance Lp.

[0083] Specifically, after grabbing or unloading materials, the lifting machinery will generally perform a rotation operation to lift the grab bucket 110 and the grabbed heavy objects above the unloading area for unloading or rotate the grab bucket 110 back to the grabbing area for another grab. During this process, the vertical direction will be affected by the lateral deflection external forces such as centrifugal force and wind load, causing the grab bucket 110 and the main lifting device 200 to deviate outward, thereby causing the main lifting pulley block 200 to contact the opening and closing rope 130 or the auxiliary lifting pulley block 320 and the lifting connector 120. According to the centrifugal force calculation formula

[0084] F ω =mω 2 r;

[0085] Wherein, m represents the weight of the grab body 110 and the grabbed object, ω represents the rotation angular velocity of the lifting machinery, and r represents the rotation radius of the grab body 110.

[0086] At the same time, the calculation formula of the gyration radius is:

[0087] r=La+Lb=La+L'×cosɑ;

[0088] Wherein, La represents the lateral distance between the arm root hinge point of the crane arm 600 and the rotation center of the crane, Lb represents the lateral distance between the rotation center of the crane and the center of gravity of the grab body 110, L' represents the arm length of the crane arm 600, and ɑ represents the horizontal angle of the crane arm 600.

[0089] Thus, the lateral deflection external force F acting on the grab bucket 110 can be obtained. 横 The calculation formula is:

[0090] F 横 =mω 2 (La+L'×cosɑ)+F' max ;

[0091] Wherein, m represents the weight of the grab bucket (110) and the grabbed object, ω represents the angular velocity of the lifting machine, La represents the lateral distance between the arm root hinge point of the lifting arm (600) and the center of rotation of the lifting machine, L' represents the arm length of the lifting arm (600), ɑ represents the horizontal angle of the lifting arm (600), and F' represents the horizontal angle of the lifting arm (600). maxIt represents the maximum value of the wind load on the grab bucket body (110).

[0092] Since the maximum deflection angle θ of the main hoisting rope (210) under the action of the lateral deflection external force is arctan (F 横 / mg), then the lateral deflection external force F 横 Substituting the calculation formula of the maximum deflection angle θ into the formula, we can get the calculation formula of the maximum deflection angle θ: θ=arctan[(mω 2 (La+L'×cosɑ)+F' max ) / mg].

[0093] In one embodiment of the present invention, the maximum value F' of the wind load on the grab bucket body max Set as:

[0094] F' max =n×(mω 2 (La+L'×cosɑ));

[0095] Where m is the weight of the grab bucket and the grabbed object, ω is the angular velocity of the lifting machinery, La is the distance between the boom root hinge and the center of rotation, L' is the boom length, ɑ is the horizontal angle of the boom, and n is set between 0.1 and 0.3.

[0096] More specifically, since the wind load is related to the shape and windward area of ​​the grab bucket 110, different grab buckets 110 are subjected to different wind loads. The maximum wind load F' of the grab bucket 110 can be taken as max =n*centrifugal force, n can be between 0.1 and 0.3, preferably 0.2, then the lateral deflection force F exerted on the grab bucket 110 is 横 The calculation formula is:

[0097] F 横 =F ω +F' max =(1+n)×mω 2 r=1.2mω 2 (La+L'×cosɑ);

[0098] In addition, the rotation angular velocity of general lifting machinery ω≤2r / min, that is, ω≤0.21rad / s. Substituting the maximum value of ω into the above formula can obtain F 横 =0.053m(La+L'×cosɑ), and then we can get the simplified calculation formula of the maximum deflection angle θ: θ=arctan[(0.053(La+L'×cosɑ)) / g].

[0099] At the same time, since the lifting height of the grab body 110 during operation is basically equivalent to the hinge point position of the arm root of the crane arm 600, the height from the grab body 110 to the arm head of the crane arm 600 can also be set to be equal to the vertical height of the crane arm 600, that is, H'=L'×sinɑ, where L' represents the arm length of the crane arm 600 and ɑ represents the horizontal angle of the crane arm 600.

[0100] Therefore, the maximum deflection distance Lp can be further calculated as: Lp = (L' × sinɑ) / tanθ. Given that L' and ɑ are known, and θ can be calculated using the simplified formula for θ, the maximum deflection distance Lp of the main hoist rope 210 under the action of a lateral deflection force can be easily determined. Consequently, when setting the first payout length of the opening and closing rope, the lateral spacing between the auxiliary hoist pulley assembly 320 and the main hoist rope 210 must be greater than or equal to the maximum deflection distance to prevent wear of the main hoist rope 210.

[0101] In one embodiment of the present invention, the first release length L1 is set to satisfy:

[0102]

[0103] Wherein, H' represents the height from the grab body 110 to the boom 600 arm head, Lc represents the pulley center distance between the first fixed pulley 611 on the boom 600 arm head and the second fixed pulley 612 on the goose head frame 610, ɑ represents the horizontal angle of the boom 600, β represents the angle between the pulley center line of the first fixed pulley 611 and the second fixed pulley 612 and the axis of the boom 600, Hh1 represents the total width of the auxiliary lifting pulley group 320, It represents the width of the pulley body of the main hoisting pulley assembly 220, and θ represents the maximum deflection angle of the main hoisting rope 210 under the action of the lateral deflection external force.

[0104] It should be noted that the total width Hh1 of the auxiliary lifting pulley block 320 refers to the entire outer contour width of the auxiliary lifting pulley block 320, and the pulley body width of the main lifting pulley block 220 is Only the width of the pulley body installed on the auxiliary lifting pulley block 320 is used to determine the position of the main lifting rope 210. At the same time, in the present invention, the total width of the main lifting pulley block 220 and the total width of the auxiliary lifting pulley block 320 can be set to be consistent, and the pulley body width of the main lifting pulley block 220 and the pulley body width of the auxiliary lifting pulley block 320 can be set to be consistent.

[0105] Specifically, the main lifting rope 210 has a rate of more than two, and after unloading is completed, the auxiliary lifting pulley group 320 connected to the opening and closing rope 130 may be in a relaxed state and located in the center perpendicular direction of the second fixed pulley 612 on the goose head frame 610. In order to ensure that the auxiliary lifting pulley group 320 does not touch the main lifting rope 210 during operation, it is necessary to ensure that the main lifting rope 210 cannot touch the outer contour of the auxiliary lifting pulley group 320 located at the center perpendicular position of the second fixed pulley 612 on the goose head frame 610.

[0106] At the same time, when the grab bucket 110 is in the unloading open state, the first release length L1 of the opening and closing rope 130 should meet the following requirements: It can be deduced that

[0107] Therefore, based on the calculation formula for the minimum value of the first pay-out length L1, the length of the opening and closing rope 130 can be directly designed. The designed opening and closing rope 130 length can meet the requirement that the lateral spacing between the auxiliary hoisting pulley assembly 320 and the main hoisting rope 210 is greater than or equal to the maximum deflection distance of the main hoisting rope 210 under the action of an external lateral deflection force. As a result, when designing the length of the opening and closing rope 130, it is no longer necessary to first verify whether the lateral spacing between the auxiliary hoisting pulley assembly 320 and the main hoisting rope 210 is greater than or equal to the maximum deflection distance of the main hoisting rope 210 under the action of an external lateral deflection force before determining whether the current design meets the requirements. If the verification result shows that the lateral spacing is less than the maximum deflection distance, the length of the opening and closing rope 130 needs to be redesigned. Of course, the present invention is not limited to this. After designing the length of the opening and closing rope 130 by calculating the minimum value of the first release length L1, it is also possible to verify the reliability of the design during pre-installation by verifying whether the lateral spacing between the auxiliary lifting pulley group 320 and the main lifting rope 210 is greater than or equal to the maximum deflection distance of the main lifting rope 210 under the action of the lateral deflection external force.

[0108] In one embodiment of the present invention, the height H' from the grab body 110 to the arm head of the boom 600 is set to be equal to the vertical height of the boom 600, and the first release length L1 is further set to satisfy:

[0109]

[0110] Wherein, L' represents the arm length of the boom 600, Lc represents the pulley center distance between the first fixed pulley 611 on the arm head of the boom 600 and the second fixed pulley 612 on the goose head frame 610, ɑ represents the horizontal angle of the boom 600, β represents the angle between the pulley center line of the first fixed pulley 611 and the second fixed pulley 612 and the axis of the boom 600, Hh1 represents the total width of the auxiliary lifting pulley group 320, It represents the width of the pulley body of the main hoisting pulley assembly 220, and θ represents the maximum deflection angle of the main hoisting rope 210 under the action of the lateral deflection external force.

[0111] Please see again Figures 1 to 4 In one embodiment of the present invention, the length L* of the lifting connector 120 is set to satisfy:

[0112] L*≥max[(Hh2×arctan(ɑ-β) / 2), (Hh2×arcsin(ɑ-β) / 2)];

[0113] Wherein, Hh2 represents the total width of the main hoisting pulley group 220, ɑ represents the horizontal angle of the boom 600, and β represents the angle between the pulley center line of the first fixed pulley 611 and the second fixed pulley 612 and the axis of the boom 600.

[0114] Furthermore, in order to prevent the main hoisting pulley block 220 from hitting the opening and closing rope 130 during the entire operation, the main hoisting pulley block 220 should be high enough, that is, the length L* of the hoisting connector 120 should be guaranteed. However, if the length L* of the hoisting connector 120 is too large, it will affect the lifting height of the grab bucket 110. Therefore, it is necessary to determine the minimum value of the length L* of the hoisting connector 120 that satisfies the condition that the main hoisting pulley block 220 does not hit the opening and closing rope 130. At the same time, in order to ensure that the main hoisting pulley block 220 does not hit the opening and closing rope 130 during the active grabbing and unloading processes, see Figure 11 The first aspect needs to be satisfied: when the main hoisting pulley assembly 220 is on the center vertical line of the first fixed pulley 611, the main hoisting pulley assembly 220 does not touch the opening and closing rope 130; see Figure 12 The second aspect needs to be satisfied: when the auxiliary lifting pulley group 320 is on the central vertical line of the second fixed pulley 612, the main lifting pulley group 220 does not touch the opening and closing rope 130.

[0115] Furthermore, when the main hoisting pulley assembly 220 is perpendicular to the center of the first fixed pulley 611, to prevent the main hoisting pulley assembly 220 from colliding with the opening and closing rope 130, the length L* of the hoisting connector 120 should satisfy the following: L* ≥ (Hh2 × arctan(ɑ-β) / 2). Furthermore, when the auxiliary hoisting pulley assembly 320 is perpendicular to the center of the second fixed pulley 612, to prevent the main hoisting pulley assembly 220 from colliding with the opening and closing rope 130, the length L* of the hoisting connector 120 should satisfy the following: L* ≥ (Hh2 × arcsin(ɑ-β) / 2). Therefore, the length L* of the hoisting connector 120 should be the greater of the minimum values ​​in the two calculation formulas.

[0116] Therefore, by limiting the minimum length of the lifting connector 120, sufficient lateral spacing can be ensured between the main lifting pulley block 220 and the opening and closing rope 130 to prevent the main lifting pulley block 220 from rubbing against the opening and closing rope 130. Preferably, the length of the lifting connector 120 can be set to be greater than or equal to 5 meters. It is important to note that since the opening and closing rope 130 is a single rope, even if it strikes the main lifting pulley block 220, it will be able to avoid it. Consequently, the chance of wear on the opening and closing rope 130 is lower than that on the main lifting rope 210.

[0117] like Figure 1 and Figure 7 As shown, in one embodiment of the present invention, the opening and closing rope 130 includes a base section 131 and an extension section 132. The base section 131 can drive the grab body 110 to switch between an unloading open state and a grabbing closed state. The extension section 132 is detachably arranged between the base section 131 and the auxiliary lifting pulley group 320 to extend the release length of the opening and closing rope 130, and the number of extension sections 132 used is determined according to the arm length of the lifting arm 600 on the lifting machinery body. That is, the opening and closing rope 130 adopts a combined type, and the length of the basic section 131 of the opening and closing rope 130 is a fixed value, and the basic section 131 can enable the grab body 110 to switch between the unloading open state and the grabbing closed state, so that there will be no connection point inside the grab body 110, thereby ensuring the smooth opening and closing of the grab body 110. The extension section 132 is added to meet the requirement that when the arm length of the lifting arm 600 increases, the lateral spacing between the auxiliary lifting pulley group 320 and the main lifting rope 210 can still meet the condition of being greater than or equal to the maximum shaking threshold of the auxiliary lifting pulley group 320, so as to achieve the purpose of improving the versatility of the grab lifting system.

[0118] Specifically, both ends of the extension section 132 may be provided with a shackle 133, and the number of the extension sections 132 is not limited to one. The number of the extension sections 132 is determined according to the arm length of the crane arm 600. When the arm length of the crane arm 600 of the lifting machinery is the shortest, in order to ensure the lifting height of the grab body 110, the extension section 132 may not be used, and the auxiliary lifting pulley group 320 may be directly connected through the base section 131. When the arm length of the crane arm 600 increases by a certain length, an extension section 132 of the same length may be added to extend the release length of the opening and closing rope 130. The last extension section 132 is connected to the auxiliary lifting pulley group 320. Different arm lengths of the crane arm 600 use different combinations of opening and closing ropes 130.

[0119] See also Figures 1 to 3 ,as well as Figure 6In one embodiment of the present invention, a wear-resistant roller 400 is provided on the side of the main lifting pulley assembly 220 and / or the auxiliary lifting pulley assembly 320 that is adjacent to the other lifting device. The addition of the wear-resistant roller 400 ensures that, even if the lifting pulley collides with the lifting rope due to shaking of the grab bucket during operation, the lifting rope will only contact the wear-resistant roller 400, thereby achieving wear-free lifting. Specifically, the wear-resistant roller 400 includes, but is not limited to, a nylon roller. Other materials that are wear-resistant and do not damage the lifting rope are also acceptable. The lifting rope includes, but is not limited to, a steel wire rope.

[0120] In one embodiment of the present invention, the main hoisting pulley assembly 220 and / or the auxiliary hoisting pulley assembly 320 are configured as multi-ratio pulley assemblies. That is, the main hoisting pulley assembly 220 and / or the auxiliary hoisting pulley assembly 320 include, but are not limited to, pulley assemblies with a double ratio, and may also be pulley assemblies with a higher ratio.

[0121] In one embodiment of the present invention, the grab bucket lifting system further includes a control device, which is communicatively connected to the lifting drive components of the main lifting device 200 and the auxiliary lifting device 300 and is configured as follows:

[0122] When it is determined that the grab body 110 is switched to the grab closed state, if a first control instruction for increasing the pulley height difference is received, the lifting drive component is controlled to prohibit execution of the first control instruction, wherein the pulley height difference is set to the height difference between the main lifting pulley group 220 and the auxiliary lifting pulley group 320;

[0123] When it is determined that the grab body 110 is switched to the unloading open state, if a second control instruction for reducing the pulley height difference is received, the lifting drive component is controlled to prohibit execution of the second control instruction.

[0124] Specifically, when the grab body 110 switches to the grabbing closed state, since the grab body 110 is completely closed, if the lifting drive of the main lifting device 200 and / or the auxiliary lifting device 300 continues to execute the first control instruction to increase the pulley height difference, the first control instruction can be: control the lifting drive of the auxiliary lifting device 300 to continue to recover the auxiliary lifting rope 310 or control the lifting drive of the main lifting device 200 to continue to release the main lifting rope 210. Both of the above will cause the main lifting rope 210 to become loose, thereby causing the rope to be tangled and the lateral spacing between the two lifting devices cannot be guaranteed, resulting in rope grinding. Therefore, after confirming that the first control instruction has been received, the corresponding lifting drive can be controlled not to respond to avoid the above problems.

[0125] At the same time, when the grab body 110 switches to the unloading open state, since the grab body 110 is fully opened, if the lifting drive of the main lifting device 200 and / or the auxiliary lifting device 300 continues to execute the second control instruction to reduce the pulley height difference, the second control instruction can be: control the lifting drive of the auxiliary lifting device 300 to continue to release the auxiliary lifting rope 310 or control the lifting drive of the main lifting device 200 to continue to retract the main lifting rope 210. Both of the above will cause the auxiliary lifting rope 310 to become loose, thereby causing the rope to be tangled and the lateral spacing between the two lifting devices cannot be guaranteed, resulting in rope grinding. Therefore, after confirming that the second control instruction has been received, the corresponding lifting drive can be controlled not to respond to avoid the above problems.

[0126] More specifically, the main lifting device 200 and the auxiliary lifting device 300 are respectively provided with a main operating handle and an auxiliary operating handle. By operating the main operating handle, the main lifting rope 210 can be retracted and extended, and by operating the auxiliary operating handle, the auxiliary lifting rope 310 can be retracted and extended. If the grab bucket 110 is determined to be switched to the grab closed state, even if the auxiliary operating handle is continued to be manipulated in the direction of retracting the auxiliary lifting rope 310, or the main operating handle is continued to be manipulated in the direction of releasing the main lifting rope 210, the corresponding lifting drive components will not respond and will stop operating. If the grab bucket 110 is determined to be switched to the unloading open state, even if the auxiliary operating handle is continued to be manipulated in the direction of releasing the auxiliary lifting rope 310, or the main operating handle is continued to be manipulated in the direction of retracting the main lifting rope 210, the corresponding lifting drive components will not respond and will stop operating.

[0127] In one embodiment of the present invention, the control device is further configured to:

[0128] When it is determined that the grab body 110 is switched to the grab closed state, if a third control instruction for reducing the pulley height difference is received, the lifting drive component is controlled to execute the third control instruction;

[0129] When it is determined that the grab bucket 110 is switched to the unloading open state, if a fourth control instruction for increasing the pulley height difference is received, the lifting drive component is controlled to execute the fourth control instruction.

[0130] Specifically, when the grab bucket 110 switches to the closed gripping state, the third control instruction for reducing the pulley height difference is received, and the grab bucket 110 is controlled to open instead of slackening the lifting rope. Therefore, the corresponding lifting drive can be controlled to respond. It is understood that the third control instruction can be used to control the lifting drive of the auxiliary lifting device 300 to continue to release the auxiliary lifting rope 310, or to control the lifting drive of the main lifting device 200 to continue to retract the main lifting rope 210. It can even be used to control the lifting drive of the auxiliary lifting device 300 to release and the lifting drive of the main lifting device 200 to retract simultaneously.

[0131] At the same time, when the grab bucket 110 switches to the unloading open state, due to receiving the third control instruction to increase the pulley height difference, the grab bucket 110 is controlled to open without causing the lifting rope to slacken, thereby controlling the corresponding lifting drive component to respond. It is understandable that the fourth control instruction can be: controlling the lifting drive component of the auxiliary lifting device 300 to continue to retract the auxiliary lifting rope 310, or controlling the lifting drive component of the main lifting device 200 to continue to pay out the main lifting rope 210, or even controlling the lifting drive component of the auxiliary lifting device 300 to retract and the lifting drive component of the main lifting device 200 to pay out simultaneously.

[0132] More specifically, when it is determined that the grab bucket 110 has switched to the grabbing closed state, if the auxiliary operating handle is continued to be turned in the direction of releasing the auxiliary lifting rope 310, or the main operating handle is continued to be turned in the direction of recovering the main lifting rope 210, the corresponding lifting drive component will respond; when it is determined that the grab bucket 110 has switched to the unloading open state, if the auxiliary operating handle is continued to be turned in the direction of recovering the auxiliary lifting rope 310, or the main operating handle is continued to be turned in the direction of releasing the main lifting rope 210, the corresponding lifting drive component will respond.

[0133] In one embodiment of the present invention, the control device is further configured to:

[0134] Receive control instructions from the main operating handle and the auxiliary operating handle respectively;

[0135] Determine the pulley height difference to be adjusted according to the control instruction;

[0136] When the grab body 110 is in the grab closed state or the unloading open state, the pulley height difference to be adjusted is compared with the current pulley height difference;

[0137] Determine whether the control command is effective based on the comparison result.

[0138] Specifically, the control instruction may include not only the control direction information of the first control instruction, the second control instruction, the third control instruction and the fourth control instruction, but also the control height information. The control height information can be reflected by the toggle stroke of the operating handle. Different toggle strokes correspond to different control height information. The control instruction with the control direction information and the control height information can determine the height to be adjusted of the lifting pulley in the corresponding lifting device, and then determine the pulley height difference to be adjusted. When it is determined to be in the grasping closed state or the unloading open state, the pulley height difference to be adjusted is compared with the current pulley height difference to determine whether the control instruction is to adjust in the direction of increasing or decreasing the pulley height difference. Based on the comparison result, it can be determined whether the corresponding lifting drive responds to the control instruction. By adding the main operating handle and the auxiliary operating handle, the operation and adjustment of the main lifting device 200 and the auxiliary lifting device 300 are more convenient.

[0139] In one embodiment of the present invention, the control device includes a controller, a first detector, and a second detector. The first detector and the second detector are used to determine the positions of the main lifting pulley assembly 220 and the auxiliary lifting pulley assembly 320 in a one-to-one correspondence. The controller is respectively connected to the first detector, the second detector, and the lifting drive components of the main lifting device 200 and the auxiliary lifting device 300, and is configured as follows:

[0140] receiving detection data from the first detector and the second detector respectively;

[0141] Determine the pulley height difference based on the test data;

[0142] When the pulley height difference reaches a preset maximum height difference, the grab body 110 is determined to be switched to a grab closed state;

[0143] When the pulley height difference reaches a preset minimum height difference, it is determined that the grab body 110 is switched to the unloading open state.

[0144] Furthermore, the opening and closing state of the grab bucket 110 is determined by the pulley height difference monitored in real time, which can ensure the reliability of the control. Figure 4 and Figure 5 As shown, when the grab body 110 is switched to the grab closed state, the second release length L2 of the opening and closing rope 130 extending from the grab body 110 is greater than the aforementioned first release length, and the preset maximum height difference is set to the second release length minus the length of the lifting connection 120, and the preset minimum height difference is set to the first release length minus the length of the lifting connection 120.

[0145] In one embodiment of the present invention, the first detector is configured as a first encoder mounted on the lifting drive of the main lifting device 200; and / or the second detector is configured as a second encoder mounted on the lifting drive of the auxiliary lifting device 300. The addition of the first and second encoders enables the height of the lifting pulley to be determined based on the rotation angle of the corresponding lifting drive. Of course, the present invention is not limited to this. Alternatively, the first and second detectors can be configured as distance detectors to detect the height of the corresponding lifting pulley.

[0146] Therefore, the grab bucket lifting system provided by the present invention has the following advantages:

[0147] 1. By using a double-rate pulley to connect the auxiliary hoisting rope and the opening and closing rope, and limiting the first pay-out length of the opening and closing rope when the grab body is in the unloaded open state, it not only solves the problem of the pulley hook wearing the hoisting rope, but also makes the maximum lifting capacity of the grab body connected to the lifting machinery no longer determined by the tension of a single rope, thereby exerting greater lifting capacity.

[0148] 2. The height difference between the main hoisting pulley group and the auxiliary hoisting pulley group is limited by the control device, which avoids the main hoisting rope or the auxiliary hoisting rope from becoming loose during operation and causing the rope to become tangled, thereby improving the reliability of the grab body connection and the grabbing efficiency.

[0149] The present invention also provides a lifting machine, wherein the lifting machine includes the grab bucket hoisting system described above. Because the lifting machine utilizes all of the technical solutions of the aforementioned embodiments, it possesses at least all of the beneficial effects brought about by the technical solutions of the aforementioned embodiments, and therefore will not be detailed here. Specifically, the lifting machine includes, but is not limited to, a crawler crane.

[0150] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0151] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0152] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0153] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A grab bucket lifting system, characterized in that: The grab bucket lifting system includes: A grab bucket device (100) comprises a grab bucket body (110), a lifting connector (120) and an opening and closing rope (130), wherein the lifting connector (120) is fixedly arranged at the upper end of the grab bucket body (110), and the opening and closing rope (130) can drive the grab bucket body (110) to switch between an unloading open state and a grabbing closed state; A main hoisting device (200) is provided on the main body of the hoisting machine, and a main hoisting rope (210) of the main hoisting device (200) is connected to the hoisting connector (120) via a main hoisting pulley block (220); A secondary lifting device (300) is provided on the main body of the lifting machine, and a secondary lifting rope (310) of the secondary lifting device (300) is connected to the opening and closing rope (130) via a secondary lifting pulley block (320); Wherein, when the grab body (110) is in an unloading open state, the auxiliary lifting pulley group (320) is located above the main lifting pulley group (220), and the first pay-out length of the opening and closing rope (130) is set to enable the lateral spacing between the auxiliary lifting pulley group (320) and the main lifting rope (210) to be greater than or equal to the maximum deflection distance of the main lifting rope (210) under the action of a lateral deflection external force.

2. The grab bucket lifting system according to claim 1, characterized in that: The calculation formula of the maximum deflection distance Lp is set as: Lp=H' / tanθ; Wherein, H' represents the height from the grab bucket (110) to the boom (600) head, and θ represents the maximum deflection angle of the main hoist rope (210) under the action of the lateral deflection external force; The calculation formula of the maximum deflection angle θ is set as: θ=arctan[(mω 2 (La+L'×cosɑ)+F' max ) / mg]; Wherein, m represents the weight of the grab bucket (110) and the grabbed object, ω represents the angular velocity of the lifting machine, La represents the lateral distance between the arm root hinge point of the lifting arm (600) and the center of rotation of the lifting machine, L' represents the arm length of the lifting arm (600), ɑ represents the horizontal angle of the lifting arm (600), and F' represents the horizontal angle of the lifting arm (600). max It represents the maximum value of the wind load on the grab bucket body (110), and g represents the acceleration due to gravity.

3. The grab bucket lifting system according to claim 2, characterized in that: The maximum value F' of the wind load on the grab bucket (110) max Set as: F' max =n×(mω 2 (La+L'×cosɑ)); Wherein, m represents the weight of the grab body (110) and the grabbed object, ω represents the rotational angular velocity of the lifting machinery, La represents the lateral distance between the arm root hinge point of the lifting arm (600) and the rotation center of the lifting machinery, L' represents the arm length of the lifting arm (600), ɑ represents the horizontal angle of the lifting arm (600), and n is set to be between 0.1 and 0.

3.

4. The grab bucket lifting system according to claim 1, characterized in that: The first release length L1 is set to satisfy: L1≥H'-[Lc×cos(ɑ-β)-(Hh1) / 2-(φ1) / 2)]×tanθ; Wherein, H' represents the height from the grab body (110) to the arm head of the boom (600), Lc represents the pulley center distance between the first fixed pulley (611) on the arm head of the boom (600) and the second fixed pulley (612) on the goose head frame (610), ɑ represents the horizontal angle of the boom (600), β represents the angle between the pulley center line of the first fixed pulley (611) and the second fixed pulley (612) and the axis of the boom (600), Hh1 represents the total width of the auxiliary lifting pulley group (320), φ1 represents the pulley body width of the main lifting pulley group (220), and θ represents the maximum deflection angle of the main lifting rope (210) under the action of the lateral deflection external force.

5. The grab bucket lifting system according to claim 4, characterized in that: The height H' from the grab bucket (110) to the boom (600) is set equal to the vertical height of the boom (600), and the first release length L1 is further set to satisfy: L1≥(L'×sinɑ)-[Lc×cos(ɑ-β)-(Hh1) / 2-(φ1) / 2)]×tanθ; Wherein, L' represents the arm length of the boom (600), Lc represents the pulley center distance between the first fixed pulley (611) on the arm head of the boom (600) and the second fixed pulley (612) on the goose head frame (610), ɑ represents the horizontal angle of the boom (600), β represents the angle between the pulley center line of the first fixed pulley (611) and the second fixed pulley (612) and the axis of the boom (600), Hh1 represents the total width of the auxiliary lifting pulley group (320), φ1 represents the pulley body width of the main lifting pulley group (220), and θ represents the maximum deflection angle of the main lifting rope (210) under the action of the lateral deflection external force.

6. The grab bucket lifting system according to claim 1, characterized in that: The length L* of the lifting connection member (120) is set to satisfy: L*≥max[(Hh2×arctan(ɑ-β) / 2), (Hh2×arcsin(ɑ-β) / 2)]; Wherein, Hh2 represents the total width of the main hoisting pulley assembly (220), ɑ represents the horizontal angle of the boom (600), and β represents the angle between the line connecting the pulley centers of the first fixed pulley (611) and the second fixed pulley (612) and the axis of the boom (600).

7. The grab bucket lifting system according to claim 1, characterized in that: The opening and closing rope (130) includes a base section (131) and an extension section (132). The base section (131) can drive the grab bucket (110) to switch between an unloading open state and a grabbing closed state. The extension section (132) is detachably arranged between the base section (131) and the auxiliary lifting pulley block (320) to extend the release length of the opening and closing rope (130). The number of the extension sections (132) used is determined according to the arm length of the lifting arm (600) on the lifting machine body. And / or, the main lifting pulley assembly (220) and / or the auxiliary lifting pulley assembly (320) are both provided with a wear-resistant roller (400) on one side close to the other lifting device, And / or, the main lifting pulley set (220) and / or the auxiliary lifting pulley set (320) are both configured as multi-rate pulley sets.

8. The grab bucket hoisting system according to any one of claims 1 to 7, characterized in that: The grab bucket lifting system further comprises a control device, wherein the control device is respectively connected to the lifting drive components of the main lifting device (200) and the auxiliary lifting device (300) and is configured to: When it is determined that the grab bucket (110) is switched to the grab closed state, if a first control instruction for increasing the pulley height difference is received, the lifting drive component is controlled to prohibit execution of the first control instruction, wherein the pulley height difference is set to the height difference between the main lifting pulley group (220) and the auxiliary lifting pulley group (320); When it is determined that the grab body (110) is switched to the unloading open state, if a second control instruction for reducing the pulley height difference is received, the lifting drive component is controlled to prohibit execution of the second control instruction.

9. The grab bucket lifting system according to claim 8, characterized in that: The control device is further configured to: When it is determined that the grab bucket (110) is switched to the grab closed state, if a third control instruction for reducing the pulley height difference is received, the lifting drive component is controlled to execute the third control instruction; When it is determined that the grab body (110) is switched to the unloading open state, if a fourth control instruction for increasing the pulley height difference is received, the lifting drive component is controlled to execute the fourth control instruction.

10. The grab bucket lifting system according to claim 8, characterized in that: The control device comprises a controller, a first detector, and a second detector. The first detector and the second detector are used to determine the positions of the main lifting pulley assembly (220) and the auxiliary lifting pulley assembly (320) in a one-to-one correspondence. The controller is respectively connected to the first detector, the second detector, and the lifting drive components of the main lifting device (200) and the auxiliary lifting device (300), and is configured as follows: receiving detection data from the first detector and the second detector respectively; Determine the pulley height difference based on the test data; When the pulley height difference reaches a preset maximum height difference, the grab body (110) is determined to switch to a grab closed state; When the pulley height difference reaches a preset minimum height difference, the grab body (110) is determined to be switched to an unloading open state.

11. The grab bucket lifting system according to claim 10, characterized in that: The first detector is configured as a first encoder installed on a lifting drive member of the main lifting device (200); and / or the second detector is configured as a second encoder installed on a lifting drive member of the auxiliary lifting device (300).

12. A lifting machine, characterized in that: The lifting machinery includes a grab bucket hoisting system according to any one of claims 1 to 11.

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