A method for preventing wire rope from getting tangled in the groove of a grab bucket crane

Abstract

This invention relates to the field of crane technology and discloses a method for preventing wire rope tangling on a grab bucket crane, comprising the following steps: S1: The grab bucket moves to directly above the material to be grabbed under the action of the trolley and crane; S2: The grab bucket opens and lowers; S3: The coordinate deviation value s1 between the grab bucket and the trolley is measured and calculated and transmitted to the crane control system; S4: The coordinate deviation value s2 between the grab bucket and the crane is measured and calculated and transmitted to the crane control system; S5: The crane control system controls the movement of the trolley and crane according to the coordinate deviation value; eliminating the vertical deflection angle of the wire rope and making the wire rope perpendicular to the drum on the crane. This method avoids tangling caused by excessive vertical deflection angle of the wire rope during lifting by pre-compensating for the displacement of the trolley and crane.

Description

Technical Field

[0001] This invention relates to the field of crane technology, and more specifically, to a method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove. Background Technology

[0002] According to the GBT3811-2008 crane design specification, when the wire rope is wound into or out of the drum, the angle between the centerline of the wire rope and the centerline of the auger should not exceed 3.5°. The grab bucket is connected to the winch via a wire rope. Grab bucket cranes are generally used in scenarios involving grabbing loose materials, such as coal yards, ore yards, or inclined sites with an angle to the horizontal plane. A grab bucket crane is a hoisting device in which the grab bucket is connected to the drum on a crane (overhead crane) via a wire rope. When the grab bucket descends onto loose material, it may tilt to varying degrees due to unevenness. During manual operation, the operator visually observes the tilting direction and degree of tilt of the grab bucket to adjust the position of the trolley and the crane, ensuring that the angle between the wire rope and the center of the auger groove does not exceed the design range when the rope is wound, thus preventing the wire rope on the drum from becoming tangled. In automated, unmanned operation, the direction and degree of tilt of the grab bucket during material handling cannot be determined. When the grab bucket tilts severely, the angle between the wire rope and the center of the spiral groove may exceed the maximum allowable angle of 3.5° as per the design standard. When the drum rewinds the rope, i.e. when the grab bucket is lifting up to grab the material, the lateral force parallel to the drum on the wire rope is too large, causing the wire rope to become disordered or jump out of the groove. This, in turn, causes the grab bucket to rotate due to uneven force on the wire rope, and the automated crane continues to operate, resulting in a safety accident.

[0003] Prior art CN201910975686.9 discloses an automatic detection method for crane wire ropes, including:

[0004] S1, Infrared signals collected by the receiving board;

[0005] S2. Extract two adjacent data points from the signal and make a judgment;

[0006] S3. When two data points change, the position of the previous data point is the current position of the wire rope in the wheel groove.

[0007] While existing technologies disclose an automatic wire rope monitoring method, the disclosed technical solution determines whether the wire rope has derailed by detecting the front and rear position signals of the wire rope, but does not disclose a technical solution to prevent the wire rope from becoming disordered in the groove. In other words, existing technologies do not solve the problem of preventing wire rope disorder during drum movement. Summary of the Invention

[0008] The technical problem solved by this invention is to overcome the defects of the prior art and provide a method for preventing the wire rope of the grab bucket crane from getting tangled in the groove.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove includes the following steps:

[0011] S1: The grab bucket moves to directly above the material to be grabbed under the action of the large and small trolleys;

[0012] S2: The grab opens and descends;

[0013] S3: Measure and calculate the coordinate deviation value s1 between the grab bucket and the trolley and transmit it to the driving control system;

[0014] S4: Measure and calculate the coordinate deviation value s2 between the grab and the trolley and transmit it to the driving control system;

[0015] S5: The trolley control system controls the movement of the trolley and the crane according to the coordinate deviation value; it eliminates the vertical deflection angle of the wire rope and makes the wire rope perpendicular to the drum on the crane.

[0016] Preferably, step S3 includes the following steps:

[0017] S31: Measure the tilting angle λ1 of the grab bucket in the direction of the trolley's movement;

[0018] S32: s1 is obtained based on the grab height h, the width d when the grab is open, and the tilting angle λ1. s1=2*sin(λ1 / 2)*cos((180-λ1) / 2-arctan(h / (d / 2)+λ1).

[0019] Preferably, the tilting angle λ1 is measured by a first tilting sensor installed on the grab bucket.

[0020] Preferably, step S4 includes the following steps:

[0021] S31: Measure the tilting angle λ2 of the grab bucket in the direction of the trolley's movement;

[0022] S32: s2 is obtained based on the grab height h, the width d when the grab is open, and the tilting angle λ2. s2=2*sin(λ2 / 2)*cos((180-λ2) / 2-arctan(h / (d / 2)+λ2).

[0023] Preferably, the tilting angle λ2 is measured by a second tilt sensor installed on the grab bucket.

[0024] Preferably, step S2 includes the following steps:

[0025] S20: The drum on the trolley starts working, and the grab bucket falls down until one end of the grab bucket just contacts the material to be grabbed;

[0026] S21: The grab bucket continues to descend until both ends of the grab bucket are completely on both sides of the material to be grabbed;

[0027] Preferably, step S5 includes the following steps:

[0028] S51: The trolley moves accordingly to compensate for the coordinate deviation value s1;

[0029] S52: The trolley moves accordingly to compensate for the coordinate deviation value s2;

[0030] S53: The actual distance of the compensated movement of the trolley and the carriage is confirmed by position sensors such as laser rangefinders, microwave positioning devices, encoders, and Gray busbars installed on the trolley and the carriage.

[0031] S54: The two ends of the grab bucket tighten to clamp the material.

[0032] Preferably, step S5 further includes the following steps:

[0033] S55: After step S54 is completed, the drum starts to work, pulling the grab bucket upward. When the grab bucket is lifted to the transport height, the drum stops working, and the grab bucket follows the trolley and the trolley to lift the material to the top of the designated position.

[0034] S56: The drum starts working again, lowering the grab bucket above the material to be grabbed, opening the grab bucket, and then rising to the transport height under the action of the drum.

[0035] Preferably, a load cell is installed under the bearing housing of the drum to obtain the weight of the grab bucket in real time.

[0036] Preferably, the vehicle control system is a PLC system.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] This application collects and calculates the deviation values ​​of the overhead crane and trolley in the direction of movement during the grabbing process, and then feeds this data back to the gantry control system. The gantry control system then controls the overhead crane and trolley to make corresponding displacement adjustments, thereby adjusting the vertical angle of the wire rope to ensure that the wire rope is perpendicular to the drum on the trolley. This effectively prevents the wire rope from becoming tangled on the drum when it begins to rotate.

[0039] 1) Before lifting materials, the deviation between the grab bucket and the trolley and the trolley is measured, and the displacement of the trolley and the trolley is adjusted in advance to avoid the trough from becoming disordered due to the excessive vertical deflection of the wire rope during lifting.

[0040] 2) The calculation of the deviation value is related to the size of the grab bucket itself, meaning that this method is applicable to different models of grab buckets and has greater applicability. Attached Figure Description

[0041] Figure 1 A flowchart of a method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove;

[0042] Figure 2 An exploded view of step S3 in a method for preventing the wire rope of a grab bucket crane from getting tangled in the groove;

[0043] Figure 3 An exploded view of step S4 in a method for preventing the wire rope of a grab bucket crane from getting tangled in the groove;

[0044] Figure 4 This is an exploded view of step S5 in a method for preventing the wire rope of a grab bucket crane from getting tangled in the groove. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0046] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0047] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0048] Example 1

[0049] like Figure 1 As shown, a method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove is disclosed, comprising the following steps:

[0050] S1: The grab bucket moves to directly above the material to be grabbed under the action of the large and small trolleys;

[0051] S2: The grab opens and descends;

[0052] S3: Measure and calculate the coordinate deviation value s1 between the grab bucket and the trolley and transmit it to the driving control system;

[0053] S4: Measure and calculate the coordinate deviation value s2 between the grab and the trolley and transmit it to the driving control system;

[0054] S5: The trolley control system controls the movement of the trolley and the crane according to the coordinate deviation value; it eliminates the vertical deflection angle of the wire rope and makes the wire rope perpendicular to the drum on the crane.

[0055] The grab bucket is connected to a drum on a trolley via a steel wire rope. When material needs to be grabbed, the grab bucket moves to a position directly above the material placement location under the action of the trolley and the main trolley. This material placement location is the grab bucket's grabbing position. After the grab bucket grabs the material, there are two possible outcomes:

[0056] 1. From the moment the grab bucket descends until it clamps the material to be grabbed, the angle of the grab bucket relative to the horizontal direction does not change. Under this condition, the angle of the wire rope connected to the grab bucket relative to the vertical direction will also not change. Naturally, under this condition, the wire rope will not be out of its groove or derail when the grab bucket is grabbing the material.

[0057] Second: When the material to be grabbed is placed on an inclined surface or is not a standard component, after the grab bucket descends, only one gripping end will initially contact the material. This first point of contact is called the first contact point. As the material continues to descend, the grab bucket rotates relative to the first contact point until the other gripping end moves to a suitable gripping position. At this point, the grab bucket tightens to clamp the material. Naturally, the angle of the grab bucket relative to the horizontal direction changes, and the angle of the wire rope connected to the grab bucket relative to the vertical direction also changes. This change in the wire rope's angle relative to the vertical direction can easily lead to the wire rope becoming tangled or derailed when the drum begins to tighten it.

[0058] To avoid wire rope groove tangling that may occur in the second scenario, this embodiment employs the following technical solution to prevent wire rope groove tangling, as detailed below:

[0059] First, under the action of the trolley and the crane, the grab bucket moves to directly above the material to be grabbed. Specifically, this is achieved by using vision sensors on the trolley or crane to scan and identify the material's location. The crane control system then moves the trolley and crane to position the grab bucket directly above the material. At this point, the grab bucket, connected to the drum on the crane via a steel cable, opens. As the cable is released, the grab bucket gradually descends until one of its gripping ends contacts the material. It continues to descend until both gripping ends are positioned at the ends of the material, at which point the grab bucket tightens, securing the material. Simultaneously, the coordinate deviation values ​​s1 and s2 between the grab bucket and the trolley are measured and calculated and transmitted to the crane control system. s1 and s2 represent the grab bucket's offset values ​​in the X-axis and Y-axis directions during the grabbing process, respectively—that is, its displacement relative to the trolley and crane. The trolley control system controls the movement of the trolley and crane based on coordinate deviation values ​​s1 and s2, eliminating the vertical deflection angle of the wire rope and ensuring it is perpendicular to the drum on the crane. Once the positions of the trolley and crane are adjusted, the wire rope is perpendicular to the drum, preventing cable tangling when the drum begins to wind up the grab bucket. By adjusting the positional deviation between the grab bucket and the trolley and crane before lifting, the risk of cable tangling is eliminated, effectively preventing this problem. Before lifting materials, measuring the deviation between the grab bucket and the trolley and crane allows for pre-emptive displacement adjustments, preventing cable tangling caused by excessive vertical deflection angle during lifting. The deviation calculation is related to the grab bucket's dimensions, making this method applicable to different grab bucket models and offering wider applicability.

[0060] Example 2

[0061] A method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove is disclosed, comprising the following steps:

[0062] S1: The grab bucket moves to directly above the material to be grabbed under the action of the large and small trolleys;

[0063] S2: The grab opens and descends;

[0064] S3: Measure and calculate the coordinate deviation value s1 between the grab bucket and the trolley and transmit it to the driving control system;

[0065] S4: Measure and calculate the coordinate deviation value s2 between the grab and the trolley and transmit it to the driving control system;

[0066] S5: The trolley control system controls the movement of the trolley and the crane according to the coordinate deviation value; it eliminates the vertical deflection angle of the wire rope and makes the wire rope perpendicular to the drum on the crane.

[0067] The difference between this embodiment and Embodiment 1 is that step S3 includes the following steps:

[0068] S31: Measure the tilting angle λ1 of the grab bucket in the direction of the trolley's movement;

[0069] S32: Calculate s1 based on the grab height h, the width d when the grab is open, and the tilting angle λ1. s1=2*sin(λ1 / 2)*cos((180-λ1) / 2-arctan(h / (d / 2)+λ1))

[0070] By measuring the tilting angle λ1 of the grab bucket in the direction of the trolley's movement, and based on the height h of the grab bucket itself and the bottom width d of the grab bucket in the open state, the deviation value s1 of the grab bucket relative to the trolley, that is, the displacement value relative to the trolley, is calculated.

[0071] Step S4 includes the following steps:

[0072] S41: Measure the tilting angle λ2 of the grab bucket in the direction of the trolley's movement;

[0073] S42: Calculate s2 based on the grab height h, the width d when the grab is open, and the tilting angle λ2. s2=2*sin(λ2 / 2)*cos((180-λ2) / 2-arctan(h / (d / 2)+λ2))

[0074] Similarly, the deviation value s2 of the grab bucket relative to the trolley is obtained, which is the displacement value relative to the trolley.

[0075] Specifically, the tilting angle λ1 can be measured by a first tilting sensor installed on the grab bucket, and the tilting angle λ2 can be measured by a second tilting sensor installed on the grab bucket. Of course, to improve the accuracy of the tilting angle, multiple tilting sensors can be used for measurement, and then the average value can be calculated.

[0076] In this embodiment, step S2 includes the following steps:

[0077] S20: The drum on the trolley starts working, and the grab bucket falls down until one end of the grab bucket just contacts the material to be grabbed;

[0078] S21: The grab bucket continues to descend until both ends of the grab bucket are completely on both sides of the material to be grabbed;

[0079] Example 3

[0080] A method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove is disclosed, comprising the following steps:

[0081] S1: The grab bucket moves to directly above the material to be grabbed under the action of the large and small trolleys;

[0082] S2: The grab opens and descends;

[0083] S3: Measure and calculate the coordinate deviation value s1 between the grab bucket and the trolley and transmit it to the driving control system;

[0084] S4: Measure and calculate the coordinate deviation value s2 between the grab and the trolley and transmit it to the driving control system;

[0085] S5: The trolley control system controls the movement of the trolley and the crane according to the coordinate deviation value; it eliminates the vertical deflection angle of the wire rope and makes the wire rope perpendicular to the drum on the crane.

[0086] The difference between this embodiment and Embodiment 1 is as follows:

[0087] Step S5 includes the following steps:

[0088] S51: The trolley moves accordingly to compensate for the coordinate deviation value s1;

[0089] S52: The trolley moves accordingly to compensate for the coordinate deviation value s2;

[0090] S53: The actual distance of the compensated movement of the trolley and the carriage is confirmed by position sensors such as laser rangefinders, microwave positioning devices, encoders, and Gray busbars installed on the trolley and the carriage.

[0091] S54: The two ends of the grab bucket tighten to clamp the material.

[0092] When the trolley control system receives signal S1, it controls the trolley to perform corresponding supplementary movement; when it receives signal S2, it controls the trolley to perform corresponding supplementary movement. This ultimately ensures the wire rope is perpendicular to the drum. To guarantee the displacement accuracy of the trolley and trolley, position sensors such as laser rangefinders, microwave positioning devices, encoders, and Gray line sensors on the trolley and trolley can confirm the actual distance of their compensatory movements. By using these sensors, the displacement accuracy of the trolley and trolley is accurately identified, thereby improving industry precision and preventing wire rope misalignment caused by inaccurate movement of either the trolley or trolley.

[0093] In this embodiment, step S5 further includes the following steps:

[0094] S55: After step S54 is completed, the drum starts to work, pulling the grab bucket upward. When the grab bucket is lifted to the transport height, the drum stops working, and the grab bucket follows the trolley and the trolley to lift the material to the top of the designated position.

[0095] S56: The drum starts working again, lowering the grab bucket above the material to be grabbed, opening the grab bucket, and then rising to the transport height under the action of the drum.

[0096] In this embodiment, a load cell can also be installed under the bearing housing of the drum to obtain the weight of the grab bucket in real time. By testing the weight of the grab bucket with the load cell, it can be determined whether the grab bucket has grabbed any material and whether any material has fallen during the hoisting process.

[0097] The vehicle control system is a PLC system. The advantage of PLC is that it runs fast and stably.

[0098] Obviously, the above embodiments are merely examples to clearly illustrate the technical solutions of the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preventing the wire rope on a grab bucket crane from becoming tangled in the groove, characterized in that, Includes the following steps: S1: The grab bucket moves to directly above the material to be grabbed under the action of the large and small trolleys; S2: The grab opens and descends; S20: The drum on the trolley starts working, and the grab bucket falls down until one end of the grab bucket just contacts the material to be grabbed; S21: The grab bucket continues to descend until both ends of the grab bucket are completely on both sides of the material to be grabbed; S3: Measure and calculate the coordinate deviation value s1 between the grab bucket and the trolley and transmit it to the driving control system; S31: Measure the tilting angle λ1 of the grab bucket in the direction of the trolley's movement; S32: s1 is obtained based on the grab height h, the width d when the grab is open, and the tilting angle λ1. s1=2*sin(λ1 / 2)*cos((180-λ1) / 2-arctan(h / (d / 2))+λ1); S4: Measure and calculate the coordinate deviation value s2 between the grab and the trolley and transmit it to the driving control system; S41: Measure the tilting angle λ2 of the grab bucket in the direction of the trolley's movement; S42: s2 is obtained based on the grab height h, the width d when the grab is open, and the tilting angle λ2. s2=2*sin(λ2 / 2)*cos((180-λ2) / 2-arctan(h / (d / 2))+λ2); S5: The trolley control system controls the movement of the trolley and the crane according to the coordinate deviation value; it eliminates the vertical deflection angle of the wire rope and makes the wire rope perpendicular to the drum on the crane. S51: The trolley moves accordingly to compensate for the coordinate deviation value s1; S52: The trolley moves accordingly to compensate for the coordinate deviation value s2; S53: The actual distance of the compensated movement of the trolley and the carriage is confirmed by laser ranging, microwave positioning, coding ruler and Gray line set on the trolley and the carriage. S54: The two ends of the grab bucket tighten to clamp the material.

2. The method for preventing the wire rope of a grab bucket crane from becoming tangled in the groove according to claim 1, characterized in that, The tilting angle λ1 is measured by a first tilt sensor installed on the grab bucket.

3. The method for preventing the wire rope of a grab bucket crane from becoming tangled in the groove according to claim 1, characterized in that, The tilting angle λ2 is measured by a second tilt sensor installed on the grab bucket.

4. The method for preventing the wire rope of a grab bucket crane from becoming tangled in the groove according to claim 1, characterized in that, Step S5 further includes the following steps: S55: After step S54 is completed, the drum starts to work, pulling the grab bucket upward. When the grab bucket is lifted to the transport height, the drum stops working, and the grab bucket follows the trolley and the trolley to lift the material to the top of the designated position. S56: The drum starts working again, lowering the grab bucket above the material to be grabbed. The grab bucket opens and then rises to the transport height under the action of the drum.

5. A method for preventing the wire rope of a grab bucket crane from becoming tangled in the groove, as described in claim 1, characterized in that... A load cell is installed under the bearing housing of the drum to obtain the weight of the grab bucket in real time.

6. A method for preventing the wire rope of a grab bucket crane from becoming tangled in the groove, as described in claim 1, characterized in that... The vehicle control system is a PLC system.

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