CN115485228A

CN115485228A - Sling monitoring device and crane system

Info

Publication number: CN115485228A
Application number: CN202080100073.1A
Authority: CN
Inventors: 田上达也
Original assignee: Hitachi Industrial Equipment Systems Co Ltd
Current assignee: Hitachi Industrial Equipment Systems Co Ltd
Priority date: 2020-04-21
Filing date: 2020-12-14
Publication date: 2022-12-16
Also published as: WO2021215043A1; JP7346354B2; JP2021172459A

Abstract

The invention provides a sling monitoring device and a crane system, which can prompt the inspection near the end of the sling to be performed intensively and is beneficial to using a winch in a safe state. The hoist control device comprises a hoisting motor (3) for rotating a winding drum for winding the sling (2), a sling swing angle detection device (110), and an inverter control device (12) for controlling the hoisting motor (3), wherein the number of times of bending of the sling (2) near the end support device is measured for each load based on the output of the sling swing angle detection device (110), the load state estimated from the output current and the rotation state of the hoisting motor (3), thereby monitoring the sling, and recording the number of times of bending for each load state.

Description

Sling monitoring device and crane system

Technical Field

The present invention relates to monitoring of a hoist rope used in a crane apparatus provided in a crane system. Among other things, it relates to techniques for detecting bending of a sling.

Background

Since a hoist rope used in a crane device or the like is deteriorated by use, it is necessary to perform periodic inspection and to perform inspection of a deteriorated state. In a 2-strand suspended crane, although the loss of the sheave passage is large in many cases, the loss near the end of the rope may be large depending on the usage. This is because when the hoist moves in the lateral direction, the hoisting weight swings, and the rope swings, so that stress is concentrated on the end of the rope (rope end).

In order to reduce stress concentration on the cable end, a rope end support device having a structure in which a rope is wound around a sheave and the cable end is locked may be used. This prevents the stress from concentrating on the end of the cable.

In addition, the influence of swinging of the hoist generated during longitudinal movement is reduced by mounting the sling end support device on the hoist via the pin.

However, although stress concentration can be reduced as compared with a simple terminal support device, it is also a site where load is concentrated and a site where inspection is necessary.

Patent document 1 describes a rope monitoring device that can monitor a rope by measuring the number of times the rope bends under a load (load) per unit length as an aid when inspecting the state of the rope, and can inspect the rope with emphasis on a portion where the rope bends more.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2010-149980

Disclosure of Invention

Problems to be solved by the invention

However, in the rope monitoring device, the rope is monitored based on the number of times of bending determined by the sheave or the drum. In this technique, the number of times of bending is measured by a pulse of an encoder of a crane system, but there is a problem that a state in the vicinity of the end portion of the rope cannot be known.

Accordingly, an object of the present invention is to know the number of times a sling as a whole is bent, including a portion that cannot be measured by a pulse of an encoder.

Means for solving the problems

In order to achieve the object, the present invention detects bending according to a periodically detected swing angle of a hoist, and counts the number of times of bending.

More specifically, the present invention relates to a sling monitoring device for a crane system for controlling the movement of a heavy object held by a holding mechanism connected to a sling, the device comprising a control unit for measuring the number of times of bending of the sling, and an information storage unit for storing the number of times of bending measured by the control unit. The control unit receives a periodically detected sling swinging angle of the sling from a sling swinging angle detection device, compares whether or not the sling swinging angle is larger than a predetermined threshold value, detects a change in the sling swinging direction of the sling using the periodically detected sling swinging angle, determines that a bend has occurred in the sling when the sling swinging angle is larger than the threshold value and the change in the sling swinging direction is detected, and counts the number of times the sling is bent.

The present invention also includes a crane system including the rope monitoring device, a monitoring method for the rope monitoring device, and a curvature counting method.

Effects of the invention

According to the present invention, the number of times the entire sling is bent can be measured, and therefore, the load state or the load state (hereinafter referred to as the load state) near the end of the sling can be monitored.

Drawings

Fig. 1 is an example of a configuration diagram of an inverter type crane system according to an embodiment of the present invention.

Fig. 2 is an example of a configuration diagram of a rope end supporting device of a hoist according to an embodiment of the present invention.

Fig. 3 shows an example of a control system of a sling monitoring device according to an embodiment of the present invention.

Fig. 4 shows an example of an inverter control device according to an embodiment of the present invention.

Fig. 5 is a view showing a state of bending of a sling according to an embodiment of the present invention.

Fig. 6 is a display example of the number of times a sling is bent in one embodiment of the invention.

Fig. 7 shows an example of a control flow for counting the number of times a sling is bent according to an embodiment of the present invention.

Fig. 8 is a diagram illustrating the principle of step S5 in one embodiment of the present invention.

FIG. 9 is a graph showing measurement data and a bending number table used in one embodiment of the present invention.

Detailed Description

An example of the structure of the inverter type crane system in the present embodiment will be described with reference to fig. 1. The hoisting motor 3 constituting the crane system is controlled by an inverter control device 12 into which an operation command is introduced from an operation input device 11. That is, the hoisting motor 3 rotates the drum around which the suspension cable 2 is wound via the speed reducer, thereby raising and lowering the suspension cable 2 and moving the weight attached to the hook 1 as the holding mechanism for the weight in the Z-axis direction.

The lateral movement motor 5 is controlled by an inverter control device 12 into which an operation command is introduced from an operation input device 11, and a weight attached to the hook 1 is moved in the X-axis direction by the lateral movement device 6 and the lateral movement bridge 7. In the present embodiment, the hook 1 is shown as an example of the holding mechanism, but other holding mechanisms such as a ring, a shackle, and a cable may be used.

The vertical movement motor 8 is controlled by a vertical movement inverter control device 13 into which an operation command is introduced from the operation input device 11, and the weight attached to the hook 1 is moved in the Y-axis direction by the vertical movement device 9 and the vertical movement bridge 10.

In this embodiment, the number of times the hoist rope 2 is bent is counted by the inverter control device 12. That is, the inverter control device 12 is used as a suspension cable monitoring device. However, a sling monitoring device may be separately provided to count the number of times of bending.

Next, an example of the structure of the sling end supporting device 14 will be described with reference to fig. 2.

The sling end support device 14 is configured to wind the sling 2 and lock the cable end portion 16. This prevents the stress from concentrating on the cable terminal portion 16. Further, by being attached to the drum 4 via the pin 15, the influence of the swinging of the hoist generated when the hoist operates in the Y-axis direction is reduced. As will be described later, in the present embodiment, the number of times the sling 2 is bent in the vicinity of the illustrated sling end support device 14 is counted. In the present embodiment, the number of times of bending is the number of times that the hoist rope 2 is bent to a predetermined hoist swing angle or more.

Next, the control of the control object (such as a motor) by the control system including the inverter control device 12 and the vertical movement inverter control device 13 will be described with reference to fig. 3. The hoisting motor 3 and the lateral movement motor 5 are controlled by an inverter control unit 103 provided in the inverter control device 12. That is, when receiving a predetermined operation command from the operation input device 11, the inverter control unit 103 generates an inverter control signal based on the operation command, and controls each inverter, the hoisting inverter 101, and the traverse inverter 102 based on the inverter control signal. The hoisting inverter 101 and the traverse inverter 102 output a frequency, a voltage, and a current necessary for driving the hoisting motor 3 and the traverse motor 5.

Further, the inverter control device 12 controls the release of the hoisting brake 106 and the lateral movement brake 107 by the electromagnetic brakes, and moves in the respective directions (Z, X) while holding the weight attached to the hook 1.

Next, an example of the configuration of the inverter control device 12 will be described with reference to fig. 4.

The inverter control device 12 includes a control unit 201, an information storage unit 202, and an output unit (not shown). The control unit 201 controls the hoisting/traversing inverter 102 based on an operation command from the operation input device 11 to drive the motors (the hoisting motor 3 and the traversing motor 5).

The control unit 201 estimates the load state corresponding to the suspension rope 2. The load state is estimated using the frequency, the current value, and the voltage obtained from the hoisting inverter 101, the weight (hoisting weight) and the output torque of the weight corresponding to the hoisting rope calculated based on these, the rotation state (pulse signal) of the hoisting motor 3 obtained from the encoder 109 (rotation detecting unit), and the like. Then, the control unit 201 controls the hoisting inverter 101 using the load state. In order to detect the rotation state of the hoisting motor 3, a pulse signal corresponding to the rotation speed generated by an encoder 109 attached to the rotation shaft of the hoisting motor 3 can be used.

The information storage unit 202 stores a threshold value for determining the load state of the drum 4 on which the inverter control device 12 is mounted. The load state is determined based on the current value output from the hoisting motor 3 and the motor rotation speed by the hoisting inverter 101 during the hoisting operation.

The control unit 201 obtains the state of the swing of the hoist by introducing the output of the hoist swing angle detection device 110 and measuring the hoist swing angle.

The hoisting weight swing angle detection device 110 may be a device capable of determining the angle of the swing of the hoisting weight, such as a method using a gyro sensor, an acceleration sensor, or the like, or a method of calculating the change in the tension of the hoisting weight (the change in the load on the sheave or the like) due to the swing of the hoisting weight.

The information storage unit 202 temporarily stores the swing angle of the hoist acquired by the control unit 201. Then, when the point at which the swing direction of the hoist changes is captured, the control unit 201 determines that the vicinity of the end of the hoist rope is bent, counts the number of times of bending, and stores the number in the information storage unit 202. The curved condition is shown in fig. 5. Fig. 5 shows a state in which the sling 2 wound around the sling end support device 14 sways left and right, that is, bends. The details of this processing will be described later with reference to fig. 7.

In addition, the information storage unit 202 stores the load state together with the number of times of bending.

Next, the display of the measurement contents (the number of bending times and the load state) will be described with reference to fig. 6. Fig. 6 shows the display content and the change thereof on a display device (not shown) connected to the inverter control device 12. On the display screen, the number of bending times near the end of the sling is displayed in a total number of bending times and in each load category. That is, the uppermost part of fig. 6 shows the total number of times of swing of the hoist counted, and below this, the load classification (the leftmost display area) and the number of times of bending (the right side of the load classification display area) at the time of the load classification are displayed together. Here, the display changes each display according to the control of the control unit 201 or the operation of the display device by the user. In this case, the display may be automatically switched at regular intervals, or may be repeatedly displayed.

The load classification is divided into, for example, 0 to 10% no load, 11 to 25% light load, 26 to 50% medium load, 51 to 75% heavy load, 76 to 100% overweight load, and 101% or more overload as a ratio to the rated load, and each bending frequency is displayed. In this way, the number of times of bending stored in the information storage unit is displayed on the display device for each load, whereby the use state of the sling can be visualized in detail. Note that the display of fig. 6 is performed by the control unit 201 using the curve order table 2022 stored in the information storage unit 202. The bending order table 2022 is shown in fig. 9, and the contents thereof will be described later.

Finally, a control flow for counting the number of times of bending is described with reference to fig. 7.

First, as a precondition of the flow, in the crane system, the weight is moved according to the control of the control system. In addition, this flow is repeatedly executed when the heavy object is moved, and at step S1, "previous value" of the swing angle of the suspended weight is stored in the information storage unit 202.

First, in step S1, the control unit 201 acquires the hoist swinging angle from the output of the hoist swinging angle detection device 110. This is performed periodically. That is, the hoist swinging angle detection device 110 periodically measures the hoist swinging angle and outputs the result every time. In step S1, the control unit 201 estimates the load state by the above-described method. Then, the control unit 201 stores the estimated load state in the column of "load (%)" of the measurement data in the information storage unit 202. At this time, the control unit 201 stores the time in the column "measurement time".

Next, in step S2, the control unit 201 determines whether or not the hoist swinging angle is equal to or larger than a predetermined angle in order to eliminate a minute hoist swinging angle. The minute swing angle of the hoist is an angle (fixed angle) stored in advance in the information storage unit 202. The reason for removing this is that if the angle is less than a certain angle, it can be determined that no bending has occurred. As a result, if it is above a certain angle, the process proceeds to step S3. If the angle is less than a predetermined angle (not equal to or greater than the predetermined angle), the process proceeds to step S4. Here, in the case of proceeding to step S3, the number of times of bending is counted together with the subsequent steps.

When the process proceeds to step S4, the process ends, and the process returns to step S1.

In step S4, the control unit 201 clears the "previous value" of the hoist swing angle stored in the information storage unit 202. The previous value refers to the hoist swinging angle (current value) stored in step S7 executed before in the repeatedly executed flow.

Next, the processing after step S3 for counting the number of times of bending will be described. In step S3, the control unit 201 compares the previous value stored in the information storage unit 202 with the hoist swinging angle (current value) acquired in step S1.

Next, in step S5, the control unit 201 determines whether the sling swinging direction has changed or not, based on the comparison result in step S4. Specifically, the control unit 201 uses the magnitude relationship between the previous value and the current value stored in the information storage unit 202. When the last value is large, it is determined that the swing direction of the hoist has changed. On the contrary, when the current value is large, it is determined that the swing direction of the hoist has not changed.

The principle of this determination will be described with reference to fig. 8. In FIG. 8, reference lines (e.g., center lines) of the slings are shown at 20-1 to 20-3, respectively. Among them, the reference line 20-1 is a reference of the position of the hoist rope 2 at the previous repetition. That is, θ 1 is stored as the last value in the information storage unit 202.

Then, the sling 2 swings to one of the reference lines 20-2 and 20-3 as the heavy object moves. First, a case where the suspension wire 2 is changed from the reference line 20-1 to the reference line 20-2 will be described. In this case, the reference line 20-2 is closer to the center line 30 than the reference line 20-1. That is, it shows that (1) the direction of the swing of the hoist from the center line 30 to the reference line 20-1 and (2) the direction from the reference line 20-1 to the reference line 20-2 are changed in different directions. Here, the hanging weight swing angle θ 1 of the reference line 20-1 and the hanging weight swing angle θ 2 (current value) of the reference line 20-2 satisfy the relationship of θ 1> θ 2. That is, since the previous value is large, it is determined that the hoisting swing direction has changed.

The case where the hoist rope 2 is changed from the reference line 20-1 to the reference line 20-3 will be described. In this case, the reference line 20-3 is farther from the center line 30 than the reference line 20-1. That is, the direction of (1) the swinging of the hoist from the center line 30 to the reference line 20-1 is the same as the direction of (2) the reference line 20-1 to the reference line 20-3. In other words, the hoisting swing of the hoist cable 2 changes in the same direction as the center line 30, the reference line 20-1, and the reference line 20-3. Here, the hanging weight swing angle θ 1 of the reference line 20-1 and the hanging weight swing angle θ 3 of the reference line 20-3 satisfy the relationship of θ 1< θ 3 (current value). That is, since the current value is large, it is determined that the hoisting swing direction has not changed.

If the previous value is not stored in the information storage unit 202 due to S4 or the first process of the previous iteration, it is determined that the change in the lifting swing direction has not occurred, and the process proceeds to step S7.

If it is determined as a result of the determination in step S5 that the hoist swinging direction has not changed, the process proceeds to step S7. If it is determined that the hoist swinging direction has changed, the process proceeds to step S6.

In step S6, the control unit 201 counts the number of times of bending. That is, the control unit 201 records information indicating that bending is determined, such as "there is" in the column "bending" of the measurement data stored in the information storage unit 202. Then, the control unit 201 sets the number of bending times +1 in the corresponding load column of the bending number table 2022 in accordance with "load (%)" corresponding to "existence" in the measurement data 2021. The control unit 201 calculates and records the total number of times of bending, which is the sum of the numbers of times of bending for each load.

As described above, the measurement data 2021 records each data estimated, measured, and the like by the control unit 201. Then, the bending order table 2022 is generated by the control unit 201 based on the measurement data 2021. Note that the recording of the bending order table 2022 may be performed every time, or may be performed after the movement of the weight is completed.

Next, in step S7, the control unit 201 overwrites the current value as the previous value in the information storage unit 202. Then, the process returns to step S1, and the process shown in the present flowchart is repeated.

In addition, the order of step S2 and step S5 in the present flowchart may be reversed or performed in parallel. That is, the change of the swing direction of the hoist may be checked (step S5), and then it may be determined whether or not the swing angle of the hoist is equal to or larger than a predetermined angle (step S2), or they may be performed in parallel. In these cases, if it is determined that the hoist swinging angle is not equal to or greater than the predetermined value, the previous value is cleared (step S4).

When predetermined conditions such as user input and power-off of the crane system are satisfied, the processing shown in the flowchart is terminated.

According to the present embodiment, it is possible to prompt an inspection of the vicinity of the end of the hoist rope to be performed with emphasis, and use the hoist in a safe state. Further, since the number of times of bending of the entire end including the sling can be known, it is possible to present a more important examination in performing the examination.

Description of the reference numerals

1 \ 8230and lifting hook

2-8230and sling

3 8230a motor for winding

4-8230and winding drum

5 8230a motor for transverse movement

6-8230a device for transverse movement

7 method 8230and bridge frame for transverse movement

8 8230a motor for longitudinal movement

9-8230and longitudinal moving device

10 method 8230and bridge frame for longitudinal movement

11 \ 8230and operation input device

12 method 8230and inverter control device

13 \ 8230and inverter control device for longitudinal movement

14-8230and end supporting device of sling

15-8230and pin

16 \ 8230and rope end part

101 \ 8230and inverter for winding

102 \ 8230and inverter for transverse movement

103 \ 8230and inverter control part

104\8230andinverter for longitudinal movement

105 \ 8230and inverter control part for longitudinal movement

106 \8230andbrake for winding

107 \ 8230and brake for transverse movement

108 \ 8230and brake for longitudinal movement

109 a 8230a coder

110 \ 8230and device for detecting swing angle of crane

201 \ 8230and control part

202 \8230andinformation storage part.

Claims

1. A wire rope monitoring device for controlling a crane system capable of moving a heavy object held by a holding mechanism connected to a wire rope, the wire rope monitoring device comprising:

a control unit that measures the number of times the sling is bent; and

an information storage unit for storing the number of times of bending measured by the control unit,

the control part is used for controlling the operation of the motor,

receiving a periodically detected sling swing angle of the sling from a sling swing angle detecting device,

comparing whether the swing angle of the sling is larger than a predetermined threshold value,

detecting a change in a swing direction of the hoist cable using the periodically detected swing angle of the hoist,

and when the swing angle of the sling is larger than a threshold value and the change of the swing direction of the sling is detected, determining that the sling is bent, and counting the bending times of the sling.

2. The sling monitoring device as defined in claim 1, wherein:

the control unit compares a previous value of the hoist swinging angle, which is stored in the information storage unit, with a current value of the hoist swinging angle, which is received from the hoist swinging angle detection device, with respect to a change in the hoist swinging direction, and detects that the hoist swinging direction has changed when the current value is smaller than the previous value.

3. The sling monitoring device as defined in claim 2, wherein:

the control unit deletes the previous value stored in the information storage unit when the current value is smaller than the threshold value, and overwrites and stores the current value in the information storage unit when the current value is larger than the threshold value.

4. A sling monitoring device as claimed in any one of claims 1 to 3, wherein:

the control part is used for controlling the operation of the motor,

estimating a load state for the sling,

the number of times of bending is stored in the information storage unit for each of the load states.

5. The sling monitoring device as defined in claim 4, wherein:

the crane system has an end support device supporting an end of the sling,

the control section measures, as the number of bends, the number of bends in the sling in the vicinity of the end support.

6. A crane system capable of moving a heavy object held by a holding mechanism connected to a hoist rope, comprising:

a control unit for measuring the number of times the sling is bent;

an information storage unit that stores the number of times of bending measured by the control unit; and

a sling swing angle detecting device periodically detecting a sling swing angle of the sling,

the control part is used for controlling the operation of the motor,

receiving the hoist swing angle from the hoist swing angle detecting means,

and when the swing angle of the sling is larger than a threshold value and the change of the swing direction of the sling is detected, judging that the sling is bent, and counting the bending times of the sling.

7. The crane system of claim 6 wherein:

the control unit compares a previous value of the hoist swinging angle stored in the information storage unit as a previous time with a current value of the hoist swinging angle received from the hoist swinging angle detection device with respect to the change in the hoist swinging direction, and detects that the hoist swinging direction has changed when the current value is smaller than the previous value.

8. The crane system of claim 7 wherein:

9. The crane system as claimed in any one of claims 6 to 8, wherein:

the control part is used for controlling the operation of the motor,

estimating a load state for the sling,

10. The crane system of claim 9 wherein:

and an end support means for supporting an end of the sling,