Method for preventing runaway speed of a crane, programmable controller and system

Abstract

The application provides a crane operation speed out-of-control prevention method, a programmable controller and a system, and relates to the technical field of cranes. The method is applied to a crane device. The crane device is provided with a PLC and a speed regulating device. The PLC is electrically connected with a brake control loop. The crane operation speed out-of-control prevention method comprises the following steps: when the speed regulating device receives a stop instruction signal, the speed regulating device sends a first brake closing signal to control the brake of the crane device to close; and after the stop instruction signal is output for a first preset time length, the PLC sends a second brake closing signal to control the brake of the crane device to close again. The whole brake action is double-controlled by the speed regulating device and the PLC, that is, the speed regulating device first performs the brake action, and then the brake is controlled by the PLC, so that the probability of the occurrence of a hook slipping or vehicle slipping event caused by the out-of-control of the operation speed of the lifting and translation mechanism of the crane is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cranes, in particular to a method for preventing speed out of control of a crane, a programmable controller and a system. BACKGROUND

[0002] At present, more and more lifting mechanisms and translation mechanisms of hoisting equipment use various frequency converters and various stator voltage regulating speed regulating devices. In actual operation, it is found that hoisting equipment using various frequency converters and stator voltage regulating speed regulating devices has a serious safety hazard: when hoisting heavy load, the lifting mechanism or the translation mechanism is from running to stopping. In this process, if the brake adjustment is not good, the heavy load will drag the hook head down to the hook after the speed is reduced to zero, or there is a car sliding phenomenon when the translation mechanism of the car stops at high speed. At this time, the speed regulating device is still in the excitation maintaining stage. At this time, the speed regulating device does not receive any operation instruction, and the brake closing signal should be sent. At this time, the heavy load drags the hook head down to the hook slowly, and the motor is in motion, so that the motor loop of the frequency converter or the stator voltage regulating speed regulating device has current passing through, which will misjudge as receiving operation instruction, so as to continue to open the brake, so that the brake cannot be stopped, resulting in speed out of control of various running mechanisms and hook or car sliding (speed out of control) accidents.

[0003] In summary, in the prior art, the speed regulating device controls the closing of the brake by detecting the actual value of the running speed of the crane lifting and translation mechanism. However, in actual production operation process, even if the speed regulating device stop signal is given, the brake cannot be accurately stopped. SUMMARY

[0004] The problem solved by the present application is how to prevent the running speed of the crane lifting and translation mechanism from being out of control to some extent.

[0005] To solve the above problems, the present application provides a method for preventing speed out of control of a crane, a programmable controller and a system.

[0006] In a first aspect, the present application provides a method for preventing speed out of control of a crane, which is applied to a crane equipment, the crane equipment is provided with a PLC and a speed regulating device, the PLC is electrically connected with a brake control loop, and the method comprises the following steps:

[0007] When the speed regulating device receives a stop instruction signal, the speed regulating device sends a first brake closing signal to control the closing of the brake of the crane equipment;

[0008] When the stop instruction signal is output for a first preset time length, the PLC sends a second brake closing signal to control the closing of the brake of the crane equipment again.

[0009] Optionally, the first brake closing signal is sent by the speed regulating device when the speed regulating device receives the stop instruction signal, comprising:

[0010] The forward and reverse signals of the running mechanism controlled by the remote control device of the crane equipment or the zero position signal of the cam controller of the crane equipment are used to determine whether the running mechanism is in a running state;

[0011] When the main hook or the auxiliary hook of the running mechanism is in a running state, if the speed regulating device of the crane equipment receives the stop instruction signal, the speed regulating device sends a first brake closing signal.

[0012] Optionally, the control mode of the crane equipment includes remote control, and the PLC sends a second brake closing signal to control the brake closing of the crane equipment again after the stop instruction signal is output for a first preset time length, comprising:

[0013] If the control mode of the crane equipment is the remote control, when the stop instruction signal is output, the PLC changes the series signal of the normally closed input point, the main lifting and lowering one gear %I4.2 point and the main lifting and rising one gear %I4.1 point from off to on, and after a preset time length, the PLC sends a set signal to set the auxiliary point %M5.1 point to on, and controls the brake output point %Q16.0 to output the second brake closing signal to control the brake of the crane equipment.

[0014] Optionally, the control mode of the crane equipment includes rack control, and the PLC sends a second brake closing signal to control the brake closing of the crane equipment again after the stop instruction signal is output for a first preset time length, comprising:

[0015] If the control mode of the crane equipment is the rack control, when the first brake closing signal is not output, the PLC controls the main lifting zero point %I0.0 point to change from off to on through the normally open input point, and after a preset time length, the PLC sends a set signal to set the auxiliary point %M5.1 point to on, and controls the brake output point %Q16.0 to output the second brake closing signal to control the brake of the crane equipment.

[0016] Optionally, the control of the brake output point %Q16.0 to output the second brake closing signal to control the brake of the crane equipment comprises:

[0017] After the brake output point %Q16.0 outputs the second brake closing signal, the relay KA1 of the brake control loop is powered on to control the brake closing.

[0018] Optionally, the brake control circuit is installed in a weak current control area of a governor control cabinet of the crane device.

[0019] Optionally, the method for preventing the crane running speed from out of control further comprises:

[0020] According to the application environment, load characteristics and use frequency of the governor of the crane device, the stop excitation holding time of the governor and the brake closing frequency of the brake are set.

[0021] Optionally, the method for preventing the crane running speed from out of control further comprises:

[0022] When the governor judges incorrectly and the first brake closing signal is not output, after the first preset time interval, the PLC sends the second brake closing signal to control the brake of the crane device to close again.

[0023] The method for preventing the crane running speed from out of control has the following advantages: the PLC and the governor are arranged on the crane device, so that when the governor receives a stop instruction, the governor first performs a deceleration action and sends a corresponding brake closing signal, the crane device first performs a brake action, receives the stop instruction signal output and after a preset time interval, the PLC outputs a corresponding brake signal, and the crane device performs a brake action again; the entire brake action is controlled by the governor and the PLC, i.e., the governor first performs a brake action, and then the PLC controls the brake to close, so that the probability of the brake being opened due to incorrect judgment of the governor is reduced, the probability of the crane lifting and translation mechanism running speed out of control and causing a hook or vehicle sliding event is reduced, and the safety of the crane running is further ensured.

[0024] In the second aspect, the application provides a programmable controller, which comprises a memory, a processor and a programmable control program stored in the memory and executable on the processor, and the programmable control program is executed by the processor to realize the method for preventing the crane running speed from out of control.

[0025] The programmable controller and the method for preventing the crane running speed from out of control have the same advantages as those of the prior art, which will not be repeated here.

[0026] In the third aspect, a system for preventing the crane running speed from out of control comprises the method for preventing the crane running speed from out of control and the programmable controller.

[0027] The system for preventing the crane running speed from out of control and the method for preventing the crane running speed from out of control have the same advantages as those of the prior art, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Flow chart of the method for preventing the speed of the crane from running out of control for the embodiment of the present application;

[0029] Figure 2 Program segment 3 in the PLC logic control program for controlling the 75-ton main hook brake for the embodiment of the present application;

[0030] Figure 3 Program segment 4 in the PLC logic control program for controlling the 75-ton main hook brake for the embodiment of the present application;

[0031] Figure 4 Program segment 7 in the PLC logic control program for controlling the 50-ton main hook brake for the embodiment of the present application;

[0032] Figure 5 Program segment 8 in the PLC logic control program for controlling the 50-ton main hook brake for the embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings.

[0034] In the first aspect, in combination with Figure 1 As shown in the drawings, the present application provides a method for preventing the speed of a crane from running out of control, which is applied to a crane device, wherein the crane device is provided with a PLC and a speed regulating device, the PLC is electrically connected with a brake control loop, and the method comprises the following steps:

[0035] When the speed regulating device receives a stop instruction signal, the speed regulating device sends a first brake closing signal to control the brake of the crane device to close.

[0036] Specifically, when the speed regulating device of the crane device receives a stop instruction, the speed regulating device sends a corresponding brake signal according to the stop instruction, i.e. a first brake closing signal; when the crane device receives the first brake closing signal sent by the speed regulating device, the brake can be controlled to close, thereby braking, wherein the speed regulating device can be a frequency converter or a stator voltage regulating device.

[0037] In the preferred embodiment of the present application, the brake can be controlled to brake by controlling a 24V relay, wherein the opening and closing of the brake is controlled by switching the normally open contact and the normally closed contact of the relay.

[0038] When the stop instruction signal is output for a first preset time length, the PLC sends a second brake closing signal to control the brake of the crane device to close again.

[0039] Specifically, when the crane device receives the first brake closing signal, the first brake action is performed, and after the stop instruction signal output lasts for a first preset time length, the PLC outputs a second brake closing signal to control the brake switch.

[0040] In the preferred embodiment of the present application, when the crane device receives the stop instruction signal output and closes the brake for a first preset time length or when the crane device does not receive the first brake closing signal, the second brake control is performed by controlling the relay of the brake. Specifically, when the crane device receives the second brake closing signal from the PLC, the 24V relay of the brake is controlled to control the brake of the crane device to act, wherein the brake is closed in time by the relay to prevent the hook slipping phenomenon.

[0041] The crane speed control method prevents the crane from running out of control by providing a PLC and a speed regulating device on the crane device, so that when the speed regulating device receives a stop instruction, the speed regulating device first performs a speed reduction action and sends a corresponding brake closing signal, the crane device first performs a brake action, receives the stop instruction signal output, and after a preset interval, the PLC outputs a corresponding brake signal, and the crane device performs a brake action again. The entire brake action is controlled by the speed regulating device and the PLC, i.e., the speed regulating device first performs the brake action, and then the PLC controls the brake to close, thereby reducing the probability of the speed regulating device misjudging the opening of the brake, and reducing the probability of the crane lifting and translation mechanism running out of control and causing the hook or vehicle slipping event, and further ensuring the safety of the crane operation.

[0042] Optionally, when the speed regulating device receives the stop instruction signal, the speed regulating device sends a first brake closing signal, which includes:

[0043] The forward and reverse signals of the running mechanism controlled by the remote control device of the crane device or the zero position signal of the cam controller of the crane device are used to determine whether the running mechanism is in a running state;

[0044] When the main hook or the auxiliary hook of the running mechanism is in a running state, if the speed regulating device of the crane device receives the stop instruction signal, the speed regulating device sends a first brake closing signal

[0045] In the embodiment, there are two control modes for the control of the speed regulation device of the crane, one is remote control, and the other is gantry control. The remote control is to judge whether the running mechanism is running through the forward and reverse signals of the running mechanism, and the gantry control is to judge whether the running mechanism is in the running state through the zero signal of the cam controller. When the main hook or the auxiliary hook of the running mechanism is in the running state, when the PLC and the speed regulation device of the crane equipment receive a stop instruction, the speed regulation device sends a first brake closing signal to control the brake to be closed first.

[0046] Optionally, the control mode of the crane equipment includes remote control, and the PLC sends a second brake closing signal to control the brake of the crane equipment to be closed again after the stop instruction signal is output for a first preset time length, including:

[0047] If the control mode of the crane equipment is the remote control, when the stop instruction signal is output, the PLC changes the series signal of the normally closed input point, the main lifting and lowering first gear %I4.2 point and the main lifting and rising first gear %I4.1 point from off to on through the normally closed input point, and after a preset time length, the PLC sends a set signal to set the auxiliary point %M5.1 point to on, and controls the brake output point %Q16.0 to output the second brake closing signal to control the brake of the crane equipment.

[0048] Specifically, whether the running mechanism is in the running state is judged through the forward and reverse signals or the zero signal of the running mechanism of the crane equipment. When the main hook or the auxiliary hook of the running mechanism is in the running state, the PLC and the speed regulation device of the crane equipment receive a stop instruction, the gear switching sequence of the main hook or the auxiliary hook of the crane equipment is zero, first gear, second gear, third gear and fourth gear, and the gear switching sequence of the main hook or the auxiliary hook of the crane equipment is fourth gear, third gear, second gear, first gear and zero. The PLC controls the brake control loop, and the gear of the main hook or the auxiliary hook of the crane equipment is switched from zero to first gear, and then increased from first gear to fourth gear, and runs at fourth gear. The whole process controls the brake not to act, and when the gear of the main hook or the auxiliary hook of the crane equipment is decreased from first gear to zero, the brake is controlled to be closed in combination with Figure 2As shown, the series signals of the main lifting down first gear %I4.2 and the main lifting up first gear %I4.1 change from off to on, the timer "TON Time" starts to count down 2 seconds, and the post bit signal "%M5.1" is on after 2 seconds. The holding brake control output "%Q16.0" is output. When the holding brake control output "%Q16.0" is output, the holding brake control loop KA1 normally closed point is disconnected, the coil of the contactor is powered off, the holding brake motor is forced to lose power, and the holding brake is tightly held on the holding brake wheel. In this embodiment, the running time (i.e., the preset time) can be 5 seconds, and can be artificially set and adjusted according to actual conditions. The gear shifting sequence is zero-1-2-3-4, and the crane device runs for 5 seconds in the 4-3-2-1-zero position. The preset time can be 2 seconds, that is, the normally open input point %M5.1 is on after 2 seconds, and the control output point %Q16.0 outputs the second holding brake closing signal to control the holding brake of the crane device.

[0049] Optionally, the control mode of the crane device includes gantry control, and the PLC sends the second holding brake closing signal to control the holding brake of the crane device again after the first preset time when the stop instruction signal is output.

[0050] If the control mode of the crane device is the gantry control, when the first holding brake closing signal is not output, the PLC controls the normally open input point, the main lifting zero %I0.0 point changes from off to on, and the PLC sends the set bit signal after the preset time. The set bit %M5.1 point is on, and the control holding brake output point %Q16.0 outputs the second holding brake closing signal to control the holding brake of the crane device.

[0051] Specifically, whether the running mechanism is in a running state is determined by the zero signal of the cam controller of the crane device. When the main hook or the auxiliary hook of the running mechanism is in a running state, the PLC and the speed regulating device of the crane device receive a stop instruction, the gear shifting sequence of the main hook or the auxiliary hook of the crane device is zero, first gear, second gear, third gear, and fourth gear, and the crane device runs for a period of time. The gear shifting sequence of the main hook or the auxiliary hook of the crane device is fourth gear, third gear, second gear, first gear, and zero. The PLC controls the holding brake control loop, the gear of the main hook or the auxiliary hook of the crane device is switched from zero to first gear, and then increased from first gear to fourth gear. The crane device runs in the fourth gear, and then decreases from the fourth gear to the first gear. The whole process controls the holding brake not to act. When the gear of the main hook or the auxiliary hook of the crane device decreases from the first gear to the zero, the PLC controls the holding brake control loop to control the holding brake of the crane device to close. Figure 3As shown, the input point "main lift zero position % I0.0" turns on the activation timer, the timer "TON Time" starts counting down 2 seconds, and the set signal is sent out after 2 seconds, the set auxiliary point % M5.1 point is turned on, and the control output point % Q16.0 outputs the second brake closing signal to control the brake of the crane equipment. The time interval of the entire gear shifting operation in this embodiment can be 5S, that is, the gear shifting sequence is zero-1-2-3-4, running for 5 seconds, and then 4-3-2-1-zero, wherein the preset time length can be 2 seconds, that is, after the normally closed contact is turned on for 2 seconds, the set signal is sent out, the normally closed contact of the brake control circuit is disconnected, the brake control circuit is controlled, and the brake is controlled to act. It should be noted that in this embodiment, the long-closed input point is a long-closed contact, and the long-open input point is a long-open contact.

[0052] In this embodiment, the selection of the control mode (remote control or frame control) can be selected according to the actual situation. Remote control is that the operator controls the operation of each mechanism of the crane through the remote controller, and frame control is that the operator needs to climb to the high-altitude cab of the crane to control the operation of each mechanism of the crane. Remote control can save the physical effort of the operator climbing to the cab (the height of the cab is greater than 30 meters), facilitate the same operator to operate in different cranes, and improve work efficiency (each operator in the cab is fixed time in the cab because of the time-consuming and laborious climbing). The operator in the high-altitude cab operates each operating mechanism of the crane, has a wide view, can observe the safety situation around the operating environment, and timely reminds the ground crane personnel.

[0053] Alternatively, the control brake output point % Q16.0 outputs the second brake closing signal to control the brake of the crane equipment.

[0054] After the brake output point % Q16.0 outputs the second brake closing signal, the relay KA1 of the brake control circuit is powered on to control the brake to close.

[0055] Specifically, the PLC controls the brake control circuit, and after the output point % Q16.0 outputs the second brake closing signal, the relay KA1 of the brake control circuit is powered on, the normally closed point of the brake control circuit KA1 is disconnected, the coil of the brake power contactor is powered off, the brake motor is forced to lose power, and the brake is tightly held on the brake wheel.

[0056] In the embodiment, when the PLC and the speed regulating device of the crane equipment receive a stop instruction, the speed regulating device preferentially performs a deceleration action and sends a first brake closing signal; the brake described in the embodiment is controlled by the speed regulating device and the PLC, which not only ensures that the high-speed rotating motor is braked to a certain extent, and then the system monitors the speed to reach a low speed to give a brake disconnection signal, and the brake is disconnected at low speed, thereby reducing the mechanical wear of the brake, but also the PLC controls the brake to ensure the probability of the system misjudging the opening of the brake and ensure the safety of the crane equipment operation.

[0057] Optionally, the brake control circuit is installed in a weak current control area of a speed regulating device control cabinet of the crane equipment.

[0058] In the embodiment, the brake control circuit is installed in a weak current control area of a speed regulating device control cabinet of the crane equipment, so that the brake output is convenient for wiring, and signal interference can be avoided.

[0059] Optionally, the method for preventing the speed of the crane from running out of control further comprises:

[0060] According to the application environment, load characteristics and use frequency of the speed regulating device of the crane equipment, the stop excitation holding time of the speed regulating device and the brake closing frequency of the brake are set.

[0061] In the embodiment, the parameters related to the brake control of the speed regulating device (frequency converter) can be set according to the application environment, load characteristics and use frequency of the speed regulating device. The stop excitation holding time of the speed regulating device is generally set to 30s by default at the factory, and is set to 1-2s in the embodiment. The brake closing time is set to 0.3-0.5s through actual measurement, and the brake frequency is set to 1-2Hz according to the start-stop frequency of the running mechanism.

[0062] Optionally, the method for preventing the speed of the crane from running out of control further comprises:

[0063] When the speed regulating device makes a mistake and the first brake closing signal is not output, after the first preset time interval, the PLC sends the second brake closing signal to control the brake of the crane equipment to close again.

[0064] Specifically, when the speed regulating device makes a mistake and the first brake closing signal is not output due to a stop instruction signal output, after the first preset time interval (2s), the PLC sends the second brake closing signal to control the brake of the crane equipment to close again.

[0065] The crane operation speed runaway prevention method provided by the application has the advantages that the PLC and the speed regulating device are arranged on the crane equipment, so that when the speed regulating device receives a stop instruction, the speed regulating device first performs a deceleration action and sends a corresponding brake closing signal, the crane equipment first performs a brake action, when there is a stop instruction signal output, the speed regulating device does not send a brake closing signal due to a logical error, and after a preset time interval, the PLC sends a corresponding brake signal, so that the probability of the brake being opened due to a logical error of the speed regulating device is ensured, the probability of a hook slipping due to the operation speed runaway of the lifting and translation mechanism of the crane is reduced, and the safety of the crane operation is further ensured.

[0066] In a preferred embodiment, the crane operation speed runaway prevention method provided by the application takes the PLC logic state of the 75-ton main hook brake control as an example, and is combined with the schematic diagrams shown in Figure 2 and Figure 3 , wherein Figure 2 is a program segment 3 in the PLC logic control program, Figure 3 is a program segment 4 in the PLC logic control program, and specifically includes the following steps:

[0067] I. Select remote control

[0068] Step 1: When all the running mechanisms of the crane are in a stationary state, switch to the remote control mode, at this time, the normally open input "selection of the crane control remote control %I1.0" in the second row of the program segment 3 and the program segment 4 is connected, and the selection of the remote control is successful.

[0069] Step 2: The remote control main hook is opened downward, the gear switching sequence is zero-1-2-3-4, and the operation is performed for 5 seconds, and the gear is switched to 4-3-2-1-zero.

[0070] Step 3: When the gear is switched from zero to 1, the normally open input point "main lifting and lowering first gear %I4.2" is connected, at this time, the brake control output "%Q16.0" is reset and not output, the relay normally closed contact in the brake control loop is not in action and is in the connected state. At this time, the normally closed input point "main lifting and lowering first gear %I4.2" in the second row of the program segment 4 is in the disconnected state, and the timer "TON Time" is reset.

[0071] Step 4: During the process of switching the gear from 1 to 4, operating the gear for 5 seconds at 4, and switching the gear from 4 to 1, the brake control output "%Q16.0" is always not output, and the timer "TON Time" is always in the reset waiting state.

[0072] Step 5: When the gear is from 4 to 0, the normally open input point "main up and down one gear % I4.2" is from on to off, reset, and wait for the on signal "% M5.1". Since the gear is back to 0, the normally closed input point "main up and down one gear % I4.2" is from off to on, and the timer "TON Time" starts counting down 2 seconds. After 2 seconds, the set signal "% M5.1" is on, and the brake control output "% Q16.0" is output.

[0073] Step 6: When the brake control output "% Q16.0" is output, the brake control circuit KA1 normally closed contact is off, the contactor K70 coil is powered off, and the forced brake motor is powered off, so that the brake is tightly clamped on the brake wheel.

[0074] In this embodiment, when the main hook is opened upward, that is, the normally open input point "main up and down one gear % I4.1" is on, the control logic is the same as the main hook opening downward.

[0075] II. Selection of frame control

[0076] Step 1: When the crane is in a stationary state, switch to frame control. At this time, the normally closed input "selection frame control remote control % I1.0" of the first line of program segment 3 and the first line of program segment 4 is on, and the selection frame control is successful.

[0077] Step 2: Frame control is judged by the zero signal of the cam controller whether the running mechanism is in running state, and remote control is judged by the forward and reverse signals of the running mechanism whether the running mechanism is running. Demonstrate frame control of main hook opening downward and upward, gear switching sequence is zero-1-2-3-4, running 5 seconds, 4-3-2-1-zero.

[0078] Step 3: First, the main hook is opened upward. When the gear is away from zero, the normally closed input "main up and down zero % I0.0" of the first line of program segment 3 is on, and the normally open input "main up and down zero % I0.0" of the first line of program segment 4 is off. At this time, the brake control output "% Q16.0" is reset and not output, and the relay KA1 normally closed contact in the brake control circuit is not actuated and is in the on state. At this time, the normally open input point "main up and down zero % I0.0" in the first line of program segment 4 is in the off state, and the timer "TON Time" is reset.

[0079] Step 4: During the process of gear from 1 to 4, running 5 seconds at 4, and gear from 4 to 1, the brake control output "% Q16.0" is always not output, and the timer "TON Time" is always in reset state.

[0080] Step 5: When the gear is from 4th gear to zero, the normally closed input point "main lift zero % I0.0" is changed from on to off, the reset is cancelled, and the set signal "% M5.1" is on. Because the gear is back to zero, the normally open input point "main lift zero % I0.0" is changed from off to on, the timer "TON Time" starts to count down for 2 seconds, and the set signal "% M5.1" is on after 2 seconds. The output of the brake control output "% Q16.0" is KA1.

[0081] Step 7: When the brake control output "% Q16.0" is output, KA1 is powered on, the brake control circuit KA1 normally closed contact is disconnected, the brake contactor K70 coil is powered off, the brake motor is forced to lose power, and the brake is clamped to the brake wheel.

[0082] In this embodiment, the main hook downward opening action process is the same as the main hook upward opening; the auxiliary hook brake control principle is the same as the main hook brake control principle.

[0083] In this embodiment, the brake control output "% Q16.0" controls the 24V relay KA1, and the normally closed contact of KA1 is connected in series with the normally closed contact of the brake output relay K06. When the crane is normally working, the brake is disconnected through K06 relay, and KA1 is slightly delayed. When the crane runs into failure, KA1 can be disconnected in time to close the brake and prevent the hook from slipping.

[0084] In another preferred embodiment, the method for preventing the crane from running out of control is illustrated by taking the 50-ton main hook brake control PLC logic state as an example. Figure 4 and Figure 5 As shown in Figure 4 is the program segment 7 in the PLC logic control program, Figure 5 is the program segment 8 in the PLC logic control program, and specifically includes the following steps:

[0085] I. Cage control

[0086] Step 1: In the state that the crane main hook running mechanism is stopped, the cage control has no remote control device. At this time, the positive and negative input points I0.1 and I0.2 of the main hook main order controller in the program segment 7 are closed, the zero input point I0.0 of the main hook main order controller is opened, the main hook zero delay brake flag M200.0 is turned on after 2 seconds, the M200.0 closed point in the program segment 8 is opened, the main hook zero delay output signal Q6.3 is powered off, the brake control relay XK3 is powered off, and the brake is clamped.

[0087] Step 2: The gear control is judged by the zero signal and the forward and reverse signals of the cam controller to determine whether the operating mechanism is in the operating state. The demonstration gear control controls the main hook to open downward and upward, and the gear switching sequence is zero-1-2-3-4, and the operation is 5 seconds, and 4-3-2-1-zero.

[0088] Step 3: First, the main hook opens upward, when the gear is away from zero, the main hook main order controller positive input point I0.1 closed point opens and negative input point I0.2 closed point closes, and the main hook main order controller zero input point I0.0 open point opens, at this time the zero return delay of the timer main hook is disconnected, the M200.0 closed point in the program segment 8 is closed, the main hook zero return delay output signal Q6.3 is powered on, the brake control relay XK3 is powered on, the system control brake relay KA1 is powered on, the KM1 contactor is powered on, and the brake is opened.

[0089] Step 4: In the process of increasing the gear from 1 to 4, operating for 5 seconds in 4, and reducing the gear from 4 to 1, at this time the zero return delay of the timer main hook is disconnected, the M200.0 closed point in the program segment 8 is closed, the main hook zero return delay output signal Q6.3 is powered on, the brake control relay XK3 is powered on, the system control brake relay KA1 is powered on, the KM1 contactor is powered on, and the brake is opened.

[0090] Step 5: When the gear is reduced from 4 to zero, at this time the main hook main order controller positive input point I0.1 closed point in the program segment 7 is closed, and the negative input point I0.2 closed point is closed, and the main hook main order controller zero input point I0.0 open point is closed, at this time the main hook zero return delay is connected after 2S, the M200.0 closed point in the program segment 8 is opened, the main hook zero return delay output signal Q6.3 is powered off, the brake control relay XK3 is powered off, the KM1 contactor is powered off, and the brake is forced to be closed. Note: The main hook downward opening action process is the same as the main hook upward action process.

[0091] In this embodiment, the brake control output "% Q6.3" controls the 24V relay XK3, and the normally open point of XK3 is connected in series with the relay KA1 normally open point of "brake output". When the crane is normally working, when the zero return stops, the KA1 normally open point opens slightly later than KA1, when the crane runs in failure, causing KA1 open point to be constantly open, XK3 can be disconnected in time, and the brake is closed in time to prevent the hook from slipping. The secondary hook brake control principle is the same as the main hook brake control principle.

[0092] In a second aspect, the present application provides a programmable controller, comprising a memory, a processor and a programmable controller program stored in the memory and executable on the processor, wherein the processor executes the programmable controller program to implement the above-mentioned method for preventing the speed of the crane from running out of control.

[0093] The programmable controller and the method for preventing the speed of the crane from running out of control have the same advantages over the prior art, which will not be repeated here.

[0094] In a third aspect, the present application provides a system for preventing the speed of the crane from running out of control, which comprises the method for preventing the speed of the crane from running out of control and the programmable controller.

[0095] The system for preventing the speed of the crane from running out of control has the same advantages over the prior art as the method for preventing the speed of the crane from running out of control, which will not be repeated here.

[0096] Although the present application is disclosed as above, the protection scope of the present application is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and these changes and modifications shall fall within the protection scope of the present application.

Claims

1. A method for preventing runaway speed of a crane, characterized in that, The method is applied to crane equipment, which is equipped with a PLC and a speed control device. The PLC is electrically connected to the brake control circuit. The method for preventing the crane's operating speed from running out of control includes: When the speed regulating device receives a stop command signal, the speed regulating device issues a first brake closing signal to control the brake of the crane equipment to close. Wherein, when the speed regulating device receives a stop command signal, the speed regulating device issues a first brake closing signal, including: The crane equipment's remote control device controls the forward and reverse signals of the operating mechanism, or the crane equipment's cam controller sends a zero-position signal to determine whether the operating mechanism is in operation. When the main hook or auxiliary hook of the running mechanism is in operation, if the speed regulating device of the crane equipment receives the stop command signal, the speed regulating device issues the first brake closing signal. After the stop command signal is output for a first preset time, the PLC sends a second brake closing signal to control the brake of the crane equipment to close again. If the control method of the crane equipment is remote control, when the stop command signal is output, the PLC changes the series signal of the main hoisting down one gear %I4.2 and the main hoisting up one gear %I4.1 through the normally closed input point from disconnected to connected. After a preset time, the PLC sends a set signal, the set auxiliary point %M5.1 is connected, and the brake output point %Q16.0 is controlled to output the second brake closing signal to control the brake of the crane equipment. If the control mode of the crane equipment is frame control, when the first brake closing signal is not output, the PLC changes the open position of the main lifting zero position %I0.0 through the normally open input point to the closed position. After a preset time, the PLC sends a set signal, sets the auxiliary position %M5.1 to the closed position, and controls the brake output point %Q16.0 to output the second brake closing signal to control the brake of the crane equipment. If the speed control device makes an error and the first brake closing signal is not output, after an interval of the first preset time, the PLC sends the second brake closing signal to control the brake of the crane equipment to close again.

2. The method for preventing uncontrolled crane operating speed according to claim 1, characterized in that, The control brake output point %Q16.0 outputs the second brake closing signal to control the brake of the crane equipment, including: After the brake output point %Q16.0 outputs the second brake closing signal, the relay KA1 of the brake control circuit is energized to control the brake to close.

3. The method for preventing uncontrolled crane operating speed according to claim 1, characterized in that, The brake control circuit is installed in the low-voltage control area of ​​the speed control device control cabinet of the crane equipment.

4. The method for preventing uncontrolled crane operating speed according to claim 1, characterized in that, The method for preventing uncontrolled crane operating speed also includes: Based on the application environment, load characteristics, and usage frequency of the speed control device of the crane equipment, the shutdown excitation holding time of the speed control device and the brake closing frequency of the brake are set.

5. A programmable controller, comprising a memory, a processor, and a programmable control program stored in the memory and executable on the processor, characterized in that, When the processor executes the programmable control program, it implements the method for preventing crane running speed from getting out of control as described in any one of claims 1 to 4.

6. A system for preventing uncontrolled speed movement of a crane, characterized in that, Applied to the method for preventing runaway crane operating speed as described in any one of claims 1-4 and the programmable controller as described in claim 5.

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