Crane and crane control device

Abstract

To provide a crane and a crane control device capable of accurately grasping brake performance.SOLUTION: A calculation unit 52 calculates brake torque during braking of a brake 22. Thus, performance of the brake 22 can be grasped on the basis of reduction of the brake torque or the like related to the calculation result. In this case, for example, when the calculation unit 52 calculates the brake torque on the basis of information including a brake operation delay, the calculation result includes an error for real brake torque. On the other hand, the calculation unit 52 calculates the brake torque with the influence of the brake operation delay when the brake 22 operates into consideration. In this case, the calculation unit 52 can accurately calculate the brake torque.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a crane and a control device for the crane. [Background technology]

[0002] Patent Document 1 describes a crane that can perform brake failure diagnosis. In the crane in Patent Document 1, the number of rotations of the drive motor's rotating shaft is automatically measured from the time when the brake is applied to the drive motor until the drive motor stops. The measured value is input to a calculation device and compared with a reference value stored in the calculation device to judge the performance of the brake. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 58-100086 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned crane, the rotation angle (or the time required) is measured and the value is compared with a threshold value to determine the operating state of the brake (fault diagnosis), but since the rotation angle is from the start of operation to the stop, the transition state in between is not taken into consideration. Therefore, there is a problem that the performance of the brake cannot be grasped accurately.

[0005] An object of the present disclosure is to provide a crane and a crane control device that can accurately grasp brake performance. [Means for solving the problem]

[0006] A crane according to one aspect of the present disclosure includes a brake that brakes the operation of the crane, and a calculation unit that calculates the brake torque when the brake is applied, the calculation unit calculating the brake torque taking into account the effect of brake application delay when the brake is applied.

[0007] The calculation unit calculates the brake torque when the brake is applied. Therefore, it is possible to grasp the performance of the brake based on the reduction in brake torque related to the calculation result. Here, for example, if the calculation unit calculates the brake torque based on information that still includes the brake application delay, the calculation result will include an error with respect to the actual brake torque. In contrast, the calculation unit calculates the brake torque taking into account the influence of the brake application delay when the brake is applied. In this case, the calculation unit can calculate the brake torque with high accuracy. This makes it possible to grasp the performance of the brake with high accuracy.

[0008] The calculation unit may calculate the brake application delay. In this case, the calculation unit can calculate the brake torque with high accuracy by using the brake application delay calculated according to the situation, as compared with the case where a brake application delay prepared in advance is used. Furthermore, it is possible to grasp the performance of the brake using the calculated brake application delay.

[0009] The brake application delay may include a mechanical delay from when the brake application starts until the braking force is applied. In this case, the calculation unit can calculate the brake torque taking into account the delay caused by the mechanical factor of the brake.

[0010] The brake operation delay may include a control delay from when a control signal is sent to the brake to when the brake operation starts. In this case, the calculation unit can calculate the brake torque taking into account a delay caused by a control factor of the brake.

[0011] The calculation unit may calculate the brake torque taking into account the influence of external factors that affect the brake torque. In this case, the calculation unit can calculate the brake torque with high accuracy by taking into account the external factors.

[0012] A crane control device according to one aspect of the present disclosure is a control device for controlling a crane equipped with a brake for braking operation, and includes a calculation unit that calculates a brake torque when the brake is applied, and the calculation unit calculates the brake torque taking into account the effect of brake operation delay when the brake is applied.

[0013] According to this crane control device, it is possible to obtain the same functions and effects as the above-mentioned crane. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a crane and a crane control device that are capable of grasping brake performance with high accuracy. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing a crane according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a block diagram showing a block configuration of a crane according to an embodiment of the present invention. [Diagram 3] 5 is a graph showing the relationship between the motor rotation speed and time immediately before the brake is applied and when the brake is applied. [Figure 4] 11 is a graph for explaining a method in which a calculation unit calculates a brake action delay using approximation. [Diagram 5] 11 is a graph for explaining a method in which a calculation unit calculates a brake operation delay by using a threshold value. [Figure 6] 4 is a flowchart showing exemplary steps of the control content of the crane control device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted.

[0017] FIG. 1 is a diagram showing a crane 100 according to an embodiment of the present invention. In FIG. 1, a container crane is illustrated as the crane 100. The crane 100 includes legs 8, 9 arranged on a quay 4, and a boom 10 that is bridged between the legs 8, 9 and extends toward the sea. The cargo handling device 2 includes a hoisting device 12 that is movable along the boom 10. The leg 8 can run on the rail 6, and the leg 9 can run on the rail 7. The lower ends 8a, 9a of the legs 8, 9 are provided with traveling devices 13 for running along the rails 6, 7, respectively. The traveling devices 13 are provided for the legs 8, 9.

[0018] Next, a block configuration of a crane 100 according to an embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a block configuration diagram showing a block configuration of a crane 100 according to an embodiment of the present invention. As shown in Fig. 2, the crane 100 includes a state detection unit 20, a drive unit 21, a brake 22, an output unit 23, and a control device 50.

[0019] The status detection unit 20 is a device that detects information indicating various states of the crane 100 and various states of the surrounding environment of the crane 100. The status detection unit 20 is composed of various detection devices, such as a load sensor that detects the load acting on the crane 100 during loading and unloading, a temperature sensor that detects the disk temperature of each motor, and an anemometer that detects the wind direction, wind speed, and the like in the surrounding environment of the crane 100. The status detection unit 20 transmits information relating to the various states to the control device 50 as a status signal.

[0020] The drive unit 21 is a device that generates drive force for executing various operations of the crane 100. The drive unit 21 is composed of a motor for moving the hoisting device 12, a motor for hoisting and lowering the hoisting device 12, a motor for the traveling device 13, a motor for a hoisting device for raising and lowering the boom section 10, and drive devices such as an inverter for driving these motors. The drive unit 21 operates based on an operation command signal transmitted from the control device 50. In addition, the drive unit 21 transmits information indicating the state of the drive unit 21, such as the rotation speed of each motor, to the control device 50 as a state signal.

[0021] The brake 22 is a device that brakes various operations of the crane 100. The brake 22 is composed of a brake device that stops the rotation of each motor included in the drive unit 21. The brake 22 stops each motor by pressing a braking force applying member such as a lining against the disk of each motor. The brake 22 operates based on an operation command signal transmitted from the control device 50. In addition, the brake 22 transmits information indicating the state of the drive unit 21, such as the rotation speed of each motor, to the control device 50 as a state signal.

[0022] The output unit 23 is a device that outputs various information to an operator. The output unit 23 is configured, for example, with a monitor that outputs information as an image, a speaker that outputs information as a sound, a warning light that outputs information as a light, etc. The output unit 23 outputs various information based on a signal from the control device 50.

[0023] The control device 50 may be configured as a computer (also called an on-board automatic control PC) including, for example, a processor, a memory, a storage, and a communication interface. The processor is a computing device such as a CPU (Central Processing Unit). The memory is a storage unit such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The storage is a storage unit (storage medium) such as a flash memory, an SSD (Solid State Drive), or an HDD (Hard Disk Drive). The communication interface is a communication device that realizes data communication. The processor controls the memory, storage, and communication interface, and realizes the function of the control device 50 described later. In the control device 50, for example, a program stored in the ROM is loaded into the RAM, and the program loaded into the RAM is executed by the CPU to realize various functions. The number of computers constituting the control device 50 may be one or more.

[0024] The control device 50 includes an operation control unit 51, a calculation unit 52, a monitoring unit 53, and an output control unit 54.

[0025] The operation control unit 51 controls the operation of the crane 100. The operation control unit 51 transmits an operation command signal to the drive unit 21 in order to execute a desired operation of the crane 100. Furthermore, when the operation of the crane 100 is to be stopped, the operation control unit 51 transmits an operation command signal to the brake 22. For example, when the crane 100 is to hoist the hoisting device 12, the operation control unit 51 transmits an operation command to the hoisting motor to perform hoisting. Furthermore, when the hoisting of the hoisting device 12 is to be stopped, the operation control unit 51 transmits an operation command signal to the brake 22 corresponding to the hoisting motor to stop the rotation of the hoisting motor.

[0026] The calculation unit 52 calculates the brake torque when the brake 22 is applied. The calculation unit 52 calculates the brake torque by monitoring a change in the motor rotation speed of the motor of the drive unit 21 at any timing when the brake 22 is applied. In this embodiment, the calculation unit 52 calculates the brake torque taking into consideration the influence of a brake operation delay when the brake 22 is applied. The brake operation delay includes a mechanical delay from when the brake 22 starts to operate until the braking force is applied. The brake operation delay also includes a control delay from when a control signal is sent to the brake 22 to when the brake 22 starts to operate.

[0027] Here, an example of a method of calculating the brake torque by the calculation unit 52 and an example of a brake operation delay will be described with reference to FIG. 3. FIG. 3 is a graph showing the relationship between the motor rotation speed and time immediately before the brake 22 operates and when the brake 22 operates. The graph at the bottom of FIG. 3 is a graph showing the timing at which the brake 22 receives an operation command signal from the control device 50. This graph shows that the control device 50 transmits an operation command signal to the brake 22 to brake at the timing when the state changes from "Open" to "Close". As shown in FIG. 3, when stopping the motor, the operation control unit 51 decelerates the motor rotating at a constant speed (for example, rated, i.e., 100% output) to a predetermined motor rotation speed, and transmits an operation command signal to the brake 22 at the timing when the motor rotation speed is decelerated to the motor rotation speed.

[0028] In the following explanation, "N" indicates the motor rotation speed (rpm) of the motor to be stopped. "TS" indicates the calculation process start time (s) when the calculation unit 52 calculates the brake torque. "TE" indicates the calculation process completion time (s) when the calculation unit 52 calculates the brake torque. "NS" indicates the motor rotation speed (rpm) at the start of the calculation process. "NE" indicates the motor rotation speed (rpm) at the completion of the calculation process. In this case, the calculation unit 52 can calculate the brake torque BT of the brake 22 by the following formula (1). "GD2" indicates the moment of inertia. BT=GD2 × (|NS-NE|) / (375 × (|TS-TE|)) …(1)

[0029] Here, as shown in FIG. 3, the slope of the graph remains at "DC1" for a time "Δt1" after the operation control unit 51 transmits an operation command signal to the brake 22. This corresponds to a control delay from when the operation control unit 51 transmits an operation command signal to when the brake 22 receives the signal and starts operating. Therefore, "Δt1" can be said to indicate a control delay time (s). The slope of the graph when the brake 22 is fully generating a braking force is indicated by "DC3". In contrast, the slope of the graph becomes "DC2", which is larger than "DC1" and smaller than "DC3", for a time "Δt2" until the slope changes from "DC1" to "DC3". This corresponds to a mechanical delay from when the brake 22 comes into contact with the disk of the motor to when the brake 22 fully generates a braking force. Therefore, "Δt2" can be said to indicate a mechanical delay time (s). The calculation unit 52 calculates the brake torque taking into account the brake operation delay when the brake 22 operates, that is, the control delay time Δt1 and the mechanical delay time Δt2. Specifically, the calculation unit 52 sets the timing when the mechanical delay time Δt2 has elapsed as the calculation process start time TS. As a result, the slope of the graph from the calculation process start time TS to the calculation completion time TE is constant at "DC3" throughout the entire range. Therefore, the calculation unit 52 can calculate the brake torque by removing brake operation delay components that would cause the graph to have a slope of "DC1" or "DC2" from the range between the calculation process start time TS and the calculation completion time TE.

[0030] The calculation unit 52 may calculate the brake torque taking into account the influence of external factors that affect the brake torque. For example, the moment of inertia GD2 varies depending on the load condition. Therefore, the calculation unit 52 may calculate the brake torque after correcting the moment of inertia GD2 to take into account the variation due to the load condition. In addition, the calculation unit 52 may calculate the brake torque after temperature correction, taking into account the variation in the friction coefficient due to the disk temperature.

[0031] The calculation unit 52 may acquire the brake application delay by calculation. An example of a calculation method by which the calculation unit 52 calculates the brake application delay will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a graph for explaining a method by which the calculation unit 52 calculates the brake application delay using approximation. Fig. 5 is a graph for explaining a method by which the calculation unit 52 calculates the brake application delay using a threshold value.

[0032] Calculation of the braking deceleration α will be described with reference to FIG. n When calculating the braking deceleration α of the vehicle, n A small time range (t n-X ~t n+Y ), i.e., the deceleration during braking α is calculated. Note that nX and nY are positive integers. f " indicates the braking deceleration when the braking force of the brake 22 is fully applied. The calculation unit 52 calculates the braking deceleration α f You can calculate α m " indicates the deceleration during braking when the braking force of the brake 22 is rising. After transmitting the operation command signal to the brake 22, the calculation unit 52 n That is, the calculation unit 52 detects the transition of the braking deceleration α while proceeding. m The calculation unit 52 estimates the time until the braking deceleration becomes "α m " and then "α f The time until this happens is estimated to be the machine delay time Δt2.

[0033] As shown in FIG. 5, the calculation unit 52 calculates the braking deceleration α n For example, the calculation unit 52 may calculate n When calculating the braking deceleration α of the vehicle, nMotor rotation speed N at n Using equation (2), the deceleration during braking α n For example, in Fig. 5, "α f " indicates the deceleration during braking when the braking force of the brake 22 is fully applied. m " indicates an example of deceleration during braking when the braking force of the brake 22 is rising. After transmitting an operation command signal to the brake 22, the calculation unit 52 n While proceeding, the braking deceleration rate α n In other words, when the control delay time Δt1 ends, the slope of the graph of the motor rotation speed changes, so the braking deceleration α n The value of the braking deceleration α corresponding to the control delay time Δt1 changes suddenly. n If a predetermined threshold value is set for the braking deceleration α n When the mechanical delay time Δt2 ends, the control delay time Δt1 can be determined to have ended. This allows the calculation unit 52 to estimate the control delay time Δt1. Also, when the mechanical delay time Δt2 ends, the slope of the graph of the motor rotation speed changes, so that the braking deceleration α n The value of the braking deceleration α corresponding to the mechanical delay time Δt2 changes suddenly. n If a predetermined threshold value is set for the braking deceleration α n When the time t2 exceeds the threshold value, it can be determined that the mechanical delay time Δt2 has ended. This allows the calculation unit 52 to estimate the mechanical delay time Δt2. α n = (NE-N n ) / (TE-t n ) …(2)

[0034] The monitoring unit 53 monitors the state of the brake 22 based on the calculation result of the calculation unit 52. Specifically, the monitoring unit 53 monitors the state of the brake 22 by monitoring the brake torque calculated by the calculation unit 52. For example, when the brake torque related to the calculation result of the calculation unit 52 is lower than a specified value, the monitoring unit 53 can determine that the performance of the brake 22 has deteriorated due to equipment failure, poor maintenance, poor adjustment, or the like. Furthermore, the monitoring unit 53 may monitor the control delay time Δt1 and the mechanical delay time Δt2 calculated by the calculation unit 52. For example, the monitoring unit 53 can determine that the performance of the brake 22 has deteriorated when at least one of the control delay time Δt1 and the mechanical delay time Δt2 is longer than a specified value.

[0035] The monitoring unit 53 may make a judgment based on multiple calculation results. For example, the monitoring unit 53 may calculate an average value of multiple calculation results and use the average value to judge the performance degradation of the brake 22. At this time, if the calculation result is obviously excessive, the monitoring unit 53 may exclude it from the calculation of the average value, regarding it as a temporary error due to an external factor. The monitoring unit 53 may also make a judgment based on a single calculation result. For example, if oil or the like adheres to the brake 22, the value will vary greatly from the previous calculation result. Therefore, the monitoring unit 53 may judge the performance degradation of the brake 22 if the calculation result deviates significantly from the standard even once.

[0036] The output control unit 54 generates information to be output by the output unit 23, and outputs the information by the output unit 23. When the monitoring unit 53 determines that there has been a deterioration in the performance of the brake 22, the output control unit 54 issues a warning to the operator. Alternatively, the output control unit 54 may only issue a warning to the operator based on the monitoring result of the monitoring unit 53, and the actual determination of the deterioration in performance of the brake 22 may be made by the operator.

[0037] Furthermore, when the manner in which the performance of the brake 22 has deteriorated is known, the output control unit 54 may output the manner in which the performance has deteriorated. For example, when "the brake application delay time is normal, but the brake torque has decreased," the monitoring unit 53 may determine that the lining or disc has deteriorated or become dirty. When "the brake application delay time has increased, but the brake torque is normal," the monitoring unit 53 may determine that the brake mechanism or control device (relay, etc.) is malfunctioning. The output control unit 54 may output the details of these malfunctions.

[0038] The monitoring of the performance degradation of the brake 22 by the control device 50 as described above may be performed every time the crane 100 is operated. In this case, the control device 50 can constantly monitor the brake 22. In addition, an operation for measuring the brake torque may be performed at the timing of a regular inspection, when the crane is installed, or the like. In this case, an operation mode (measurement mode) that makes it easier for the calculation unit 52 to perform calculations may be set. For example, the operation control unit 51 may operate the brake 22 at an earlier timing than during normal operation. For example, the operation control unit 51 may operate the brake 22 at an earlier timing (for example, at the timing when the brake 22 is decelerated to a very slow speed during normal operation) in the measurement mode.

[0039] Next, an example of the control contents by the control device 50 of the crane 100 according to this embodiment will be described. Fig. 6 is a flowchart showing exemplary steps of the control contents by the control device 50 of the crane 100 according to this embodiment. The process shown in Fig. 6 is executed when the crane 100 is operating in a measurement mode during a loading and unloading operation or a periodic inspection.

[0040] First, the calculation unit 52 acquires information indicating various states from the state detection unit 20, the drive unit 21, and the brake 22 (step S1). Next, the calculation unit 52 calculates the brake torque and the brake action delay of the brake 22 (step S2). Next, the monitoring unit 53 determines whether or not the performance of the brake 22 has deteriorated based on the calculation result in step S2 (step S3).

[0041] If the monitoring unit 53 determines that the performance of the brake 22 has not deteriorated (YES in step S3), it stores the calculation result in a storage unit or the like. The monitoring unit 53 may then take into consideration the calculation result stored in the storage unit the next time it makes a determination. On the other hand, if the monitoring unit 53 determines that the performance of the brake 22 has deteriorated (NO in step S3), the output control unit 54 controls the output unit 23 to issue a warning (step S5) and stores the calculation result in a storage unit or the like.

[0042] Next, the operation and effect of the crane 100 and the control device 50 for the crane 100 according to this embodiment will be described.

[0043] The calculation unit 52 calculates the brake torque when the brake 22 is applied. Therefore, it is possible to grasp the performance of the brake 22 based on the reduction in brake torque related to the calculation result. Here, for example, if the calculation unit 52 calculates the brake torque based on information that still includes the brake application delay, the calculation result will include an error with respect to the actual brake torque. In contrast, the calculation unit 52 calculates the brake torque taking into account the influence of the brake application delay when the brake 22 is applied. In this case, the calculation unit 52 can calculate the brake torque with high accuracy. This makes it possible to grasp the performance of the brake 22 with high accuracy.

[0044] The calculation unit 52 may calculate the brake application delay. In this case, the calculation unit 52 can calculate the brake torque more accurately by using the brake application delay calculated according to the situation, as compared to the case where a brake application delay prepared in advance is used. Furthermore, it is also possible to grasp the performance of the brake using the calculated brake application delay.

[0045] The brake operation delay may include a mechanical delay (mechanical delay time Δt2) from when the operation of the brake 22 starts until the braking force acts. In this case, the calculation unit 52 can calculate the brake torque taking into account the delay caused by the mechanical factor of the brake 22.

[0046] The brake operation delay may include a control delay (control delay time Δt1) from when a control signal is transmitted to the brake 22 to when the brake 22 starts to operate. In this case, the calculation unit 52 can calculate the brake torque taking into account a delay caused by a control factor of the brake 22.

[0047] The calculation unit 52 may calculate the brake torque taking into account the influence of external factors that affect the brake torque. In this case, the calculation unit 52 can calculate the brake torque with high accuracy by taking into account the external factors.

[0048] The control device 50 of the crane 100 in this embodiment is a control device 50 that controls the crane 100 equipped with a brake 22 that brakes operation, and is equipped with a calculation unit 52 that calculates the brake torque when the brake 22 is applied, and the calculation unit 52 calculates the brake torque taking into account the effect of brake operation delay when the brake is applied.

[0049] According to this crane control device 50, it is possible to obtain the same functions and effects as the crane 100 described above.

[0050] The present invention is not limited to the above-described embodiments.

[0051] For example, the calculation unit 52 does not need to calculate the brake operation delay, and may obtain it by reading it from a storage unit or the like.

[0052] 4 and 5 is merely an example, and the calculation unit 52 may change the calculation method of the brake operation delay as appropriate. Also, the calculation method of the brake torque shown in FIG. 3 and formula (1) is merely an example, and the calculation unit 52 may change the calculation method of the brake torque as appropriate.

[0053] The type of crane 100 is not limited to a container crane as shown in FIG. 1, and other types of cranes such as an overhead crane or a bridge crane may be used. [Explanation of symbols]

[0054] 22...brake, 50...control device, 52...calculation unit, 100...crane.

Claims

1. A brake for controlling the operation of the crane; A calculation unit that calculates a brake torque when the brake is applied; A monitoring unit that monitors a state of the brake based on a calculation result of the calculation unit, The calculation unit calculates the brake torque taking into consideration an effect of a brake operation delay when the brake is operated, The monitoring unit monitors the state of the brake by monitoring the brake torque calculated by the calculation unit during operation of the crane during normal operation.

2. The crane according to claim 1 , wherein the calculation unit calculates the brake operation delay.

3. The crane according to claim 1 or 2, wherein the brake operation delay includes a mechanical delay from when the brake operation starts until the braking force is applied.

4. The crane according to any one of claims 1 to 3, wherein the brake operation delay includes a control delay from when a control signal is transmitted to the brake to when the brake operation starts.

5. A crane described in any one of claims 1 to 4, wherein the calculation unit estimates the control delay time by grasping the transition of deceleration during braking as time advances after an operation command signal is sent to the brake.

6. The calculation unit estimates a time from a braking deceleration at the time of rise of the braking force of the brake to a braking deceleration at the time when the braking force of the brake is fully applied as a mechanical delay time, The crane according to claim 5 , wherein the monitoring unit monitors the control delay time and the machine delay time.

7. The crane according to any one of claims 1 to 4, wherein the calculation unit calculates the brake torque taking into account an influence of an external factor that affects the brake torque.

8. A crane control device for controlling a crane equipped with a brake for braking an operation, comprising: A calculation unit that calculates a brake torque when the brake is applied; A monitoring unit that monitors a state of the brake based on a calculation result of the calculation unit, The calculation unit calculates the brake torque taking into consideration an effect of a brake operation delay when the brake is operated, A crane control device, wherein the monitoring unit monitors the state of the brake by monitoring the brake torque calculated by the calculation unit during operation of the crane during normal operation.

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