JPS61235395A - Travelling positioning method of crane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for determining the running position of a crane. Specifically, the present invention relates to a method for determining the traveling position of a crane. The present invention relates to a method for stopping the running of a running wheel through different braking processes as necessary while taking into account the relationship with other running wheels. This is used in the field of cranes, for example in coil yards, which run along two wide, separated tracks.

[Prior art]

When rolled steel strips are coiled in a steel mill and transported to the next process, the coils are first stored in a coil yard. The coil yard has many coil skids arranged in an orderly manner, and coils are brought in from the previous process and taken out to the next process using cranes installed on the yard. The crane is equipped with a girder that runs vertically on the coil skid and a club that runs horizontally on the girder.Tongs for grasping the coil are suspended from the club, and a pair of claws are inserted into the coil hole. This allows the coil to be lifted, lowered and transported.

By the way, since the girder is provided so as to straddle the yard, the distance between both tracks is significantly longer than the longitudinal width of the girder. Moreover, since the club moves sideways on the girder and suspends the coil, the center of gravity of the crane itself fluctuates. In addition, a certain amount of clearance is secured between the collar provided on the running wheel and the track. As a result of these factors, the girder often moves in a meandering manner on the track. Although such a change in posture during movement does not pose a particular problem, a large change in posture is not allowed in order to grasp the coil or place the coil on the coil skid accurately. In other words, in order for the claws of the tongs to be inserted into the coil holes at the position where the girder is stopped, and for the slanted supports arranged opposite to each other to safely support the coil with pillows, it is necessary to place the tongs in a predetermined position. The vehicle must be stopped within a certain range, and its posture must also be within a certain allowable range. Therefore, when operating the girder, which influences the attitude of the tongs, it is desirable to be able to not only stop it at a predetermined position but also be able to correct the attitude before stopping.

From this point of view, there is a crane in which running wheels that move along two separate tracks are driven by electric motors that are independently provided for each track. Position detectors such as synchronized resolvers are installed on both tracks to detect the position of the crane, and based on the current position detected by the position detectors, the electric motor can reduce the speed necessary to reach the target stop position. This is done by electrical braking.

According to this kind of control, regardless of whether the girder is meandering or not, when the crane reaches a predetermined position before the target stop position, from that point on, the electric motor is electrically braked by blanking, etc. is applied, and the running wheels are decelerated for each trajectory.

When the predetermined electrical braking is completed, the crane should have reached the target stop position, and finally the rotation of the running wheels is completely stopped by mechanical braking such as an electromagnetic brake. As a result, if the crane is meandering, the running wheels along the leading track will be braked at an early point, and the running wheels along the trailing track will start braking at a later point, allowing the lagging side to catch up to the leading side to some extent. become. Therefore, the attitude of the crane is significantly modified in the stopped state.

However, each deceleration and stop is performed by independent braking of both types of motors without any relation to the running wheels on the other track, so when an unpredictable load occurs transiently through the girder, the above-mentioned The disadvantage is that the control becomes unstable. Moreover, the crane is required to behave differently depending on the track, and there is the problem that unreasonable forces may be applied to the crane's mechanical system, including the support structure for the running wheels. In addition, a position detector is required for each trajectory, and a speed control device that performs arithmetic processing based on the position detector is also essential for each electric motor, resulting in a considerable cost increase.

Furthermore, in the position detector, there may be a case where the crane cannot be stopped at the desired stop target position due to detection errors in the resolver itself, slippage in the touch roller in contact with the track, and the like.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to stop the crane within the target stopping position range and to correct the stopping posture of the crane without applying excessive force to the crane. It is an object of the present invention to provide a crane travel positioning method that can be realized using a simple and inexpensive control device.

[Structure of the invention]

To explain the features of the present invention, in the first invention, the dog on the first side track where the position detector is provided is the dog on the second side track where the position detector is not provided. If the dog is detected before the dog, the running wheels on the first track are coasted from a predetermined speed value, and at the same time, the running wheels on the second track are maintained at a predetermined speed value and run at a constant speed. When a stop command dog is detected on the track on which the vehicle is traveling at a constant speed, the driving of the electric motor that is causing the vehicle to travel at a constant speed is released and both running wheels are mechanically braked at the same time.

In the second invention, when the dog on the second side track is detected before the dog on the first side track, the electric braking of the electric motor on the second side track is maintained and the running wheels are controlled. It further decelerates, and at the same time, on the first side track, the drive of the electric motor is released and the running wheels coast from the current speed, and a stop command dog on the coasting track is detected. This means that both running wheels are mechanically braked at the same time.

In the third invention, when the dog on the first side track is detected before the dog on the second side track, the running wheels on the first side track are mechanically braked, and at the same time, The running wheels on the second side track are maintained at a predetermined speed value and run at a constant speed, and when a stop command dog is detected on the track running at a constant speed, the drive of the electric motor that is running at a constant speed is released. This is to mechanically brake the running wheels.

In the fourth invention, when the dog on the second side track is detected before the dog on the first side track, the drive of the electric motor on the second side track is released and the running wheels are mechanically moved. At the same time, the electrical braking of the electric motor on the first side track is maintained to decelerate the running wheels to a predetermined speed value, and when a stop command dog on the track on which the deceleration is running is detected, the This is to mechanically brake the running wheels.

〔Example〕

The method of the present invention will be explained in detail below using a crane to which it is applied. Figure 1 is an overall view of a coil yard 1 and an overhead crane 2 moving above it. During this period, the coils are stored on a large number of coil skids 3 arranged in an orderly manner. The overhead crane 2 transports the coil appropriately, and consists of a girder 2a that runs vertically above the skid 3 and a club 2b that runs horizontally above it, and the club is equipped with coil tongs 5 that can be raised and lowered to hold the coil 4 between them. has been done.

In order to make lane 2 run vertically in this way, two tracks 6A and 6B separated from each other are laid on the upper side wall of coil yard 1, and running wheels 7 and 8 moving along the tracks are arranged independently for each track. It is driven by a provided electric motor (not shown).

As shown in FIG. 2, a position detector 9 such as a synchro resolver is provided on one of the tracks, for example 6A, for detecting the longitudinal position of the crane.

This is a known device consisting of a touch roller that moves in contact with the track 6A and a resolver that detects the number of revolutions thereof, and constantly detects the position of one side of the girder via the track 6A. In addition, if errors cannot be avoided due to slips in the rotation of the rollers, the detected values can be made even more accurate by making it possible to correct fixed points using phototubes every 10 m along the trajectory. It can be done.

In response to the position signal detected by the position detector 9, the electric motors on both of the above-mentioned trajectories block until the running speed when reaching the stop target position reaches a predetermined decelerated speed value, for example, 5% speed. Electric braking can be applied based on rankings, etc. The predetermined speed value for this braking is determined as a percentage of the crane's normal running speed (2) depending on the inertia of the crane or coil and the magnitude of the frictional force between the track and the running wheels. However, a value that allows the crane to fall within a predetermined stop target position range is determined in advance, and is selected, such as the above-mentioned 0.05V.

Note that the crane is separately instructed as to which skid to stop among the many coil skids 3, so the crane is calculated from the current position of the crane by the position detector 9, and the crane is at the target stop position. When the vehicle reaches a predetermined position, the motor is decelerated by the route curve. In that case, the distance between the current position detected by the position detector 9 and its target stop position is sequentially detected, the speed to be taken at that time is calculated, and the above-mentioned control is performed for that distance up to the target stop position. I can continue.

Next, the configuration of an apparatus for realizing the present invention will be described with reference to FIG. 3, although it partially overlaps with the above description. Crane 2
The position detector 9 detects the position of the crane on the track 6A side, and the speed from the generator 12.13 that receives the detection signal and calculates the rotational speed of the electric motor 10.11 and detects the current rotational speed of the electric motor. A speed control unit 14 that commands a controlled speed while observing the speed, and a stop command dog 15 as shown in FIG. 2 provided in parallel with each trajectory 6A, 6B.
, 16, and an electromagnetic brake 19.20 that stops the running wheels 7.8 by mechanical force based on the detection signal thereof. Note that since the present invention relates to stop control of the crane 2 in the longitudinal direction, descriptions regarding the structure and function of the horizontally traveling club 2b and its stop control will be omitted.

According to such a device, the meandering crane 2 can be stopped within the range where the stop command dogs 15 and 16 are located, which is the stop target position, while correcting the posture of the meandering crane 2 as described below.

In the following description, in either case, the predetermined speed value 0.05V is the speed at which the traveling speed is reduced when the target stop position is reached, based on the position detected by the position detector 9.
The electric motors 10 and 11 include a speed control section 14 so that
Assume that the vehicle is in a running state with electrical braking applied according to a command from the vehicle.

First, (i) each trajectory 6A at the stop target position.

Among the stop command dogs 15 and 16 provided for each 6B,
Regarding the case where the dog 15 on the first side track 6A where the position detector 9 is provided is detected by the phototube 17 before the dog 16 on the second side track 6B where the position detector 9 is not provided. state

In this case, as shown in FIG.
The speed of the running wheels 7 at is set to a predetermined speed value o, osv due to the above-mentioned electrical braking. Therefore, the running wheel 7 is caused to coast from a speed of 0.05V, and the running speed is slightly reduced. On the other hand, since the running wheels 8 on the second side track 6B are delayed, the phototube 18 has not yet detected the stop command dog 16, but the speed of the running wheels 8 is set to the predetermined speed value of 0.05V by the above-mentioned control. It has become. Therefore, at the same time as the above-mentioned coasting starts, the speed of the running wheels 8 on the second side track 6B is maintained at a predetermined speed value of 0.05V, and constant speed running is started. 4. In other words, since the running wheels 8 travel at a faster speed than the running wheels 7 from that point on, the track 6B side of the crane 2 approaches the track 6A side, causing a state! The crane that was in 3M has its posture slightly modified as in condition N. Next, when the stop command dog 16 on the track 6B running at a constant speed is detected by the phototube 18, the drive of the electric motor 11 that is running at a constant speed is released, and at the same time, both running wheels 7°8 are stopped. At the same time, the electromagnetic brakes 19 and 20 mechanically brake the running wheels to a stop. At that time, since the speed of the running wheels 7 was low, the distance required for stopping is also shorter than in the case of the running wheels 8. Therefore, the posture is further corrected as in state P.

In addition, the speed at the time is shown corresponding to the position of the crane 2 on each track at the top and bottom of FIG. 4 to facilitate understanding.

In this way, even if the crane 2 is in a meandering state during normal travel, its posture is corrected when it stops, so that the coil tongs 5 can clamp the coil and the coil can be mounted on the coil skid 3 smoothly. done to.

Next, (ii) the stop command dog 16 on the second side track 6B where the position detector 9 is not provided
A case will be described in which the phototube 18 is detected before the dog 15 on the first side track 6A where the phototube 18 is provided.

In this case, as shown in FIG. 5, since the running wheel 7 on the track 6A has not reached the stop command dog 15, its speed has not been reduced to the predetermined speed value of 0.05V. Therefore, the speed of the running wheels 8 on the track 6B is also o, o
The speed is higher than sv, for example, 0.10■. Therefore, the electric braking of the electric motor on the second side track 6B is maintained to further decelerate the running wheel 8 to a predetermined speed value of 0.05V. On the other hand, since the running wheels 7 on the first side track 6A are delayed, the phototube 17 has not yet detected the stop command dog 15. Therefore, the speed of the running wheels 7 is set to o and iov by the above-mentioned control. Therefore, at the same time as the stop command dog 16 is detected, the drive of the electric motor on the first side track 6A is canceled and the speed at that time is 0. I
The running wheels 7 are coasted from the OV. That is, since the running wheel 7 travels at a faster speed than the running wheel 8 from that point on, the track 6A side of the crane 2 approaches the track 6B side, and the crane, which was in the state Q, is now in the state! : Posture is slightly modified like iR. Next, when the stop command dog 15 on the coasting track 6A is detected by the phototube 17,
The drive of the electric motor 11 that maintains electric braking and causes the running wheels 8 to run at a reduced speed is released, and at the same time, both running wheels 7°8
is simultaneously mechanically braked by electromagnetic brakes 19,20. At this time, since the speed of the running wheels 8 is low, the distance required for stopping is also shorter than that for the running wheels 7. Therefore, the posture is further corrected as in state S.

Incidentally, if the above-mentioned combination of item (i) and item (ii) is adopted, one system can be achieved in which predetermined control is achieved regardless of which side of the crane is leading.

Next, (iii) the first
The stop command dog 15 on the side track 6A is the same as the dog 6 on the second side track 6B where the position detector 9 is not provided.
The case where the detection is earlier will be described.

This is the same situation as in item (i).

In FIG. 6, the running wheels 7 on the first side track 6A have a predetermined speed value of 0.05V, and are mechanically braked by the electromagnetic brake 19 at the same time as the above-mentioned dog 15 is detected. At this time, the running wheels 8 on the second side track 6B have also reached the predetermined speed value of 0.05V, but this speed is maintained and the running wheels 8 are caused to travel at a constant speed. After that, when the stop command dog 16 on the track 6B running at a constant speed is detected, the drive of the electric motor 11 that is running at a constant speed is released,
The running wheels 8 are mechanically braked. As a result, the attitude of the crane is corrected, and its stop position falls within the range of the stop target position where the stop command dog is installed.

Finally, (iv) the second
The stop command dog 16 on the side track 6B is the dog 15 on the first side track 6A where the position detector 9 is provided.
The case where the detection is earlier will be described.

This is the same situation as in item (ii).

In FIG. 7, although the running wheels 8 on the second side track 6B have not reached the predetermined speed values o and osv, the drive of the electric motor 11 is released and the running wheels 8 are mechanically braked. At the same time, the electrical braking of the electric motor 10 on the first side track 6A is maintained to move the running wheels 7 to a predetermined speed value o, osv.
decelerate to. Thereafter, when the stop command dog 15 on the track 6A on which the vehicle is traveling at deceleration is detected, its running wheels are mechanically braked.

Incidentally, if the above-mentioned combination of item (iii) and item (iv3) is adopted, one system can be achieved in which the predetermined control is achieved regardless of which side of the crane is leading.

〔Effect of the invention〕

As described in detail above, the present invention provides for the detection of a dog on a first side track where a position detector is provided and a dog on a second side track where a position sensor is not provided before and after detection. Since the speed control of the running wheels on each track is different and both running wheels are mechanically braked upon detection of the stop command dog, the crane can be stopped within the range of a predetermined stop target position. Furthermore, even if the crane is meandering during normal travel, it can correct its posture without applying excessive force to the crane when it stops, and the coil tongs can be used to clamp the coil or the coil can be mounted on the coil skid. is done smoothly.

Moreover, it can be realized with a simple and inexpensive device that is controlled by receiving a signal from one position detector.

[Brief explanation of the drawing]

Figure 1 is an overall diagram of the arrangement of overhead cranes in the coil yard, Figure 2 is a schematic diagram of the configuration of the crane that moves above the coil skid, Figure 3 is a schematic system diagram of each component used to control the crane, and Figure 4 is a schematic diagram of the configuration of the crane that moves above the coil skid. 7 to 7 are explanatory diagrams of the stopping operation of the crane according to the present invention. 2.-- Crane, 6A, 6B-. Track, 7, 8.-- Running wheel, 9.-- Position detector, 10.11-- Electric motor,
15.16---Stop command dog, 17.18---Phototube, 19.20---Electromagnetic brake.

Claims (4)

[Claims] (1) Running wheels moving along two separate tracks,
Each track is driven by an independent electric motor, and a position detector is provided on one track to detect the crane position. Based on the detected current position of the crane, the target stop position is reached. In the crane, the electric motor is electrically braked so that the traveling speed is reduced to a predetermined speed value when the motor is stopped. If the dog on the first side track where the position detector is installed is detected earlier than the dog on the second side track where the position detector is not installed, the dog on the first side track is detected. The running wheels are coasted from the predetermined speed value, and at the same time, the running wheels on the second track are maintained at the predetermined speed value and run at a constant speed, and a stop command dog on the track running at the constant speed is set. A method for determining the running position of a crane, characterized in that, when detected, the driving of an electric motor that is running at a constant speed is released, and both running wheels are mechanically braked at the same time. (2) The running wheels move along two separate tracks,
Each track is driven by an independent electric motor, and a position detector is provided on one track to detect the crane position. Based on the detected current position of the crane, the target stop position is reached. In the crane, the electric motor is electrically braked so that the traveling speed is reduced to a predetermined speed value when the motor is stopped. Of these, the second one is not provided with the position detector.
If the dog on the side track is detected before the dog on the first side track where the position detector is installed, the electrical braking of the motor on the second side track is maintained and the running wheels are further moved. At the same time, on the first track, the motor is deactivated and the running wheels are coasted from the current speed, and when a stop command dog on the coasting track is detected. , a crane traveling positioning method characterized by mechanically braking both traveling wheels simultaneously. (3) The running wheels move along two separate tracks,
Each track is driven by an independent electric motor, and a position detector is provided on one track to detect the crane position. Based on the detected current position of the crane, the target stop position is reached. In the crane, the electric motor is electrically braked so that the traveling speed is reduced to a predetermined speed value when the motor is stopped. If the dog on the first side track where the position detector is installed is detected earlier than the dog on the second side track where the position detector is not installed, the dog on the first side track is detected. The running wheels are mechanically braked, and at the same time, the running wheels on the second side track are maintained at the predetermined speed value and run at a constant speed, and a stop command dog is detected on the track running at the constant speed. A method for determining the running position of a crane, characterized in that the drive of the electric motor that is running at a constant speed is released and the running wheels of the crane are mechanically braked. (4) The running wheels move along two separate tracks,
Each track is driven by an independent electric motor, and a position detector is provided on one track to detect the crane position. Based on the detected current position of the crane, the target stop position is reached. In the crane, the electric motor is electrically braked so that the traveling speed is reduced to a predetermined speed value when the motor is stopped. Of these, the second one is not provided with the position detector.
If a dog on the side track is detected before a dog on the first track where the position detector is installed, the drive of the electric motor on the second track is released and the running wheels are mechanically moved. braking, and at the same time maintains the electrical braking of the electric motor on the first side track to decelerate the running wheels to the predetermined speed value, and when a stop command dog on the track on which the deceleration is running is detected, the A crane traveling positioning method characterized by mechanically braking the traveling wheels.