JPH0544981U - Unloading failure detection device for automatic crane - Google Patents

Abstract

(57) [Summary] [Purpose] Completely unmanned automatic cranes will be achieved by reliably detecting load suspension failure. [Composition] Lifting magnet 15 suspension beam 10
And the distance limited reflection type steel plate detectors 11 and 13 are respectively installed on the mounting table (roller table 12) and the thick steel plate, and the light emitting and receiving type steel plate detector is installed in the space on the mounting table.
By installing 14 and detecting the presence or absence of a thick steel plate using each of the steel plate detectors at a predetermined winding height of the lifting magnet, it is possible to reliably detect a load hanging failure that occurs during lifting and unloading.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a load suspension failure detection device for an automatic crane for lifting and transporting thick steel plates by a lifting magnet in a thick plate factory or warehouse.

[0002]

[Prior Art]

 In recent years, automatic cranes in plate mills and warehouses are in the situation where the control mechanism for automatic operation is improving more and more due to rapid technological development related to computing functions including computers and various sensors. Unmanned driving is also being attempted. Then, lifting magnets are generally used as suspenders for autonomous driving.

As described above, in order to ensure safe and reliable unmanned operation by fully automating an automatic crane using a lifting magnet, a lifting magnet that requires the finest control and adjustment as an automatic operation function is used. The operations of lifting and releasing thick steel plates must be performed completely and accurately. However, a measurement technique capable of reliably detecting lifting and release has not been established, and various proposals have been made for that purpose.

For example, Japanese Unexamined Patent Publication No. 56-48392 discloses a device that detects a magnetic flux in a magnetic circuit formed by a lifting magnet and a steel plate attracted to determine whether the steel plate is adsorbed or released (loading failure). Has been done. Further, according to Japanese Patent Laid-Open No. 60-148790, by superposing an AC magnetic field on the DC magnetic field of a DC lifting magnet and comparing the detected value of the magnetoresistance change of the AC magnetic field with the set value, the adsorption of the steel sheet A method of detecting is proposed.

[0005]

[Problems to be Solved by the Invention] The above-described technology is one that uses magnetic flux and magnetic resistance to determine whether or not a load has been suspended, and is not completely reliable because it does not directly monitor the steel sheet itself. Hard to say. In the current situation where there is no means for reliably detecting the failure to lift the load, the automatic operation control function of the crane itself has progressed to the state where fully unmanned operation is possible, but the load that occasionally occurs Due to the failure, it has not been fully automated as a whole, and there remains a problem that unmanned operation cannot be performed with sufficient reliability.

This invention is to detect the load suspension failure by directly monitoring the condition of the thick steel plate itself when transporting the thick steel plate by using the lifting magnet. It is an object of the present invention to provide a load suspension failure detection device that can achieve the above.

[0007]

[Means for Solving the Problems]

 An automatic crane load-hanging failure detection device according to the present invention is an automatic crane load-hanging failure detection device for lifting and transporting thick steel plates by a lifting magnet. And a limited distance type reflection type steel plate detector installed opposite to the transported steel plate, and a light emitting and receiving steel plate detector installed facing each other in the longitudinal direction of the steel plate in the space on the mounting table. The above-mentioned conventional problems have been solved by using and, and the control circuit used for this has a lifting height detector of the lifting magnet and the lifting magnet at the predetermined winding position. A signal transmitter that outputs a detection command signal to each steel plate detector, and a detection processing unit that determines load suspension failure from the output signal of each steel plate detector. It allowed the reliable detection of the suspended load failure by way provided.

[0008]

[Action]

 In this invention, a limited distance type reflection type steel plate detector is installed on the lifting beam of the lifting magnet and the mounting table of the thick steel plate, and when lifting the thick steel plate, when the lifting magnet is wound up to a predetermined height, At the time of release, after landing once and releasing operation, in the process of rewinding the lifting magnet, both of the steel plate detectors are used to detect the load suspension failure. This distance-limited reflective steel plate detector detects the presence or absence of a steel plate by, for example, using ultrasonic waves to capture the reflected waves from the steel plate within a predetermined limited distance range. H is predetermined according to the thickness of the thick steel plate.

[0009] In case of insufficient load suspension, only one longitudinal direction of the thick steel plate may be separated from the lifting magnet and the other may be attracted. In order to detect this, in this invention, the light emitting and receiving type steel plate detectors are installed facing each other in the longitudinal direction of the thick steel plate in the space on the mounting table, and when only one of the thick steel plates is detached as described above. Since the light is shielded between the light emitter and the light receiver, it is possible to detect a load suspension failure.

Further, the operation of the load suspension failure detection device will be described based on an example of the control circuit shown in FIG. The control circuit is provided with a lifting height detector 16 of the lifting magnet to detect the lifting height of the lifting magnet. As the winding height detector 16, for example, a PLG (pulse generator) attached to a winding drum is used. When the detected value of the winding height detector 16 reaches a predetermined height h, a detection command signal is output to each of the steel plate detectors 11, 13 and 14 by the signal transmitter 17. A pulse counter, for example, is used as the signal transmitter 17, and the predetermined height h depends on the thickness of the thick steel plate, the number of simultaneous hangings, the limited distance H, etc. Has been entered in. The results (presence or absence of thick steel plate) detected by the steel plate detectors 11, 13 and 14 in this manner are input to the detection processing unit 18.

Here, when the thick steel plate is lifted, the thick steel plate is adsorbed and the lifting magnet is wound up to a predetermined height h, and when the thick steel plate is unloaded, it is temporarily landed and then released. When the lifting magnet is wound up again to the predetermined height h, a detection command is output to the steel beam detectors 11 and 13 installed on the suspension beam and the mounting table. When the thick steel plate is lifted or unloaded, the detection command is output to the steel plate detectors 11 and 13 at the same time as the detection command is output to the steel plate detector 14 on the mounting table, and Detect the presence or absence.

[0012] These detection results are input to the detection processing unit 18 to determine whether or not there is a load suspension failure. If there is no load suspension failure, hoisting continues as is, but a load suspension failure should occur. In such a case, the operation command for hoisting, adsorbing, and (releasing) hoisting is output again to the hoisting control device of the crane, and the above-mentioned load suspension failure is checked again. Reference numeral 19 is a warning device such as a bell that is issued when it is determined that the load has not been hung even after the above operation is repeated once or several times.

[0013]

【Example】

 1 to 5 show an embodiment according to the present invention, FIG. 1 is a perspective view showing the installation state of each steel plate detector, FIG. 2 is an explanatory view of lifting a thick steel plate, and FIG. 3 is a case of unloading FIG. 4 is an explanatory view when a part of the thick steel plate is detached when hoisting, and FIG. 5 is an explanatory view when a part of the thick steel plate remains adsorbed when unloading Is.

In FIG. 1, lifting magnets 15-1, 15-2, 15-3, ... Are suspended from an automatic crane (not shown) and suspended in a suspension beam 10 so that the lifting magnets 15 can be moved up and down. .. The thick steel plate placing table in this example is the roller table 12, but it may be a simple thick steel plate placing table or a transfer device such as a transfer device. Distance-limited reflection type steel plate detectors 11-1, 11-2, 11-3 ... Are installed on the suspension beam 10, and a similar distance-limited type reflection steel plate detector 13 is also installed in the roller table 12. -1, 13-2, 13-3 ... are installed. Further, in the upper space of the roller table 12, a light emitting and receiving type steel plate consisting of a light emitter 14a and a light receiver 14b along the roller table 12 The maximum thickness of the thick steel plate that the detector 14 conveys from the upper surface of the roller table 12 by this automatic crane. It is installed at a height of 2 to 4 times the height.

FIG. 2 shows an example in which the thick steel plate 20 is hung up when it is lifted up. When the lifting magnet 15 is wound up to the height h, the steel plate detectors 11-1, 11-2, 11-3. .. and detection commands are output to 13-1, 13-2, 13-3 ..., but since the thick steel plate 20 does not exist within the limited distance H set in the steel plate detector 11, The steel plate detectors 11-1, 11-2, 11-3 ... Output signals indicating no steel plate. On the other hand, on the steel plate detector 13 side, since the thick steel plate 20 exists within the range of the limited distance H ′, the steel plate detectors 13-1, 13-2, 13-3 ... To do. At the same time, the steel plate detector 14 outputs a signal indicating that there is no steel plate because the light is not shielded between the light projector 14a and the light receiver 14b. Based on these signals, the detection processing unit 18 (FIG. 6) determines that the suspension is incomplete.

FIG. 3 shows the case where two thick steel plates 20-1 and 20-2 are suspended at the same time and the thick steel plate 20-1 is not released when unloading. Outputs the presence of steel plate. On the other hand, the steel plate detector 14 outputs no steel plate, but the detection processing unit determines that the release is insufficient based on the signals of both steel plates detected by the steel plate detectors 11 and 13. In FIGS. 2 and 3, if a part of the thick steel plate in the longitudinal direction is hanging down, the steel plate detector 14 outputs a signal indicating that the steel plate is present.

FIG. 4 is a suspension failure when one end of the steel plate 20-2 hangs down without being attracted to the lifting magnet 15 when two thick steel plates 20-1 and 20-2 are simultaneously lifted. In this case as well, the detection processing unit determines that there is suspension failure based on the steel plate presence signal of the steel plate detector 14. FIG. 5 shows an example in which one end of the thick steel plate 20-1 is not released when the thick steel plates 20-1 and 20-2 are simultaneously hung and unloading. Similarly, the detection processing unit determines from the signal from the steel plate detector 14 that the release is insufficient.

In the case of FIGS. 4 and 5, the steel plate detectors 11-1, 11-2, 11-3 ... And 13-1, 13-2, 13-3 ... Are steel plates. The presence signal and the absence signal are output by reversing from a position in the longitudinal direction of the thick steel plate, but it is impossible for the detection processing unit to determine whether the cause is that the thick steel plate is short. Therefore, the detection result of the steel plate detector 14 gives accurate information.

When the load suspension failure detection device according to the present invention was implemented in an automatic crane in a yard for shipping thick plates, no accidents due to suspension failure or release failure were found.

[0020]

[Effect of the device]

 By implementing the load lifting failure detection device of the automatic crane according to the present invention, the lifting failure and the release failure can be completely prevented, so that the automatic crane is completely unmanned and a great labor-saving effect is brought about. It was

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a suspension failure detection example that occurs when lifting thick steel plates.

FIG. 3 is an explanatory diagram of an example of detection of release failure that occurs when unloading two thick steel plates.

FIG. 4 is an explanatory diagram of a partial hanging failure detection example that occurs when two thick steel plates are lifted.

FIG. 5 is an explanatory diagram of a partial release failure detection example that occurs when unloading two thick steel plates.

FIG. 6 is a view for explaining an embodiment of the control circuit used in the present invention together with the operation.

[Explanation of symbols]

 10 Hanging beam 11 Reflective steel plate detector with limited distance 12 Roller table 13 Reflective steel plate detector with limited distance 14 Light emitting and receiving steel plate detector 15 Lifting magnet 16 Winding height detector 17 Signal transmitter 18 Detection processing unit 19 Alarm apparatus

Claims (2)

[Scope of utility model registration request] 1. A load-hanging failure detecting device for an automatic crane for hoisting and transporting thick steel plate by a lifting magnet, comprising: a lifting beam of a lifting magnet and a mounting table of the thick steel plate facing a transported thick steel plate. Cranes having a limited distance type reflection type steel plate detector installed respectively and a light emitting and receiving type steel plate detector installed facing each other in the longitudinal direction of the thick steel plate in the space on the mounting table. Unloading failure detection device. 2. A lifting height detector of a lifting magnet, a signal transmitter for outputting a detection command signal to each of the steel plate detectors at a predetermined winding position of the lifting magnet, and a load suspension failure based on an output signal of each steel plate detector. The load-hanging failure detection device for an automatic crane according to claim 1, further comprising a control circuit having a detection processing unit that determines whether the load is insufficient.