JPS59142685A - Detector for steel sheet number lifted by lifting electromagnet - Google Patents

Abstract

PURPOSE:To improve the counting precision by receiving a spot which is projected from a laser light source with an optical distance meter and converting the ruggedness due to the outlines of side faces of a steel sheet to a voltage difference and discriminating this voltage difference to count the number of the steel sheet. CONSTITUTION:Simultaneously with the rise of an electromagnet 3 from a stored steel sheet 5, an optical distance meter 6 and a laser light source 7 are driven downward. The reflected light of the spot irradiated from the light source 7 is received by the optical distance meter 6 to generate a voltage corresponding to the distance from the steel sheet 5. According as the light source 7 and the distance meter 6 are driven downward, the distance from the spot is changed in accordance with the shape of end faces of the steel sheet and the distance meter 6 generates a detection waveform in accordance with this change. The detected waveform is sent to a discriminating device 8 and is analyzed there to count the number of the steel sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the number of steel plates lifted by a lifting electromagnet.

In steel works and the like, lifting electromagnets (hereinafter referred to as electromagnets) are generally used to transport steel plates. The present invention aims to provide a detection device that can detect the number of steel plates lifted by an electromagnet with high precision and is suitable for automated and unmanned electromagnet systems.

The following methods are known as conventional methods for detecting the number of steel plates.

1) Lifting - A method in which a weight detection device is attached to the crane, the total weight of the steel plates to be lifted is measured, and the number of plates to be lifted is calculated backwards from that value.

2) Utilizing the fact that the saturation magnetic flux of the steel plate inner wire is arbitrarily determined by the steel plate thickness, the total thickness of the two steel plates is detected from the magnetic flux and divided by the known steel plate thickness to determine the number of sheets to be lifted. .

In method 1), the weight of both the external suspension beam of the suspended steel plate and the electromagnet is measured, so there is a problem with the resolution of the weight measuring element.

Furthermore, the method 2) has the problem that the accuracy is significantly reduced due to gaps caused by dirt, rust, or distortion on the surface of each steel plate.

In order to solve the problems of such known techniques and achieve the above object, the present invention enables highly accurate detection of the number of steel plates by physically measuring the number of steel plates using a laser beam and a light wave distance meter. An example will be explained.

In FIG. 1, 1 is an overhead crane, and girder 12 is a traversing trolley. 3 Electromagnets with a device for selecting the number of steel plates to be lifted; 4 is the steel plate to be lifted by this electromagnet. Reference numeral 5 designates storage steel plates stacked on the floor, from the top of which a predetermined number of steel plates are lifted by the electromagnet 3.

6 is an optical distance meter, and 7 is a laser light source. Reference numeral 8 designates a determination device consisting of a microcomputer for data analysis and drive instruction, 9 a lifting device, and ]0 a rotating table.

3 to 5 show details of the elevating device 9 of the distance detecting device comprising the optical distance meter 6 and the laser light source 7. optical distance meter 6
The laser light source 7 is firmly fixed on an elevating table 9b which moves up and down by the rotation of an elevating screw shaft 9a so that their relative positions do not move. This lifting platform 9b has a lifting guide rod 9C.
You will be guided up and down smoothly. Reference numeral 11 denotes a pulse motor driven by a drive instruction from the determination device, and a screw shaft 9a is attached to the output shaft of the pulse motor. The optical distance meter 6 and laser light source 7 fixed to the lifting platform 9b are always set to be located slightly above the upper end of the storage steel plate 5 (FIGS. 1 and 10).

At the same time as the electromagnet 3 is disconnected from the storage copper plate 5, irradiation from the laser light source 7 is started. At the same time, optical distance meter 6
and the laser light source 7 is driven downward. Then, the optical distance meter 6 receives the reflected light from the irradiation spot (second
Figure) An image is formed on one of the rows of internal photosensors depending on the distance from the steel plate, and a voltage (2) corresponding to the distance is generated via a digital-to-analog converter (Figure 7).

As the laser light source 7 and the optical distance meter 6 are driven downward, the distance to the light spot changes in accordance with the shape of the end face of the steel plate, as shown by a in FIG. 6, and the optical distance meter 6 changes accordingly. A detection waveform is generated (Fig. 7). The detected waveform is sent to the determination device 8, where the waveform is analyzed and the number of steel plates is counted.

Once the number of sheets has been counted, the lowering of the lifting platform 9b to which the optical distance meter 6 and the laser light source 7 are fixed is stopped in response to a command from the determining device 8, and the determining device 8 waits for the next command to complete the ground cutting. FIG. 8 shows the equipment configuration 1 including the crane controller 13 that performs the above operations.

Next, an example of the procedure for counting the number of sheets will be explained with reference to FIGS. 6 to 7 and 9.

1) Turn on the power of the electromagnet 3 and start counting at the point (0 in FIG. 9) where the sent voltage waveform exceeds the reference voltage v2 (FIG. 9).

2) If the difference between the peak voltage average value of tn and the peak voltage average value of tn-)1 (b in Fig. 9) is greater than or equal to the set value, count.

3) For cases where the level difference is extremely small ■1. Determine the set voltage value of v2 in advance, and when the voltage rises to ■2 and vl
Make sure to count it even when it falls to . child\
The reason for setting ■1 <■2 is to prevent erroneous counting even when noise (FIG. 9 d) is on the detected voltage waveform (FIG. 9).

4) Finally ■. When the voltage decreases to , it is determined that the position is below the lowest end of the suspended steel plate 4, and the measurement is stopped, and the optical distance meter 6,
The laser light source 7 and the lifting device 9 are stopped.

In the above configuration, the distance detection device is not an optical distance meter, but
For example, it may be a distance measuring device that uses an image defocus correction method as used in automatic focus cameras.

Further, although the optical range finder 6, laser light source 7, and lifting device 9 are integrated and placed on the ground, they may be hung from above depending on the usage conditions. In this case, in order to prevent precision deterioration due to shaking of the electromagnet 6 and the steel plate, it is preferable to attach the electromagnet 3 to the electromagnet 3 as shown in FIG. In this example, one side of the inverted beam is used as a lifting device 9, and a weight 12 is provided at the other end to balance the weight of this portion.

In addition, even with the above-ground method, by installing the turntable 10, the direction can be changed as shown in the imaginary line in Figure 1, so that other piles 5 (first
(Fig.) also includes one set of optical distance meter 6 and laser light source 7.
This can be handled by a lifting device 9.

As explained above, the present invention uses a laser light source that projects from the side onto a suspended steel plate, receives the spot projected from the laser light source with an optical distance meter, and converts the unevenness caused by the hoop on the side of the steel plate into a voltage difference. Then, this voltage waveform was determined by a determination device so that a predetermined number of sheets could be counted. According to this method, the counting accuracy is significantly improved compared to methods such as attaching a weight detector to a conventional lifting crane or using the fact that the amount of saturation magnetic flux inside the steel plate is uniquely determined by the thickness of the steel plate. do. This has made it possible to automate and unmanned electromagnets more safely.

[Brief explanation of the drawing]

FIG. 1 shows a lifting electromagnet equipped with the detection device of the present invention. Figure 2 is a view in the direction of the ■ arrow in Figure 1. FIG. 3 is a front view of the lifting device. Figure 4 is a right side view of Figure 3. FIG. 5 is a top view of FIG. 3. FIG. 6 shows the unevenness of the side surface of the suspended steel plate. Figure 7 shows the voltage waveform detected by the optical distance meter. FIG. 8 is a block diagram of the equipment configuration of the detection device according to the present invention. FIG. 9 is a time-voltage relationship diagram of the detected voltage waveform; FIG. 1θ is another fifth embodiment of the present invention. In the figure: 1 Overhead crane girder 2 Traversing trolley 3 Electromagnet with a device for selecting the number of steel plates to be lifted 4 Steel plates to be lifted 5, 5 Storage steel plates 6 Optical VP distance meter 7 Laser light source 8 (consisting of a microcomputer for data analysis and drive instructions) Judgment device 9 Lifting device
9a Screw shaft 9b Lifting platform 9
C guide rod 10 Turntable] 1 Pulse motor 12 Balance weight 13 Automatic crane controller 14 Operator's cab and above Applicant Sumitomo Heavy Industries, Ltd. Sub-Attorney Patent Attorney Isamu Ohashi 11- Figure 1 Figure 2 Figure 6 Figure 37 Figure 8 Figure 9 Figure 10 497

Claims (1)

[Claims] A lifting electromagnet with a lifting steel plate number selection device for lifting steel plates stored on the floor, a laser light source that projects from the side to the six lifting plates, and a light that receives the spot projected from the laser light source. A device for detecting the number of suspended silver plates using a lifting electromagnet, consisting of a lifting device that moves up and down a lifting platform equipped with a distance meter, and a device for determining the voltage waveform detected and generated by an optical distance meter.