JP6645336B2 - How to operate the crop conveyor - Google Patents

Description

  The present invention relates to a method of operating a crop conveyor for collecting cut crops generated in a hot rolling process.

  When the hot-rolled steel sheet is finish-rolled by a continuous hot-finish rolling mill, the finish-rolling is performed so that the steel sheet being rolled is not clogged due to poor biting, and poor quality parts do not occur when wound into coils. First, the crop at the front and rear ends of the rough bar is cut by a crop shear provided before the finish rolling mill. The cut crop is conveyed to a crop collection box by a crop conveyor installed at a lower stage of the crop shear.

  The crop conveyor has a structure for receiving and transporting a crop falling from the upper part. When receiving a crop falling from the upper part, the crop conveyor receives a large impact force. Therefore, the conveyor is greatly worn, maintenance of the conveyor becomes frequent, and replacement frequency is often increased.

  Patent Document 1 proposes a crop cutting method for hot-rolled steel material, which comprises changing a lead rate of a peripheral speed of a crop shear drum with respect to a moving speed to be cut in accordance with a cutting width of a crop. 1, there is no description about the transport of the crop after cutting.

  Patent Literature 2 proposes a method for automatically shearing a cropped portion of a rolled steel sheet based on information on the shape of the cropped portion of the rolled steel sheet. Patent Document 2 describes that this shearing method can suppress the occurrence of trouble at the time of conveying a crop portion on a conveyor, but does not describe specific trouble.

  After all, Patent Documents 1 and 2 do not describe measures for the conveyor when the crop is cut or dropped.

  Patent Document 3 proposes a crop conveyor provided with an impact-resistant body for receiving an impact due to a crop drop below a transport body near a crop drop position. However, there is a limit to the impact relaxation force of the impact-resistant body, the service life is short, and it is not suitable for long-term use, and there is a concern that the impact-resistant body must be replaced frequently after all.

JP 06-190405 A JP 2013-099841 A Japanese Utility Model Publication No. 58-191923

  The crop conveyor arranged in the hot rolling process is a chain-type conveyor that transports the crop cut from the hot-rolled rough bar to a crop recovery box. The structure is such that a crop falling from a rolling line is received and conveyed. When the crop falls, it receives a large impact, and thus has a problem that its life is short. In addition, there is also a problem that the life of the conveyer fluctuates due to fluctuations in the crop shape and the dropping state.

  The present invention has been made in view of the above problems and the related art, and has an object to extend the life of a crop conveyor without disposing another facility such as an impact-resistant body, and to provide a method of operating a crop conveyor that solves the problems. The purpose is to do.

  2. Description of the Related Art Conventionally, a crop conveyor has been continuously operated by rotating a rotating gear of the conveyor at a constant speed, and transports a crop dropped on a running conveyor to a crop collection box.

  With the impact when the crop falls on the conveyor, the conveyor is often damaged, but the present inventors have found that dropping the crop on a stopped conveyor is less than dropping it on a running conveyor. It has been found that the degree of damage to the conveyor can be reduced and the number of repairs is small. This will be described later.

  The present invention has been made based on the above findings, and the gist is as follows.

  (1) A method of operating a crop conveyor that transports crops cut in a rolling process, the method comprising operating a crop conveyor intermittently, stopping a conveyor chain, corresponding to a crop drop pitch, and operating the crop conveyor intermittently. .

  (2) The crop conveyor operating method according to (1), wherein the crop cut by rolling is dropped onto the conveyor while the conveyor chain is stopped.

  (3) While the conveyor chain is stopped, the crop cut by rolling is dropped on the conveyor, and the crop cut by the next rolling is dropped on the crop on the dropped conveyor, and the crop is dropped to one location on the conveyor. The crop conveyor operating method according to (2), wherein a plurality of crops are accumulated.

  (4) After accumulating a plurality of crops at one location on the conveyor, operate the conveyor chain, stop the conveyor chain corresponding to the next crop drop pitch, and place a plurality of crops at another location on the conveyor. The crop conveyor operating method according to (3), wherein crops are accumulated.

  (5) The operation method of the crop conveyor according to the above (4), wherein a plurality of crop accumulation points are provided on a conveyor.

According to the present invention, the life of the conveyor chain is long, replacement cycle of the conveyor, extends from a conventional 2 years 4 years, also damage trouble conveyors which suddenly occurs is reduced, the repair times The rolling efficiency is reduced, and the utility loss of fuel, electric power, and the like required for slab heating before rolling can be reduced.

It is a figure which shows the driving | running aspect of a crop conveyor typically. It is a figure which shows the repair frequency of a crop conveyor.

  The operation method of the crop conveyor of the present invention (hereinafter, sometimes referred to as “the operation method of the present invention”) is a method of operating a crop conveyor that transports crops cut in a rolling process, unlike a conventional continuous operation, which differs from a conventional continuous operation. The basic idea is to stop the conveyor chain and operate the crop conveyor intermittently in response to the pitch.Specifically, during the stop of the conveyor chain, the crop cut by rolling is dropped on the conveyor. I do.

  Hereinafter, the operation method of the present invention will be described with reference to the drawings.

  As described above, conventionally, the crop conveyor is operated continuously by rotating the rotating gear of the conveyor at a constant speed, and transports the crop dropped on the running conveyor to the crop collection box.

  However, the present inventors have conceived of temporarily stopping the conveyor chain and operating the conveyor intermittently. The replacement frequency was investigated. As a result, it was found that dropping the crop onto the conveyor during operation stop can reduce the degree of damage to the conveyor and dropping the number of repairs less than dropping the crop onto the conveyor during operation.

  Here, FIG. 1 schematically shows an operation mode of the crop conveyor.

  After the rough rolling and before the finish rolling, the crop 1a generated by cutting the leading end of the rolled material is disposed at the crop drop position 4 below the crop drop position 4, and falls on the conveyor 5 that is not operating ( (See "arrow 4a" in the figure). While the operation of the conveyor 5 is stopped, the crops 1a generated by the next cutting are dropped onto the crops 1b generated by the previous cutting, and a predetermined number of crops are deposited at the crop depositing point 1z of the conveyor.

  After a predetermined number of crops are deposited at the crop accumulation location, the conveyor 5 is operated, the next crop accumulation location is positioned below the crop drop location 4, and the conveyor chain is stopped. The time interval at which the crop falls is equivalent to the rolling interval. During this time, the conveyor is operated to move the crop accumulation location, and a predetermined number of crops are similarly accumulated at this crop accumulation location.

  A plurality of crop deposit locations are provided on the conveyor. FIG. 1 shows three crop accumulation locations 1x, 1y, and 1z, but the crop accumulation locations may be set as appropriate according to the rolling interval and the length of the conveyor. Further, the predetermined number of crops to be deposited at one crop deposition location may be appropriately set in consideration of the width, length, thickness, weight, and the like of the crop generated in the rolling order.

When a predetermined number of crops are deposited separately at a plurality of crop deposition locations, the conveyor stop time and operating time can be calculated by the following equations (1) and (2).
Conveyor stop time = (number of deposited crops) x (rolling interval) (1)
Conveyor operation time = (Conveyor rotation cycle) / 2 ÷ (Number of crop accumulation points) (2)

  According to the above equations (1) and (2), the stop time and the operation time of the conveyor are calculated, and as shown in FIG. 1, the conveyor 5 is operated, and the crop on the conveyor 5 is transported to the crop collection box 6.

  The reason that the crop conveyor is intermittently operated, the crop is dropped on the conveyor that is not operating, and the next crop is dropped on the dropped crop, thereby extending the life of the crop conveyor, It is considered as follows.

  When the crop is dropped, the conveyor naturally receives an impact, but (a) during operation of the conveyor, tension in the tension direction is constantly acting on the movable parts of the chain, and the fatigue and wear and tear of the conveyor due to the impact, Although increased by this tensile stress, (b) during the stoppage of the operation of the conveyor, since the stress in the tensile direction does not act, the degree of fatigue and wear of the conveyor due to impact is small.

  As described above, according to the operation method of the present invention, fatigue and wear of the crop conveyor are reduced, and the life of the conveyor is extended.

  Next, an example of the present invention will be described. The conditions in the example are one condition example adopted to confirm the operability and effects of the present invention, and the present invention is based on this one condition example. It is not limited. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

(Example 1)
Operate the hot rolled crop conveyor intermittently. The operation is performed by combining the stop time and the operation time according to the rolling pitch, that is, the crop falling pitch. In the case of a rolled material having a plate width of 1000 mm or more and a large crop weight, three crops were deposited at three locations on the conveyor, and the stop time and the operation time of the conveyor were set as shown in Table 1.

  On the other hand, in a rolled material having a sheet width of less than 1000 mm and a small crop weight, six crops are to be deposited at five locations on the conveyor, and the stop time and the operation time of the conveyor are set as shown in Table 1. .

  In accordance with the operation plan shown in Table 1, a conveyor operation for collecting dropped crops was performed.

FIG. 2 shows the number of times the conveyor was repaired in two years when the crop conveyor was operated according to the invention example and the comparative example. In the invention example, the repair of the damage that has occurred suddenly (sudden repair) is eliminated, and the number of planned repairs is reduced. In the last two years, crop conveyors are long life, replacement cycle of the conveyors could be extended from the prior two years to four years.

As described above, according to the present invention, the life of the conveyor chain is long, replacement cycle of the conveyor, extends from a conventional 2 years 4 years, also suddenly conveyors damage trouble is reduced to generate As a result, the number of repairs is reduced, the rolling efficiency is stabilized, and the utility loss of fuel, electric power and the like required for slab heating before rolling can be reduced. Therefore, the present invention has high applicability in the steel industry.

Claims (4)

Method of operating a crop conveyor for conveying the crop cut by the rolling process, the crop cut by rolling while stopping the conveyor chain stops the conveyor chain so as to fall into a conveyor, operated the crop conveyor intermittently An operation method for a crop conveyor, comprising: Wherein during the stop of the conveyor chain, to drop the crop cut by the rolling conveyor, further, on the crop on the fallen conveyor, to drop the crop cut by the following rolling, a plurality of the one place on the conveyor The crop conveyor operating method according to claim 1 , wherein the crops are accumulated. After accumulating a plurality of crops at one location on the conveyor, operating the conveyor chain, corresponding to the next crop drop pitch, stopping the conveyor chain, and accumulating a plurality of crops at another location on the conveyor. The method according to claim 2 , wherein the crop conveyor is operated. The method for operating a crop conveyor according to claim 3 , wherein a plurality of the collecting points of the plurality of crops are provided on a conveyor.

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