JP4946355B2 - Slab tip conveyance failure detection method and width reduction press method in slab width reduction press equipment - Google Patents

Description

  The present invention relates to a method for detecting the occurrence of a conveyance failure at a slab tip in a width reduction press facility for performing a width reduction press on a slab, and a width reduction press method using the method.

  In a hot rolling line, a width reduction press facility (also referred to as a sizing press facility) is installed on the line, and the material (slab) is subjected to reduction in the plate width direction (width reduction press) to form a predetermined plate width. In some cases, rough rolling and finish rolling are performed (see, for example, Patent Document 1).

  FIG. 1 is a perspective view schematically showing a state where a width reduction press is applied to a slab by a width reduction press facility.

  Generally, the slab width reduction press equipment includes a pinch roll (hereinafter also referred to as PR) 5 disposed on the entrance-side upper surface, and a feed roll (hereinafter also referred to as FR) disposed on the entrance-side lower surface and having driving ability. ) 6, a press die 2 for pressing the slab 1 under width reduction, and an upper hold for restraining the slab 1 during width reduction pressing from the vertical direction (plate thickness direction) in order to suppress buckling of the slab 1. A roll (hereinafter also referred to as upper HR) 3 and a lower hold roll (hereinafter also referred to as lower HR) 4 are provided. In addition, 7 in FIG. 1 is a table roll.

  Usually, the upper hold roll 3 can be moved up and down (and the lower hold roll 4 if necessary), and the height position is changed according to the plate thickness of the slab 1, thereby the upper hold roll 3 and the lower hold roll. The interval (gap) between the rolls 4 is adjusted to restrain the slab 1.

  Accordingly, the slab width reduction press facility restrains the slab 1 from the vertical direction by the pinch roll 5 and the feed roll 6 and conveys the slab 1 by the driving ability (conveying force) of the feed roll 6 while holding the roll 3, 4, while the slab 1 is restrained, the operation of reciprocating the press die 2 in the horizontal direction and reducing the slab 1 in the plate width direction is repeated in sequence, so that the total length of the slab 1 from the tip 1a to the tail end 1b of the slab 1 is predetermined. Molded to the width of the plate.

  At that time, if the slab 1 is buckled during the width reduction pressing, it is very difficult to correct the buckling after that, so the slab 1 is appropriately restrained from the tip 1a by the hold rolls 3 and 4. Therefore, it is important not to cause buckling.

Therefore, in order to restrain the slab 1 from the tip 1a by the hold rolls 3 and 4, the position in the transport direction of the slab 1 is tracked based on a slab tip detection signal from a slab detection sensor (not shown) installed on the entry side. Thus, the timing for installing the hold rolls 3 and 4 at a predetermined height position (the timing for starting the restraint of the slab 1 by the hold rolls 3 and 4) is determined.
JP-A-6-154810

  As described above, the width reduction pressing is performed while the slab 1 is constrained by the hold rolls 3 and 4, but the following problems may occur at that time.

  First, in order to restrain the slab 1 from the tip 1a by the hold rolls 3 and 4, the accuracy of the slab detection sensor for detecting the slab tip 1a and the tracking accuracy are very important. However, the accuracy of the slab detection sensor and tracking is not always sufficient, and the error causes variations in the restraint timing of the slab tip 1a. Due to this variation, when the restraint start timing of the slab 1 by the hold rolls 3 and 4 is too early, as shown in FIG. Defects may occur.

  Moreover, even if the restraint start timing of the slab 1 by the hold rolls 3 and 4 is appropriate, if the restraint force (pressing force) of the hold rolls 3 and 4 is too high, as shown in FIG. Even if the leading end of the slab 1 passes due to the influence of the plate thickness increase accompanying the reduction press, the subsequent conveyance of the slab 1 may not be performed at all and a conveyance defect may occur.

  Further, in addition to the above, there is a possibility that a conveyance failure may occur due to interference with equipment due to bending, warping, warping or the like of the slab 1.

  In a hot rolling line, in order to prevent a slab temperature fall and to improve productivity, it is necessary to detect a conveyance failure early and to take an appropriate measure. In addition, if a conveyance failure occurs, an excessive load is applied to the feed roll 6 and the like, causing a device failure. If the device protection function is activated and the device is stopped, the productivity is reduced.

  However, until now, few proposals have been made on methods for early detection of conveyance failure at the slab tip.

  The present invention has been made in view of the above circumstances, and in a slab width reduction press facility, it is possible to detect a conveyance failure of the slab tip portion at an early stage, thereby enabling an appropriate treatment. It is an object of the present invention to provide a slab tip conveyance failure detection method in a slab width reduction press facility and a width reduction press method using the same.

  In order to solve the above problems, the present invention has the following features.

  [1] When the slab is reduced in width by the slab width reduction press facility installed in the hot rolling line, the rotation amount of the feed roll, the drive output of the feed roll, the height position of the upper hold roll or the upper hold roll, A slab tip conveyance failure detection method in a slab width reduction press facility, wherein a conveyance failure of a slab tip portion is detected based on an interval between lower hold rolls.

  [2] The occurrence of a conveyance failure at the slab tip is detected by the rotation amount of the feed roll and the feed output of the feed roll, and the slab tip is held by the height position of the upper hold roll or the interval between the upper hold roll and the lower hold roll. The method for detecting defective slab conveyance in the slab width reduction press facility according to the above [1], wherein it is determined whether the roll has passed before or after passing.

  [3] When the conveyance failure of the slab tip is detected by the method described in [2] above, the upper hold roll is raised when the slab tip has not passed through the hold roll, and the slab tip has passed through the hold roll. The slab width reduction press method by the slab width reduction press equipment characterized by lowering the pressure of the upper hold roll.

  By this invention, the conveyance failure of the slab front-end | tip part in a slab width reduction press installation can be detected at an early stage, and it becomes possible to perform an appropriate treatment by it. As a result, it is possible to ensure the quality of the rolled material by preventing the temperature reduction of the slab due to the delay in treatment, and it is possible to eliminate waste such as disposal processing of the rolled material, thereby improving productivity. .

  One embodiment of the present invention is described below.

  As shown in FIG. 1, the slab width reduction press facility according to an embodiment of the present invention is driven by a pinch roll (hereinafter also referred to as PR) 5 disposed on the entry side upper surface and an entry side lower surface. A feed roll 6 (hereinafter also referred to as FR) 6 having a capacity, a press die 2 for pressing the slab 1 under a width reduction, and a slab 1 during the width reduction pressing up and down to suppress buckling of the slab 1 An upper hold roll (hereinafter also referred to as “upper HR”) 3 and a lower hold roll (hereinafter also referred to as “lower HR”) 4 constrained from the direction (plate thickness direction) are provided. In addition, 7 in FIG. 1 is a table roll.

  Here, the upper hold roll 3 can be moved up and down, and the height position is changed according to the plate thickness of the slab 1, thereby adjusting the interval between the upper hold roll 3 and the lower hold roll 4, The slab 1 during the width reduction press is restrained.

  Thereby, this slab width reduction press equipment restrains slab 1 from the up-and-down direction with pinch roll 5 and feed roll 6, and while holding slab 1 with the drive capability (conveyance force) of feed roll 6, hold roll 3, 4, while the slab 1 is constrained, the press mold 2 is reciprocated in the horizontal direction to continuously reduce the slab 1 in the plate width direction, and the slab 1 full length from the front end 1a to the tail end 1b of the slab 1 is predetermined. Molded to the width of the plate.

  Here, the restraint of the slab 1 by the hold rolls 3 and 4 starts immediately after the tip 1a of the slab 1 passes the hold roll position. However, if the upper hold roll 3 is lowered before the passage of the slab tip 1a due to a tracking error in the carrying direction position of the slab tip, the slab tip 1a collides with the hold roll, and the slab is poorly conveyed. Will occur.

  Therefore, in this embodiment, a slab conveyance failure in the width reduction press facility is detected based on the following concept.

  In general, as a method of detecting a slab conveyance failure, the hold roll 3 according to the current position of the upper hold roll 3 with respect to the thickness of the slab 1 (or the gap between the upper hold roll 3 and the lower hold roll 4), It is possible to detect that 4 sandwiches the slab 1. However, the thickness of the slab 1 at this time needs to take into account the increase in thickness due to the width reduction press, but it is difficult to accurately predict the amount of increase in the slab thickness due to the width reduction press. The threshold value of whether or not the slab 1 is sandwiched includes an error of the slab thickness increase prediction model. For this reason, when a conveyance failure is detected only by the operating position (height position) of the upper hold roll 3, the model error may be delayed in detection or erroneously detected.

  As another method of detecting a slab conveyance failure, a method of detecting a conveyance failure from a change in the rotation amount (rotational speed) of the feed roll 6 can be considered. However, when the feed roll 6 has a large driving capability, if the feed roll 6 and the slab 1 slip, the amount of rotation of the feed roll 6 does not change as shown in FIG. Defect detection is impossible.

  In contrast, in this embodiment, the rotation amount (rotation speed) of the feed roll 6, the drive output of the feed roll 6, and the height position of the upper hold roll 3 (or the upper hold roll 3 and the lower hold roll). 4), a slab conveyance failure is detected.

  That is, when a slab conveyance failure occurs, as shown in FIG. 3A, even when the rotation amount of the feed roll 6 does not change due to the slip between the feed roll 6 and the slab 1, as shown in FIG. As shown in FIG. 4, since the load of the feed roll 6 increases and the driving force of the feed roll 6 becomes a relatively large output with respect to the normal conveying force (necessary conveying force), the driving force of the feed roll 6 A conveyance failure can be detected by the increase.

  At that time, as shown in FIG. 3C, when the height position of the upper hold roll 3 (height position from the lower hold roll 4) is less than the slab thickness, the slab tip is held by the hold roll 3, 4, when it is judged that a conveyance failure has occurred before passing through the hold rolls 3 and 4, and the height position of the upper hold roll 3 (height position from the lower hold roll 4) is almost slab thickness Is determined that a conveyance failure has occurred after the tip of the slab has passed the hold rolls 3 and 4.

  FIG. 4 shows a procedure for detecting a slab conveyance failure based on the above concept.

  (S1) It is determined whether or not the tip of the slab 1 has arrived at the position of the hold rolls 3 and 4 by tracking. If it has arrived, the process proceeds to (S2), and if it has not arrived, (S1) is repeated.

  (S2) It is checked whether or not the rotation amount (rotation speed) of the feed roll 6 within a predetermined time is within a predetermined rotation amount (rotation speed). If it is within the range of the predetermined rotation amount, the process proceeds to (S3), and if it is outside the range of the predetermined rotation amount, the process proceeds to (S5).

  (S3) It is checked whether or not the driving force of the feed roll 6 is equal to or greater than a threshold value determined from the normal conveyance force. If the driving force is greater than or equal to the threshold, the process proceeds to (S5), and if the driving force is less than the threshold, the process proceeds to (S4).

  (S4) It is determined that slab transport is normal (normal transport).

  (S5) The conveyance of the slab is determined to be defective (conveyance failure), and the process proceeds to (S6).

  (S6) It is checked whether the height position of the upper hold roll 3 (or the gap between the upper hold roll 3 and the lower hold roll 4) is less than the slab thickness. If it is less than the slab thickness, the process proceeds to (S7), and if it is greater than or equal to the slab thickness, the process proceeds to (S8).

  (S7) This conveyance failure is determined as a conveyance failure before the slab tip passes through the hold rolls 3 and 4.

  (S8) This conveyance failure is determined as a conveyance failure after the slab tip passes through the hold rolls 3 and 4.

  As described above, it is possible to detect the occurrence of a slab conveyance failure and the timing of its occurrence.

  Then, when it is determined that the slab tip has a conveyance failure before passing through the hold rolls 3 and 4, the upper hold roll 3 is raised so that the slab tip can pass through the hold rolls 3 and 4.

  On the other hand, when it is determined that the leading end of the slab has failed to be conveyed after passing through the hold rolls 3 and 4, the pressing (pressing pressure) of the upper hold roll 3 is reduced so that the conveyance of the slab can be resumed. In this case, the conveyance of the slab can be resumed by raising the height position of the upper hold roll 3. However, if the height position of the upper hold roll 3 is raised, there is a concern about buckling. It is desirable to resume the conveyance of the slab by reducing the pressure of the slab.

  In this way, in this embodiment, it is possible to early detect a slab tip conveyance failure in the slab width reduction press facility, thereby making it possible to take appropriate measures. As a result, it is possible to ensure the quality of the rolled material by preventing the temperature reduction of the slab due to the delay in treatment, and it is possible to eliminate waste such as disposal processing of the rolled material, thereby improving productivity. .

It is a perspective view which shows typically the state which is giving the width reduction press to the slab by the width reduction press equipment. It is explanatory drawing of conveyance defect generation | occurrence | production of a slab front-end | tip part. It is a figure which shows the idea of the conveyance defect detection in one Embodiment of this invention. It is a figure which shows the procedure of the conveyance defect detection in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Slab 1a Slab tip 1b Slab tail 2 Press die 3 Upper hold roll 4 Lower hold roll 5 Pinch roll 6 Feed roll 7 Table roll

Claims (3)

  When rolling down the slab with the slab width rolling press equipment installed in the hot rolling line, the amount of rotation of the feed roll, the drive output of the feed roll, the height position of the upper hold roll or the upper hold roll and the lower hold roll Slab front end conveyance failure detection method in a slab width reduction press facility, wherein a conveyance failure of the slab front end portion is detected based on the interval of the slab.   The feed roll rotation amount and feed roll drive output detect the occurrence of poor conveyance at the slab tip, and the slab tip passes the hold roll depending on the height position of the upper hold roll or the distance between the upper and lower hold rolls. The method for detecting a conveyance failure of a slab tip portion in a slab width reduction press facility according to claim 1, wherein whether it is before or after passing is determined.   The method according to claim 2 detects a slab tip conveyance failure, raises the upper hold roll if the slab tip has not passed the hold roll, and raises the upper hold roll if the slab tip has passed the hold roll. A slab width reduction press method using a slab width reduction press facility, characterized by lowering the pressure of a roll.

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