Automatic measurement and optimization method for impact prompt drop of seamless steel pipe hot continuous rolling mill

Abstract

The invention discloses an automatic measurement and optimization method for impact prompt drop of a seamless steel tube hot continuous rolling mill, and the method comprises the steps: carrying out a plurality of rolling tests for a steel tube of one specification, reading the actual speed of a motor from a steel biting point to a set ending time point at a preset time interval during each rolling test, and calculating the actual speed of the motor; the minimum actual speed is selected; calculating a speed average value of the plurality of minimum actual speeds and a difference value between the speed average value and a given process speed of the motor; and taking the difference value as a speed drop compensation value corresponding to the steel pipe of the current specification. The optimization method comprises the steps of determining a speed drop compensation value corresponding to a steel pipe according to the specification of the steel pipe; before steel biting, the speed obtained after the given process speed is superposed with the speed drop compensation value serves as the motor running speed, and after steel biting, the given process speed serves as the motor running speed. Correlation between the steel pipe specification information and the prompt drop compensation value can be achieved, accurate compensation during rolling of steel pipes of different specifications is guaranteed, and the rolling quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rolling control, and in particular to an automatic measurement and optimization method for impact speed drop of a seamless steel pipe hot rolling mill. Background Art

[0002] During the hot rolling process of seamless steel pipes, the hot rolling mill will experience impact speed drop when biting steel. Impact speed drop means that the speed of the rollers suddenly decreases under the impact of the steel pipe. The sudden decrease in the speed of the rollers will lead to a decrease in the metal flow rate per second, which will cause the thickness of the steel pipe head to exceed the standard. In severe cases, it will also cause steel piling and rolling jamming.

[0003] In order to solve the impact speed drop problem, the speed compensation method is usually used at present. The speed compensation method specifically refers to adding a predetermined speed compensation value to the given process speed of the hot rolling mill motor before the hot rolling mill bites the steel, and canceling the added speed compensation value after the hot rolling mill bites the steel. However, the existing speed compensation value is calculated and determined based on the motor operating parameters and roll operating parameters of the hot rolling mill, without considering the influence of steel pipes of different specifications, and cannot fully adapt to the rolling of steel pipes of different specifications. In the actual rolling process, over-compensation or under-compensation is prone to occur, affecting the rolling effect. Summary of the invention

[0004] In order to solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides an automatic measurement and optimization method for the impact speed drop of a seamless steel pipe hot rolling mill.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, a method for automatically measuring the impact drop of a seamless steel pipe hot rolling mill is provided, the method comprising:

[0007] For a steel pipe of a certain specification, multiple rolling tests are carried out without speed compensation. In each rolling test, the actual speed of the motor is read once every preset time from the steel biting point to the set end time point, and the minimum actual speed is selected from the multiple actual speeds read;

[0008] Calculating a speed average of a plurality of minimum actual speeds, and calculating a difference between the speed average and a given process speed of the motor;

[0009] The difference is used as the speed drop compensation value corresponding to the current specification of steel pipe.

[0010] In some optional implementations, the time interval between the set end time point and the steel biting point is 250 ms.

[0011] In some optional implementations, the preset time is 5 ms.

[0012] In some optional embodiments, the number of rolling tests is 3 or more.

[0013] In some optional embodiments, the method further comprises:

[0014] After the minimum actual speed is selected, the amplitude of the obtained minimum actual speed is checked. If the obtained minimum actual speed is valid, the obtained minimum actual speed is retained. If the obtained minimum actual speed is invalid, the obtained minimum actual speed is deleted.

[0015] In a second aspect, a method for optimizing impact speed reduction of a seamless steel pipe hot rolling mill is also provided, the method comprising:

[0016] According to the specifications of the steel pipe, the speed drop compensation value corresponding to the steel pipe is determined, and the speed drop compensation value corresponding to the steel pipe is determined by the above-mentioned automatic measurement method for impact speed drop of seamless steel pipe hot rolling mill;

[0017] When rolling steel pipes, before biting the steel, the speed after superimposing the acceleration drop compensation value on the given process speed is used as the motor running speed. After biting the steel, the acceleration drop compensation value is cancelled and the given process speed is used as the motor running speed.

[0018] In some optional embodiments, the method further comprises:

[0019] From the steel biting point to the set end time point, the actual speed of the motor is read once at a preset interval, and the minimum actual speed is selected from the multiple actual speeds read;

[0020] Calculate the difference between the minimum actual speed and the given process speed, and determine whether the difference is within a preset range;

[0021] If the difference is not within the preset range, an early warning is issued.

[0022] In some optional embodiments, the method further comprises:

[0023] If the difference is not within the preset range, the difference between the given process speed plus the acceleration / deceleration compensation value and the minimum actual speed is used as the updated acceleration / deceleration compensation value.

[0024] In some optional embodiments, the method further comprises:

[0025] If the difference is not within the preset range, the above-mentioned automatic measurement method for impact speed drop of seamless steel pipe hot rolling mill is used again to determine the speed drop compensation value corresponding to the steel pipe.

[0026] In some optional embodiments, the method further comprises:

[0027] If the difference is not within the preset range, the speed drop compensation value corresponding to the steel pipe remains unchanged.

[0028] The main advantages of the technical solution of the present invention are as follows:

[0029] The method for automatically measuring and optimizing the impact speed drop of a seamless steel pipe hot rolling mill of the present invention measures the change in motor speed through actual rolling tests for steel pipes of different specifications, and uses the difference between the average value of multiple minimum actual speeds obtained through multiple rolling tests and a given process speed as the speed drop compensation value corresponding to the steel pipe of the corresponding specification, and continuously optimizes and adjusts the speed drop compensation value according to the actual rolling conditions, thereby realizing the association between the steel pipe specification information and the speed drop compensation value, ensuring accurate compensation during the rolling of steel pipes of different specifications, avoiding over-compensation or under-compensation, and improving the rolling quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the embodiments of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 A flow chart of an automatic measurement method for impact speed drop of a seamless steel pipe hot rolling mill provided by an embodiment of the present invention;

[0032] Figure 2 A flow chart of a method for optimizing impact speed reduction of a seamless steel pipe hot rolling mill provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] The technical solution provided by the embodiments of the present invention is described in detail below with reference to the accompanying drawings.

[0035] refer to Figure 1 In a first aspect, an embodiment of the present invention provides a method for automatically measuring the impact drop of a seamless steel pipe hot rolling mill, the method comprising the following steps:

[0036] Step 101, for a steel pipe of a certain specification, multiple rolling tests are performed without speed compensation. In each rolling test, the actual speed of the motor is read once every preset time interval from the steel biting point to the set end time point, and the minimum actual speed is selected from the multiple actual speeds read;

[0037] Step 102, calculating a speed average of a plurality of minimum actual speeds, and calculating a difference between the speed average and a given process speed of the motor;

[0038] Step 103, using the difference as the speed drop compensation value corresponding to the steel pipe of the current specification.

[0039] The automatic impact speed drop measurement method for a seamless steel pipe hot rolling mill provided in an embodiment of the present invention measures the change in motor speed through actual rolling tests for steel pipes of different specifications, and uses the difference between the average value of multiple minimum actual speeds obtained through multiple rolling tests and a given process speed as the speed drop compensation value corresponding to the steel pipe of the corresponding specification. The association between the steel pipe specification information and the speed drop compensation value can be achieved, thereby ensuring accurate compensation during the rolling of steel pipes of different specifications, avoiding over-compensation or under-compensation, and improving the rolling quality.

[0040] Further, in an embodiment of the present invention, in the above step 101, the end time point is set according to the actual situation, as long as it is ensured that the motor can completely drop in speed from the steel biting point to the set end time point.

[0041] Optionally, for a conventional hot rolling mill, the time interval between the end time point and the steel-biting point is set to 250 ms, that is, the end time point is set to 250 ms after the steel-biting point.

[0042] Furthermore, in the embodiment of the present invention, in the above step 101, the preset time is specifically set according to actual conditions.

[0043] Optionally, for a conventional hot rolling mill, the preset time is set to 5 ms, that is, the actual speed of the motor is read every 5 ms.

[0044] It should be noted that when the end time point is set at 250ms after the steel biting point and the preset time is set to 5ms, 50 actual speed data can be read in each rolling test.

[0045] Further, in the embodiment of the present invention, during the steel pipe rolling process, the time point when the rolling force suddenly increases is used as the steel biting point.

[0046] Furthermore, in an embodiment of the present invention, in order to improve the accuracy of the obtained speed drop compensation value, in the above step 101, the number of rolling tests is more than 3 times.

[0047] Further, in an optional implementation of the embodiment of the present invention, the method for automatically measuring the impact speed drop of a seamless steel pipe hot rolling mill further includes:

[0048] After the minimum actual speed is selected, the amplitude of the obtained minimum actual speed is checked. If the obtained minimum actual speed is valid, the obtained minimum actual speed is retained. If the obtained minimum actual speed is invalid, the obtained minimum actual speed is deleted.

[0049] In the embodiment of the present invention, by performing amplitude verification on the obtained minimum actual speed and retaining or deleting the minimum actual speed according to the amplitude verification result, the influence of erroneous data can be avoided and the accuracy of the obtained speed drop compensation value can be improved.

[0050] It should be noted that when the speed average of multiple minimum actual speeds is subsequently calculated, the minimum actual speed retained after amplitude verification is used.

[0051] It should be noted that the amplitude verification adopts a conventional verification method, which will not be described in detail here.

[0052] refer to Figure 2 In a second aspect, an embodiment of the present invention further provides a method for optimizing impact speed reduction of a seamless steel pipe hot rolling mill, the method comprising the following steps:

[0053] Step 201, determining the speed drop compensation value corresponding to the steel pipe according to the specifications of the steel pipe;

[0054] In the embodiment of the present invention, the speed drop compensation value corresponding to the steel pipe is determined by using the above-mentioned automatic measurement method for impact speed drop of seamless steel pipe hot rolling mill.

[0055] Step 202, when rolling the steel pipe, before biting the steel, the motor running speed is the speed obtained by superimposing the speed drop compensation value on the given process speed. After biting the steel, the speed drop compensation value is cancelled and the motor running speed is the given process speed.

[0056] The impact speed drop optimization method for a seamless steel pipe hot rolling mill provided in an embodiment of the present invention determines the speed drop compensation value corresponding to the current rolled steel pipe and performs speed compensation by utilizing the speed drop compensation values ​​corresponding to steel pipes of different specifications obtained by the above-mentioned impact speed drop automatic measurement method for a seamless steel pipe hot rolling mill. This ensures accurate compensation during steel pipe rolling, avoids over-compensation or under-compensation, and improves rolling quality.

[0057] Further, in an optional implementation of the embodiment of the present invention, the impact speed reduction optimization method of the seamless steel pipe hot rolling mill also includes:

[0058] Step 203, from the steel biting point to the set end time point, the actual speed of the motor is read once every preset time interval, and the minimum actual speed is selected from the multiple actual speeds read;

[0059] Step 204, calculating the difference between the minimum actual speed and the given process speed, and determining whether the difference is within a preset range;

[0060] Step 205: If the difference is not within the preset range, an early warning is issued.

[0061] It should be noted that, for steel pipes of the same specification, the end time point and the preset time set in step 203 are the same as the end time point and the preset time set in the above-mentioned automatic measurement method for impact speed drop of seamless steel pipe hot rolling mill.

[0062] It should be noted that the preset range is set according to the actual accuracy requirements.

[0063] In the embodiment of the present invention, by monitoring and judging the actual speed of the motor after speed compensation, it is possible to promptly know when a large deviation occurs, so as to subsequently optimize and adjust the speed drop compensation value, thereby ensuring the rolling quality.

[0064] Furthermore, in an optional implementation of the embodiment of the present invention, the above step 205 may also include:

[0065] If the difference is not within the preset range, the difference between the given process speed plus the acceleration / deceleration compensation value and the minimum actual speed is used as the updated acceleration / deceleration compensation value.

[0066] It should be noted that if the difference is within the preset range, the speed drop compensation value corresponding to the steel pipe remains unchanged.

[0067] In an embodiment of the present invention, if the difference between the minimum actual speed after speed compensation and the given process speed is not within a preset range, the difference between the speed after the given process speed is superimposed on the speed drop compensation value and the minimum actual speed can be used as an updated speed drop compensation value. When the steel pipe is subsequently rolled, before biting the steel, the speed after the given process speed is superimposed on the updated speed drop compensation value is used as the motor operating speed. After biting the steel, the speed drop compensation value is canceled and the given process speed is used as the motor operating speed. The speed drop compensation value can be continuously optimized and adjusted according to the actual rolling conditions, thereby ensuring accurate compensation during steel pipe rolling and improving rolling quality.

[0068] Furthermore, in an optional implementation of the embodiment of the present invention, the above step 205 may also include:

[0069] If the difference is not within the preset range, the above-mentioned automatic measurement method for impact speed drop of seamless steel pipe hot rolling mill is used again to determine the speed drop compensation value corresponding to the steel pipe.

[0070] It should be noted that if the difference is within the preset range, the speed drop compensation value corresponding to the steel pipe remains unchanged.

[0071] In an embodiment of the present invention, if the difference between the minimum actual speed after speed compensation and the given process speed is not within a preset range, the above-mentioned impact speed drop automatic measurement method of the seamless steel pipe hot rolling mill can be reused to determine the speed drop compensation value corresponding to the steel pipe. When the steel pipe is subsequently rolled, before biting the steel, the speed after the given process speed is superimposed with the re-determined speed drop compensation value is used as the motor operating speed. After biting the steel, the speed drop compensation value is canceled and the given process speed is used as the motor operating speed. The speed drop compensation value can be continuously optimized and adjusted according to the actual rolling conditions, thereby ensuring accurate compensation during steel pipe rolling and improving rolling quality.

[0072] Furthermore, in an optional implementation of the embodiment of the present invention, the above step 205 may also include:

[0073] If the difference is not within the preset range, the speed drop compensation value corresponding to the steel pipe remains unchanged.

[0074] It should be noted that if the difference is within the preset range, the speed drop compensation value corresponding to the steel pipe remains unchanged.

[0075] Taking into account the influence of some accidental factors that may cause the difference to be outside the preset range, in an embodiment of the present invention, when the difference between the minimum actual speed after speed compensation and the given process speed is outside the preset range, the speed drop compensation value corresponding to the steel pipe may also be kept unchanged. When the steel pipe is subsequently rolled, before biting the steel, the speed after the given process speed plus the speed drop compensation value is used as the motor operating speed. After biting the steel, the speed drop compensation value is canceled and the given process speed is used as the motor operating speed.

[0076] Among them, if the difference between the minimum actual speed after speed compensation obtained by two consecutive rollings and the given process speed is not within the preset range, the difference between the speed after the given process speed is superimposed on the speed drop compensation value and the minimum actual speed obtained by the most recent rolling is used as the updated speed drop compensation value, or the above-mentioned impact speed drop automatic measurement method of the seamless steel pipe hot rolling mill is reused to determine the speed drop compensation value corresponding to the steel pipe, so as to ensure accurate compensation during steel pipe rolling and improve rolling quality.

[0077] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, "front", "back", "left", "right", "upper" and "lower" in this article are all referenced to the placement state shown in the accompanying drawings.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for automatically measuring the impact drop of a seamless steel pipe hot rolling mill, characterized in that: The method comprises: For a steel pipe of a certain specification, multiple rolling tests are carried out without speed compensation. In each rolling test, the actual speed of the motor is read once every preset time from the steel biting point to the set end time point, and the minimum actual speed is selected from the multiple actual speeds read; Calculating a speed average of a plurality of minimum actual speeds, and calculating a difference between the speed average and a given process speed of the motor; The difference is used as the speed drop compensation value corresponding to the current specification of steel pipe.

2. The automatic measurement method for impact drop of seamless steel pipe hot rolling mill according to claim 1, characterized in that: The time interval between the set end time point and the steel biting point is 250ms.

3. The automatic measurement method for impact drop of seamless steel pipe hot rolling mill according to claim 1, characterized in that: The preset time is 5ms.

4. The automatic measurement method for impact drop of seamless steel pipe hot rolling mill according to claim 1, characterized in that: The number of rolling tests was 3 or more.

5. The automatic measurement method for impact drop of seamless steel pipe hot rolling mill according to claim 1, characterized in that: The method further comprises: After the minimum actual speed is selected, the amplitude of the obtained minimum actual speed is checked. If the obtained minimum actual speed is valid, the obtained minimum actual speed is retained. If the obtained minimum actual speed is invalid, the obtained minimum actual speed is deleted.

6. A method for optimizing impact speed reduction of a seamless steel pipe hot rolling mill, characterized in that: The method comprises: According to the specifications of the steel pipe, the speed drop compensation value corresponding to the steel pipe is determined, and the speed drop compensation value corresponding to the steel pipe is determined by the automatic measurement method for impact speed drop of a seamless steel pipe hot rolling mill according to any one of claims 1 to 5; When rolling steel pipes, before biting the steel, the speed after superimposing the acceleration drop compensation value on the given process speed is used as the motor running speed. After biting the steel, the acceleration drop compensation value is cancelled and the given process speed is used as the motor running speed.

7. The impact speed reduction optimization method for a seamless steel pipe hot rolling mill according to claim 6, characterized in that: The method further comprises: From the steel biting point to the set end time point, the actual speed of the motor is read once at a preset interval, and the minimum actual speed is selected from the multiple actual speeds read; Calculate the difference between the minimum actual speed and the given process speed, and determine whether the difference is within a preset range; If the difference is not within the preset range, an early warning is issued.

8. The impact speed reduction optimization method for a seamless steel pipe hot rolling mill according to claim 7, characterized in that: The method further comprises: If the difference is not within the preset range, the difference between the given process speed plus the acceleration / deceleration compensation value and the minimum actual speed is used as the updated acceleration / deceleration compensation value.

9. The impact speed reduction optimization method for a seamless steel pipe hot rolling mill according to claim 7, characterized in that: The method further comprises: If the difference is not within the preset range, the speed drop compensation value corresponding to the steel pipe is determined by reusing the automatic measurement method for impact speed drop of a seamless steel pipe hot rolling mill as described in any one of claims 1 to 5.

10. The impact speed reduction optimization method for a seamless steel pipe hot rolling mill according to claim 7, characterized in that: The method further comprises: If the difference is not within the preset range, the speed drop compensation value corresponding to the steel pipe remains unchanged.

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