A prestressed short stress rolling mill with automatic roll gap adjustment

Abstract

A short-stress rolling mill with automatic roll gap adjustment and prestressing belongs to the technical field of steel rolling equipment, and specifically relates to an improvement of the structure of a short-stress rolling mill. The present invention provides a short-stress rolling mill with automatic roll gap adjustment and prestressing, which has high processing accuracy and high production efficiency. The present invention includes a pull rod axially fixed in a frame body, and an upper roll box and a lower roll box are respectively arranged on the upper and lower sides of the frame body, and an upper main nut is arranged in the upper roll box, and a lower main nut is arranged in the lower roll box, and the upper main nut and the lower main nut are connected to the pull rod through positive and negative threads, and it is characterized in that: a main oil chamber is arranged between the upper part of the upper roll box and the lower part of the upper main nut, and between the lower part of the lower roll box and the upper part of the lower main nut, and a return oil disc spring of the main oil chamber is arranged between the pull rod and the upper roll box, and the lower roll box; a prestressing system of the pull rod and a real-time monitoring system for the roll box spacing are arranged on the frame body.

Description

Technical Field

[0001] The invention belongs to the technical field of steel rolling equipment, and in particular relates to an improvement on the structure of a short stress rolling mill. Background Art

[0002] The existing short-stress rolling mill, whose upper and lower roll boxes, spherical pads, main nuts and pull rods constitute a stress loop. Since the stress line of this type of rolling mill is much shorter than that of the frame type rolling mill, it is called a short-stress rolling mill. Short-stress rolling mills are mainly used in the production of small profiles.

[0003] Before rolling, the rolling mill needs to pre-set the distance between the roll gaps according to the profile size. Since there are gaps between the various components of the rolling mill, when the rollers apply pressure to the parts, the gaps between the various components of the rolling mill will change. The superposition of multiple changes will cause the distance of the roll gaps to change, increase the error, and easily cause the product size to exceed the specified range.

[0004] In order to avoid the above problems, it is necessary to load prestress on the rollers in advance, which is the advent of prestressed rolling mills. Prestressed rolling mills usually use elastic materials to provide prestress for the rollers, thereby eliminating the gaps between the workpieces. However, since the elastic material causes changes in force as the size changes, the prestress cannot be kept constant.

[0005] At the same time, during the continuous operation of the rolling mill, the roll gap will change due to wear and other factors, resulting in large dimensional deviations between the initial and final products, and the product precision cannot be accurately controlled; and during use, once the roll gap distance is out of tolerance, production must be stopped and the rolling mill must be replaced. Summary of the invention

[0006] The present invention aims at the above problems and provides a prestressed short stress rolling mill with high processing accuracy and high production efficiency and automatic roll gap adjustment.

[0007] To achieve the above-mentioned purpose of the present invention, the present invention adopts the following technical scheme, which includes a pull rod axially fixed in the frame body, an upper roller box and a lower roller box are respectively arranged on the upper and lower sides of the frame body, the upper roller box is provided with an upper main nut, the lower roller box is provided with a lower main nut, the upper main nut and the lower main nut are connected to the pull rod through positive and negative threads, and is characterized in that: a main oil chamber is arranged between the upper part of the upper roller box and the lower part of the upper main nut, and between the lower part of the lower roller box and the upper part of the lower main nut, and an oil return disc spring of the main oil chamber is arranged between the pull rod and the upper roller box, and between the lower roller box; a prestressed system of the pull rod and a real-time monitoring system for the roller box spacing are arranged on the frame body, and the prestressed system includes An upper frame end cover and a lower frame end cover, an upper prestressed piston is disposed above the upper frame end cover, and a lower prestressed piston is disposed below the lower frame end cover; an upper auxiliary oil chamber matched with the upper prestressed piston is disposed between the lower part of the upper roller box and the sleeve body of the lower part of the upper main nut; a lower auxiliary oil chamber matched with the lower prestressed piston is disposed between the upper part of the lower roller box and the sleeve body of the upper part of the lower main nut; the real-time monitoring system comprises an upper displacement sensor and a lower displacement sensor disposed on the upper and lower sides of the frame, the upper displacement sensor corresponds to the upper roller box, the lower displacement sensor corresponds to the lower roller box, the upper displacement sensor and the lower displacement sensor are connected to a central processing unit, the central processing unit is connected to a hydraulic system, and the hydraulic system is connected to the main oil chamber and the auxiliary oil chamber through a hydraulic pipeline.

[0008] As a preferred solution of the present invention, an upper spherical pad cooperating with an upper main nut is arranged in the main oil chamber of the upper roller box, and a lower spherical pad cooperating with a lower main nut is arranged in the main oil chamber of the lower roller box, and the oil inlet of the main oil chamber corresponds to the gap between the spherical pad and the main nut.

[0009] As another preferred embodiment of the present invention, secondary nuts are provided on the pull rod above the upper main nut and below the lower main nut, pressure covers corresponding to the secondary nuts are provided on the upper roller box and the lower roller box, and the oil return disc spring is provided between the pressure cover and the secondary nut.

[0010] As a third preferred embodiment of the present invention, an axial fixing platform is provided in the middle of the pull rod, and a bearing assembly cooperating with the axial fixing platform is provided in the frame body; the bearing assembly is fixed between the frame body and the pull rod through an upper frame end cover and a lower frame end cover.

[0011] Beneficial effects of the present invention: 1. The present invention controls the approach and separation of the upper roller box and the lower roller box through the hydraulic system, and cooperates with the real-time detection system and the central processor to realize the function of online adjustment of the roller gap. The product accuracy is effectively controlled to avoid the situation of shutdown due to product size out of tolerance.

[0012] 2. In the present invention, a sleeve structure is provided on the upper main nut and the lower main nut. Compared with the prior art, the main nut with increased length, the roller box and the prestressed piston of the frame end cover form an auxiliary cylinder. When the auxiliary cylinder is filled with oil, the pull rod is subjected to tension to form prestress of the pull rod, which is the so-called prestressed rolling mill.

[0013] 3. When the present invention does not require automatic adjustment of the roll gap, the oil in the main oil chamber can be drained, and the main nut and the spherical pad form a tight fit under the action of the oil return disc spring and the auxiliary oil chamber, and then the auxiliary oil chamber oil drain valve is opened. At this time, the oil return disc spring plays a certain prestressing role, even if the present invention is the same as the operating method of the existing rolling mill.

[0014] 4. Due to the structural characteristics of the present invention, the coordination of the main oil chamber, the auxiliary oil chamber, the roller box and the main nut can not only achieve the effect of prestressing, but also provide the larger rolling force required for the operation of the rolling mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention.

[0016] In the attached drawings, 1 is the lower main nut, 2 is the spherical pad, 3 is the lower prestressed piston, 4 is the lower frame end cover, 5 is the lower displacement sensor, 6 is the frame body, 7 is the upper displacement sensor, 8 is the upper frame end cover, 9 is the upper roller box, 10 is the upper prestressed piston, 11 is the auxiliary oil chamber, 12 is the main oil chamber, 13 is the upper main nut, 14 is the oil return disc spring, 15 is the pressure cover, 16 is the pull rod, 17 is the auxiliary nut, 18 is the pull rod drive mechanism, 19 is the axial fixing table, 20 is the bearing assembly, 21 is the lower roller box, and 22 is the sleeve body. DETAILED DESCRIPTION

[0017] The present invention includes a pull rod 16 axially fixedly arranged in a frame body 6, an upper roller box 9 and a lower roller box 21 are respectively arranged on the upper and lower sides of the frame body 6, an upper main nut 13 is arranged in the upper roller box 9, and a lower main nut 1 is arranged in the lower roller box 21, and the upper main nut 13 and the lower main nut 1 are connected to the pull rod 16 through positive and negative threads, and is characterized in that: a main oil chamber 12 is arranged between the upper part of the upper roller box 9 and the lower part of the upper main nut 13, and between the lower part of the lower roller box 21 and the upper part of the lower main nut 1, and an oil return disc spring 14 of the main oil chamber 12 is arranged between the pull rod 16 and the upper roller box 9, and the lower roller box 21; a prestressed system of the pull rod 16 and a real-time monitoring system for the roller box spacing are arranged on the frame body 6, and the prestressed system includes an upper frame end cover 8 and a lower frame which are respectively arranged on the upper and lower sides of the frame body 6. End cover 4, upper prestressed piston 10 is arranged above the upper frame end cover 8, and lower prestressed piston 3 is arranged below the lower frame end cover 4; an upper auxiliary oil chamber 11 cooperating with the upper prestressed piston 10 is arranged between the lower part of the upper roller box 9 and the sleeve 22 of the lower part of the upper main nut 13; a lower auxiliary oil chamber 11 cooperating with the lower prestressed piston 3 is arranged between the upper part of the lower roller box 21 and the sleeve 22 of the upper part of the lower main nut 1; the real-time monitoring system includes an upper displacement sensor 7 and a lower displacement sensor 5 arranged on the upper and lower sides of the frame, the upper displacement sensor 7 corresponds to the upper roller box 9, and the lower displacement sensor 5 corresponds to the lower roller box 21, the upper displacement sensor 7 and the lower displacement sensor 5 are connected to the central processing unit, the central processing unit is connected to the hydraulic system, and the hydraulic system is connected to the main oil chamber 12 and the auxiliary oil chamber 11 through a hydraulic pipeline.

[0018] As a preferred solution of the present invention, an upper spherical pad 2 cooperating with the upper main nut 13 is provided in the main oil chamber 12 of the upper roller box 9, and a lower spherical pad 2 cooperating with the lower main nut 1 is provided in the main oil chamber 12 of the lower roller box 21, and the oil inlet of the main oil chamber 12 corresponds to the gap between the spherical pad 2 and the main nut.

[0019] As another preferred embodiment of the present invention, a secondary nut 17 is provided on the pull rod 16 above the upper main nut 13 and below the lower main nut 1, a pressure cover 15 corresponding to the secondary nut 17 is provided on the upper roller box 9 and the lower roller box 21, and the oil return disc spring 14 is provided between the pressure cover 15 and the secondary nut 17.

[0020] As a third preferred embodiment of the present invention, an axial fixing platform 19 is provided in the middle of the pull rod 16, and a bearing assembly 20 cooperating with the axial fixing platform 19 is provided in the frame body 6; the bearing assembly 20 is fixed between the frame body 6 and the pull rod 16 through the upper frame end cover 8 and the lower frame end cover 4.

[0021] The hydraulic system is connected to the main oil chamber 12 through a high-pressure oil circuit, and is connected to the auxiliary oil chamber 11 through a low-pressure oil circuit; the pressure of the main oil chamber 12 is greater than the pressure of the auxiliary oil chamber 11; the pressure of the main oil chamber 12 provides rolling force.

[0022] A pull rod driving mechanism 18 is disposed at the upper end of the pull rod 16 .

[0023] The bearing assembly 20 may be composed of a needle bearing and a thrust bearing.

[0024] Working process: 1. The pull rod driving mechanism 18 controls the pull rod 16 to rotate. The pull rod 16 is axially fixed and can only rotate under the restriction of the bearing assembly 20 and the axial fixing platform 19.

[0025] 2. The upper main nut 13 and the lower main nut 1 form a whole with the roller box through the spherical washer 2, the auxiliary nut 17, the disc spring and the pressure cover 15. When the pull rod 16 rotates, the upper main nut 13 and the lower main nut 1, the upper roller box 9 and the lower roller box 21 move toward or in the opposite direction.

[0026] 3. During operation, the preset roll gap is A. First, the roll gap is adjusted to A+ (1-50mm) by mechanical adjustment (rotation of the pull rod 16), and the pull rod 16 remains axially stationary. The main oil chamber 12 is filled with oil, so that the upper roll box 9 and the lower roll box 21 move toward each other. After the preset roll gap distance A is reached through the position information transmitted by the upper displacement sensor 7 and the lower displacement sensor 5, the upper roll box 9 and the lower roll box 21 remain stationary. Then the auxiliary oil chamber 11 is filled with oil, and the upper roll box 9 and the lower roll box 21 move back and forth. After the auxiliary oil chamber 11 reaches the preset pressure, the pull rod 16 reaches the specified prestressed state. At the same time, due to the large pressure acting on the upper main nut 13 and the lower main nut 1, the upper main nut 13 and the lower main nut 1 and the pull rod 16 are locked. During the rolling process, the pressure of the auxiliary oil chamber 11 remains unchanged, and the upper main nut 13 and the lower main nut 1 and the pull rod 16 remain locked. At this time, if the roll gap distance is increased, the high-pressure oil chamber is filled with oil again, and the required roll gap value is finally achieved through the action of the automatic central processing unit. At this point, the roll gap adjustment before the rolling mill is working is completed.

[0027] When the rolling mill is working, if the roll gap (or the size of the steel after rolling) changes, the upper displacement sensor 7 and the lower displacement sensor 5 convert the sensed position change into an electrical signal and transmit it to the central processor. The central processor compares it with the preset value and sends a command to the hydraulic system to instruct the main oil chamber 12 and the auxiliary oil chamber 11 to respectively fill or drain oil, thereby ensuring that the distance A of the roll gap remains unchanged with the preset value, that is, realizing automatic control of the roll gap.

[0028] Specifically, the present invention is composed of a spherical pad 2, an upper roller box 9 and a lower roller box 21 to form a single-acting main oil cylinder (main oil chamber 12). When the rolling mill is working, it bears the rolling force. The oil inlet depends on the hydraulic system. The high-pressure oil acts on the spherical pad 2. Since the main nut does not move when the pull rod 16 is stationary, the oil pressure pushes the upper roller box 9 and the lower roller box 21 to move toward each other (the upper roller box 9 moves downward, and the lower roller box 21 moves upward) through the spherical pad 2, so that the roll gap is reduced. The return oil relies on the disc spring and the force of the auxiliary oil chamber 11 on the roll box to push the upper roll box 9 and the lower roll box 21 to move away from each other, so that the roll gap is increased.

[0029] The single-acting auxiliary oil cylinder is composed of the extended upper main nut 13, the lower main nut 1, the upper frame end cover 8, the lower frame end cover 4, the upper roller box 9 and the lower roller box 21. When oil is fed, the oil pressure acts on the upper frame end cover 8, the lower frame end cover 4, the upper roller box 9 and the lower roller box 21. Since the upper frame end cover 8 and the lower frame end cover 4 are fixed on the frame, and the frame is fixed on the rolling mill base (not shown) and is a stationary part, the oil pressure pushes the upper roller box 9 and the lower roller box 21 to move in the back direction, so that the tie rod 16 is subjected to a pulling force, that is, the tie rod 16 is prestressed.

[0030] An automatic central processor for keeping the roll gap unchanged is formed by the upper displacement sensor 7, the lower displacement sensor 5, the central processor, and the hydraulic system. When the rolling mill of the present invention is working, the upper displacement sensor 7 and the lower displacement sensor 5 are used to sense the position information of the roll box in real time and transmit the information to the central processor. The central processor calculates the change of the roll gap by comparing it with the preset value. If the roll gap exceeds the preset value, an oil inlet or oil drain signal is sent to the hydraulic system of the high-pressure oil cylinder, thereby adjusting the position of the roll box, and finally achieving the purpose of automatic control of the roll gap.

[0031] When it is not necessary to realize automatic roll gap in the production process, the oil in the main oil chamber 12 is drained first, and the upper main nut 13 and the lower main nut 1 form a tight fit with the spherical pad 2 under the action of the oil return disc spring 14 and the auxiliary oil cylinder, and then the oil drain valve of the auxiliary oil chamber 11 is opened (conventional technical means not shown in the figure), which is the same as the operating method currently used in the rolling mill.

[0032] By lengthening the upper main nut 13 and the lower main nut 1, the high-pressure main oil chamber 12 and the low-pressure auxiliary oil chamber 11 are organically formed into a whole, which not only realizes the effect of prestressing, but also provides the larger rolling force required for the operation of the rolling mill.

[0033] When the rolling mill of the present invention is used in the whole line (consisting of multiple rolling mills), the following adjustments can be made to multiple or single rolling mills on the production line at the same time: A. According to the different temperatures of each interval section of each blank, the roll gap of each rolling mill is preset in the central processor.

[0034] B. According to the different process requirements of rough, medium and finish rolling, the roll gap of each rolling mill is preset in the central processor or adjusted online.

[0035] C. Adjust the roll gap of each rolling mill online according to the different conditions that occur during the use of each rolling mill (such as changes in roll wear, fit clearance, etc.).

[0036] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A prestressed short stress rolling mill with automatic roll gap adjustment, comprising a tie rod (16) axially fixedly arranged in a frame body (6), an upper roll box (9) and a lower roll box (21) are respectively arranged on the upper and lower sides of the frame body (6), an upper main nut (13) is arranged in the upper roll box (9), and a lower main nut (1) is arranged in the lower roll box (21), and the upper main nut (13) and the lower main nut (1) are connected to the tie rod (16) through positive and negative threads, characterized in that: A main oil chamber (12) is provided between the upper part of the upper roller box (9) and the lower part of the upper main nut (13), and between the lower part of the lower roller box (21) and the upper part of the lower main nut (1). An oil return disc spring (14) of the main oil chamber (12) is provided between the tie rod (16) and the upper roller box (9), and between the lower roller box (21). A prestressing system of the tie rod (16) and a real-time monitoring system for the roller box spacing are provided on the frame body (6). The prestressing system includes an upper frame end cover (8) and a lower frame end cover (4) respectively provided on the upper and lower sides of the frame body (6). An upper prestressing piston (10) is provided above the upper frame end cover (8), and a lower prestressing piston (3) is provided below the lower frame end cover (4). An upper auxiliary oil chamber (11) cooperating with the upper prestressed piston (10) is arranged between the lower part of the upper roller box (9) and the sleeve (22) of the lower part of the upper main nut (13); a lower auxiliary oil chamber (11) cooperating with the lower prestressed piston (3) is arranged between the upper part of the lower roller box (21) and the sleeve (22) of the upper part of the lower main nut (1); the real-time monitoring system comprises an upper displacement sensor (7) and a lower displacement sensor (5) arranged on the upper and lower sides of the frame, the upper displacement sensor (7) corresponds to the upper roller box (9), the lower displacement sensor (5) corresponds to the lower roller box (21), the upper displacement sensor (7) and the lower displacement sensor (5) are connected to a central processing unit, and the central processing unit The device is connected to a hydraulic system, and the hydraulic system is connected to a main oil chamber (12) and a secondary oil chamber (11) through a hydraulic pipeline; an upper spherical pad (2) cooperating with an upper main nut (13) is provided in the main oil chamber (12) of the upper roller box (9), and a lower spherical pad (2) cooperating with a lower main nut (1) is provided in the main oil chamber (12) of the lower roller box (21); an oil inlet of the main oil chamber (12) corresponds to a gap between the spherical pad (2) and the main nut; secondary nuts (17) are provided on the pull rod (16) above the upper main nut (13) and below the lower main nut (1); and the upper roller box (9) and the lower roller box (21) are provided with spherical pads (2) corresponding to the secondary nuts (17). The pressure cover (15) is provided with a return oil disc spring (14) between the pressure cover (15) and the auxiliary nut (17); an axial fixing platform (19) is provided in the middle of the pull rod (16); a bearing assembly (20) cooperating with the axial fixing platform (19) is provided in the frame body (6); the bearing assembly (20) is fixed between the frame body (6) and the pull rod (16) through an upper frame end cover (8) and a lower frame end cover (4); the hydraulic system is connected to the main oil chamber (12) through a high-pressure oil circuit, and the hydraulic system is connected to the auxiliary oil chamber (11) through a low-pressure oil circuit; the pressure of the main oil chamber (12) is greater than the pressure of the auxiliary oil chamber (11); and the pressure of the main oil chamber (12) provides rolling force.

2. The prestressed short stress rolling mill with automatic roll gap adjustment according to claim 1, characterized in that: A pull rod driving mechanism (18) is provided at the upper end of the pull rod (16).

3. The prestressed short stress rolling mill with automatic roll gap adjustment according to claim 1, characterized in that: The bearing assembly (20) may be composed of a needle bearing and a thrust bearing.

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