A two-roller test mill driven by a hydraulic motor

Abstract

The present invention discloses a two-roll test mill driven by a hydraulic motor, belonging to the technical field of two-roll mills for the metallurgical industry. The two-roll test mill of the present invention comprises an encoder, a hydraulic motor, a gearbox, a coupling, a frame, a screw with a screw nut, a handwheel assembly, a roller bearing seat, a roller group, and a hydraulic control system. The handwheel assembly comprises a mounting flange, a connecting shaft, a conductive slip ring, an angle sensor, a connector, a bearing, a spring, a feedback rod, a connecting plate, a limit device, and a handwheel. The hydraulic control system comprises a motor, a hydraulic pump, a relief valve, a servo valve, a hydraulic motor, and a signal amplifier. The two-roll test mill of the present invention can achieve zero-speed starting rolling and low-speed, high-torque rolling, and can output the rated torque at startup. During operation, the slab can be placed first, and then the mill can be started for rolling, thus avoiding the occurrence of entrainment and hooking, and the operation is flexible and safe. In addition, the handwheel has a force feedback function, allowing the operator to sense the magnitude of the rolling force in real time.

Description

Technical Field

[0001] The invention belongs to the technical field of two-roller rolling mills used in the metallurgical industry, and in particular relates to a two-roller test rolling mill driven by a hydraulic motor. Background Art

[0002] The steel industry is the foundation of a nation's industrial development. Plate and strip steel products are widely used in the military, aerospace, agriculture, construction, home appliances, automotive, and other industries, and are a key raw material for the national economy. Rolling is currently the most common steel processing method in industry. To improve productivity, optimize production processes, and develop a variety of products, repeated rolling tests are necessary.

[0003] Existing rolling mills typically use DC motors or asynchronous variable-frequency motors to drive the rollers. DC motors draw high current at low speeds, causing rapid motor heating and making them unsuitable for prolonged low-speed operation. Asynchronous variable-frequency motors typically use VF control and have a minimum speed limit (for example, the YVP series asynchronous variable-frequency motors have an operating frequency range of 5-100Hz). These motors are prone to triggering overcurrent alarms during full-load startup and low-speed, high-torque output. Therefore, existing rolling mills cannot meet the requirements for low-speed, high-torque rolling.

[0004] In addition, since the existing rolling mill cannot be started at full load, when rolling operations are required, the motor must be started first, and the rolling sample can only be fed into the rolling mill after the roller speed stabilizes. This feeding operation is very prone to entrainment and hooking, which is very dangerous to the operator. Summary of the Invention

[0005] Aiming at the problems that the current test rolling mill is dangerous to operate and cannot adapt to low-speed and high-torque rolling during operation, the present invention provides a two-roller test rolling mill driven by a hydraulic motor.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A two-roller test mill driven by a hydraulic motor, comprising an encoder, a hydraulic motor, a gear box, a coupling, a frame, a screw with a screw nut, a hand wheel assembly, a roller bearing seat, a roller group and a hydraulic control system;

[0008] The gearbox is provided with an input shaft and two output shafts, wherein the input shaft is connected to the hydraulic motor, and the output shafts are respectively connected to the roller group through couplings, and the two output shafts rotate in opposite directions;

[0009] The encoder is installed at the end of the hydraulic motor input shaft and is used to detect the speed of the hydraulic motor;

[0010] The roller group includes an upper roller and a lower roller, both ends of the roller group are installed in the frame through bearing seats, and the upper roller and the bearing seats on both sides of the upper roller are arranged in the frame to slide up and down;

[0011] The pressing nut screw is set above the bearing seats on both sides of the upper roller. The pressing nut is fixed to the frame. The end of the screw contacts the bearing seat. The screw can be rotated to adjust the gap between the rollers.

[0012] The handwheel assembly consists of a mounting flange, a connecting shaft A, a conductive slip ring, an angle sensor, a connector, a bearing, a spring, a connecting shaft B, a feedback rod, a connecting plate, a limit device and a handwheel; the mounting flange is rigidly connected to the connecting shaft A; the connecting shaft A and the connecting shaft B are coaxially connected through a bearing, and the connecting shaft A and the connecting shaft B can rotate but cannot slide axially; the connecting plate is rigidly connected to the connecting shaft A and the angle sensor respectively through bolts; the rotating shaft of the angle sensor is rigidly connected to the feedback rod, and at the same time, in order to increase the strength of the angle sensor, a shaft is installed between the rotating shaft of the angle sensor and the connecting plate. The invention relates to a bearing support; a signal line of the rotation angle sensor is led out through a conductive slip ring; the feedback rod is flexibly connected to the connection disk through two springs, and the springs have a pre-tensioning force; two limit devices are installed on the connection disk for limiting the feedback rod; the limit devices are mainly used to limit the feedback rod and also have a safety protection function; the feedback rod can rotate together with the rotation shaft of the rotation angle sensor within the range of the limit devices; when the feedback rod rotates, the length of the two springs changes; the feedback rod is rigidly connected to the B connection shaft (708) through a connector; the hand wheel is rigidly connected to the B connection shaft;

[0013] The hydraulic control system consists of a motor, a hydraulic pump, a relief valve, a servo valve, a hydraulic motor, and a signal amplifier; the motor serves as a power source, is connected to the hydraulic pump, and drives the hydraulic pump to rotate; the hydraulic pump supplies oil to the servo valve; the relief valve is connected to the outlet of the hydraulic pump to adjust the pressure at the outlet of the hydraulic pump; the servo valve is connected to the two oil ports of the hydraulic motor to control the speed and direction of the hydraulic motor; the signal amplifier is connected to the servo valve and the angle sensor respectively, and is used to amplify the output signal of the angle sensor and send it to the servo valve.

[0014] The gear box is a speed reducer.

[0015] Working process:

[0016] When the handwheel is stationary, the angle sensor output signal is 0. After amplification, the signal sent to the servo valve is also 0. At this time, the servo valve spool is in the middle position and the hydraulic motor stops.

[0017] When the operator turns the handwheel clockwise, the handwheel drives the feedback lever to rotate a certain angle. The angle sensor detects the angle and outputs a signal proportional to the angle. This signal is amplified and connected to the servo valve. The servo valve spool moves, and high-pressure oil enters the motor. The hydraulic motor outputs torque, driving the roller to rotate clockwise.

[0018] When the rolling torque suddenly increases, the motor speed decreases, the angle difference between the A connecting shaft and the B connecting shaft increases, the angle sensor detects that the angle increases, the angle sensor output signal increases, and this signal is amplified by the signal amplifier and sent to the servo valve. At this time, the servo valve port opening increases, the hydraulic motor output torque increases, overcoming the rolling torque, and the motor speed increases until the roll rotation angle is synchronized with the handwheel rotation angle; when the rolling torque suddenly decreases, the motor speed increases, the angle difference between the A connecting shaft and the B connecting shaft decreases, the angle sensor detects that the angle decreases, the angle sensor output signal decreases, and this signal is amplified by the signal amplifier and sent to the servo valve. At this time, the servo valve port opening decreases, the hydraulic motor output torque decreases, and the motor speed decreases until the roll rotation angle is synchronized with the handwheel rotation angle;

[0019] When the operator turns the handwheel counterclockwise, the angle sensor detects the angle change and outputs a signal proportional to the angle. This signal is amplified and connected to the servo valve, causing the servo valve core to move in the opposite direction. At this time, high-pressure oil enters the motor, and the motor outputs torque, driving the roller to rotate counterclockwise.

[0020] When the operator stops turning the handwheel, the angle sensor output signal is 0, the servo valve is in the middle position, and the motor will slow down and stop rotating.

[0021] When the rolling torque is large, the opening degree of the servo valve needs to be increased. At this time, the angle difference between the connecting shaft A and the connecting shaft B becomes larger, that is, the torque applied by the operator on the handwheel becomes larger; similarly, when the rolling torque is small, the torque applied by the operator on the handwheel is small. Therefore, the operator can sense the size of the rolling torque by feeling the torque applied to the handwheel. This function is the force feedback function.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention can realize zero-speed starting rolling. During operation, the slab to be rolled can be placed first, and then the hand wheel is turned to roll, which avoids the occurrence of entrainment and hooking, and the operation is safer.

[0024] 2. The rolling mill of the present invention can achieve low-speed and high-torque rolling.

[0025] 3. The present invention has a force feedback function, and the operator can sense the magnitude of the rolling torque by feeling the torque acting on the hand wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the overall structure of a two-roller test rolling mill driven by a hydraulic motor of the present invention;

[0027] Figure 2 A half-section schematic diagram of the structure of a handwheel assembly in a two-roll test rolling mill driven by a hydraulic motor according to the present invention;

[0028] Figure 3 A schematic diagram of the structure of a handwheel assembly in a two-roll test mill driven by a hydraulic motor according to the present invention (the handwheel is not shown);

[0029] Figure 4 This is a schematic diagram of the structure of the hydraulic control system in the two-roll test mill driven by the hydraulic motor of the present invention;

[0030] Figure 5 This is the simulation diagram built in AMEsim software;

[0031] Figure 6 This is a schematic diagram of the pressure change curve at port A and port B of the motor;

[0032] Figure 7 Schematic diagram of the handwheel rotation angle curve and the handwheel torque curve;

[0033] Figure 8 The output torque curve of the motor and the set load torque curve.

[0034] Figure markings: 1. Encoder; 2. Hydraulic motor; 3. Gearbox; 4. Coupling; 5. Frame; 6. Press-down nut screw; 7. Handwheel assembly; 701. Mounting flange; 702. Connecting shaft A; 703. Conductive slip ring; 704. Angle sensor; 705. Connector; 706. Bearing; 707. Spring; 708. Connecting shaft B; 709. Feedback rod; 710. Connecting plate; 711. Handwheel; 712. Limiting device; 8. Roll bearing seat; 9. Roll group; 901. Upper roller; 902. Lower roller; 10. Hydraulic control system; 1001. Motor; 1002. Hydraulic pump; 1003. Overflow valve; 1004. Servo valve; 1005. Signal amplifier. DETAILED DESCRIPTION

[0035] Example 1

[0036] A two-roll test rolling mill driven by a hydraulic motor, comprising an encoder 1, a hydraulic motor 2, a gear box 3, a coupling 4, a frame 5, a screw nut 6, a handwheel assembly 7, a roller bearing seat 8, a roller group 9 and a hydraulic control system 10;

[0037] The gearbox 3 is a speed reducer, which has an input shaft and two output shafts. The input shaft is connected to the hydraulic motor 2, and the output shafts are connected to the roller group 9 through the coupling 4. The two output shafts rotate in opposite directions.

[0038] The encoder 1 is installed at the end of the input shaft of the hydraulic motor 2 and is used to detect the rotation speed of the hydraulic motor 2;

[0039] The roller group 9 includes an upper roller 901 and a lower roller 902. Both ends of the roller group 9 are mounted in the frame 5 via bearing seats. The upper roller 901 and the bearing seats on both sides of the upper roller 901 are arranged in the frame to slide up and down.

[0040] The pressing nut screw 6 is set above the bearing seats on both sides of the upper roller 901, the pressing nut is fixed to the frame, the screw is rotated, and the end of the screw is in contact with the bearing seat to adjust the gap between the rollers 9;

[0041] The handwheel assembly 7 consists of a mounting flange 701, a connecting shaft A 702, a conductive slip ring 703, an angle sensor 704, a connector 705, a bearing 706, a spring 707, a connecting shaft B 708, a feedback rod 709, a connecting disk 710, a limit device 712 and a handwheel 711; the mounting flange 701 is rigidly connected to the connecting shaft A 702; the connecting shaft A 702 and the connecting shaft B 708 are coaxially connected through a bearing 706, and the connecting shaft A 702 and the connecting shaft B 708 can rotate but cannot slide axially; the connecting disk 710 is rigidly connected to the connecting shaft A 702 and the angle sensor 704 respectively by bolts; the rotating shaft of the angle sensor 704 is rigidly connected to the feedback rod 709, and at the same time, in order to increase the strength of the angle sensor 704, the rotating shaft of the angle sensor 704 is Bearing supports are installed between the connecting disks 710; the signal line of the angle sensor 704 is led out through the conductive slip ring 703; the feedback rod 709 is flexibly connected to the connecting disk 710 through two springs 707, and the springs 707 have a pre-tensioned force; two limit devices 712 are installed on the connecting disk 710 for limiting the feedback rod 709; the limit devices 712 are mainly used to limit the feedback rod 709, and in addition, they also have a safety protection function; the feedback rod 709 can rotate together with the rotating shaft of the angle sensor 704 within the range of the limit devices 712; when the feedback rod 709 rotates, the length of the two springs 707 changes; the feedback rod 709 is rigidly connected to the B connecting shaft 708 through the connector 705; the handwheel 711 is rigidly connected to the B connecting shaft 708;

[0042] The hydraulic control system 10 consists of a motor 1001, a hydraulic pump 1002, a relief valve 1003, a servo valve 1004, a hydraulic motor 2, and a signal amplifier 1005; the motor 1001 serves as a power source, is connected to the hydraulic pump 1002, and drives the hydraulic pump 1002 to rotate; the hydraulic pump 1002 supplies oil to the servo valve 1004; the relief valve 1003 is connected to the outlet of the hydraulic pump 1002, and is used to adjust the pressure at the outlet of the hydraulic pump 1002; the servo valve 1004 is connected to the two oil ports of the hydraulic motor 2, and is used to control the speed and direction of the hydraulic motor 2; the signal amplifier 1005 is respectively connected to the servo valve 1004 and the angle sensor 704, and is used to amplify the output signal of the angle sensor 704 and send it to the servo valve 1004.

[0043] Example 2

[0044] Working process:

[0045] When the hand wheel 711 is stationary, the output signal of the rotation angle sensor 704 is 0. After being amplified by the signal amplifier 1005, the signal sent to the servo valve 1004 is also 0. At this time, the valve core of the servo valve 1004 is in the middle position and the hydraulic motor 2 stops.

[0046] When the operator turns the hand wheel 711 clockwise, the rotation angle sensor 704 detects the angle change and outputs a signal proportional to the angle. This signal is amplified by the signal amplifier 1005 and then connected to the servo valve. The servo valve spool moves, and high-pressure oil enters the hydraulic motor 2. The hydraulic motor 2 outputs torque, driving the roller 9 to rotate clockwise.

[0047] When the operator turns the hand wheel 711 counterclockwise, the angle sensor 704 detects the angle change and outputs a signal proportional to the angle. This signal is amplified by the signal amplifier 1005 and then connected to the servo valve 1004. The spool of the servo valve 1004 moves in the opposite direction. At this time, high-pressure oil enters the hydraulic motor 2, and the hydraulic motor 2 outputs torque, driving the roller 9 to rotate counterclockwise.

[0048] When the operator stops turning the hand wheel 705, the angle sensor 704 outputs a signal of 0, the servo valve 1004 is in the middle position, and the motor decelerates and stops rotating.

[0049] Simulation parameters:

[0050] Hydraulic motor displacement: 5000mL; set load maximum: 50kN; reducer reduction ratio: 2; handwheel spring stiffness: 2N / degress; amplifier gain: 10.

[0051] The simulation results are as follows Figures 5-7 As shown, Figure 5 This is a simulation diagram built in AMEsim software. Figure 6The pressure change curve of the motor A port and B port can be seen from the figure. In the first 0.5 seconds, the pressure difference between the motor A and B ports gradually increases, remains constant from 0.5 seconds to 3.5 seconds, and gradually decreases to 0 from 3.5 seconds to 4.5 seconds. The change trend of the pressure difference between the motor A and B ports is consistent with the set load torque. Figure 7 The handwheel rotation angle curve and the handwheel torque curve are shown in the figure. It can be seen from the figure that during the whole process, the operator used a torque of about 1.2Nm to rotate the handwheel at a constant speed, rotating the handwheel 600 degrees. Figure 8 The output torque curve of the motor and the set load torque curve are shown in the figure. It can be seen from the figure that the motor output torque is basically equal to half of the load torque. This is because the transmission ratio of the gearbox is 2.

[0052] In summary, compared to conventional rolling mills, the hydraulic motor-driven two-roll test mill of the present invention can achieve zero-speed start-up rolling and meet the requirements of low-speed, high-torque rolling. During operation, the slab can be placed first, and then the mill starts rolling, avoiding the risk of entrainment and hooking, and providing flexible and safe operation.

[0053] Any matters not described in detail in this specification are prior art known to those skilled in the art. Although the above description of the present invention is based on specific embodiments to facilitate understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the specific embodiments. As long as various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, such modifications will be obvious to those skilled in the art, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. A two-roll test mill driven by a hydraulic motor, characterized in that: It consists of an encoder (1), a hydraulic motor (2), a gear box (3), a coupling (4), a frame (5), a screw nut (6), a handwheel assembly (7), a roller bearing seat (8), a roller group (9) and a hydraulic control system (10); The gearbox (3) is provided with an input shaft and two output shafts, the input shaft is connected to the hydraulic motor (2), the output shafts are respectively connected to the roller group (9) through the coupling (4), and the two output shafts rotate in opposite directions; The encoder (1) is mounted on the end of the input shaft of the hydraulic motor (2) and is used to detect the rotation speed of the hydraulic motor (2); The roller group (9) comprises an upper roller (901) and a lower roller (902), and both ends of the roller group (9) are mounted in the frame (5) via bearing seats, and the upper roller (901) and the bearing seats on both sides of the upper roller (901) are arranged in the frame to slide up and down; The pressing nut screw (6) is arranged above the bearing seats on both sides of the upper roller (901), the pressing nut is fixed to the frame, the screw is rotated, and the end of the screw contacts the bearing seat to adjust the gap of the roller group (9); The handwheel assembly (7) is composed of a mounting flange (701), a connecting shaft A (702), a conductive slip ring (703), a rotation angle sensor (704), a connector (705), a bearing (706), a spring (707), a connecting shaft B (708), a feedback rod (709), a connecting plate (710), a limit device (712) and a handwheel (711); the mounting flange (701) is rigidly connected to the connecting shaft A (702); the connecting shaft A (702 ) is coaxially connected to the B connecting shaft (708) through a bearing (706), and the A connecting shaft (702) and the B connecting shaft (708) can rotate but cannot slide in the axial direction; the connecting plate (710) is rigidly connected to the A connecting shaft (702) and the angle sensor (704) respectively through bolts; the rotating shaft of the angle sensor (704) is rigidly connected to the feedback rod (709), and in order to increase the strength of the angle sensor (704), the angle sensor (70 4) is provided with a bearing support between the rotating shaft and the connecting disk (710); the signal line of the rotation angle sensor (704) is led out through the conductive slip ring (703); the feedback rod (709) is flexibly connected to the connecting disk (710) through two springs (707), and the springs (707) have a pre-tensioning force; two limiting devices (712) are installed on the connecting disk (710) for limiting the feedback rod (709); the limiting device (712) is used to limit the feedback rod (709) is limited, and in addition, it also has a safety protection function; the feedback rod (709) can rotate together with the rotation shaft of the angle sensor (704) within the range of the limiting device (712); when the feedback rod (709) rotates, the length of the two springs (707) changes; the feedback rod (709) is rigidly connected to the B connecting shaft (708) through the connecting body (705); the hand wheel (711) is rigidly connected to the B connecting shaft (708); The hydraulic control system (10) is composed of a motor (1001), a hydraulic pump (1002), a relief valve (1003), a servo valve (1004), a hydraulic motor (2), and a signal amplifier (1005); the motor (1001) is connected to the hydraulic pump (1002) as a power source to drive the hydraulic pump (1002) to rotate; the hydraulic pump (1002) supplies oil to the servo valve (1004); the relief valve (1003) is connected to the outlet of the hydraulic pump (1002) to adjust the pressure at the outlet of the hydraulic pump (1002); the servo valve (1004) is connected to the two oil ports of the hydraulic motor (2) to control the speed and direction of the hydraulic motor (2); the signal amplifier (1005) is connected to the servo valve (1004) and the rotation angle sensor (704) respectively, and is used to amplify the output signal of the rotation angle sensor (704) and send it to the servo valve (1004).

2. A two-roll test mill driven by a hydraulic motor according to claim 1, characterized in that: The gear box (3) is a speed reducer.

3. A method for operating a two-roll testing mill driven by a hydraulic motor as claimed in claim 1, characterized in that: When the operator turns the hand wheel (711), the roller will rotate accordingly; When the hand wheel (711) is stationary, the output signal of the rotation angle sensor (704) is 0, and the signal amplified by the signal amplifier (1005) to the servo valve (1004) is also 0. At this time, the valve core of the servo valve (1004) is in the middle position, and the hydraulic motor (2) stops moving. When the operator turns the hand wheel (711) clockwise, the hand wheel (711) drives the feedback rod (709) to rotate a certain angle. The angle sensor (704) detects the angle and outputs a signal proportional to the angle. The signal is amplified by the signal amplifier (1005) and connected to the servo valve. The servo valve core moves. At this time, high-pressure oil enters the hydraulic motor (2). The hydraulic motor (2) outputs torque. After overcoming the rolling torque, it drives the roller group (9) to rotate clockwise. When the rolling torque suddenly increases, the motor speed decreases. The angle difference between the A connecting shaft (702) and the B connecting shaft (708) increases. The angle sensor (704) detects that the angle increases, and the output signal of the angle sensor (704) increases. This signal is amplified by the signal amplifier (1005). Then, the signal to the servo valve (1004) also increases. At this time, the valve opening of the servo valve (1004) increases, the output torque of the hydraulic motor (2) increases, and the rolling torque is overcome. The motor speed increases until the roll rotation angle is synchronized with the hand wheel rotation angle. When the rolling torque suddenly decreases, the motor speed increases, the angle difference between the A connecting shaft (702) and the B connecting shaft (708) decreases, the angle sensor (704) detects that the angle decreases, and the output signal of the angle sensor (704) decreases. This signal is amplified by the signal amplifier (1005), and the signal to the servo valve (1004) also decreases. At this time, the valve opening of the servo valve (1004) decreases, the output torque of the hydraulic motor (2) decreases, and the motor speed decreases until the roll rotation angle is synchronized with the hand wheel rotation angle. When the operator turns the hand wheel (711) counterclockwise, the rotation angle sensor (704) detects the angle change and outputs a signal proportional to the angle change. This signal is amplified by the signal amplifier (1005) and then connected to the servo valve (1004). The valve core of the servo valve (1004) moves in the opposite direction. At this time, high-pressure oil enters the hydraulic motor (2), and the hydraulic motor (2) outputs torque, driving the roller group (9) to rotate counterclockwise. When the operator stops turning the hand wheel (711), the output signal of the rotation angle sensor (704) is 0, the servo valve (1004) is in the middle position, and the motor will slow down and stop rotating; When the rolling torque is large, the opening degree of the servo valve (1004) needs to be increased. At this time, the angle difference between the A connecting shaft (702) and the B connecting shaft (708) needs to be increased, that is, the torque applied by the operator to the handwheel (711) becomes larger; similarly, when the rolling torque is small, the torque applied by the operator to the handwheel (711) is small, so the operator can sense the size of the rolling torque by feeling the torque applied to the handwheel (711). This function is the force feedback function.

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