Synchronous control device for lifting hydraulic cylinders of stepping cooling bed of continuous casting machine

Abstract

The invention discloses a synchronous control device of a continuous casting machine stepping cooling bed lifting hydraulic cylinder, which comprises a quadruple synchronizer, an electro-hydraulic reversing valve, a front hydraulic reversing valve and four control units, the quadruple synchronizer comprises four cylinder barrels which are connected end to end and respectively correspond to the four control units; a right lower oil port and a right upper oil port are formed in the right end of the right cavity of each cylinder barrel, a left lower oil port and a left upper oil port are formed in the left end of the left cavity of each cylinder barrel, and the pistons in the four cylinder barrels share one piston rod; wherein the cylindrical surface of the piston in one cylinder barrel is provided with an undercutting groove, the side wall of the cylinder barrel is provided with a groove left oil port and a groove right oil port which correspond to the undercutting groove, and each control unit comprises a left one-way valve, a right one-way valve, a rear hydraulic reversing valve, a hydraulic control one-way valve and a lifting hydraulic cylinder. The quadruple synchronizer adopts a reciprocating oil supply mode, not only can obtain higher synchronization precision and ensure stable operation of the stepping cooling bed, but also has no special requirement on the volume of the cavity in the cylinder barrel, and can reduce the volume of the quadruple synchronizer.

Description

Technical Field

[0001] The invention relates to a synchronous control device for a hydraulic cylinder lifting a stepping cooling bed of a continuous casting machine, which can effectively eliminate the synchronization error of four hydraulic cylinders lifting a cooling bed and belongs to the technical field of metallurgical equipment. Background Art

[0002] The walking cooling bed is an important equipment of the continuous casting machine in the steelmaking plant. The ingots produced by the continuous casting machine are cooled and straightened through the cooling bed, and then discharged and stacked. The walking cooling bed of the continuous casting machine consists of a fixed frame and a movable frame. The movable frame is driven by a transverse mechanism and a lifting mechanism to realize the flipping and cooling of the continuous casting ingots. The transverse mechanism consists of two transverse hydraulic cylinders, and the lifting mechanism includes four lifting hydraulic cylinders. At present, there are several synchronization modes for the lifting hydraulic cylinders of the walking cooling bed of the continuous casting machine: 1. Use the flow synchronization control method of throttle valve, speed regulating valve, synchronization valve, and flow dividing and collecting valve. The synchronization accuracy of this method is greatly affected by the oil temperature and the load of the cooling bed, the synchronization accuracy is not high, and the workload of manual adjustment is large.

[0003] Second, using a synchronous motor to achieve synchronization can achieve higher synchronization accuracy, but due to the relatively large internal pressure loss of the synchronous motor, it is advisable to achieve higher synchronization accuracy in only one direction.

[0004] 3. A control method using volume synchronization of synchronous cylinders can also achieve higher synchronization accuracy, but each chamber of the synchronous cylinder must be greater than or equal to the volume of the hydraulic cylinder to be synchronized, resulting in a large volume of the synchronous cylinder. It is particularly difficult to manufacture synchronous cylinders used for high pressure, large flow, and long stroke. To achieve synchronization of a large number of large hydraulic cylinders, the synchronous cylinders must be made very large. The middle chamber of the synchronous cylinder is filled with fluid when the system is used for the first time, and it cannot be filled by itself through the system cycle. An oil injection port must be designed here separately, and partial oil leakage in the middle chamber cannot be automatically compensated, resulting in the hydraulic cylinder being unable to achieve position synchronization, affecting the system synchronization accuracy.

[0005] Therefore, the existing synchronization modes of the hydraulic cylinders for lifting the walking cooling bed of the continuous casting machine are not ideal and cannot ensure the stable operation of the walking cooling bed. It is very necessary to design a synchronization control device for the hydraulic cylinders for lifting the walking cooling bed of the continuous casting machine with high synchronization accuracy. Summary of the invention

[0006] The purpose of the present invention is to provide a synchronous control device for lifting hydraulic cylinders of a walking cooling bed of a continuous casting machine in view of the drawbacks of the prior art, so as to improve the synchronization accuracy of the hydraulic cylinders for lifting the cooling bed and ensure the stable operation of the walking cooling bed.

[0007] To achieve the above object, the present invention adopts the following technical solution: A synchronous control device for lifting the hydraulic cylinder of a step-type cooling bed of a continuous casting machine comprises a four-way synchronizer, an electro-hydraulic reversing valve, a front hydraulic reversing valve and four control units, wherein the four-way synchronizer comprises four cylinder barrels which are coaxial with each other and connected end to end, the four cylinder barrels respectively correspond to the four control units, the inner cavity of each cylinder barrel is divided into a right chamber and a left chamber by a piston, the right end of the right chamber is provided with a right lower oil port and a right upper oil port, the left end of the left chamber is provided with a left lower oil port and a left upper oil port, the pistons in the four cylinder barrels share a piston rod, a countersunk groove is provided on the cylindrical surface of the piston in one of the cylinder barrels, and a groove left oil port and a groove right oil port corresponding to the countersunk groove are provided on the side wall of the cylinder barrel, the groove left oil port is located on the left side of the groove right oil port, when the piston is at the rightmost end of the cylinder barrel, the groove left oil port is connected to the groove right oil port by the countersunk groove, and when the piston is at the leftmost end of the cylinder barrel, the groove right oil port is connected to the right chamber; each The control unit includes a left one-way valve, a right one-way valve, a rear hydraulic reversing valve, a hydraulically controlled one-way valve and a lifting hydraulic cylinder. The control oil circuits of the front hydraulic reversing valve and the rear hydraulic reversing valve in each control unit are connected to the right oil port of the slot, and the left oil port of the slot is connected to the oil tank through a pipeline; in each control unit, the rod chamber of the lifting hydraulic cylinder is connected to the oil tank through a pipeline, and the rodless chamber is connected to the upper right oil port or the upper left oil port on the corresponding cylinder barrel through the rear hydraulic reversing valve. The hydraulically controlled one-way valve is connected between the rod chamber and the rodless chamber of the lifting hydraulic cylinder, the control oil circuit of the hydraulically controlled one-way valve is connected to the A port of the electro-hydraulic reversing valve, and the B port of the electro-hydraulic reversing valve is connected to the oil inlet end of the left one-way valve or the right one-way valve through the front hydraulic reversing valve, and the oil outlet ends of the left one-way valve and the right one-way valve are respectively connected to the lower right oil port and the lower left oil port on the corresponding cylinder barrel, the T port of the electro-hydraulic reversing valve is connected to the oil tank, and the P port is connected to the pressure oil.

[0008] In the synchronous control device for lifting the hydraulic cylinder of the walking cooling bed of the continuous casting machine, a sealing ring is provided between the piston and the inner wall of the cylinder.

[0009] In the synchronous control device for lifting the hydraulic cylinder of the walking cooling bed of the continuous casting machine, the four cylinder barrels have exactly the same size, the four pistons have exactly the same size, and the positions of the four pistons in the four cylinder barrels are also the same.

[0010] The pistons in the cylinders of the four-way synchronizer of the present invention automatically reciprocate under the action of the electro-hydraulic reversing valve, the front hydraulic reversing valve and the control unit, and the left chamber and the right chamber in the cylinder alternately supply oil to the rodless chamber of the lifting hydraulic cylinder through the rear hydraulic reversing valve, so that the piston of the lifting hydraulic cylinder rises to the highest position. This reciprocating oil supply method can not only obtain higher synchronization accuracy, but also has no special requirements for the volume of the chamber in the cylinder, which can reduce the volume of the four-way synchronizer and is beneficial to the integration of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0012] Figure 1 It is the hydraulic principle diagram of the present invention; Figure 2 It is a schematic diagram of the structure of a quadruple synchronizer, where: Figure 2 (a) is the state when the piston is at the far right; Figure 2 (b) is the state when the piston is at the far left.

[0013] The numbers in the figure are as follows: 1. Quadruple synchronizer, 2. Electro-hydraulic reversing valve, 3. Front hydraulic reversing valve, 4. Left non-return valve, 5. Right non-return valve, 6. Rear hydraulic reversing valve, 7. Hydraulic control non-return valve, 8. Lifting hydraulic cylinder, 9. Cylinder barrel, 10. Countersunk groove, 11. Piston rod, 12. Left oil port of groove, 13. Right oil port of groove, 14. Lower right oil port, 15. Upper right oil port, 16. Right chamber, 17. Left chamber, 18. Lower left oil port, 19. Upper left oil port, 20. Piston. DETAILED DESCRIPTION

[0014] Aiming at the drawbacks of the prior art, the present invention provides a synchronous control device for the lifting hydraulic cylinders of a continuous casting machine stepping cooling bed, so as to improve the control accuracy of four cooling bed lifting hydraulic cylinders and eliminate synchronization errors.

[0015] See also Figure 1 The present invention mainly includes a quadruple synchronizer 1, an electro-hydraulic reversing valve 2, a front hydraulic reversing valve 3 and four control units, each control unit includes a left check valve 4, a right check valve 5, a rear hydraulic reversing valve 6, a hydraulically controlled check valve 7 and a lifting hydraulic cylinder 8.

[0016] See also Figure 2 The four-way synchronizer 1 includes four cylinder barrels 9 which are coaxial and connected end to end. A piston 20 is arranged inside each cylinder barrel 9. The piston 20 is in sliding contact with the inner wall of the cylinder barrel 9 and a sealing ring is arranged between the piston 20 and the inner wall of the cylinder barrel 9. The inner cavity of each cylinder barrel 9 is divided into a right chamber 16 and a left chamber 17 by the piston 20. A right lower oil port 14 and a right upper oil port 15 are arranged at the right end of the right chamber 16, and a left lower oil port 18 and a left upper oil port 19 are arranged at the left end of the left chamber 17. The four pistons 20 in the four cylinder barrels 9 share a piston rod 11. A countersunk groove 10 is arranged on the cylindrical surface of the piston 20 in one of the cylinder barrels 9. A groove left oil port 12 and a groove right oil port 13 corresponding to the countersunk groove 10 are arranged on the side wall of the cylinder barrel 9, and the groove left oil port 12 is located on the left side of the groove right oil port 13. When the piston 20 is at the rightmost end of the cylinder 9, the undercut groove 10 connects the left oil port 12 of the groove with the right oil port 13 of the groove. When the piston 20 is at the leftmost end of the cylinder 9, the right oil port 13 of the groove is connected with the right chamber 16 of the cylinder 9. The sizes of the four cylinders 9 and the four pistons 20 are exactly the same, and the positions of the four pistons 20 in the four cylinders 9 are also the same, so the volumes of oil supplied to the four lifting hydraulic cylinders 8 are exactly the same when the four pistons move.

[0017] See also Figure 1 The control oil circuits of the front hydraulic reversing valve 3 and the rear hydraulic reversing valve 6 in each control unit are connected to the right oil port 13 of the tank, and the left oil port 12 of the tank is connected to the oil tank through a pipeline.

[0018] The four control units correspond to the four cylinders 9 of the quadruple synchronizer 1 respectively. In each control unit, the rod chamber of the lifting hydraulic cylinder 8 is connected to the oil tank through a pipeline, and the rodless chamber is connected to the upper right oil port 15 or the upper left oil port 19 on the corresponding cylinder 9 through the rear hydraulic reversing valve 6. The hydraulically controlled one-way valve 7 is connected between the rod chamber and the rodless chamber of the lifting hydraulic cylinder 8. The control oil circuit of the hydraulically controlled one-way valve 7 is connected to the A port of the electro-hydraulic reversing valve 2. The B port of the electro-hydraulic reversing valve 2 is connected to the oil inlet end of the left one-way valve 4 or the right one-way valve 5 through the front hydraulic reversing valve 3. The oil outlet ends of the left one-way valve 4 and the right one-way valve 5 are respectively connected to the lower right oil port 14 and the lower left oil port 18 on the corresponding cylinder 9. The electro-hydraulic reversing valve 2 is a hydraulic component that controls the lifting and lowering of the four lifting hydraulic cylinders 8 of the cooling bed. The T port of the electro-hydraulic reversing valve 2 is connected to the oil tank, and the P port is connected to the pressure oil.

[0019] When the electromagnet 2DT of the electro-hydraulic reversing valve 2 is energized, the pressure oil of the electro-hydraulic reversing valve 2 is supplied to the front hydraulic reversing valve 3, and the piston 20 in each control unit reciprocates under the action of the rear hydraulic reversing valve 6. The left chamber 17 and the right chamber 16 in the cylinder 9 alternately supply oil to the rodless chamber of the lifting hydraulic cylinder 8 through the rear hydraulic reversing valve 6 until the piston 20 of the lifting hydraulic cylinder 8 in the four control units rises to the highest position, the electromagnet 2DT of the electro-hydraulic reversing valve 2 loses power, and the piston of the lifting hydraulic cylinder 8 stays at the highest position for a certain period of time, and then the electromagnet 1DT of the electro-hydraulic reversing valve 2 is energized, and the pressure oil enters the control oil circuit of the hydraulic control check valve 7 of each control unit through the electro-hydraulic reversing valve 2, so that the rod chamber and the rodless chamber of the lifting hydraulic cylinder 8 are connected, and the pistons 20 and piston rods 11 of the four lifting hydraulic cylinders 8 descend to the bottom of the hydraulic cylinder under the action of the deadweight of the cooling bed, and the electromagnet 1DT of the electro-hydraulic reversing valve 2 loses power.

[0020] The working process of the present invention will be further described below in conjunction with the accompanying drawings.

[0021] In the initial state, the electromagnet 1DT of the electro-hydraulic reversing valve 2 is de-energized, the electromagnet 2DT is de-energized, and the cooling bed is at the lowest position; the pistons 20 in the four cylinders 9 of the quadruple synchronizer 1 are all at the rightmost end, such as Figure 2 As shown in (a), the undercut groove 10 connects the left oil port 12 of the groove with the right oil port 13 of the groove, the left oil port 12 of the groove is connected to the oil tank, and the valve cores of the rear hydraulic reversing valve 6 and the front hydraulic reversing valve 3 connected to the right oil port 13 are in the left position under the action of the spring force.

[0022] 1. Cooling bed rises like Figure 1As shown, the electromagnet 1DT of the electro-hydraulic reversing valve 2 loses power, while the electromagnet 2DT gains power. The pressure oil port (P port) of the electro-hydraulic reversing valve 2 is connected to the B port, and the pressure oil enters the front hydraulic reversing valve 3 and opens the right check valve 5 through the right lower oil port 14 and the right chamber 16 of the cylinder 9, pushing the piston 20 to move to the left, squeezing the left chamber 17 of the cylinder 9. The left lower oil port 18 at the left end of the left chamber 17 is closed by the left check valve 4, so the pressure oil enters the rodless chamber of the lifting hydraulic cylinder 8 from the upper left oil port 19 through the rear hydraulic reversing valve 6, and the hydraulic oil in the rod chamber of the lifting hydraulic cylinder 8 flows into the oil tank through the return oil pipeline. When the piston 20 reaches the leftmost end of the cylinder 9, the right oil port 13 of the groove is connected to the right chamber 16 of the cylinder 9, while the left oil port 12 of the groove is not connected to the right chamber 16 of the cylinder 9, as shown in FIG. Figure 2 As shown in (b), the oil in the right chamber 16 is high-pressure oil, and the pressure of the right oil port 13 of the groove increases. The rear hydraulic reversing valve 6 and the front hydraulic reversing valve 3 connected to the right oil port 13 control the oil port pressure to increase, so that their valve cores overcome the spring force and are in the right position. At this time, the pressure oil from the electro-hydraulic reversing valve 2 opens the left check valve 4 through the front hydraulic reversing valve 3 and enters the left chamber 17 of the cylinder 9 from the lower left oil port 18, pushing the piston 20 to move to the right. At this time, the lower right oil port 14 is sealed by the right check valve 5, and the hydraulic oil in the right chamber 16 can only be supplied from the upper right oil port 15 to the rodless chamber of the lifting hydraulic cylinder 8 through the rear hydraulic reversing valve 6. After the piston 20 moves rightward to the rightmost end, the groove 10 connects the right oil port 13 of the groove with the left oil port 12 of the groove, and the left oil port 12 of the groove connects to the oil tank, and the pressure of the control oil circuit of the rear hydraulic reversing valve 6 and the front hydraulic reversing valve 3 connected to the right oil port 13 of the groove also drops to a low pressure state, and their valve cores return to the left position under the action of the spring force. As long as the electromagnet 2DT of the electro-hydraulic reversing valve 2 is energized and the lifting hydraulic cylinder 8 has not risen to the right position, the left chamber 17 and the right chamber 16 of the four cylinder barrels 9 will alternately supply oil to the rodless chambers of the four lifting hydraulic cylinders 8 until the cooling bed rises to the highest position.

[0023] 2. The cooling bed moves forward The electromagnet 1DT of the electro-hydraulic reversing valve 2 loses power, the electromagnet 2DT loses power, the four-way synchronizer 1 is locked through the left check valve 4 and the right check valve 5 of each control unit, and the rodless cavity of the lifting hydraulic cylinder 8 is also locked, and the cooling bed moves forward horizontally.

[0024] 3. Cooling bed drops After the cooling bed is transversely moved into position, the electromagnet 1DT of the electro-hydraulic reversing valve 2 is energized, and the electromagnet 2DT is de-energized. The pressure oil of the electro-hydraulic reversing valve 2 enters the control circuit of the hydraulic control check valve 7, opens the hydraulic control check valve 7, and the rodless chamber of the lifting hydraulic cylinder 8 is connected with the rod chamber. The piston and piston rod of the lifting hydraulic cylinder 8 descend under the action of the deadweight of the cooling bed, and the excess hydraulic oil in the rod chamber of the lifting hydraulic cylinder 8 flows back to the oil tank through the return oil pipeline. When the cooling bed descends to the lowest position, the electromagnet 1DT of the electro-hydraulic reversing valve 2 is de-energized, and the electromagnet 2DT is de-energized.

[0025] 4. The cooling bed moves backwards After the cooling bed drops to the lowest position, the electromagnet 1DT of the electro-hydraulic reversing valve 2 loses power, the electromagnet 2DT loses power, the cooling bed self-locks at the lowest position, and the cooling bed moves horizontally backward.

[0026] After the cooling bed is moved horizontally into place, the electromagnet 1DT of the electro-hydraulic reversing valve 2 loses power, and the electromagnet 2DT loses power, and then the next rising action is performed.

[0027] The beneficial effects of the present invention are: 1. The present invention adopts the same volume synchronization control method as the synchronous cylinder, and can obtain higher synchronization accuracy. Since the four-link synchronizer adopts a hydraulically controlled reciprocating oil supply method to supply oil to the lifting hydraulic cylinder, it can not only solve the problem of oil trapped in the middle cavity of the synchronous cylinder, but also eliminate the position synchronization error and the cumulative error of the system caused by leakage, and effectively reduce the influence of the manufacturing accuracy of the four-link synchronizer, the system sealing, etc. on the synchronization accuracy.

[0028] 2. The four-way synchronizer can automatically and repeatedly supply oil to the lifting hydraulic cylinder, so the four-way synchronizer can be miniaturized, which is conducive to the integration of the hydraulic system.

[0029] 3. The four-way synchronizer can be filled with fluid by itself through system circulation, and after some of the fluid leaks, it can automatically compensate to achieve position synchronization.

Claims

1. A synchronous control device for lifting hydraulic cylinders of a continuous casting machine step cooling bed, characterized in that: The invention comprises a four-way synchronizer (1), an electro-hydraulic reversing valve (2), a front hydraulic reversing valve (3) and four control units. The four-way synchronizer (1) comprises four cylinder barrels (9) which are coaxial with each other and connected end to end. The four cylinder barrels (9) correspond to the four control units respectively. The inner cavity of each cylinder barrel (9) is divided into a right chamber (16) and a left chamber (17) by a piston (20). The right end of the right chamber (16) is provided with a right lower oil port (14) and a right upper oil port (15). The left end of the left chamber (17) is provided with a left lower oil port (18) and a left upper oil port (19). The four cylinder barrels ( The pistons (20) in the cylinder (9) share a piston rod (11), a recessed groove (10) is provided on the cylindrical surface of the piston (20) in one cylinder (9), and a groove left oil port (12) and a groove right oil port (13) corresponding to the recessed groove (10) are provided on the side wall of the cylinder (9), the groove left oil port (12) is located on the left side of the groove right oil port (13), when the piston (20) is at the rightmost end of the cylinder (9), the recessed groove (10) connects the groove left oil port (12) and the groove right oil port (13), when the piston (20) is at the leftmost end of the cylinder (9), the groove right oil port (13) is connected to the groove left oil port (12), and when the piston (20) is at the leftmost end of the cylinder (9), the groove right oil port (13) is connected to the groove right oil port (13). The front and rear hydraulic reversing valves (3) and the rear hydraulic reversing valves (6) in each control unit are connected to the right chamber (16); each control unit comprises a left check valve (4), a right check valve (5), a rear hydraulic reversing valve (6), a hydraulically controlled check valve (7) and a lifting hydraulic cylinder (8); the control oil circuits of the front hydraulic reversing valve (3) and the rear hydraulic reversing valve (6) in each control unit are connected to the right oil port (13) of the slot, and the left oil port (12) of the slot is connected to the oil tank through a pipeline; in each control unit, the rod chamber of the lifting hydraulic cylinder (8) is connected to the oil tank through a pipeline, and the rodless chamber is connected to the upper right oil port (15) or the upper left oil port (12) on the corresponding cylinder barrel (9) through the rear hydraulic reversing valve (6). The hydraulic control one-way valve (7) is connected to the oil port (19), the hydraulic control one-way valve (7) is connected between the rod chamber and the rodless chamber of the lifting hydraulic cylinder (8), the control oil circuit of the hydraulic control one-way valve (7) is connected to the A port of the electro-hydraulic reversing valve (2), the B port of the electro-hydraulic reversing valve (2) is connected to the oil inlet end of the left one-way valve (4) or the right one-way valve (5) through the front hydraulic reversing valve (3), the oil outlet ends of the left one-way valve (4) and the right one-way valve (5) are respectively connected to the lower right oil port (14) and the lower left oil port (18) on the corresponding cylinder barrel (9), the T port of the electro-hydraulic reversing valve (2) is connected to the oil tank, and the P port is connected to the pressure oil.

2. The synchronous control device for lifting hydraulic cylinder of a continuous casting machine step cooling bed according to claim 1 is characterized in that: A sealing ring is provided between the piston (20) and the inner wall of the cylinder (9).

3. A synchronous control device for lifting hydraulic cylinders of a continuous casting machine step cooling bed according to claim 1 or 2, characterized in that: The four cylinder barrels (9) have exactly the same size, the four pistons (20) have exactly the same size, and the positions of the four pistons (20) in the four cylinder barrels (9) are also the same.

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