A hydraulic synchronous control system for three cylinders with two different cylinder diameters

Abstract

The application discloses a three-cylinder two-different-stroke hydraulic synchronous control system, which is characterized in that when the a end of a two-position four-way reversing valve is electrified, a third hydraulic control check valve is opened, when the b end of a proportional reversing valve is electrified, hydraulic oil passes through the third hydraulic control check valve, the proportional reversing valve, a first hydraulic control check valve and a first ball valve to enter a synchronous hydraulic cylinder, the synchronous hydraulic cylinder piston rod is retracted, the hydraulic oil in the right cavity of the synchronous hydraulic cylinder enters the rodless cavities of a first execution hydraulic cylinder, a second execution hydraulic cylinder and a third execution hydraulic cylinder through the first oil port, the second oil port and the third oil port of the synchronous hydraulic cylinder respectively, and the first execution hydraulic cylinder, the second execution hydraulic cylinder and the third execution hydraulic cylinder with different strokes realize high-precision synchronous action under the condition of unbalanced load.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical hydraulic technology, in particular to a three-cylinder two-different-diameter hydraulic synchronous control system; the hydraulic synchronous control system can realize high synchronization precision under the condition that three cylinders with different diameters and rod diameters (two of which have the same diameter and rod diameter) and three execution hydraulic cylinders have uneven loads; the system is suitable for the synchronous action of three different-diameter hydraulic cylinders in metallurgical machinery. BACKGROUND

[0002] Currently, when adjusting the water ring height of an online heat treatment, the water ring height cannot be adjusted frequently, and the water ring height adjustment needs to be restored by using a hand operator to drive forcibly each time; there are seven groups of water rings in the online heat treatment, and the height adjustment of each group of water rings is realized by using two four-way directional valves, a proportional directional valve, three hydraulic control check valves, a ball valve, and control of the ascending and descending of three execution hydraulic cylinders; the three execution hydraulic cylinders are connected in series through a hydraulic pipeline, and form a whole through a water ring installation frame; because the three execution hydraulic cylinders bear uneven loads, the three execution hydraulic cylinders are out of synchronization, which causes the guide slide rod of the water ring installation frame to be blocked, and often causes equipment failure and shutdown. SUMMARY

[0003] The present application aims to overcome the deficiencies of the prior art, and provides a three-cylinder two-different-diameter hydraulic synchronous control system; the system mainly solves the problem of the asynchronization of three different-diameter hydraulic cylinders in the height adjustment of the water ring of an online heat treatment.

[0004] The technical scheme provided by the present application is as follows: a three-cylinder two-different-diameter hydraulic synchronous control system, comprising a hydraulic pipeline, a two-position four-way directional valve is arranged on the hydraulic pipeline, the two-position four-way directional valve is connected with a proportional directional valve through a third hydraulic control check valve; the special feature is that the proportional directional valve is connected with a synchronous hydraulic cylinder through a first hydraulic control check valve and a first ball valve; the first oil port, the second oil port, and the third oil port of the synchronous hydraulic cylinder are connected with the rodless cavity of a first execution hydraulic cylinder, a second execution hydraulic cylinder, and a third execution hydraulic cylinder, respectively; the rod cavity of the first execution hydraulic cylinder, the second execution hydraulic cylinder, and the third execution hydraulic cylinder is connected with a second ball valve, a second hydraulic control check valve, and a proportional directional valve through a hydraulic pipeline; the effective area of the three cavities of the synchronous hydraulic cylinder is equal to the area of the corresponding rodless cavity of the first execution hydraulic cylinder, the second execution hydraulic cylinder, and the third execution hydraulic cylinder, respectively, so as to ensure the synchronous action of the first execution hydraulic cylinder, the second execution hydraulic cylinder, and the third execution hydraulic cylinder.

[0005] Further, the piston rod of the first, second and third execution hydraulic cylinders is retracted to the bottom, a two-position four-way reversing valve is connected to the hydraulic pipeline, the two-position four-way reversing valve is connected to the first, second and third hydraulic control check valves, the third hydraulic control check valve is connected to the synchronous hydraulic cylinder through a proportional reversing valve, a first hydraulic control check valve and a first ball valve, the first, second and third oil ports of the synchronous hydraulic cylinder are connected to the fourth, fifth and sixth hydraulic control check valves, the fourth, fifth and sixth hydraulic control check valves are connected to a three-position four-way reversing valve through a pressure reducing valve, and the piston rod of the synchronous hydraulic cylinder is triggered to detect the signals of the first and second signal detection switches installed on the synchronous hydraulic cylinder, so that the hydraulic oil in the synchronous hydraulic cylinder is replaced.

[0006] Further, the fourth, fifth and sixth hydraulic control check valves are controlled to be opened by the three-position four-way reversing valve.

[0007] Further, the two-position four-way reversing valve is connected to the first, second and third hydraulic control check valves, the third hydraulic control check valve is connected to the rod cavity of the first, second and third execution hydraulic cylinders through a proportional reversing valve, a second hydraulic control check valve and a second ball valve, the rodless cavity of the first, second and third execution hydraulic cylinders is connected to the first, second and third oil ports of the synchronous hydraulic cylinder through a first overflow valve, a second overflow valve and a third overflow valve, and the synchronous action cumulative error is eliminated.

[0008] The beneficial effects of the present application are as follows:

[0009] 1. The present application can achieve high synchronization accuracy under the condition that the three execution hydraulic cylinders have different cylinder diameters and rod diameters (two of the hydraulic cylinders have the same cylinder diameter and rod diameter) and the loads of the three execution hydraulic cylinders are uneven.

[0010] 2. The hydraulic control circuit of the present application can realize quick automatic oil replacement function and ensure the cleanliness of the hydraulic oil in the synchronous hydraulic cylinder.

[0011] 3. The hydraulic control circuit of the present application can automatically eliminate synchronization error and realize automatic deviation correction. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is the hydraulic control principle diagram of the present application.

[0013] Figure: 1 proportional directional valve, 2.1 first hydraulic control check valve, 2.2 second hydraulic control check valve, 2.3 third hydraulic control check valve, 3 two-position four-way directional valve, 4 synchronous hydraulic cylinder, 5 three-position four-way directional valve, 6.1 first overflow valve, 6.2 second overflow valve, 6.3 third overflow valve, 8.1 fourth hydraulic control check valve, 8.2 fifth hydraulic control check valve, 8.3 sixth hydraulic control check valve, 9.1 first execution hydraulic cylinder, 9.2 second execution hydraulic cylinder, 9.3 third execution hydraulic cylinder, 10.1 first ball valve, 10.2 second ball valve, 11 pressure reducing valve, LS0 first signal detection switch, LS1 second signal detection switch. Embodiment

[0014] In order to better understand and implement, the present application is described in detail below in conjunction with the drawings.

[0015] As Figure 1 shown, a three-cylinder two-different-bore hydraulic synchronous control system, including hydraulic pipeline, hydraulic pipeline on the installation of two-position four-way directional valve 3, two-position four-way directional valve 3 through the third hydraulic control check valve 2.3 connection proportional directional valve 1; proportional directional valve 1 through the first hydraulic control check valve 2.1, the first ball valve 10.1 connection synchronous hydraulic cylinder 4; the first oil port A1, the second oil port A2, the third oil port A3 of synchronous hydraulic cylinder 4 are connected with the rodless cavity of first execution hydraulic cylinder 9.1, second execution hydraulic cylinder 9.2, third execution hydraulic cylinder 9.3 respectively; synchronous hydraulic cylinder 4 is controlled by two-position four-way directional valve 3, proportional directional valve 1, synchronous hydraulic cylinder 4 piston rod retraction, synchronous hydraulic cylinder 4 hydraulic oil through the first oil port A1, the second oil port A2, the third oil port A3 of synchronous hydraulic cylinder 4 is discharged into the rodless cavity of first execution hydraulic cylinder 9.1, second execution hydraulic cylinder 9.2, third execution hydraulic cylinder 9.3 respectively, because the effective area of the three cavities of synchronous hydraulic cylinder 4 is equal to the area of the corresponding rodless cavity of first execution hydraulic cylinder 9.1, second execution hydraulic cylinder 9.2, third execution hydraulic cylinder 9.3 respectively, so as to ensure the synchronous action of first execution hydraulic cylinder 9.1, second execution hydraulic cylinder 9.2, third execution hydraulic cylinder 9.3; at the same time, the hydraulic oil in the rod cavity of first execution hydraulic cylinder 9.1, second execution hydraulic cylinder 9.2, third execution hydraulic cylinder 9.3 is discharged back to the tank through second ball valve 10.2, second hydraulic control check valve 2.2, proportional directional valve 1.

[0016] When the piston rods of the first, second and third hydraulic cylinders 9.1, 9.2 and 9.3 are retracted to the bottom, and the pressure of the pressure reducing valve 11 is set to 50 bar, the first, second and third hydraulic control check valves 2.1, 2.2 and 2.3 are opened by the two-position four-way reversing valve 3, the hydraulic oil enters the proportional reversing valve 1 through the third hydraulic control check valve 2.3, and then enters the synchronous hydraulic cylinder 4 through the first hydraulic control check valve 2.1 and the first ball valve 10.1, so that the piston rod of the synchronous hydraulic cylinder 4 is pushed back, and the hydraulic oil in the synchronous hydraulic cylinder 4 is discharged through the first, second and third oil ports A1, A2 and A3, respectively, and then enters the three-position four-way reversing valve 5 through the fourth, fifth and sixth hydraulic control check valves 8.1, 8.2 and 8.3 controlled by the three-position four-way reversing valve 5, and then is discharged back to the hydraulic oil tank through the pressure reducing valve 11; the piston rod of the synchronous hydraulic cylinder 4 triggers the signals of the first and second signal detection switches LS0 and LS1 installed on the synchronous hydraulic cylinder 4, so that the hydraulic oil in the synchronous hydraulic cylinder 4 is replaced; when the signal of the first signal detection switch LS0 disappears, the closed hydraulic oil in the synchronous hydraulic cylinder 4 is completely discharged; when the hydraulic oil flows through the three-position four-way reversing valve 5 to the pressure reducing valve 11, and then enters the synchronous hydraulic cylinder 4 through the first, second and third oil ports A1, A2 and A3 of the synchronous hydraulic cylinder 4 through the fourth, fifth and sixth hydraulic control check valves 8.1, 8.2 and 8.3, respectively, and pushes the piston rod of the synchronous hydraulic cylinder 4 out, the replacement of the hydraulic oil in the synchronous hydraulic cylinder 4 is completed when the piston rod of the synchronous hydraulic cylinder 4 triggers the second detection switch LS1.

[0017] After the first, second and third hydraulic cylinders 9.1, 9.2 and 9.3 operate for a period of time, height errors may occur due to various reasons, and when the piston rods of the first, second and third hydraulic cylinders 9.1, 9.2 and 9.3 are completely retracted, the piston rod of the hydraulic cylinder with errors cannot be retracted to the bottom, at this time, the first, second and third hydraulic cylinders 9.1, 9.2 and 9.3 continue to be in the descending state, and the hydraulic oil in the rodless cavity of the hydraulic cylinder which does not completely fall back can be discharged to the oil tank through the first, second and third overflow valves 6.1, 6.2 and 6.3 (the set pressure is 20 bar lower than the system pressure P) connected thereto, and when the piston rods of the three hydraulic cylinders are completely retracted, the error elimination is completed.

[0018] The working principle of the three-cylinder two-different-diameter hydraulic synchronous control system is as follows:

[0019] The water ring rising action flow is as follows:

[0020] The a end of the two-position four-way directional valve 3 is powered on, and the first hydraulic control check valve 2.1 and the second hydraulic control check valve 2.2 are opened. The b end of the proportional directional valve 1 is powered on, and the hydraulic oil enters the left cavity of the synchronous hydraulic cylinder 4 through the first hydraulic control check valve 2.1 and the first ball valve 10.1, respectively, and pushes the piston of the synchronous hydraulic cylinder 4 to push the hydraulic oil in the right cavity of the synchronous hydraulic cylinder 4 into the rodless cavity of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3. The hydraulic oil in the rod cavity of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3 enters the proportional directional valve 1 through the second ball valve 10.2 and the second hydraulic control check valve 2.2 and is discharged to the oil tank, so as to realize the synchronous rising of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3.

[0021] Water ring descending action flow:

[0022] The a end of the two-position four-way directional valve 3 is powered on, and the first hydraulic control check valve 2.1, the second hydraulic control check valve 2.2 and the third hydraulic control check valve 2.3 are opened. The a end of the proportional directional valve 1 is powered on, and the hydraulic oil enters the rod cavity of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3 through the second hydraulic control check valve 2.2 and the ball valve 10.2, respectively, and pushes the piston of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3 to make the hydraulic oil in the rodless cavity of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3 enter the synchronous hydraulic cylinder 4 through the first oil port A1, the first oil port A2 and the first oil port A3 of the synchronous hydraulic cylinder 4, respectively. The piston rod of the synchronous hydraulic cylinder 4 is stretched out, and at the same time, the hydraulic oil in the left cavity of the synchronous hydraulic cylinder 4 is discharged to the oil tank through the first ball valve 10.1, the first hydraulic control check valve 2.1 and the proportional directional valve 1, so as to realize the synchronous descending of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3.

[0023] Because the hydraulic oil in the right cavity of the synchronous hydraulic cylinder 4 and the rodless cavities of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2 and the third execution hydraulic cylinder 9.3 is in a closed state, the hydraulic oil will deteriorate after long-term use. The fast automatic oil change action flow is as follows:

[0024] When the piston rod of the synchronous hydraulic cylinder 4 retracts and triggers the first signal detection switch LS0, the synchronous hydraulic cylinder 4 stops moving, then the a end of the proportional reversing valve 1, the a end of the two-position four-way reversing valve 3, and the b end of the three-position four-way reversing valve 5 are electrified, hydraulic oil passes through the three-position four-way reversing valve 5 and the pressure reducing valve 11, and enters the right cavity of the synchronous hydraulic cylinder 4 through the fourth hydraulic control check valve 8.1, the fifth hydraulic control check valve 8.2, and the sixth hydraulic control check valve 8.3, respectively, to push out the piston rod of the synchronous hydraulic cylinder 4, and the hydraulic oil in the left cavity of the synchronous hydraulic cylinder 4 is discharged through the first ball valve 10.1, the first hydraulic control check valve 2.1, and the proportional reversing valve 1, when the piston rod of the synchronous hydraulic cylinder 4 extends and triggers the second signal detection switch LS1, the automatic oil changing program is completed.

[0025] After the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2, and the third execution hydraulic cylinder 9.3 have been running for a period of time, height error accumulation may occur due to various reasons, and when the error accumulation reaches a certain degree, the following program needs to be executed to eliminate the error accumulation: first, the piston rods of the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2, and the third execution hydraulic cylinder 9.3 are completely retracted, and the piston rod of the execution hydraulic cylinder with errors cannot be completely retracted to the bottom, at this time, the first execution hydraulic cylinder 9.1, the second execution hydraulic cylinder 9.2, and the third execution hydraulic cylinder 9.3 are kept in the descending state, and the hydraulic oil in the rodless cavity of the execution hydraulic cylinder that does not completely fall back can be discharged to the oil tank through the first overflow valve 6.1 (set pressure is 20 bar lower than the system pressure P), the second overflow valve 6.2 (set pressure is 20 bar lower than the system pressure P), and the third overflow valve 6.3 (set pressure is 20 bar lower than the system pressure P), and when the three execution hydraulic cylinder piston rods are completely retracted, the error elimination is completed.

[0026] During the water ring height adjustment process, synchronization errors may accumulate due to various reasons, and when the accumulated error reaches a certain degree, the following process is needed to eliminate the error:

[0027] First, the water ring lowering operation is performed, the piston rods of the three execution hydraulic cylinders are retracted, and the piston is ensured to be retracted to the bottom. After the three execution hydraulic cylinders and the piston rods are completely retracted and a delay of 10s is maintained, the execution hydraulic cylinders that have not been retracted to the position can continue to fall back until they are completely retracted to the position. At this time, the excess hydraulic oil is discharged back to the oil tank through the first overflow valve 6.1, the second overflow valve 6.2, and the third overflow valve 6.3. Thus, the action of automatically eliminating the synchronization error is completed. The set pressure of the overflow valve 6 is 20 bar lower than the system pressure P.

[0028] It should be understood that the technical features not described in detail in the specification are all prior art. Although the embodiments of the present application are described above in combination with the drawings, the present application is not limited to the specific embodiments described above, and the specific embodiments described above are only illustrative and not limiting. Those skilled in the art can make more forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims. These are all within the protection scope of the present application.

Claims

1. A three-cylinder hydraulic synchronous control system with two different cylinder diameters, comprising hydraulic pipelines, wherein a two-position four-way directional valve (3) is provided on the hydraulic pipelines, and the two-position four-way directional valve (3) is connected to a proportional directional valve (1) through a third hydraulically controlled check valve (2.3); characterized in that, The proportional directional valve (1) is connected to the synchronous hydraulic cylinder (4) via the first hydraulically controlled check valve (2.1) and the first ball valve (10.1); the first oil port (A1), the second oil port (A2), and the third oil port (A3) of the synchronous hydraulic cylinder (4) are connected one-to-one with the rodless chamber of the first actuator hydraulic cylinder (9.1), the rodless chamber of the second actuator hydraulic cylinder (9.2), and the rodless chamber of the third actuator hydraulic cylinder (9.3); the first actuator hydraulic cylinder (9.1), the second actuator hydraulic cylinder (9.2), and the third actuator hydraulic cylinder (9.3) are connected to the rodless chamber of the third actuator hydraulic cylinder (9.3). The rod chamber of the actuator hydraulic cylinder (9.3) is connected to the second ball valve (10.2), the second hydraulic check valve (2.2), and the proportional directional valve (1) via hydraulic lines; the effective area of ​​the three chambers of the synchronous hydraulic cylinder (4) is equal to the area of ​​the rodless chamber of the corresponding first actuator hydraulic cylinder (9.1), second actuator hydraulic cylinder (9.2), and third actuator hydraulic cylinder (9.3), respectively, to ensure that the first actuator hydraulic cylinder (9.1), second actuator hydraulic cylinder (9.2), and third actuator hydraulic cylinder (9.3) operate synchronously; The rodless chambers of the first hydraulic cylinder (9.1), the second hydraulic cylinder (9.2), and the third hydraulic cylinder (9.3) are connected one-to-one with the outlets of the fourth hydraulic check valve (8.1), the fifth hydraulic check valve (8.2), and the sixth hydraulic check valve (8.3). The hydraulic lines are connected to a two-position four-way directional valve (3). The two-position four-way directional valve (3) is connected to the control ports of the first hydraulic check valve (2.1), the second hydraulic check valve (2.2), and the third hydraulic check valve (2.3). The third hydraulic check valve (2.3) is connected to the synchronous hydraulic valve through the proportional directional valve (1), the first hydraulic check valve (2.1), and the first ball valve (10.1). The cylinder (4) is connected; the first oil port (A1), the second oil port (A2), and the third oil port (A3) of the synchronous hydraulic cylinder (4) are connected one-to-one with the inlet of the fourth hydraulic control check valve (8.1), the inlet of the fifth hydraulic control check valve (8.2), and the inlet of the sixth hydraulic control check valve (8.3). The fourth hydraulic control check valve (8.1), the fifth hydraulic control check valve (8.2), and the sixth hydraulic control check valve (8.3) are connected to the three-position four-way directional valve (5) through the pressure reducing valve (11). The piston rod of the synchronous hydraulic cylinder (4) realizes the replacement of hydraulic oil in the synchronous hydraulic cylinder (4) by triggering the signals of the first signal detection switch (LS0) and the second signal detection switch (LS1) installed on the synchronous hydraulic cylinder (4).

2. The hydraulic synchronous control system for three cylinders with two different cylinder diameters according to claim 1, characterized in that, The fourth hydraulic control check valve (8.1), the fifth hydraulic control check valve (8.2), and the sixth hydraulic control check valve (8.3) are opened by a three-position four-way directional valve (5).

3. The hydraulic synchronous control system for three cylinders with two different cylinder diameters according to claim 1, characterized in that, The two-position four-way directional valve (3) is connected to the first hydraulic control check valve (2.1), the second hydraulic control check valve (2.2), and the third hydraulic control check valve (2.3) respectively. The third hydraulic control check valve (2.3) is connected to the rod chambers of the first actuator hydraulic cylinder (9.1), the second actuator hydraulic cylinder (9.2), and the third actuator hydraulic cylinder (9.3) through the proportional directional valve (1), the second hydraulic control check valve (2.2), and the second ball valve (10.2). The rodless chambers of the first actuator hydraulic cylinder (9.1), the second actuator hydraulic cylinder (9.2), and the third actuator hydraulic cylinder (9.3) are connected to the first oil port (A1), the second oil port (A2), and the third oil port (A3) of the synchronous hydraulic cylinder (4) through the first relief valve (6.1), the second relief valve (6.2), and the third relief valve (6.3) respectively, thereby eliminating the cumulative error of synchronous action.

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