Tandem synchronous hydraulic cylinder lifting device

Abstract

The utility model relates to a serial connection type synchronous hydraulic cylinder lifting device which comprises a main hydraulic cylinder, a main sliding rod and a main central pipe, the main hydraulic cylinder comprises a main cylinder body, a main piston movably arranged in the main cylinder body, the main sliding rod is arranged on the main piston and provided with a main oil cavity communicated with a main rod cavity, and the main central pipe is arranged in the main cylinder body; the slave hydraulic cylinder comprises a slave cylinder body, a slave piston movably arranged in the slave cylinder body, a slave sliding rod which is arranged on the slave piston and is provided with a slave oil cavity communicated with a slave rod cavity, and a slave central pipe arranged in the slave cylinder body; the connecting pipe is respectively connected with the second oil port and the third oil port; and the oil pressure area of the master rod cavity is the same as that of the slave rodless cavity. According to the serial connection type synchronous hydraulic cylinder lifting device, the oil pressure area of the main rod cavity is equal to the oil pressure area of the auxiliary rodless cavity, so that synchronous stretching and retracting of the two cylinders are achieved, and it can be guaranteed that the retracting speeds and the retracting positions of piston rods of the two cylinders are completely equal.

Description

Technical Field

[0001] The utility model relates to a hydraulic lifting device, in particular to a series-type synchronous hydraulic cylinder lifting device. Background Art

[0002] Large equipment usually requires two hydraulic cylinders to lift synchronously. If no synchronous measures are considered on the equipment and the two hydraulic cylinders are simply connected to the hydraulic system, due to the machining accuracy problems of the hydraulic cylinders, the movements of the two cylinders are usually asynchronous. This asynchronous phenomenon will, in the lightest case, result in insufficient positioning accuracy of the equipment, and in the worst case, may damage the equipment.

[0003] Generally, a hydraulic synchronous valve is equipped in the hydraulic system to control the movements of the two hydraulic cylinders. Since the accuracy of the hydraulic synchronous valve itself is poor, usually 3-5%, but in some industries with high accuracy requirements, the synchronous accuracy of the synchronous valve cannot meet the use requirements. Summary of the Utility Model

[0004] To solve the problem of insufficient synchronous accuracy of the above two hydraulic cylinders, the utility model provides a series-type synchronous hydraulic cylinder lifting device, and the specific technical solution is as follows:

[0005] A series-type synchronous hydraulic cylinder lifting device includes: a main hydraulic cylinder, including a main cylinder body, a main piston movably arranged in the main cylinder body, a main sliding rod arranged on the main piston and provided with a main oil cavity communicated with the main rod cavity, and a main central tube arranged in the main cylinder body. The main central tube is also movably inserted on the main piston and communicated with the main oil cavity. The main cylinder body is also provided with a first oil port communicated with the main rodless cavity and a second oil port communicated with the main central tube; a slave hydraulic cylinder, including a slave cylinder body, a slave piston movably arranged in the slave cylinder body, a slave sliding rod arranged on the slave piston and provided with a slave oil cavity communicated with the slave rod cavity, and a slave central tube arranged in the slave cylinder body. The slave central tube is also movably inserted on the slave piston and communicated with the slave oil cavity. The slave cylinder body is also provided with a third oil port communicated with the slave rodless cavity and a fourth oil port communicated with the slave central tube; and a connecting pipe, respectively connected with the second oil port and the third oil port; wherein, the oil pressure area of the main rod cavity is the same as the oil pressure area of the slave rodless cavity.

[0006] It further includes: a check valve arranged on the main cylinder body. The main cylinder body is provided with a third oil passage communicated with the main rod cavity and the second oil port. The check valve is arranged on the third oil passage. The third oil inlet of the third oil passage is communicated with the main rodless cavity when the main piston moves to the highest position.

[0007] Compared with the prior art, the utility model has the following beneficial effects:

[0008] A lifting device of a series-connected synchronous hydraulic cylinder provided by the utility model realizes the synchronous telescoping of two cylinders by making the oil pressure area of the main rod chamber equal to the oil pressure area of the slave rodless chamber, and can ensure that the retraction speeds and positions of the piston rods of the two cylinders are exactly equal. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic structural diagram of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0010] The present utility model will be further described below in conjunction with the accompanying drawings.

[0011] As Figure 1 shown, a lifting device of a series-connected synchronous hydraulic cylinder includes a main hydraulic cylinder 1, a slave hydraulic cylinder 5 and a connecting pipe 8.

[0012] The main hydraulic cylinder 1 includes a main cylinder body 10, a main piston 21, a main sliding rod 22, a main central pipe 3 and a one-way valve 4. The main cylinder body 10 is provided with a main piston hole and a first oil port 11, a second oil port 12 and a third oil passage 13 that are uniformly communicated with the main piston hole. The main piston 21 is movably inserted into the main piston hole. The main piston 21 divides the main piston hole into a main rod chamber 17 and a main rodless chamber 16. The main rodless chamber 16 is communicated with the first oil port 11. The main rod chamber 17 is communicated with the third oil inlet 14 of the third oil passage 13. The one-way valve 4 is installed on the third oil passage 13. The third oil passage 13 is communicated with the second oil port 12 through the one-way valve 4. The second oil port 12 is communicated with the main central pipe 3. The main central pipe 3 is installed on the main cylinder body 10 and is movably inserted into the main piston 21 and the main sliding rod 22, and a sealing ring is installed between the main central pipe 3 and the main piston 21. The main oil chamber 23 is provided inside the main sliding rod 22. The main oil chamber 23 is communicated with the main central pipe 3. The main oil chamber 23 is communicated with the main rod chamber 17 through a fifth oil hole 24.

[0013] The slave hydraulic cylinder 5 includes a slave cylinder body 50, a slave piston 61, a slave sliding rod 62 and a slave central pipe 7. The slave cylinder body 50 is provided with a slave piston hole, a fourth oil port 54 and a third oil port 53 that is communicated with the slave piston hole. The slave piston 61 is movably inserted into the slave piston hole, dividing the slave piston hole into a slave rod chamber 57 and a slave rodless chamber 56. The third oil port 53 is communicated with the slave rodless chamber 56. The slave central pipe 7 is installed on the slave cylinder body 50 and is communicated with the fourth oil port 54. The slave central pipe 7 is also movably inserted into the slave piston 61 and the slave sliding rod 62, and a sealing ring is installed between the slave central pipe 7 and the slave piston 61. The slave oil chamber 63 is provided on the slave sliding rod 62. The slave oil chamber 63 is communicated with the slave rod chamber 57 through a sixth oil hole 64. The oil pressure area of the main rod chamber 17 is the same as the oil pressure area of the slave rodless chamber 56.

[0014] The connecting pipe 8 is respectively connected to the second oil port 12 and the third oil port 53.

[0015] The third oil inlet 14 of the third oil circuit 13 communicates with the main rodless cavity 16 when the main piston 21 moves to the highest position.

[0016] Synchronous lifting:

[0017] The first oil port 11 is connected to the pressure oil port, and the fourth oil port 54 is connected to the oil tank.

[0018] The pressure oil enters the main rodless cavity 16 through the first oil port 11. The pressure oil pushes the main sliding rod 22 to extend upward. At the same time, the oil in the main rod chamber 17 returns, and the pressure oil enters the main oil chamber 23, and then enters the second oil port 12 through the main central pipe 3; the oil returning from the main rod chamber 17 also enters the second oil port 12 through the third oil circuit 13 and the check valve 4, then enters the third oil port 53 through the connecting pipe 8, and then the pressure oil enters the slave rodless cavity 56. The pressure oil pushes the slave piston 61 to extend upward. At the same time, the oil returning from the slave rod chamber 57 enters the slave oil chamber 63, and then enters the fourth oil port 54 through the slave central pipe 7 and returns to the oil tank.

[0019] During the extension process of the above-mentioned main and slave cylinders, all the oil discharged from the main rod chamber 17 enters the slave rodless cavity 56. Since the structural design has ensured that the oil pressure area of the main rod chamber 17 is equal to the area of the slave rodless cavity 56, and the hydraulic oil is incompressible, it can ensure that the extension speeds and positions of the two cylinder pistons are exactly the same, thus realizing the synchronous extension of the two cylinders.

[0020] In order to eliminate the position deviation at the end of the extension of the two cylinders, it also has an automatic deviation correction function at the end of the extension. When the main sliding rod 22 is fully extended to the end position, its main piston 21 will cross the third oil inlet 14 on the cylinder wall, making the third oil circuit 13 communicate with the main rodless cavity 16. Suppose the main sliding rod 22 is fully extended to the end position, while the slave piston 61 rod has not been extended in place. At this time, the pressure oil in the main rodless cavity 16 will enter the slave rodless cavity 56 through the third oil circuit 13, the check valve 4, the second oil port 12, the connecting pipe 8, and the third oil port 53, pushing the slave sliding rod 62 to be fully extended, thus eliminating the position deviation at the end of the two cylinders.

[0021] Synchronous retraction:

[0022] The fourth oil port 54 is connected to the pressure oil port, and the first oil port 11 is connected to the oil tank.

[0023] The pressure oil enters through the fourth oil port 54, enters the slave oil chamber 63 after passing through the slave central pipe 7, and then enters the slave rod chamber 57. The pressure oil pushes the slave piston 61 to retract downward. At the same time, the oil returning from the slave rodless cavity 56 enters the second oil port 12 from the third oil port 53 and the connecting pipe 8, then enters the main oil chamber 23 through the main central pipe 3, and then enters the main rod chamber 17 from the main oil chamber 23. The pressure oil pushes the main sliding rod 22 to retract downward. At the same time, the oil returning from the main rodless cavity 16 returns to the oil tank through the first oil port 11.

[0024] During the retraction of the main and auxiliary cylinders, all the oil discharged from the rodless chamber 56 enters the main rod chamber 17. Since the structural design has ensured that the oil pressure area of ​​the rodless chamber 56 is equal to the oil pressure area of ​​the main rod chamber 17, and the hydraulic oil is incompressible, it is possible to ensure that the retraction speed and position of the sliding rods of the two cylinders are completely equal, thereby achieving synchronous retraction of the two cylinders.

[0025] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the claims of the present invention.

Claims

1. A tandem synchronous hydraulic cylinder lifting device, characterized in that: include: A master hydraulic cylinder (1) comprises a master cylinder body (10), a master piston (21) movably arranged in the master cylinder body (10), a master sliding rod (22) arranged on the master piston (21) and provided with a master oil chamber (23) communicating with a master rod chamber (17), and a master center tube (3) arranged in the master cylinder body (10); the master center tube (3) is also movably inserted on the master piston (21) and communicates with the master oil chamber (23); the master cylinder body (10) is also provided with a first oil port (11) communicating with a master rodless chamber (16), and a second oil port (12) communicating with the main center tube (3); A slave hydraulic cylinder (5) comprises a slave cylinder body (50), a slave piston (61) movably arranged in the slave cylinder body (50), a slave sliding rod (62) arranged on the slave piston (61) and provided with a slave oil chamber (63) communicating with a slave rod chamber (57), and a slave center tube (7) arranged in the slave cylinder body (50), wherein the slave center tube (7) is also movably inserted in the slave piston (61) and communicates with the slave oil chamber (63), and the slave cylinder body (50) is also provided with a third oil port (53) communicating with a slave rodless chamber (56) and a fourth oil port (54) communicating with the slave center tube (7); and A connecting pipe (8) connected to the second oil port (12) and the third oil port (53) respectively; The oil pressure area of ​​the main rod chamber (17) is the same as the oil pressure area of ​​the slave rodless chamber (56).

2. A tandem synchronous hydraulic cylinder lifting device according to claim 1, characterized in that: Also includes: A one-way valve (4) is arranged on the main cylinder body (10), and the main cylinder body (10) is provided with a third oil circuit (13) which is connected with the main rod chamber (17) and the second oil port (12). The one-way valve (4) is arranged on the third oil circuit (13), and the third oil inlet (14) of the third oil circuit (13) is connected with the main rodless chamber (16) when the main piston (21) moves to the highest point.

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