A double-stroke expansion and contraction oil cylinder

Abstract

The present invention discloses a double-stroke expansion and contraction oil cylinder, which comprises a connecting flange, a cylinder barrel and a connecting body. The left and right sides of the cylinder barrel are respectively provided with a first cylinder head and a second cylinder head. A multi-channel distributor is fixedly installed on the outer side of the connecting body, and a multi-channel rotary joint is rotatably connected to the top of the multi-channel distributor. A main piston moving cavity and an auxiliary piston moving cavity with the same axis are arranged inside the cylinder barrel, and a movable main piston and an auxiliary piston are respectively installed in the main piston moving cavity and the auxiliary piston moving cavity; one end of the piston rod on the main piston passes through the auxiliary piston and the second cylinder head and enters the cavity of the connecting body, and the other end of the piston rod passes through the first cylinder head and the connecting flange; compared with the existing double-stroke expansion and contraction oil cylinder, on the premise of ensuring reliable functions, the structure is simpler, the manufacturing cost is lower, and there is no need to add an additional electrical control system, thus simplifying the operation.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic equipment, and more specifically, to a double-stroke expansion and contraction oil cylinder. Background Art

[0002] The expansion and contraction oil cylinder is a key device on the mandrels of the uncoiler and coiler of metal strip, and is the power source for the mandrel to achieve expansion and contraction.

[0003] At present, in order to improve production efficiency, reduce floor space, and lower equipment costs, steel mills are gradually starting to use a reversible rolling method with two coiler mandrels and a single-stand rolling mill. The inlet-side coiler mandrel on this reversible rolling mill needs to undertake both the coiling and uncoiling tasks of metal steel. Since when the mandrel is uncoiling, its expanded diameter needs to have a certain over-expansion amount relative to the theoretical inner diameter of the steel coil, and when the mandrel is coiling, its expanded diameter should be the same as the theoretical inner diameter of the steel coil, the coiler mandrel on the inlet side of the reversible rolling mill is generally equipped with a double-stroke expansion and contraction oil cylinder to achieve the coiling and uncoiling functions of the mandrel.

[0004] At present, there are two types of conventional double-stroke expansion and contraction oil cylinders. One is a double-chamber double-piston type double-stroke expansion and contraction oil cylinder, and the other is a double-stroke expansion and contraction oil cylinder with a displacement sensor and an electrical control system on the oil cylinder to achieve the control of the oil cylinder stroke. The structure is relatively complex and the cost is relatively high.

[0005] In view of the problems in the related art, no effective solution has been proposed yet. Summary of the Invention

[0006] In view of the above technical problems in the related art, the present invention provides a double-stroke expansion and contraction oil cylinder, which can reliably achieve the double-stroke function of the oil cylinder with a simpler structure, effectively reduce the manufacturing cost of the oil cylinder, and can overcome the above deficiencies of the prior art.

[0007] To achieve the above technical purpose, the technical solution of the present invention is realized as follows: A double-stroke expansion and contraction oil cylinder includes a connecting flange, a cylinder barrel, and a connecting body. First cylinder heads and second cylinder heads are respectively provided on the left and right sides of the cylinder barrel. A multi-channel distributor is fixedly installed on the outer side of the connecting body. A multi-channel rotary joint is rotatably connected to the top of the multi-channel distributor. A main piston moving cavity and a sub-piston moving cavity with the same axis are provided inside the cylinder barrel. A movable main piston and a sub-piston are respectively installed in the main piston moving cavity and the sub-piston moving cavity. One end of the piston rod on the main piston passes through the sub-piston and the second cylinder head and enters the cavity of the connecting body, and the other end of the piston rod passes through the first cylinder head and the connecting flange.

[0008] The cylinder barrel is provided with a first oil inlet on the space formed by the second cylinder head and the auxiliary piston, and the cylinder barrel is provided with a second oil inlet on the space formed by the auxiliary piston and the main piston; the cylinder barrel is provided with a third oil inlet on the space formed by the first cylinder head and the main piston;

[0009] The multi-channel distributor is provided with an oil outlet that is matched and communicated with the first oil inlet, the second oil inlet, and the third oil inlet through oil pipes, and the multi-channel rotary joint is provided with an oil inlet that is matched and communicated with the multi-channel distributor.

[0010] Further, the first cylinder head is fixedly connected to the connecting flange, and the second cylinder head is fixedly connected to the connecting body.

[0011] Further, the connecting flange is provided with a fourth oil inlet communicating with the jaw cylinder, and the fourth oil inlet is communicated with the multi-channel distributor through an oil pipe.

[0012] Further, the diameter of the circular hole of the main piston moving cavity is smaller than the diameter of the circular hole of the auxiliary piston moving cavity.

[0013] Further, the multi-channel rotary joint has four oil inlets, and the oil inlets of the multi-channel rotary joint are connected to the hydraulic system workstation.

[0014] Further, seals are provided at the connections of the first cylinder head and the second cylinder head with the piston rod of the main piston.

[0015] Further, baffles for fixing the seals are provided on the outer sides of the first cylinder head and the second cylinder head.

[0016] Further, oil seals are provided on the outer sides of the main piston near the side wall of the main piston moving cavity and the outer side of the auxiliary piston near the side wall of the auxiliary piston moving cavity.

[0017] The beneficial effects of the present invention: Compared with the existing double-stroke expansion and contraction oil cylinder, on the premise of ensuring reliable functions, the structure is simpler, the manufacturing cost is lower, and there is no need to add an additional electrical control system, which simplifies the operation. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of a double-stroke expansion and contraction oil cylinder according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of a double - stroke expansion and contraction oil cylinder according to an embodiment of the present invention Figure 1 ;

[0021] Figure 3 is a schematic diagram of a double - stroke expansion and contraction oil cylinder according to an embodiment of the present invention Figure 2 ;

[0022] Figure 4 is a schematic diagram of a double - stroke expansion and contraction oil cylinder according to an embodiment of the present invention Figure 3 .

[0023] In the figure: 1. Connecting flange; 2. Cylinder barrel; 2 - 1. First cylinder head; 2 - 2. Second cylinder head; 2 - 3. Main piston moving cavity; 2 - 4. Sub - piston moving cavity; 3. Connecting body; 4. Multi - channel distributor; 5. Multi - channel rotary joint; 6. Main piston; 7. Sub - piston; 8. First oil inlet; 9. Second oil inlet; 10. Third oil inlet; 11. Fourth oil inlet; 12. Sealing element; 13. Baffle; 14. Oil seal. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0025] As Figure 1 shown, a double - stroke expansion and contraction oil cylinder according to an embodiment of the present invention includes a connecting flange 1, a cylinder barrel 2 and a connecting body 3. The left and right sides of the cylinder barrel 2 are respectively provided with a first cylinder head 2 - 1 and a second cylinder head 2 - 2. A multi - channel distributor 4 is fixedly installed on the outer side of the connecting body 3. A multi - channel rotary joint 5 is rotatably connected to the top of the multi - channel distributor 4. The inner side of the cylinder barrel 2 is provided with a main piston moving cavity 2 - 3 and a sub - piston moving cavity 2 - 4 on the same axis. The main piston moving cavity 2 - 3 and the sub - piston moving cavity 2 - 4 are respectively provided with a movable main piston 6 and a sub - piston 7; One end of the piston rod on the main piston 6 passes through the sub - piston 7 and the second cylinder head 2 - 2 and enters the cavity of the connecting body 3, and the other end of the piston rod passes through the first cylinder head 2 - 1 and the connecting flange 1;

[0026] The cylinder barrel 2 is provided with a first oil inlet 8 in the space formed by the second cylinder head 2 - 2 and the sub - piston 7, and the cylinder barrel 2 is provided with a second oil inlet 9 in the space formed by the sub - piston 7 and the main piston 6; The cylinder barrel 2 is provided with a third oil inlet 10 in the space formed by the first cylinder head 2 - 1 and the main piston 6;

[0027] The multi-channel distributor 4 is provided with an oil outlet that is connected in a matching manner with the first oil outlet 8, the second oil outlet 9, and the third oil outlet 10 through oil pipes, and the multi-channel rotary joint 5 is provided with an oil inlet that is connected in a matching manner with the multi-channel distributor 4.

[0028] Furthermore, the first cylinder head 2-1 is fixedly connected to the connecting flange 1, and the second cylinder head 2-2 is fixedly connected to the connecting body 3.

[0029] In a specific embodiment of the present invention, the connecting flange 1 is provided with a fourth oil outlet 11 that communicates with the jaw cylinder, and the fourth oil outlet 11 is connected to the multi-channel distributor 4 through an oil pipe.

[0030] In a specific embodiment of the present invention, the diameter of the circular hole of the main piston moving cavity 2-3 is smaller than the diameter of the circular hole of the auxiliary piston moving cavity 2-4.

[0031] In a specific embodiment of the present invention, the multi-channel rotary joint 5 has four oil inlets, and the oil inlets of the multi-channel rotary joint 5 are connected to a hydraulic system workstation.

[0032] In a specific embodiment of the present invention, seals 12 are provided at the connection parts of the first cylinder head 2-1 and the second cylinder head 2-2 with the piston rod of the main piston 6.

[0033] In a specific embodiment of the present invention, baffles 13 for fixing the seals 12 are provided on the outer sides of the first cylinder head 2-1 and the second cylinder head 2-2.

[0034] In a specific embodiment of the present invention, oil seals 14 are provided on the outer sides of the main piston 6 close to the side wall of the main piston moving cavity 2-3 and the auxiliary piston 7 close to the side wall of the auxiliary piston moving cavity 2-4.

[0035] In order to facilitate the understanding of the above technical solution of the present invention, the above technical solution of the present invention will be described in detail below through specific usage methods.

[0036] The present invention provides a double-stroke expansion and contraction oil cylinder, which can be used in, but not limited to, the coiler mandrel on the entrance side of a reversible rolling mill, further reducing equipment costs.

[0037] A double-stroke expansion and contraction oil cylinder mainly includes a connecting flange 1, a cylinder barrel 2, a connecting body 3, and other accessories such as a first cylinder head 2-1 connecting the connecting flange 1 and the cylinder barrel 2 and a second cylinder head 2-2 connecting the cylinder barrel 2 and the connecting body 3.

[0038] The multi-channel rotary joint 5 is provided with four oil inlets. The multi-channel rotary joint 5 is connected to the hydraulic system workstation. The hydraulic oil is supplied from the hydraulic station. The multi-channel rotary joint 5 is also provided with an oil discharge port. The hydraulic oil flows into the four oil inlets of the multi-channel rotary joint 5. The multi-channel rotary joint 5 is connected to the multi-channel distributor 4. The multi-channel distributor 4 has oil outlets corresponding to its four oil inlets. The four oil outlets are respectively connected to the first oil outlet 8, the second oil outlet 9, the third oil outlet 10 and the fourth oil outlet 11 through four oil pipes.

[0039] The multi-channel distributor 4 and the multi-channel rotary joint 5 are fixedly installed on the connecting body 3. The connecting body 3 is fixedly connected to the second cylinder head 2-2. The cylinder barrel 2 is provided with the first oil outlet 8, the second oil outlet 9 and the third oil outlet 10.

[0040] The inner circle of the cylinder barrel 2 is in a stepped shape, forming a main piston moving cavity 2-3 and a sub-piston moving cavity 2-4. A main piston 6 is installed in the main piston moving cavity 2-3, and an oil seal 14 is provided to prevent the internal leakage of the hydraulic oil. The piston rod of the main piston 6 passes through the through holes provided between the first cylinder head 2-1 and the second cylinder head 2-2 on both sides.

[0041] A sub-piston 7 is installed at the right end of the main piston 6. The sub-piston 7 is installed in the sub-piston moving cavity 2-4, and an oil seal is also provided to prevent the internal leakage of the hydraulic oil. Seals 12 are provided at the connections between the first cylinder head 2-1 and the second cylinder head 2-2 and the piston rod of the main piston 6 to prevent the oil cylinder from leaking oil. The baffle 13 provided outside the seal 12 is used to fix the relative positions of the seal 12 and the cylinder head.

[0042] The connecting flange 1 is installed at the left end of the first cylinder head 2-1 to connect the oil cylinder and the drum.

[0043] Except that the fourth oil outlet 11 on the connecting flange 1 finally leads to the jaw oil cylinder, the staggered oil supply of the other three oil circuits jointly realizes the double-stroke function of the oil cylinder. There are three oil cavities provided in the cylinder barrel 2, namely, oil cavity one between the first cylinder head 2-1 and the main piston 6, oil cavity two between the sub-piston 7 and the second cylinder head 2-2, and oil cavity three between the main piston 6 and the sub-piston 7. The three oil cavities are respectively supplied with oil by the third oil outlet 10, the first oil outlet 8 and the second oil outlet 9.

[0044] As Figure 2 shown, when the second oil outlet 9 is supplied with oil and the other two oil inlets return oil, at this time, oil pressure is generated in the oil cavity two, pushing the main piston 6 to move to the left and pushing the sub-piston 7 to move to the right until the main piston 6 abuts against the first cylinder head 2-1 and the sub-piston abuts against the second cylinder head 2-2.

[0045] As Figure 3As shown, when the third oil inlet 10 admits oil and the other two oil inlets return oil, an oil pressure is generated in oil chamber one, pushing the main piston 6 to move rightward, and at the same time driving the auxiliary piston 6 to move rightward until the auxiliary piston 6 abuts against the second cylinder head 2-2 and the main piston 6 abuts against the auxiliary piston 7.

[0046] As Figure 4 shown, when the first oil inlet 8 and the third oil inlet 10 admit oil and the other oil inlet returns oil, an oil pressure is generated in oil chamber one and oil chamber three, pushing the main piston 6 to move rightward and the auxiliary piston 7 to move leftward respectively. Since the right end face area of the auxiliary piston 7 is larger than the left end face area of the main piston 6, the pressure received by the auxiliary piston 7 is greater than the pressure received by the main piston 6. Therefore, when there is an oil discharge port and the end faces of the main piston 6 and the auxiliary piston 7 are in contact, the auxiliary piston 7 will push the main piston 6 to move leftward. However, there is a step on the cylinder barrel 2 to mechanically limit the auxiliary piston 7. At this time, the auxiliary piston 7 is fixed against the step of the cylinder barrel 2. Under continuous oil supply, the main piston 6 will abut against the auxiliary piston and the auxiliary piston 7 will abut against the step of the cylinder barrel 2.

[0047] The Figures 2-4 dynamic change constituted by... is the working principle for the first stroke of this double stroke, and the dynamic change between... and... or between... and... is the working principle for the second stroke of this double stroke oil cylinder. Figure 3 and Figure 2 or Figure 1 and Figure 2 is the working principle for the second stroke of this double stroke oil cylinder.

[0048] In summary, by means of the above technical solution of the present invention, compared with the existing double stroke expansion and contraction oil cylinder, the structure is simpler, the manufacturing cost is lower, and there is no need to add an additional electrical control system, simplifying the operation while ensuring reliable functions.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A double-stroke expansion and contraction oil cylinder, comprising a connecting flange (1), a cylinder barrel (2) and a connecting body (3), characterized in that, a first cylinder head (2-1) and a second cylinder head (2-2) are respectively arranged on the left and right sides of the cylinder barrel (2), a multi-channel distributor (4) is fixedly installed on the outer side of the connecting body (3), a multi-channel rotary joint (5) is rotatably connected to the top of the multi-channel distributor (4), a main piston moving cavity (2-3) and a sub-piston moving cavity (2-4) with the same axis are arranged inside the cylinder barrel (2), and a movable main piston (6) and a sub-piston (7) are respectively installed in the main piston moving cavity (2-3) and the sub-piston moving cavity (2-4); one end of the piston rod on the main piston (6) passes through the sub-piston (7) and the second cylinder head (2-2) and enters the cavity of the connecting body (3), and the other end of the piston rod passes through the first cylinder head (2-1) and the connecting flange (1); the cylinder barrel (2) is provided with a first oil inlet (8) in the space formed by the second cylinder head (2-2) and the sub-piston (7), and the cylinder barrel (2) is provided with a second oil inlet (9) in the space formed by the sub-piston (7) and the main piston (6); the cylinder barrel (2) is provided with a third oil inlet (10) in the space formed by the first cylinder head (2-1) and the main piston (6); the multi-channel distributor (4) is provided with an oil outlet that is matched and communicated with the first oil inlet (8), the second oil inlet (9) and the third oil inlet (10) through an oil pipe, and the multi-channel rotary joint (5) is provided with an oil inlet that is matched and communicated with the multi-channel distributor (4); the first cylinder head (2-1) is fixedly connected with the connecting flange (1), and the second cylinder head (2-2) is fixedly connected with the connecting body (3); a fourth oil inlet (11) communicating with the jaw oil cylinder is arranged on the connecting flange (1), and the fourth oil inlet (11) is communicated with the multi-channel distributor (4) through an oil pipe; the diameter of the round hole of the main piston moving cavity (2-3) is smaller than the diameter of the round hole of the sub-piston moving cavity (2-4); the multi-channel rotary joint (5) has four oil inlets, and the oil inlets of the multi-channel rotary joint (5) are connected to the hydraulic system workstation.

2. A double-stroke expansion and contraction oil cylinder according to claim 1, characterized in that, sealing members (12) are arranged at the joints of the first cylinder head (2-1) and the second cylinder head (2-2) with the piston rod of the main piston (6).

3. A double-stroke expansion and contraction oil cylinder according to claim 2, characterized in that, baffles (13) for fixing the sealing members (12) are arranged on the outer sides of the first cylinder head (2-1) and the second cylinder head (2-2).

4. A double-stroke expansion and contraction oil cylinder according to claim 1, characterized in that, oil seals (14) are arranged on the outer sides of the main piston (6) close to the side wall of the main piston moving cavity (2-3) and the sub-piston (7) close to the side wall of the sub-piston moving cavity (2-4).

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