Full hydraulic control type hydraulic system for controlling automatic reciprocating of oil cylinder

Abstract

The invention discloses a full-hydraulic-control type hydraulic system for controlling automatic reciprocating of an oil cylinder. The device is composed of an oil pump, an outlet filter, an overflow valve, a pressure reducing valve, a one-way valve, a two-position four-way hydraulic reversing valve, a three-position four-way hydraulic reversing valve, an oil cylinder, a first cartridge valve, a second cartridge valve, a first back pressure valve, a second back pressure valve, a first hydraulic control one-way valve, a second hydraulic control one-way valve, a cooler, a return oil filter and an oil tank. Mechanical and hydraulic pressure combination is adopted, no electric control participates, safety is high, reliability is good, the service life is long, operation is easy and convenient, debugging and using are convenient for a user, and the anti-explosion device is suitable for various application occasions with anti-explosion requirements.

Description

Technical Field

[0001] The invention relates to automatic reciprocating control of an oil cylinder, in particular to an automatic reciprocating control system of an oil cylinder adopting a full hydraulic control type, and belongs to the technical field of hydraulic transmission. Background Art

[0002] In the field of hydraulic transmission, oil cylinders are key actuators that convert hydraulic energy into mechanical energy and are widely used in situations that require linear reciprocating motion or swinging motion. Traditional electromagnetically controlled reversing hydraulic systems may have stability and reliability issues under harsh working conditions. In situations with high explosion-proof requirements, high requirements are placed on the safety and stability of hydraulic systems. Existing electromagnetically controlled hydraulic systems cannot meet the needs of specific industries in terms of explosion-proof performance, such as petroleum, chemical, mining and other fields. Therefore, in explosion-proof situations, in order to meet specific safety standards and regulatory requirements, and to achieve the same function as the traditional electromagnetically controlled oil cylinder automatic reciprocating, a specially designed, non-electrically controlled, mechanical-hydraulic combined hydraulic system is required. Summary of the invention

[0003] The purpose of the present invention is to provide a highly efficient and safe fully hydraulically controlled automatic reciprocating cylinder system for the above-mentioned application occasions with special requirements for explosion-proof performance.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder comprises an oil pump, an outlet filter, a relief valve, a pressure reducing valve, a check valve, a two-position four-way hydraulic reversing valve, a three-position four-way hydraulic reversing valve, an oil cylinder, a first cartridge valve, a second cartridge valve, a first back pressure valve, a second back pressure valve, a first hydraulically controlled check valve, a second hydraulically controlled check valve, a cooler, an oil return filter and an oil tank.

[0005] The oil cylinder has a total of 6 oil ports. In addition to the 2 main oil ports, on the side opposite to the main oil ports, 2 small holes with a diameter of 2 mm are opened at the left and right ends of the piston stroke, respectively. From left to right, they are K1 port, K2 port, K3 port and K4 port, among which K1 port and K4 port are respectively close to the left and right cylinder heads. The center distance between K2 port and K1 port is 10 mm larger than the length of the piston, the center distance between K3 port and K4 port is 10 mm larger than the length of the piston, and the center distance between K2 port and K3 port is equal to the required working stroke of the piston.

[0006] The oil pump suction port and oil drain port are respectively connected to the oil tank, and the oil outlet is connected to the inlet of the outlet filter; The outlet of the outlet filter is connected to the inlets of the relief valve, the pressure reducing valve and the check valve respectively; the outlet of the relief valve is connected to the inlet of the cooler; the outlet of the pressure reducing valve is connected to the P port of the two-position four-way hydraulic reversing valve; its oil drain port is connected to the oil tank separately; the outlet of the check valve is connected to the P port of the three-position four-way hydraulic reversing valve; The T port of the two-position four-way hydraulic reversing valve is connected to the inlet of the cooler, and the A port and the B port thereof are respectively connected to the left and right hydraulic control ports of the three-position four-way hydraulic reversing valve, and the left and right hydraulic control ports of the two-position four-way hydraulic reversing valve are respectively connected to the inlets of the first back pressure valve and the second back pressure valve; The A and B ports of the three-position four-way hydraulic reversing valve are respectively connected to the left and right main oil ports of the oil cylinder, and the T port thereof is connected to the inlet of the cooler. The left and right hydraulic control ports are also respectively connected to the K ports of the first hydraulically controlled check valve and the second hydraulically controlled check valve; The left and right main oil ports of the oil cylinder are also connected to the outlets of the second back pressure valve and the first back pressure valve respectively, the K1 port and K2 port of the oil cylinder are connected to the X port and A port of the first cartridge valve respectively, and the K3 port and K4 port are connected to the A port and X port of the second cartridge valve respectively; The B port of the first cartridge valve is connected to the inlet of the first back pressure valve, and the B port of the second cartridge valve is connected to the inlet of the second back pressure valve; The B port of the first hydraulically controlled one-way valve is connected to the inlet of the first back pressure valve, and the A port is connected to the inlet of the cooler; the B port of the second sequence valve is connected to the inlet of the second back pressure valve, and the A port is connected to the inlet of the cooler; The outlet of the cooler is connected to the inlet of the return oil filter, and the outlet of the return oil filter is connected to the oil tank.

[0007] Furthermore, the pressure reducing valve is a pilot-operated pressure reducing valve, and the set pressure is not less than the pressure required for the switching of the three-position four-way hydraulic reversing valve.

[0008] Furthermore, the opening pressure of the one-way valve is not less than the pressure required for the switching of the three-position four-way hydraulic reversing valve.

[0009] Preferably, the control oil ports at both ends of the two-position four-way hydraulic reversing valve have damping holes with a diameter of 0.7 mm.

[0010] Preferably, the middle position function of the three-position four-way hydraulic reversing valve is an H-type function.

[0011] Furthermore, the first hydraulically controlled one-way valve and the second hydraulically controlled one-way valve are both of internal leakage type, and their reverse opening pressures are equal and both are less than the set pressure of the pressure reducing valve; the B ports of the first hydraulically controlled one-way valve and the second hydraulically controlled one-way valve are both provided with a damping hole with a diameter of 0.7 mm.

[0012] Furthermore, the connection type of the left oil ports of the two-position four-way hydraulic reversing valve is the same as the connection type of the left oil ports of the three-position four-way hydraulic reversing valve, and the connection type of the right oil ports of the two-position four-way hydraulic reversing valve is the same as the connection type of the right oil ports of the three-position four-way hydraulic reversing valve.

[0013] Furthermore, the first back-pressure valve and the second back-pressure valve are both composed of one-way valves, and the opening pressures of the two are equal, both set to 5 bar.

[0014] Furthermore, the cooler is a water-cooled type. The advantages and beneficial effects of the present invention are:

[0015] (1) The present invention adopts a combination of mechanical and hydraulic pressures, has no electronic control involvement, has high safety, and is suitable for various applications with explosion-proof requirements.

[0016] (2) The present invention defines or explains the pressure setting of each hydraulic control element in the system, which facilitates user debugging and use.

[0017] (3) The two-position hydraulic reversing valve of the present invention controls the reversing of the oil cylinder. During the non-reversing period of the oil cylinder, the hydraulic pressure difference of the control oil at both ends always maintains a certain value, ensuring that the oil cylinder will not be disordered during operation; the three-position hydraulic reversing valve adopts an H-type middle position function, and the reversing pressure shock is small. These two aspects are conducive to ensuring high reliability and long service life of the system under harsh conditions.

[0018] (4) The present invention has a one-button operation function, and the oil cylinder can automatically reciprocate, which is simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Attached Figure 1 This is a schematic diagram of a fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to the present invention; In the figure, 1 is an oil pump, 2 is an outlet filter, 3 is an overflow valve, 4 is a pressure reducing valve, 5 is a check valve, 6 is a two-position four-way hydraulic reversing valve, 7 is a three-position four-way hydraulic reversing valve, 8 is an oil cylinder, 9-1 is a first cartridge valve, 9-2 is a second cartridge valve, 10-1 is a first back pressure valve, 10-2 is a second back pressure valve, 11-1 is a first hydraulically controlled check valve, 11-2 is a second hydraulically controlled check valve, 12 is a cooler, 13 is an oil return filter, and 14 is an oil tank. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0021] like Figure 1 The figure shows a schematic diagram of a fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder of the present invention, comprising an oil pump 1, an outlet filter 2, a relief valve 3, a pressure reducing valve 4, a check valve 5, a two-position four-way hydraulic reversing valve 6, a three-position four-way hydraulic reversing valve 7, an oil cylinder 8, a first cartridge valve 9-1, a second cartridge valve 9-2, a first back pressure valve 10-1, a second back pressure valve 10-2, a first hydraulically controlled check valve 11-1, a second hydraulically controlled check valve 11-2, a cooler 12, an oil return filter 13 and an oil tank 14.

[0022] The oil cylinder 7 has a total of 6 oil ports. In addition to the 2 main oil ports, on the side opposite to the main oil ports, 2 small holes with a diameter of 2 mm are opened at the left and right ends of the piston stroke, respectively, from left to right, respectively K1 port, K2 port, K3 port and K4 port, wherein K1 port and K4 port are respectively close to the left and right cylinder heads, the center distance between K2 port and K1 port is 10 mm larger than the length of the piston, the center distance between K3 port and K4 port is 10 mm larger than the length of the piston, and the center distance between K2 port and K3 port is equal to the required working stroke of the piston.

[0023] The suction port and the oil drain port of the oil pump 1 are respectively connected to the oil tank 14, and the oil outlet is connected to the inlet of the outlet filter 2; the outlet of the outlet filter 2 is respectively connected to the inlets of the relief valve 3, the pressure reducing valve 4 and the check valve 5, the outlet of the relief valve is connected to the inlet of the cooler 12, the outlet of the pressure reducing valve 4 is connected to the P port of the two-position four-way hydraulic reversing valve 6, the oil drain port is separately connected to the oil tank 14, and the outlet of the check valve 5 is connected to the P port of the three-position four-way hydraulic reversing valve 7; The T port of the two-position four-way hydraulic reversing valve 6 is connected to the inlet of the cooler 12, and its A port and B port are respectively connected to the left and right hydraulic control ports of the three-position four-way hydraulic reversing valve 7, and the left and right hydraulic control ports of the two-position four-way hydraulic reversing valve 6 are respectively connected to the inlet of the first back pressure valve 10-1 and the second back pressure valve 10-2; the A and B ports of the three-position four-way hydraulic reversing valve 7 are respectively connected to the left and right main oil ports of the cylinder 8, and its T port is connected to the inlet of the cooler 12, and the left and right hydraulic control ports are respectively connected to the inlet of the cylinder 8. The left and right main oil ports of the oil cylinder 8 are also connected to the outlets of the second back pressure valve 10-2 and the first back pressure valve 10-1 respectively; the K1 port and K2 port of the oil cylinder 8 are respectively connected to the X port and A port of the first cartridge valve 9-1, and the K3 port and K4 port are respectively connected to the A port and X port of the second cartridge valve 9-2; the B port of the first cartridge valve 9-1 is connected to the first back pressure valve 10-2. -1, the B port of the second cartridge valve 9-2 is connected to the inlet of the second back-pressure valve 10-2; the B port of the first hydraulically controlled one-way valve 11-1 is connected to the inlet of the first back-pressure valve 10-1, and the A port is connected to the inlet of the cooler 12; the B port of the second hydraulically controlled one-way valve 11-2 is connected to the inlet of the second back-pressure valve 10-2, and the A port is connected to the inlet of the cooler 12; the outlet of the cooler 12 is connected to the inlet of the return oil filter 13, and the outlet of the return oil filter 13 is connected to the oil tank 14.

[0024] The pressure reducing valve 4 is a pilot-operated pressure reducing valve, and the set pressure is not less than the pressure required for the reversing of the three-position four-way hydraulic reversing valve 7. The opening pressure of the one-way valve 5 is not less than the pressure required for the reversing of the three-position four-way hydraulic reversing valve 7. The control oil ports at both ends of the two-position four-way hydraulic reversing valve 6 are provided with damping holes with a diameter of 0.7 mm. The middle position function of the three-position four-way hydraulic reversing valve 6 is an H-type function. The first hydraulically controlled one-way valve 11-1 and the second hydraulically controlled one-way valve 11-2 are both of internal leakage type, and the reverse opening pressure is equal, which is less than the set pressure of the pressure reducing valve 4; the B ports of the first hydraulically controlled one-way valve 11-1 and the second hydraulically controlled one-way valve 11-2 are both provided with damping holes with a diameter of 0.7 mm. The connection type of each oil port at the left position of the two-position four-way hydraulic reversing valve 6 is the same as that of each oil port at the left position of the three-position four-way hydraulic reversing valve 7, and the connection type of each oil port at the right position of the two-position four-way hydraulic reversing valve 6 is the same as that of each oil port at the right position of the three-position four-way hydraulic reversing valve 7. The first back pressure valve 9-1 and the second back pressure valve 9-2 are both composed of one-way valves, and the opening pressures of the two are equal, both set to 5 bar. The cooler 12 is a water-cooled type.

[0025] Combine the following Figure 1 Explain the working principle of the entire system.

[0026] After the oil pump 1 is started, its outlet pressure oil enters the pressure reducing valve 4 and the check valve 5 through the outlet filter 2, and the excess oil flows back to the oil tank 14 through the overflow valve 3 and the cooler 12; since the opening of the check valve 5 requires a certain pressure, the maximum pressure of the oil flowing through the pressure reducing valve 4 is the set pressure of the pressure reducing valve 4, and the minimum is the opening pressure of the check valve 5. The pressure oil then passes through the two-position four-way hydraulic reversing valve 6 and enters the left control oil port of the three-position four-way hydraulic reversing valve 7 to control the three-position four-way hydraulic reversing valve When the check valve 7 is in the left position, the oil from the check valve 5 enters the right chamber of the oil cylinder 8 through the P and B ports of the three-position four-way hydraulic reversing valve 7, pushing the piston of the oil cylinder 8 to move to the left; when the right end face of the piston of the oil cylinder 8 moves to the left to exceed the K2 position of the oil cylinder 8, the pressure oil in the right chamber of the oil cylinder 8 flows into the A port of the cartridge valve 9-1 through the K2 port, the cartridge valve 9-1 opens, and the pressure of the oil in the right chamber of the oil cylinder 8 is fed back to the left control oil port of the two-position four-way hydraulic reversing valve 6, forcing the two-position four-way hydraulic reversing valve 6 to move to the left. The directional valve 6 is placed in the left position for operation; at this time, the oil from the pressure reducing valve 4 acts on the right control oil port of the three-position four-way hydraulic reversing valve 7 and the K port of the second hydraulically controlled one-way valve 11-2 after passing through the two-position four-way hydraulic reversing valve 6, forcing the three-position four-way hydraulic reversing valve 7 to work in the right position, and the second hydraulically controlled one-way valve 11-2 to open in the reverse direction; the right position operation of the three-position four-way hydraulic reversing valve 7 causes the piston of the oil cylinder 8 to start to move to the right, and the reverse opening of the second hydraulically controlled one-way valve 11-2 causes the two-position four-way hydraulic reversing valve 7 to work in the right position. The pressure of the right control oil port of the hydraulic reversing valve 6 is unloaded, while the pressure of the left control oil port is limited by the opening pressure of the first back pressure valve 10-1; therefore, after the two-position four-way hydraulic reversing valve 6 is switched, the pressure of the left control oil port is always greater than the pressure of the right control oil port, until the left end face of the piston of the cylinder 8 moves to a position exceeding K3, and then the pressure of the right control oil port of the two-position four-way hydraulic reversing valve 6 becomes greater than the pressure of the left control oil port, thereby causing the cylinder 8 to switch to move to the left.

[0027] The above is only a preferred specific embodiment of the present invention. Of course, the present invention may also have other various embodiments. Without departing from the spirit and essence of the present invention, any technician familiar with the technical field can make various corresponding equivalent changes and deformations according to the present invention, which should all fall within the protection scope of the claims attached to the present invention.

Claims

1. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder, characterized in that: The invention comprises an oil pump (1), an outlet filter (2), a relief valve (3), a pressure reducing valve (4), a check valve (5), a two-position four-way hydraulic reversing valve (6), a three-position four-way hydraulic reversing valve (7), an oil cylinder (8), a first cartridge valve (9-1), a second cartridge valve (9-2), a first back pressure valve (10-1), a second back pressure valve (10-2), a first hydraulically controlled check valve (11-1), a second hydraulically controlled check valve (11-2), a cooler (12), an oil return filter (13) and an oil tank (14).

2. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 1, characterized in that: The oil cylinder (8) has a total of 6 oil ports. In addition to the 2 main oil ports, on the side opposite to the main oil ports, 2 small holes with a diameter of 2 mm are opened at the left and right ends of the piston stroke, respectively, from left to right, namely port K1, port K2, port K3 and port K4, wherein port K1 and port K4 are respectively close to the left and right cylinder heads. The center distance between port K2 and port K1 is 10 mm larger than the length of the piston. The center distance between port K3 and port K4 is 10 mm larger than the length of the piston. The center distance between port K2 and port K3 is equal to the required working stroke of the piston.

3. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 2, characterized in that: The oil pump (1) has a suction port and an oil drain port connected to an oil tank (14) respectively, and an oil outlet connected to an inlet of an outlet filter (2); The outlet of the outlet filter (2) is connected to the inlets of the overflow valve (3), the pressure reducing valve (4) and the check valve (5) respectively; the outlet of the overflow valve is connected to the inlet of the cooler (12); the outlet of the pressure reducing valve (4) is connected to the P port of the two-position four-way hydraulic reversing valve (6); its oil drain port is separately connected to the oil tank (14); and the outlet of the check valve (5) is connected to the P port of the three-position four-way hydraulic reversing valve (7); The T port of the two-position four-way hydraulic reversing valve (6) is connected to the inlet of the cooler (12), and the A port and the B port thereof are respectively connected to the left and right hydraulic control ports of the three-position four-way hydraulic reversing valve (7), and the left and right hydraulic control ports of the two-position four-way hydraulic reversing valve (6) are respectively connected to the inlets of the first back-pressure valve (10-1) and the second back-pressure valve (10-2); The A and B ports of the three-position four-way hydraulic reversing valve (7) are respectively connected to the left and right main oil ports of the oil cylinder (8), the T port thereof is connected to the inlet of the cooler (12), and the left and right hydraulic control ports are also respectively connected to the K ports of the first hydraulically controlled check valve (11-1) and the second hydraulically controlled check valve (11-2); The left and right main oil ports of the oil cylinder (8) are also respectively connected to the outlets of the second back pressure valve (10-2) and the first back pressure valve (10-1); the K1 port and K2 port of the oil cylinder (8) are respectively connected to the X port and the A port of the first cartridge valve (9-1); and the K3 port and K4 port are respectively connected to the A port and the X port of the second cartridge valve (9-2); The B port of the first cartridge valve (9-1) is connected to the inlet of the first back pressure valve (10-1), and the B port of the second cartridge valve (9-2) is connected to the inlet of the second back pressure valve (10-2); The B port of the first hydraulically controlled one-way valve (11-1) is connected to the inlet of the first back-pressure valve (10-1), and the A port is connected to the inlet of the cooler (12); the B port of the second hydraulically controlled one-way valve (11-2) is connected to the inlet of the second back-pressure valve (10-2), and the A port is connected to the inlet of the cooler (12); The outlet of the cooler (12) is connected to the inlet of the oil return filter (13), and the outlet of the oil return filter (13) is connected to the oil tank (14).

4. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The pressure reducing valve (4) is a pilot-operated pressure reducing valve, and the set pressure is not less than the pressure required for the switching of the three-position four-way hydraulic reversing valve (7).

5. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The opening pressure of the one-way valve (5) is not less than the pressure required for the switching of the three-position four-way hydraulic reversing valve (7).

6. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The control oil ports at both ends of the two-position four-way hydraulic reversing valve (6) are provided with damping holes with a diameter of 0.7 mm.

7. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The middle position function of the three-position four-way hydraulic reversing valve (7) is an H-type function.

8. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The first hydraulically controlled one-way valve (11-1) and the second hydraulically controlled one-way valve (11-2) are both of internal leakage type, and their reverse opening pressures are equal and both are less than the set pressure of the pressure reducing valve (4); and the B ports of the first hydraulically controlled one-way valve (11-1) and the second hydraulically controlled one-way valve (11-2) are both provided with a damping hole with a diameter of 0.7 mm.

9. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The connection type of the left oil ports of the two-position four-way hydraulic reversing valve (6) is the same as the connection type of the left oil ports of the three-position four-way hydraulic reversing valve (7), and the connection type of the right oil ports of the two-position four-way hydraulic reversing valve (6) is the same as the connection type of the right oil ports of the three-position four-way hydraulic reversing valve (7).

10. A fully hydraulically controlled hydraulic system for controlling the automatic reciprocation of an oil cylinder according to claim 3, characterized in that: The first back-pressure valve (10-1) and the second back-pressure valve (10-2) are both composed of one-way valves, and the opening pressures of the two are equal, both set to 5 bar, and the cooler (12) is a water-cooled type.

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