Hydraulic system for forming end part of non-welding pipeline

Abstract

The utility model discloses an end portion forming hydraulic system of a non-welding pipeline, which comprises a two-stage oil cylinder, a second-stage piston is movably arranged in a cylinder body of the two-stage oil cylinder, a piston rod of the second-stage piston is movably connected with a first-stage piston, and a piston rod of the first-stage piston is movably sleeved on the piston rod of the second-stage piston. A piston rod of the I-stage piston is connected with the clamping die; a piston rod of the II-stage piston is connected with the forming die; a first cavity of the two-stage oil cylinder is communicated with the second end of the supercharger, the first end of the supercharger is connected with the second end of the single-phase sequence valve, and the first end of the single-phase sequence valve is connected with the first end of the M-type three-position four-way electromagnetic reversing valve. The oil return end of the supercharger is connected with the input end of the two-position electromagnetic one-way valve. According to the utility model, clamping and forming actions can be realized through a set of hydraulic mechanism, so that the operation steps are simplified, and the requirements on workers are reduced.

Description

Technical Field

[0001] This utility model relates to a hydraulic control system for marine machining equipment, specifically to a hydraulic system for end forming of non-welded pipes. Background Technology

[0002] Currently, welding is the most common method for connecting pipelines. The advantages of welding are high reliability and long service life. However, welding involves numerous procedures and strict requirements. Connecting pipelines made of special materials requires specialized equipment and auxiliary materials. Furthermore, welding is inefficient, consumes a lot of energy, generates significant pollution, poses numerous safety hazards, and can harm human health. These drawbacks mean that welding is no longer adequate for the demands of modern society, especially given the growing international emphasis on human health and safety, environmental protection, and energy conservation.

[0003] Developing non-welding connection methods for pipe connections is a continuous area of ​​research and development within the industry. One common non-welding pipe connection method utilizes pipe end forming connections; specifically, for example... Figure 1 As shown, a shoulder is formed at the end of the pipe to be connected; the distance between the shoulder and the pipe end is H; the shoulder is composed of a first shoulder cone surface a and a second shoulder cone surface b arranged opposite to each other; since the local strength of the shoulder is higher than that of the pipe, the connection is very reliable and has good vibration and impact resistance, and will not be pulled out even in the extreme case of pipe burst.

[0004] Currently, the shoulder forming method for pipe ends can employ electric, pneumatic, hydraulic, or hybrid drive methods. Electric and pneumatic power units are suitable for non-ferrous metal pipes with smaller diameters and thinner walls; for large-diameter pipes with wall thicknesses of 1mm or more and diameters of 5mm or more, hydraulic power units are typically used. However, existing hydraulic power units require separate operation of two hydraulic mechanisms for clamping and forming the shoulder during the shoulder forming process. A reset operation is required after each forming, resulting in numerous control buttons and complex operation steps, placing high demands on operators. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a hydraulic system for end forming of non-welded pipes, which can realize clamping and forming actions through a set of hydraulic mechanisms, thereby simplifying the operation steps and reducing the requirements for workers.

[0006] To solve the above-mentioned technical problems, the technical solution of the non-welded pipe end forming hydraulic system of this utility model is as follows:

[0007] The system includes a two-stage hydraulic cylinder 7. A second-stage piston 72 is movably mounted within the cylinder body of the two-stage hydraulic cylinder 7, forming a first cavity A between the second-stage piston 72 and the cylinder body. The piston rod of the second-stage piston 72 is movably connected to a first-stage piston 71, forming a second cavity B between the first-stage piston 71 and the second-stage piston 72. The piston rod of the first-stage piston 71 is movably sleeved on the piston rod of the second-stage piston 72. A third cavity C is formed between the piston rod of the first-stage piston 71 and the cylinder body. The piston rod of the first-stage piston 71 is connected to a clamping mold, and the piston rod of the second-stage piston 72 is connected to a forming mold. The first cavity A of the two-stage hydraulic cylinder 7 is connected to the second end N2 of a booster 6, and the first end N1 of the booster 6 is connected to the second end of a single-phase sequence valve 5. The first end of the sequence valve 5 is connected to the first end of the M-type three-position four-way solenoid directional valve 1; the return oil end N3 of the booster 6 is connected to the input end of the two-position solenoid check valve 3; the second chamber B of the two-stage cylinder 7 is connected to the second end of the M-type three-position four-way solenoid directional valve 1 through a pipe; the oil inlet P of the M-type three-position four-way solenoid directional valve 1 is connected to the oil inlet of the H-type three-position four-way solenoid directional valve 2; the second chamber B of the two-stage cylinder 7 is connected to the second end of the solenoid sequence valve 4 through a pipe, and the first end of the solenoid sequence valve 4 is connected to the first end of the H-type three-position four-way solenoid directional valve 2; the third chamber C of the two-stage cylinder 7 is connected to the second end of the H-type three-position four-way solenoid directional valve 2 through a pipe.

[0008] In another embodiment, the left side of the M-type three-position four-way solenoid valve 1 is the second electromagnet 7Y2, and the right side is the third electromagnet 7Y3. When not energized, the M-type three-position four-way solenoid valve 1 is in the neutral position, and the M-type three-position four-way solenoid valve 1 is connected to the H-type three-position four-way solenoid valve 2. When the second electromagnet 7Y2 is energized, the left-position valve core of the M-type three-position four-way solenoid valve 1 is activated. When the third electromagnet 7Y3 is energized, the right-position valve core of the M-type three-position four-way solenoid valve 1 is activated.

[0009] In another embodiment, the left side of the H-type three-position four-way solenoid valve 2 is the fifth electromagnet 7Y5, and the right side is the first electromagnet 7Y7; when not energized, the H-type three-position four-way solenoid valve 2 is in the neutral position; when the fifth electromagnet 7Y5 is energized, the right-position valve core of the H-type three-position four-way solenoid valve 2 is activated; when the first electromagnet 7Y7 is energized, the left-position valve core of the H-type three-position four-way solenoid valve 2 is activated.

[0010] In another embodiment, the left side of the two-position electromagnetic check valve 3 is the fourth electromagnet 7Y4; when not energized, the two-position electromagnetic check valve 3 is in the right-hand straight-through position; when the fourth electromagnet 7Y4 is energized, the two-position electromagnetic check valve 3 is in the left-hand cut-off position.

[0011] In another embodiment, the left side of the electromagnetic reversing sequence valve 4 is the sixth electromagnet 7Y6; when not energized, the electromagnetic reversing sequence valve 4 reverses the flow of oil; when the sixth electromagnet 7Y6 is energized, the electromagnetic reversing sequence valve 4 is in the straight-through position, and the electromagnetic reversing sequence valve 4 connects the second chamber B of the two-stage oil cylinder 7 with the H-type three-position four-way electromagnetic reversing valve 2.

[0012] In another embodiment, the oil inlet P and oil return T1 of the M-type three-position four-way solenoid directional valve 1 are respectively connected to the pump station oil tank.

[0013] In another embodiment, the return port T2 of the H-type three-position four-way solenoid directional valve 2 is connected to the pump station oil tank.

[0014] In another embodiment, the oil return port T1 of the two-position electromagnetic check valve 3 is connected to the oil return port of the oil tank.

[0015] The technical effects that this utility model can achieve are:

[0016] This invention employs a combination of an M-type three-position four-way solenoid directional valve and an H-type three-position four-way solenoid directional valve. The M-type three-position four-way solenoid directional valve has an M-type neutral position function, characterized by rapid stop response and high reliability. The H-type three-position four-way solenoid directional valve has an H-type neutral position function, characterized by smooth switching and minimal impact. Therefore, this invention combines the advantages of both: rapid stop response, high reliability, smooth switching, and significantly improved lifespan under impact.

[0017] This invention can set a molding pressure of up to 800 bar through a booster, thereby providing high-pressure power to achieve reliable clamping and molding.

[0018] This invention uses an electromagnetic reversing sequence valve and a single-phase sequence valve to set the back pressure value, which can increase system damping, reduce system impact, and improve stability.

[0019] The piston rods of the first-stage piston and the second-stage piston of this invention can move independently or simultaneously. This invention can complete both clamping and forming actions using a single hydraulic cylinder, significantly reducing the size of the equipment.

[0020] This invention, through the design of the hydraulic circuit, enables precise clamping and resetting of the first-stage piston, as well as forming and resetting of the second-stage piston. By utilizing two-stage cylinders and solenoid valves, this invention allows for immediate resetting after forming, simplifying operation, providing a user-friendly interface, and enabling one-button forming.

[0021] This invention controls the extension and retraction of two-stage pistons by controlling whether each solenoid valve is energized or not. The operation process is simple and it is suitable for carbon steel or stainless steel pipes with an outer diameter of 6-42mm and a wall thickness of 1-7mm. The maximum working pressure can reach 800bar. Attached Figure Description

[0022] Those skilled in the art will understand that the following description is merely illustrative of the principles of this invention, and these principles can be applied in various ways to achieve many different alternative implementations. These descriptions are only intended to illustrate the general principles of the teachings of this invention and are not intended to limit the inventive concept disclosed herein.

[0023] Embodiments of the present invention are illustrated in conjunction with the accompanying drawings, which are incorporated in and form part of this specification, and together with the foregoing general description and the following detailed description of the drawings, serve to explain the principles of the present invention.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] Figure 1 This is a schematic diagram of the end of a pipe with a shoulder.

[0026] Figure 2 This is a schematic diagram of the hydraulic system for end forming of the non-welded pipe of this utility model.

[0027] Explanation of the reference numerals in the figure:

[0028] 1 is a type M three-position four-way solenoid directional valve; 2 is a type H three-position four-way solenoid directional valve.

[0029] 3 is a two-position solenoid check valve, and 4 is a solenoid reversing sequence valve.

[0030] 5 is a single-phase sequence valve, and 6 is a booster.

[0031] 7 is a two-stage hydraulic cylinder.

[0032] 71 is a Class I piston, and 72 is a Class II piston. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "first," "second," and similar words used herein do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Words such as "comprising" mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects. Words such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0034] like Figure 2 As shown, the hydraulic system for end forming of non-welded pipes of this utility model includes two-stage cylinders 7. A second-stage piston 72 is movably disposed inside the cylinder of the two-stage cylinder 7, forming a first cavity A between the second-stage piston 72 and the cylinder body. The piston rod of the second-stage piston 72 is movably connected to a first-stage piston 71, forming a second cavity B between the first-stage piston 71 and the second-stage piston 72. The piston rod of the first-stage piston 71 is movably sleeved on the piston rod of the second-stage piston 72. A third cavity C is formed between the piston rod of the first-stage piston 71 and the cylinder body.

[0035] The piston rod of the first-stage piston 71 is connected to the clamping mold, which is used to clamp the steel pipe. When the piston rod of the first-stage piston 71 extends into place, the piston rod of the first-stage piston 71 drives the clamping mold to clamp the steel pipe into place.

[0036] The piston rod of the stage II piston 72 is connected to the forming mold, which is used to form the steel pipe; when the piston rod of the stage II piston 72 extends to the position, the piston rod of the stage II piston 72 drives the forming mold to form the steel pipe into position;

[0037] The first chamber A of the two-stage hydraulic cylinder 7 is connected to the second end N2 of the booster 6. The first end N1 of the booster 6 is connected to the second end of the single-phase sequence valve 5. The first end of the single-phase sequence valve 5 is connected to the first end of the M-type three-position four-way solenoid directional valve 1.

[0038] The return oil end N3 of the turbocharger 6 is connected to the input end of the two-position solenoid check valve 3; the return oil port T1 of the two-position solenoid check valve 3 is connected to the return oil port of the oil tank.

[0039] Specifically, the left side of the two-position solenoid check valve 3 is equipped with a 7Y4 electromagnet; when de-energized, the two-position solenoid check valve 3 is in the right-hand straight-through position, at which time the oil in the first chamber A can flow back to the pump station oil tank through the booster 6 and the return port T1 of the two-position solenoid check valve 3; when the 7Y4 electromagnet is energized, the two-position solenoid check valve 3 is in the left-hand cut-off position, at which time the oil cannot pass through; the pump station is used to provide pressurized oil for this hydraulic system;

[0040] The second end of the M-type three-position four-way solenoid directional valve 1 is connected to the second chamber B of the two-stage hydraulic cylinder 7 via a pipeline.

[0041] The oil inlet P and oil return T1 of the M-type three-position four-way solenoid directional valve 1 are respectively connected to the pump station oil tank.

[0042] The oil inlet P of the M-type three-position four-way solenoid valve 1 is connected to the oil inlet of the H-type three-position four-way solenoid valve 2.

[0043] Specifically, the left side of the M-type three-position four-way solenoid directional valve 1 is equipped with a 7Y2 electromagnet, and the right side is equipped with a 7Y3 electromagnet. When not energized, the M-type three-position four-way solenoid directional valve 1 is in the neutral position. Since it is in the M-type neutral position, the oil from the oil inlet P flows through the M-type three-position four-way solenoid directional valve 1 to the H-type three-position four-way solenoid directional valve 2. When the 7Y2 electromagnet is energized, the left valve core of the M-type three-position four-way solenoid directional valve 1 is activated. At this time, the oil passes through the single-phase sequence valve 5 and the booster 6 in sequence and enters the A chamber of the two-stage cylinder 7. When the 7Y3 electromagnet is energized, the right valve core of the M-type three-position four-way solenoid directional valve 1 is activated, and the oil enters the B chamber of the two-stage cylinder 7.

[0044] The second chamber B of the two-stage cylinder 7 is connected to the second end of the electromagnetic reversing sequence valve 4 through a pipeline. The first end of the electromagnetic reversing sequence valve 4 is connected to the first end of the H-type three-position four-way electromagnetic reversing valve 2. The second end of the H-type three-position four-way electromagnetic reversing valve 2 is connected to the third chamber C of the two-stage cylinder 7 through a connecting hose 8. The return port T2 of the H-type three-position four-way electromagnetic reversing valve 2 is connected to the pump station oil tank.

[0045] Specifically, the left side of the H-type three-position four-way solenoid directional valve 2 is equipped with a 7Y5 solenoid, and the right side with a 7Y7 solenoid. When not energized, the H-type three-position four-way solenoid directional valve 2 is in the neutral position. Since it is in the H-type neutral position, the H-type three-position four-way solenoid directional valve 2 does not work, and the oil returns to the pump station oil tank through the return port T2. When the 7Y5 solenoid is energized, the right valve core of the H-type three-position four-way solenoid directional valve 2 works, and the oil enters the C chamber of the two-stage cylinder 7. When the 7Y7 solenoid is energized, the left valve core of the H-type three-position four-way solenoid directional valve 2 works, and the oil enters the B chamber of the two-stage cylinder 7 through the solenoid directional sequence valve 4.

[0046] The left side of the electromagnetic reversing sequence valve 4 is equipped with a 7Y6 electromagnet; when no power is supplied, the electromagnetic reversing sequence valve 4 can only reverse (i.e., Figure 1 The oil flows downwards; a back pressure value (e.g., 150 bar) is set to prevent the oil pressure in chamber B of the two-stage cylinder 7 from exceeding this back pressure value. Therefore, the electromagnetic reversing sequence valve 4 can act as a safety valve. When the 7Y6 electromagnet is energized, the electromagnetic reversing sequence valve 4 is in the straight-through position. The electromagnetic reversing sequence valve 4 connects chamber B of the two-stage cylinder 7 to the H-type three-position four-way electromagnetic reversing valve 2. At this time, the oil can flow straight through without resistance.

[0047] When the oil is in the forward direction ( Figure 1 When the oil flows in the upward direction (as described in the original text), the single-phase sequence valve 5 operates, allowing the oil to flow unimpeded through the valve to the booster 6. The booster 6 amplifies the working pressure, increasing the pressure provided by the pump station from 175 bar to 800 bar. When the oil flows in the reverse direction (i.e., when the oil flows in the upward direction), the single-phase sequence valve 5 operates, allowing the oil to flow unimpeded through the valve to the booster 6. Figure 1 When the flow is in the downward direction, the sequence valve on the right side of the electromagnetic reversing sequence valve 4 is in the working position; the reverse working pressure value of the electromagnetic reversing sequence valve 4 is set (e.g., 20 bar). This back pressure setting value serves as a reverse flow damping, which can reduce the impact of the stage II piston 72 resetting.

[0048] The working principle of this utility model is as follows:

[0049] Piston rod reset control of two-stage hydraulic cylinder 7:

[0050] Power is supplied to the 7Y7 electromagnet of the H-type three-position four-way solenoid valve 2, and the right-position valve core of the H-type three-position four-way solenoid valve 2 is activated, so that the pressure value of the C-chamber system reaches the pressure value of 175 bar set by the pump station.

[0051] Then, power is simultaneously supplied to the 7Y7 solenoid of the H-type three-position four-way solenoid directional valve 2, the 7Y4 solenoid of the two-position solenoid check valve 3, and the 7Y3 solenoid of the M-type three-position four-way solenoid directional valve 1, so that the pressure of the B chamber system is smoothly converted to the II-stage piston 72 retraction preparation state.

[0052] Then, power continues to be supplied to the 7Y4 electromagnet of the two-position solenoid check valve 3 and the 7Y3 electromagnet of the M-type three-position four-way solenoid directional valve 1, so that the two-position solenoid check valve 3 is in the cut-off position, the oil circuit is blocked, and the right valve core of the M-type three-position four-way solenoid directional valve 1 is activated, so that the oil enters the B chamber of the two-stage cylinder 7; so that the second-stage piston 72 of the two-stage cylinder 7 retracts to the left end until it contacts the inner side of the cylinder, and the first-stage piston 71 of the two-stage cylinder 7 retracts to the right end.

[0053] Then, power is simultaneously supplied to the 7Y5 electromagnet of the H-type three-position four-way solenoid directional valve 2 and the 7Y6 electromagnet of the solenoid directional sequence valve 4. At this time, the right-position valve core of the H-type three-position four-way solenoid directional valve 2 is activated, allowing the oil to enter the C chamber of the two-stage cylinder 7 through the H-type three-position four-way solenoid directional valve 2. At the same time, the oil in the B chamber returns to the pump station oil tank through the solenoid directional sequence valve 4 and the H-type three-position four-way solenoid directional valve 2, causing the I-stage piston 71 of the two-stage cylinder 7 to retract to the left end and contact the II-stage piston 72.

[0054] At this point, the first-stage piston 71 and the second-stage piston 72 of the two-stage hydraulic cylinder 7 have completed their reset, preparing for molding.

[0055] Piston rod forming operation control of two-stage hydraulic cylinder 7:

[0056] Power is supplied to the 7Y2 electromagnet of the M-type three-position four-way solenoid directional valve 1, and the left-position valve core of the M-type three-position four-way solenoid directional valve 1 is activated. At this time, the oil flows through the M-type three-position four-way solenoid directional valve 1, the single-phase sequence valve 5, and the booster 6 in sequence, and enters the A chamber of the two-stage cylinder 7, causing the first-stage piston 71 and the second-stage piston 72 of the two-stage cylinder 7 to extend simultaneously. The oil in the C chamber returns to the pump station oil tank through the H-type three-position four-way solenoid directional valve 2, so that the first-stage piston 71 is clamped in place.

[0057] At the same time, power is supplied to the 7Y2 electromagnet of the M-type three-position four-way solenoid directional valve 1 and the 7Y6 electromagnet of the solenoid directional sequence valve 4, and the stage II piston 72 continues to extend. The oil in chamber B returns to the pump station oil tank through the solenoid directional sequence valve 4 and the H-type three-position four-way solenoid directional valve 2, so that the stage II piston 72 is formed in place.

[0058] The 7Y6 electromagnet of the electromagnetic reversing sequence valve 4 and the 7Y2 electromagnet of the M-type three-position four-way electromagnetic reversing valve 1 are de-energized in sequence, so that the A, B and C chambers of the two-stage hydraulic cylinder 7 are in damping protection, protecting the quality of the formed structure and avoiding impact.

[0059] Then perform a reset operation:

[0060] Power is supplied to the 7Y2 electromagnet of the M-type three-position four-way solenoid directional valve 1 to keep the stage I piston 71 in a clamped state.

[0061] Power is supplied to the 7Y7 electromagnet of the H-type three-position four-way solenoid valve 2, and the right-position valve core of the H-type three-position four-way solenoid valve 2 operates to maintain the pressure value of chamber C.

[0062] Then, power is simultaneously supplied to the 7Y7 solenoid of the H-type three-position four-way solenoid directional valve 2, the 7Y4 solenoid of the two-position solenoid check valve 3, and the 7Y3 solenoid of the M-type three-position four-way solenoid directional valve 1, so that the pressure of the B chamber system is smoothly converted to the II-stage piston 72 retraction preparation state.

[0063] Then, power continues to be supplied to the 7Y4 electromagnet of the two-position solenoid check valve 3 and the 7Y3 electromagnet of the M-type three-position four-way solenoid directional valve 1, so that the two-position solenoid check valve 3 is in the cut-off position, the oil circuit is blocked, and the right valve core of the M-type three-position four-way solenoid directional valve 1 is activated, so that the oil enters the B chamber of the two-stage cylinder 7; so that the second-stage piston 72 of the two-stage cylinder 7 retracts to the left end until it contacts the inner side of the cylinder, and the first-stage piston 71 of the two-stage cylinder 7 retracts to the right end.

[0064] Then, power is simultaneously supplied to the 7Y5 electromagnet of the H-type three-position four-way solenoid directional valve 2 and the 7Y6 electromagnet of the solenoid directional sequence valve 4. At this time, the right-position valve core of the H-type three-position four-way solenoid directional valve 2 is activated, allowing the oil to enter the C chamber of the two-stage cylinder 7 through the H-type three-position four-way solenoid directional valve 2. At the same time, the oil in the B chamber returns to the pump station oil tank through the solenoid directional sequence valve 4 and the H-type three-position four-way solenoid directional valve 2, causing the I-stage piston 71 of the two-stage cylinder 7 to retract to the left end and contact the II-stage piston 72.

[0065] At this point, the first-stage piston 71 and the second-stage piston 72 of the two-stage hydraulic cylinder 7 have completed their reset, preparing for the next molding process.

[0066] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A hydraulic system for forming the end of a non-welded pipe, characterized in that, The two-stage oil cylinder comprises a cylinder body, a second-stage piston movably arranged in the cylinder body, a first cavity formed between the second-stage piston and the cylinder body, a first-stage piston movably connected to the piston rod of the second-stage piston, a second cavity formed between the first-stage piston and the second-stage piston, a piston rod of the first-stage piston movably sleeved on the piston rod of the second-stage piston, a third cavity formed between the piston rod of the first-stage piston and the cylinder body, and a piston rod of the first-stage piston connected to a clamping die and a piston rod of the second-stage piston connected to a forming die. The first cavity of the two-stage oil cylinder is connected to the second end of the supercharger, the first end of the supercharger is connected to the second end of the single-phase sequence valve, the first end of the single-phase sequence valve is connected to the first end of the M-type three-position four-way electromagnetic reversing valve, and the oil return end of the supercharger is connected to the input end of the two-position electromagnetic check valve. The second cavity of the two-stage oil cylinder is connected to the second end of the M-type three-position four-way electromagnetic reversing valve through a pipeline, and the oil inlet of the M-type three-position four-way electromagnetic reversing valve is connected to the oil inlet of the H-type three-position four-way electromagnetic reversing valve. The second cavity of the two-stage oil cylinder is connected to the second end of the electromagnetic reversing sequence valve through a pipeline, and the first end of the electromagnetic reversing sequence valve is connected to the first end of the H-type three-position four-way electromagnetic reversing valve. The third cavity of the two-stage oil cylinder is connected to the second end of the H-type three-position four-way electromagnetic reversing valve through a pipeline.

2. The hydraulic non-welded pipe end forming system of claim 1, wherein, The left side of the M-type three-position four-way electromagnetic reversing valve is a second electromagnet, and the right side is a third electromagnet; when no electricity is supplied, the M-type three-position four-way electromagnetic reversing valve is located at a middle position, the M-type three-position four-way electromagnetic reversing valve is connected to the H-type three-position four-way electromagnetic reversing valve; when the second electromagnet is powered on, the left valve core of the M-type three-position four-way electromagnetic reversing valve works; when the third electromagnet is powered on, the right valve core of the M-type three-position four-way electromagnetic reversing valve works.

3. The hydraulic non-welded pipe end forming system of claim 1, wherein, The left side of the H-type three-position four-way electromagnetic reversing valve is a fifth electromagnet, and the right side is a first electromagnet; when no electricity is supplied, the H-type three-position four-way electromagnetic reversing valve is located at a middle position; when the fifth electromagnet is powered on, the right valve core of the H-type three-position four-way electromagnetic reversing valve works; when the first electromagnet is powered on, the left valve core of the H-type three-position four-way electromagnetic reversing valve works.

4. The hydraulic non-welded pipe end forming system of claim 1, wherein, The left side of the two-position electromagnetic check valve is a fourth electromagnet; when no electricity is supplied, the two-position electromagnetic check valve is in a right-position straight-through position; when the fourth electromagnet is powered on, the two-position electromagnetic check valve is in a left-position cut-off position.

5. The hydraulic non-welded pipe end forming system of claim 1, wherein, The left side of the electromagnetic reversing sequence valve is a sixth electromagnet; when no electricity is supplied, the electromagnetic reversing sequence valve reversely passes through oil; when the sixth electromagnet is powered on, the electromagnetic reversing sequence valve is in a straight-through position, and the electromagnetic reversing sequence valve connects the second cavity of the two-stage oil cylinder to the H-type three-position four-way electromagnetic reversing valve.

6. The hydraulic non-welded pipe end forming system of claim 1, wherein, The oil inlet and the oil return port of the M-type three-position four-way electromagnetic reversing valve are respectively connected to a pump station oil tank.

7. The hydraulic non-welded pipe end forming system of claim 1, wherein, The oil return port of the H-type three-position four-way electromagnetic reversing valve is connected to the pump station oil tank.

8. The hydraulic non-welded pipe end forming system of claim 1, wherein, The oil return port of the two-position electromagnetic check valve is connected to an oil tank oil return port.

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