A hydraulic push rod oil feeding hard pipe

Abstract

The utility model provides a kind of oil feeding hard pipe for hydraulic push rod, including oil feeding hard pipe main body, hard pipe joint, oil feeding inner fin, detection coating and protective coating, the both ends of the oil feeding hard pipe main body are respectively installed with the hard pipe joint, the inner wall of the oil feeding hard pipe main body is provided with the oil feeding inner fin, the outer surface of the oil feeding hard pipe main body is sequentially provided with the detection coating and protective coating;The spiral inner fin of the oil feeding hard pipe inner wall can guide oil orderly spiral flow to reduce resistance and speed up, and also can be inner wall reinforcing rib to improve radial rigidity;The oil-soluble rare earth fluorescent agent is contained in the outer surface detection coating, and the oil liquid with fluorescent agent can be quickly positioned when the hard pipe cracks, and the antioxidant keeps it stable, realizes early warning and does not need to stop.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic oil delivery rigid pipe technology, and particularly relates to a hydraulic oil delivery rigid pipe for hydraulic push rods. Background Technology

[0002] Hydraulic actuators, as core components in engineering machinery, mining equipment, and automated production lines, rely directly on the oil transmission efficiency and structural reliability of the hydraulic delivery pipe for operational stability. As a critical channel for high-pressure oil in hydraulic systems, the hydraulic delivery pipe must simultaneously meet four core requirements: low flow resistance transmission, high structural rigidity, easy fault detection, and strong environmental weather resistance. However, existing technologies still suffer from the following shortcomings that urgently need to be addressed: The imbalance between flow field and stiffness is a common problem in traditional hydraulic push rods. The hydraulic push rods often use smooth inner walls for their oil delivery tubes. To improve radial stiffness, the tube wall thickness needs to be increased, which leads to an increase in the weight of the tube and an increase in the resistance to oil flow. This results in a lag in the extension and retraction response of the hydraulic push rod. Although some improved solutions add circumferential inner fins to enhance stiffness, the fin structure disrupts the axial flow field of the oil and easily generates radial vortices, which in turn exacerbates pressure loss. This makes it impossible to meet the dual requirements of "low flow resistance" and "high stiffness".

[0003] Delayed fault detection and high maintenance costs are common problems with hydraulic push rods. Cracks and leaks in the oil delivery pipe (initial oil leakage <0.1mL / min) are common faults. Existing detection methods mainly rely on ultrasonic testing or shutdown pressure holding tests: the former requires specialized equipment and personnel and has low detection efficiency (testing a single pipe takes ≥30 minutes); the latter requires stopping the equipment and can only detect cracks that have already caused obvious leaks, which cannot achieve "early warning" and leads to the expansion of the fault (such as oil contamination of equipment, insufficient system pressure).

[0004] Therefore, it is essential to invent a hydraulic push rod with a rigid oil delivery tube. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a hydraulic push rod oil delivery rigid pipe, including an oil delivery rigid pipe body, a rigid pipe joint, an oil delivery inner fin, a detection coating and a protective coating. The rigid pipe joint is installed at both ends of the oil delivery rigid pipe body, the oil delivery inner fin is provided on the inner wall of the oil delivery rigid pipe body, and the detection coating and the protective coating are sequentially provided on the outer surface of the oil delivery rigid pipe body.

[0006] Preferably, the oil delivery inner fins inside the main body of the oil delivery rigid pipe are spiral fin structures, and the path of the oil delivery inner fins is the same as the path of the main body of the oil delivery rigid pipe.

[0007] Preferably, the root corner of the inner fin for oil delivery is connected to the main body of the rigid oil delivery pipe with a rounded corner, the height of the inner fin for oil delivery is less than 0.3 mm, the helix angle is less than 45 degrees, and the surface of the inner fin for oil delivery is coated with a PTFE coating to form a low-viscosity surface.

[0008] Preferably, the detection coating on the outer surface of the oil delivery rigid pipe body is an oil-soluble rare earth fluorescent agent layer, forming a detection surface, and a hindered amine antioxidant is added, and a protective coating is formed on the detection coating.

[0009] Preferably, the protective coating is formed using an elastic zinc-based anti-corrosion coating to create the protective surface.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The inner wall of the main body of the oil delivery rigid pipe of this utility model adopts a spiral structure of oil delivery inner fins, and the fin path is consistent with the path of the main body of the rigid pipe: on the one hand, the spiral fins can guide the oil to form an orderly spiral flow along the axial direction, reduce the generation of radial eddies, and combined with the parameter optimization of "height < 0.3mm, spiral angle < 45°", reduce pressure loss and shorten the response time of hydraulic push rod extension and retraction; on the other hand, the spiral fins are equivalent to the inner wall reinforcing ribs, and with the "root rounded transition" design (stress concentration factor reduced to below 1.4), the radial stiffness is improved under the same pipe wall thickness.

[0011] The detection coating on the outer surface of the main body of the oil delivery tube of this utility model uses an oil-soluble rare earth fluorescent agent and adds a hindered amine antioxidant. When a crack appears in the tube, the oil penetrates and exposes the fluorescent agent. Under 365nm ultraviolet light irradiation, it can be quickly located by the naked eye within 2m, which improves the detection efficiency and does not require shutdown. The hindered amine antioxidant can ensure that the fluorescent agent is stable for a long time in the range of -40℃ to 180℃, avoid high temperature failure, realize the fault detection closed loop of "early warning-rapid location", and reduce the maintenance cost caused by the expansion of faults. Attached Figure Description

[0012] Figure 1 This is a partial cross-sectional structural diagram of the present invention.

[0013] Figure 2 This is a half-sectional structural diagram of the present invention.

[0014] In the picture: 1. Main body of the oil delivery rigid pipe; 2. Rigid pipe connector; 3. Inner fins for oil delivery; 4. Detection coating; 5. Protective coating. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0016] In the description of the embodiments, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model based on the specific circumstances.

[0017] As attached Figure 1 To be continued Figure 2 As shown: This utility model provides a hydraulic push rod oil delivery rigid pipe, including an oil delivery rigid pipe body 1, a rigid pipe connector 2, an oil delivery inner fin 3, a detection coating 4, and a protective coating 5. The rigid pipe connector 2 is respectively installed at both ends of the oil delivery rigid pipe body 1, the oil delivery inner fin 3 is provided on the inner wall of the oil delivery rigid pipe body 1, and the detection coating 4 and the protective coating 5 are sequentially provided on the outer surface of the oil delivery rigid pipe body 1.

[0018] Furthermore, the oil delivery inner fin 3 inside the oil delivery rigid pipe body 1 is a spiral fin structure. The oil delivery inner fin 3 and the oil delivery rigid pipe body 1 are manufactured using a cold-drawing integrated forming process, and the materials of the two are consistent. The spiral path of the oil delivery inner fin 3 is completely coincident with the axial path of the oil delivery rigid pipe body 1, that is, the center line of the spiral fin is collinear with the pipe axis of the oil delivery rigid pipe body 1, and the lead of the spiral fin is set to 5-8 times the outer diameter of the oil delivery rigid pipe body 1 (for example, when the outer diameter of the oil delivery rigid pipe body 1 is 18mm, the lead is 90-144mm), so as to adapt to the axial transmission direction of the oil in the oil delivery rigid pipe body 1, avoid the generation of radial eddies in the oil due to path deviation, and ensure the stability of oil flow. At the same time, the spiral structure can form a continuous flow channel with the inner wall of the oil delivery rigid pipe body 1, reducing local pressure loss during oil transmission.

[0019] Furthermore, the connection between the root corner of the inner fin 3 and the inner wall of the main body 1 of the oil delivery pipe adopts an arc transition design, forming a rounded corner with a radius R ≥ 0.2 mm. This rounded corner is formed by electrolytic polishing, which can reduce the stress concentration factor at the root of the inner fin 3 from 3.2 in the traditional right-angle transition to below 1.4, effectively improving the fatigue resistance of the inner fin 3 under high-pressure cycling conditions. The height of the inner fin 3 is set to 0.1-0.25 mm (less than 0.3 mm). This height range can ensure that the radial stiffness of the main body 1 of the oil delivery pipe is increased by 30%-40% while avoiding the increase in oil flow resistance due to excessive fin height. The helix angle of the inner fin 3 is set to... The angle range of 30-42° (less than 45°) can guide the oil to form an orderly spiral flow, reduce turbulence, and coordinate with the height parameters of the inner fin 3 to ensure that the oil pressure loss is controlled within 8%-12%. In addition, the surface of the inner fin 3 is coated with a PTFE (polytetrafluoroethylene) coating with a thickness of 5-8μm through plasma spraying. The adhesion between this coating and the surface of the inner fin 3 is ≥5MPa, forming a low-viscosity surface with a roughness Ra≤0.6μm. This can significantly reduce the adhesion of contaminants such as metal debris and sludge to the fin surface, reducing the amount of contaminants by more than 60%, while improving the smoothness of oil transmission and reducing wear on the fin surface.

[0020] Furthermore, the detection coating 4 on the outer surface of the oil delivery rigid pipe body 1 is an oil-soluble rare earth fluorescent agent layer. This coating uses Eu³+ doped aluminate as the core fluorescent material (fluorescence excitation wavelength of 365nm, emission wavelength of 615nm, and visible distance ≥2m), supplemented with 5-10wt% dioctyl phthalate as a plasticizer. It is uniformly coated on the outer surface of the oil delivery rigid pipe body 1 using an electrostatic spraying process, with the coating thickness controlled at 10-15μm, forming a complete and continuous detection surface. To improve the temperature stability and anti-aging performance of the fluorescent agent, 0.5-1.0wt% hindered amine antioxidant is also added to the detection coating 4. An oxygenating agent (preferably Tinuvin 770) can extend the half-life of the fluorescent agent to more than 5 years in the temperature range of -40℃ to 180℃, avoiding fluorescence failure due to high temperature or oxidation; the adhesion between the detection coating 4 and the outer surface of the oil delivery hard pipe body 1 is ≥4MPa, and it completely covers the outer surface of the oil delivery hard pipe body 1 (including the transition area near the hard pipe joints at both ends), without any missing coating or pinhole defects; a protective coating 5 is also formed on the detection coating 4, the detection coating 4 provides a uniform and flat substrate for the protective coating 5, and there is no chemical reaction between the two, ensuring that the fluorescent performance of the detection coating 4 is not affected after the protective coating 5 is formed.

[0021] Furthermore, the protective coating 5 is formed by applying an elastic zinc-based anti-corrosion coating. This coating uses 60-70 wt% ultrafine zinc powder (particle size 5-10 μm) as the anti-corrosion functional component, 20-25 wt% elastic polyurethane resin as the film-forming agent, and 5-10 wt% xylene as a diluent. It is uniformly coated onto the outer surface of the test coating 4 using a roller coating process, with a coating thickness of 20-30 μm, forming a complete protective surface. The protective coating 5 has excellent elasticity and adhesion properties, with an elongation of ≥18%, which can adapt to the slight deformation of the oil-lubricated hard pipe body 1 under vibration conditions (amplitude ≤1.0 mm), preventing the coating from opening. The protective coating 5 is not cracked or peeled off, and the adhesion between the protective coating 5 and the test coating 4 is ≥3MPa. The transition area between the protective coating 5 and the hard pipe joints (not shown) at both ends of the oil delivery hard pipe body 1 is treated with rounded corner coating to ensure no coating breaks. In addition, the protective coating 5 has excellent anti-corrosion performance. After testing with a neutral salt spray test (5% NaCl solution, 35℃), it showed no rust or blistering within 48 hours, which is more than twice the anti-corrosion time of traditional galvanized coatings. It can effectively isolate the contact between external moisture, dust and corrosive media and the test coating 4, protect the fluorescent agent of the test coating 4 from premature failure, and provide additional anti-corrosion protection for the oil delivery hard pipe body 1.

[0022] The working principle is as follows: First, the high-pressure oil in the hydraulic system enters the main body of the oil delivery hard pipe 1 through the hard pipe joint 2, and is transmitted along the internal channel of the oil delivery hard pipe 1 to provide power medium for the hydraulic push rod.

[0023] The spiral structure of the inner fin 3 of the oil delivery system plays a guiding role in the oil transmission process, guiding the oil to form an orderly spiral flow state, reducing radial turbulence and eddies in the main body 1 of the oil delivery pipe, making the oil flow more stably along the axial direction, and improving the transmission efficiency.

[0024] The PTFE low-viscosity coating on the surface of the oil delivery inner fin 3 reduces the frictional resistance between the oil and the fin surface, while also reducing the adhesion of contaminants such as metal debris and sludge to the fin surface, keeping the internal channels of the oil delivery hard pipe body 1 clean, and preventing contaminants from entering the hydraulic push rod with the oil and affecting its operation.

[0025] When the main body 1 of the oil delivery rigid pipe is working normally, the protective coating 5 covers the outside of the detection coating 4, isolating the external moisture, dust and corrosive media from contact with the detection coating 4, protecting the fluorescent agent in the detection coating 4 from premature destruction, and at the same time providing anti-corrosion protection for the main body 1 of the oil delivery rigid pipe to resist external environmental erosion.

[0026] When a crack appears in the main body 1 of the oil delivery pipe, the high-pressure oil will penetrate through the crack to the outer surface, exposing the oil-soluble rare earth fluorescent agent in the detection coating 4 along with the oil. Under ultraviolet light, it will emit identifiable fluorescence, thus visually displaying the location of the crack and enabling rapid detection and location of the fault.

[0027] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. A hydraulic push rod oil delivery rigid pipe, characterized in that, It includes an oil delivery hard pipe body (1), a hard pipe connector (2), an oil delivery inner fin (3), a detection coating (4), and a protective coating (5). The hard pipe connector (2) is installed at both ends of the oil delivery hard pipe body (1). The oil delivery inner fin (3) is provided on the inner wall of the oil delivery hard pipe body (1). The detection coating (4) and the protective coating (5) are sequentially provided on the outer surface of the oil delivery hard pipe body (1).

2. The hydraulic push rod oil delivery rigid pipe as described in claim 1, characterized in that: The oil delivery inner fin (3) inside the oil delivery hard pipe body (1) is a spiral fin structure, and the path of the oil delivery inner fin (3) is the same as that of the oil delivery hard pipe body (1).

3. The hydraulic push rod oil delivery rigid pipe as described in claim 2, characterized in that: The root corner of the inner fin (3) of the oil delivery is connected to the main body (1) of the oil delivery hard pipe with a rounded corner. The height of the inner fin (3) of the oil delivery is less than 0.3 mm and the helical angle is less than 45 degrees. The surface of the inner fin (3) of the oil delivery is formed by coating with PTFE to form a low-viscosity surface.

4. The hydraulic push rod oil delivery rigid pipe as described in claim 3, characterized in that: The detection coating (4) on the outer surface of the main body (1) of the oil delivery pipe is an oil-soluble rare earth fluorescent agent layer, forming a detection surface, and a hindered amine antioxidant is added. A protective coating (5) is formed on the detection coating (4).

5. The hydraulic push rod oil delivery rigid pipe as described in claim 4, characterized in that: The protective coating (5) is formed by using an elastic zinc-based anti-corrosion coating to form a protective surface.

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