Servo hydraulic cylinder for roughing mill

Abstract

A servo hydraulic cylinder for a roughing mill comprises a cylinder barrel and a piston assembly which can move linearly and is arranged in the cylinder barrel, and is characterized in that an annular cavity is formed in the cylinder barrel in the length direction, the cross section of the annular cavity is in a circular ring shape, and the annular cavity is filled with high-thermal-conductivity gel materials; the outer surface, away from the oil way, of the cylinder barrel is provided with micropores which are formed in the radial direction and can be communicated with the annular inner cavity, the gel material seeps out of the micropores, and a layer of cooling film is formed on the surface of the cylinder barrel. The hydraulic cylinder has the advantages that the micropores are formed in the surface of the cylinder barrel, the annular inner cavity is machined in the inner wall side of the cylinder barrel, the gel material seeps out through the micropores to form a cooling film by means of the characteristics of the gel material, heat can be effectively absorbed and dissipated through the high-temperature-resistant design of the bionic sweat gland, and therefore the stability and high efficiency of the hydraulic cylinder in the high-temperature environment are guaranteed.

Description

Technical Field

[0001] The invention relates to a hydraulic cylinder device, in particular to a servo hydraulic cylinder used for a rough rolling mill. Background Art

[0002] At present, servo hydraulic cylinders are widely used in the adjustment and control of the rolling process of roughing mills. However, traditional servo hydraulic cylinders often have the disadvantages of slow response speed and large friction resistance, and do not consider cooling in high temperature environments, which affects the working efficiency and service life of roughing mills.

[0003] In the prior art, the existing patent number ZL201510040160.3 "A low-friction hydraulic cylinder based on micro-circular pits" discloses a low-friction hydraulic cylinder based on micro-circular pits, wherein the gap between the outer wall of the piston of the hydraulic cylinder and the inner wall of the cylinder barrel of the hydraulic cylinder is δ=10-15 μm. Micro-circular pits are provided on the outer wall of the piston or the inner wall of the cylinder barrel of the hydraulic cylinder, and the micro-circular pits are equally spaced along the axial direction and along the circumferential direction, and the spacing of the micro-circular pits along the axial direction and along the circumferential direction is l=40-60 μm. The micro-circular pits are variable diameter circular micro-pits, and the pit diameter of each micro-circular pit is d=(0.4-0.6)l, and the depth of each micro-circular pit is h=(0.2-0.4)d. The cross-sectional contour line of the circular micro-pit along the radial direction is one of an inverted normal distribution curve, a multi-segment circular arc and a parabola. The hydraulic cylinder is a single-piston rod hydraulic cylinder or a double-piston rod hydraulic cylinder.

[0004] The above patent discloses a low-friction hydraulic cylinder technology based on micro-circular pits, which has the characteristics of low friction, low wear, high dynamic response and low leakage. However, in this patent, both the inner surface of the cylinder barrel and the outer surface of the piston of the hydraulic cylinder need to be processed with micro-circular pits, and a cross-sectional contour design method with complex shapes such as multiple arcs and parabolas is adopted. Although it helps to reduce wear, it requires high processing accuracy and may lead to a significant increase in manufacturing costs. In addition, the micro-circular pits are distributed at equal intervals along the axial direction and along the circumferential direction. This arrangement may cause the accumulation of oil in specific areas and cannot be evenly distributed on the entire surface of the cylinder barrel, thereby affecting the lubrication effect of the hydraulic cylinder and reducing the efficiency of reducing friction.

[0005] In summary, the existing servo hydraulic cylinders used in rough rolling mills still have the above-mentioned shortcomings and need to be further improved and perfected. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a servo hydraulic cylinder with efficient operation and fast response performance in view of the above-mentioned existing technical status, and the servo hydraulic cylinder is particularly suitable for the high-temperature operation requirements of a roughing mill.

[0007] The technical solution adopted by the present invention to solve the above technical problems is: a servo hydraulic cylinder for a rough rolling mill, comprising a cylinder barrel and a piston assembly which can move linearly in the cylinder barrel, characterized in that: the cylinder barrel is provided with an annular cavity which is opened along the length direction and has a circular ring cross-section, and the annular cavity is filled with a gel material with high thermal conductivity; the cylinder barrel is provided with micropores which are opened along the radial direction and can communicate with the annular inner cavity on the outer surface avoiding the oil path, and the gel material seeps out from the micropores and forms a cooling film on the surface of the cylinder barrel.

[0008] In order to ensure that the cooling film on the cylinder surface can be evenly distributed, preferably, the micropores are evenly opened along the outer surface of the cylinder, and the diameter of each micropore is 90 to 100 microns, and the spacing between adjacent micropores is 1 to 3 mm.

[0009] In order to facilitate the injection of gel material and oil circuit into the cylinder barrel respectively and facilitate operation, preferably, the cylinder barrel includes a gel injection port communicated with the annular inner cavity and an oil injection port communicated with the oil circuit.

[0010] In order to reduce the friction of the piston in reciprocating linear motion and lower the wear rate, preferably, the piston assembly includes a piston rod and a piston arranged in front of the piston rod, and the outer surface of the piston is provided with staggered pits.

[0011] As a further preferred embodiment, the cylinder barrel includes a cylinder body, a cylinder cover and a cylinder bottom, the front end of the cylinder cover is also provided with a gland to prevent the guide sleeve from loosening, and the inner surface of the gland is provided with staggered pits. These pits can store oil and reduce friction resistance and wear of components.

[0012] As a further preference, the cross section of the pit is cylindrical, the depth of each pit is 3 to 5 μm, the diameter of each pit is 8 to 10 μm, and the intervals between adjacent pits in the axial and circumferential directions are 45 to 50 μm respectively.

[0013] In order to ensure the stability and centering of the piston during movement, it is preferred that the two ends of the piston are wedge-shaped structures, and the angle θ between the inclined surface of the wedge-shaped structure and the axis of the cylinder is 4.5° to 5°, and the maximum length H of the inclined surface of the wedge-shaped structure projected along the axial direction of the cylinder is 10 to 12 mm. The design of the wedge-shaped structure can form a wedge-shaped oil film when the piston moves, forming a dynamic pressure support, and this support force helps the piston maintain stable movement in the cylinder.

[0014] Preferably, the piston rod has a hollow cross-section structure near the cylinder head, the hollow cross-section is circular, and the ratio of the diameter of the hollow cross-section of the piston rod to the diameter of the piston rod is 0.5 to 0.7. The hollowing of the piston rod can reduce the mass of the piston rod, thereby increasing the speed of system response.

[0015] In order to accurately control the displacement and speed of the servo hydraulic cylinder, preferably, a sensor for detecting the displacement and speed of the servo hydraulic cylinder is also provided in the cylinder body, and the detection rod of the sensor extends into the hollow section of the piston rod, and a protective cover is also provided at the tail of the sensor at the rear end of the cylinder bottom.

[0016] In order to ensure the continuous efficient operation and rapid response of the servo hydraulic cylinder in a high temperature environment, preferably, the gel material is injected into the annular cavity by the following method, specifically, comprising the following steps:

[0017] Step 1: Ensure that the gel injection port is unobstructed, and use the injection equipment to preheat the high thermal conductivity gel material to a flow temperature of 60℃~70℃;

[0018] Step 2: insert the nozzle of the injection device into the gel injection port, and slowly inject the gel material until the material fills the entire annular inner cavity; observe the micropores on the surface of the cylinder to confirm that the gel material gradually seeps out of the micropores, and the seeped gel material forms a uniform cooling film on the surface of the cylinder;

[0019] Step 3: After the gel material is injected, seal the gel injection port to prevent the gel material from leaking.

[0020] After the servo hydraulic cylinder has been working for a period of time, the gel material leakage should be checked regularly to observe whether the cooling film on the cylinder surface is uniform and maintains a good cooling effect. According to the inspection results, the gel material should be replenished in time to ensure that the gel material in the annular cavity is always sufficient to maintain the temperature stability and high efficiency of the hydraulic cylinder. The above-mentioned gel injection and maintenance method is particularly suitable for the needs of roughing mills in high temperature working environments.

[0021] Compared with the prior art, the advantages of the present invention are: micropores are opened on the surface of the cylinder, and an annular inner cavity is processed on the inner wall side of the cylinder, and the characteristic that the shape of the gel material changes with temperature is utilized, that is, the gel material remains viscous at low temperatures, and when the temperature rises to the high temperature conditions of the working environment, the fluidity of the gel material changes, and the gel material seeps out through the micropores to form a cooling film. This bionic sweat gland high temperature resistant design can effectively absorb and dissipate heat, thereby ensuring the stability and efficiency of the hydraulic cylinder in a high temperature environment;

[0022] In addition, the present invention also integrates the design of staggered pits, the dynamic pressure support of the wedge-shaped structure piston, and the hollowing treatment of the piston rod, so that the servo hydraulic cylinder has the performance of efficient operation and rapid response in a high temperature environment, which is particularly suitable for the high temperature operation requirements of the rough rolling mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of the assembly structure of the servo hydraulic cylinder according to an embodiment of the present invention.

[0024] Figure 2 This is a developed view of the inner surface of the gland and the outer surface of the piston of the servo hydraulic cylinder according to an embodiment of the present invention.

[0025] Figure 3 Schematic diagram of the piston wedge structure of the servo hydraulic cylinder according to an embodiment of the present invention.

[0026] Figure 4 This is a developed view of the outer surface of the cylinder barrel of the servo hydraulic cylinder according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1 to Figure 4 This embodiment discloses a servo hydraulic cylinder device for a rough rolling mill, wherein the servo hydraulic cylinder includes a cylinder barrel and a piston assembly which is linearly movable and arranged in the cylinder barrel.

[0029] The cylinder includes a cylinder body 11, a cylinder cover 12 and a cylinder bottom 13, the piston assembly includes a piston rod 21 and a piston 22 arranged in front of the piston rod 21, and the front end of the cylinder cover 12 is also provided with a gland 14 to prevent the guide sleeve from loosening. The cylinder body 11 is provided with an annular cavity opened along the length direction and having a circular cross-section, and the annular cavity is used to inject a high thermal conductivity gel material 5;

[0030] like Figure 1 , Figure 4 As shown, the cylinder body 11 is provided with a first gel injection port 111, a second gel injection port 112, a first oil injection port 113 and a second oil injection port 114, and the cylinder body 11 is also provided with radially opened micropores 3 that can communicate with the annular inner cavity on the outer surface avoiding the oil path. The gel material 5 can seep out of the micropores 3 and form a cooling film on the surface of the cylinder.

[0031] In order to ensure that the cooling film on the cylinder surface can be evenly distributed, the micropores 3 are evenly spaced along the outer surface of the cylinder body 11, and the diameter of each micropore 3 is 90 to 100 microns, and the spacing between adjacent micropores 3 is 1 to 3 mm.

[0032] In order to effectively reduce friction, staggered pits 4 are provided on the inner surface of the gland 14 and the outer surface of the piston 22. These pits 4 are cylindrical, with a depth of 3 to 5 μm, a diameter of 8 to 10 μm, and a distribution interval of 45 to 50 μm in the axial and circumferential directions. Figure 2 As shown, these pits 4 can be used to store oil, thereby effectively reducing the friction resistance and wear of the equipment during operation.

[0033] In this embodiment, the pits 4 are arranged in a staggered manner. This arrangement breaks the fixed flow path, allowing the oil to be more evenly distributed on the entire surface, ensuring that each area can be effectively lubricated, avoiding the disadvantages of the conventional aligned arrangement, allowing the lubricating oil to better cover the entire surface, effectively reducing the friction and wear of the gland 14 and the piston 22, thereby improving the overall performance of the hydraulic cylinder.

[0034] In addition, the two ends of the piston 22 of this embodiment are processed into a wedge-shaped structure, so that the piston 22 can form a wedge-shaped oil film when moving, forming a dynamic pressure support, and ensuring the stability and centering of the piston 22 during movement. The angle θ between the inclined surface of the wedge-shaped structure and the axis of the cylinder is 4.5° to 5°, and the maximum length H of the inclined surface of the wedge-shaped structure projected along the axial direction of the cylinder is 10 to 12 mm, see Figure 3 shown.

[0035] When the piston 22 in the servo hydraulic cylinder moves axially in the cylinder barrel, the wedge-shaped structure squeezes and accelerates the lubricating oil in the wedge-shaped gap, thereby forming a pressure distribution. As the piston 22 moves, the pressure in the oil film generates a dynamic pressure support force in the wedge-shaped area, which helps the piston 22 maintain smooth movement in the cylinder barrel. The dynamic pressure support provides uniform fluid pressure, so that the piston 22 is evenly stressed during movement, thereby reducing vibration and swing. The pressure distribution of the wedge-shaped oil film helps to automatically adjust the position of the piston 22 so that it always remains in the center of the cylinder barrel, reducing deviation and tilt.

[0036] In order to further reduce friction, the piston rod 21 and the inner wall of the cylinder barrel of this embodiment are also coated with molybdenum disulfide, which can further reduce friction during movement. This molybdenum disulfide coating has excellent lubrication and high temperature resistance, and can effectively extend the service life of the hydraulic cylinder.

[0037] In order to reduce the mass of the piston rod 21, the piston rod 21 of this embodiment is also hollowed near the cylinder head 12, which can effectively reduce the mass of the piston rod 21 and improve the system response speed. Specifically, the piston rod 21 adopts a hollow section structure, the hollow section is circular, and the hollow section of the piston rod 21 is fixed to the earring 8 connected to the supporting hydraulic cylinder by friction welding; and considering the balance between weight and strength, the ratio of the diameter of the hollow section of the piston rod 21 to the diameter of the piston rod 21 is preferably 0.5 to 0.7.

[0038] In order to accurately control the displacement and speed of the servo hydraulic cylinder, a sensor 6 for detecting the displacement and speed of the servo hydraulic cylinder is also provided in the cylinder body. In this embodiment, a protective cover 7 is also provided at the tail of the sensor 6 at the rear end of the cylinder bottom 13. The measuring rod 61 of the sensor 6 extends to the inside of the hollow section of the piston rod 21. The outside of the sensor 6 is also provided with a matching magnetic ring 62. The sensor 6 is used to accurately control the displacement and speed of the servo hydraulic cylinder. The material of the protective cover 7 can be high-strength alloy steel or ceramic. The thickness of the protective cover 7 is usually 7 to 10 mm. The protective cover in this thickness range can provide sufficient support and protection on the one hand, and maintain suitable weight and mechanical properties on the other hand.

[0039] The gel material 5 of this embodiment remains in a viscous state at room temperature, and the surface tension and capillary action in the micropores 3 keep the gel material 5 stationary in the micropores 3. When the temperature rises to the high temperature condition of the working environment, the viscosity of the gel material 5 decreases, and the fluidity of the gel material 5 increases. At this time, under the action of capillary action and thermal drive effect, the gel material 5 gradually seeps out from the micropores 3 and covers the surface of the cylinder barrel to form a cooling film. The cooling film can effectively absorb and dissipate the heat generated by the hydraulic cylinder during operation, thereby ensuring the stability and efficiency of the hydraulic cylinder in a high temperature environment.

[0040] In order to make the cooling film formed by the gel material 5 evenly cover the surface of the cylinder, this embodiment provides a method for injecting the gel material 5. The gel material 5 is injected from the specially designed first gel injection port 111 and the second gel injection port 112. The specific injection method is as follows:

[0041] Step 1: Ensure that the gel injection port is unobstructed, and use an injection device to preheat the high thermal conductivity gel material 5 to an appropriate flow temperature, usually 60° C. to 70° C.;

[0042] Step 2: insert the nozzle of the injection device into the first gel material 5 injection port and the second gel injection port 112, and slowly inject the gel material 5 until the material fills the entire annular inner cavity. During the injection process, a uniform speed should be maintained to avoid the generation of bubbles. At the same time, observe the micropores 3 on the surface of the cylinder to confirm that the gel material 5 gradually seeps out of the micropores 3, and the seeped gel material 5 forms a uniform cooling film on the surface of the cylinder.

[0043] Step 3: After the injection is completed, the first gel material 5 injection port and the second gel injection port 112 are sealed to ensure that the gel material 5 does not leak.

[0044] After the servo hydraulic cylinder has been working for a period of time, the leakage of gel material 5 should be checked regularly to observe whether the cooling film on the cylinder surface is uniform and maintains a good cooling effect. According to the inspection results, the gel material 5 should be replenished in time to ensure that the gel material 5 in the annular cavity is always sufficient to maintain the temperature stability and high efficiency of the hydraulic cylinder.

[0045] This embodiment uses the injection and maintenance method of the gel material 5 mentioned above, the integration of the bionic sweat gland high temperature resistant design of the micropore 3 structure, the design of the pit 4 array, the dynamic pressure support of the wedge-shaped structure, the molybdenum disulfide coating and the hollowing treatment of the piston rod 21, so that the servo hydraulic cylinder has the performance of efficient operation and rapid response in a high temperature environment, which is particularly suitable for the high temperature operation requirements of the rough rolling mill.

[0046] In the specification and claims of the present invention, terms indicating directions, such as "front", "rear", "up", "down", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as explanations and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A servo hydraulic cylinder for a rough rolling mill, comprising a cylinder barrel and a piston assembly disposed in the cylinder barrel and capable of linear movement, characterized in that: The cylinder is provided with an annular cavity opened along the length direction and having a circular cross-section, and the annular cavity is filled with a gel material (5) with high thermal conductivity; the cylinder is provided with micropores (3) opened along the radial direction and connected to the annular inner cavity on the outer surface avoiding the oil path, and the gel material (5) seeps out from the micropores (3) and forms a cooling film on the surface of the cylinder.

2. The servo hydraulic cylinder for a rough rolling mill according to claim (1), characterized in that: The micropores (3) are evenly arranged along the outer surface of the cylinder, and the diameter of each micropore (3) is 90 to 100 micrometers, and the spacing between adjacent micropores (3) is 1 to 3 mm.

3. The servo hydraulic cylinder for a rough rolling mill according to claim 1, characterized in that: The cylinder comprises a gel injection port which can be communicated with the annular inner cavity and an oil injection port which can be communicated with the oil circuit.

4. The servo hydraulic cylinder for a rough rolling mill according to claim 1, characterized in that: The piston assembly comprises a piston rod (21) and a piston (22) arranged at the front of the piston rod (21); the outer surface of the piston (22) is provided with staggered recesses (4).

5. The servo hydraulic cylinder for a rough rolling mill according to claim 1, characterized in that: The cylinder barrel comprises a cylinder body (11), a cylinder cover (12) and a cylinder bottom (13); a pressure cover (14) is provided at the front end of the cylinder cover (12) to prevent the guide sleeve from loosening; and the inner surface of the pressure cover (14) is provided with staggered pits (4).

6. The servo hydraulic cylinder for a rough rolling mill according to claim 4 or 5, characterized in that: The cross section of the pit (4) is cylindrical, the depth of each pit (4) is 3 to 5 μm, the diameter of each pit (4) is 8 to 10 μm, and the intervals between adjacent pits (4) in the axial and circumferential directions are 45 to 50 μm respectively.

7. The servo hydraulic cylinder for a rough rolling mill according to claim 4, characterized in that: The two ends of the piston (22) are wedge-shaped structures, and the angle θ between the inclined surface of the wedge-shaped structure and the axis of the cylinder is 4.5° to 5°, and the maximum length H of the inclined surface of the wedge-shaped structure projected along the axial direction of the cylinder is 10 to 12 mm.

8. The servo hydraulic cylinder for a rough rolling mill according to claim 4, characterized in that: The piston rod (21) has a hollow cross-section structure near the cylinder head (12), the hollow cross-section is circular, and the ratio of the diameter of the hollow cross-section of the piston rod (21) to the diameter of the piston rod (21) is 0.5 to 0.

7.

9. The servo hydraulic cylinder for a rough rolling mill according to claim 8, characterized in that: A sensor (6) for detecting the displacement and speed of the servo hydraulic cylinder is also provided in the cylinder body, the detection rod of the sensor (6) extends into the hollow section of the piston rod (21), and a protective cover (7) is also provided at the rear end of the cylinder bottom (13) at the tail of the sensor (6).

10. The servo hydraulic cylinder for a rough rolling mill according to claim 3, characterized in that: The gel material (5) is injected into the annular cavity by the following method, which specifically comprises the following steps: Step 1: Ensure that the gel injection port is unobstructed, and use an injection device to preheat the high thermal conductivity gel material (5) to a flow temperature of 60° C. to 70° C.; Step 2: insert the nozzle of the injection device into the gel injection port, and slowly inject the gel material (5) until the material fills the entire annular inner cavity; observe the micropores (3) on the surface of the cylinder, confirm that the gel material (5) gradually seeps out from the micropores (3), and the seeped gel material (5) forms a uniform cooling film on the surface of the cylinder; Step 3: After the gel material (5) is injected, the gel injection port is sealed to prevent the gel material (5) from leaking.

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