Locking cylinder sealing and fixing mode

Abstract

The invention discloses a locking cylinder sealing and fixing mode, and relates to the technical field of metallurgical rolling mill equipment, and the mode comprises the specific steps of S100, designing a three-stage interlocking structure, S200, pressing a guide sleeve into a cylinder body to enable a clamping groove and a boss to be coplanar, S300, assembling a sealing ring, S400, pushing an end cover and then rotating to form second-stage interlocking, and S500, axially fixing with a bolt to complete fixing. A three-level load bearing system is formed through radial interlocking of the annular groove in the inner wall of the end cover and the radial boss of the cylinder body, circumferential interlocking of the second annular boss of the end cover and the stepped clamping groove of the guide sleeve and the force guiding effect of the chamfered inclined face, when radial impact is borne, impact force is converted into axial component force through the inclined face, and then the axial component force is converted into axial component force through the inclined face. And a meshing structure of the radial boss and the groove bears a main load, and finally, the rotary displacement of the end cover is limited through the circumferential clamping groove, so that the radial load completely avoids the bolt and is only transmitted to the cylinder body and the guide sleeve through the rigid interlocking structure, and the bolt is prevented from being sheared and fractured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgical rolling mill equipment, in particular to a locking cylinder sealing and fixing method. BACKGROUND

[0002] In the steel rolling production equipment, the locking cylinder is the core locking component of the rolling mill core, and its sealing performance directly affects the equipment operation stability and service life. The end sealing structure of the locking cylinder needs to meet the requirements of dust prevention, leakage prevention and impact resistance. Especially during the rolling mill core replacement process, the several-ton heavy mill core is prone to accidental collision with the locking cylinder end cover when it falls. At this time, the fixing reliability of the sealing end cover becomes the key. The traditional locking cylinder adopts the structure of directly connecting the end cover and the cylinder body with bolts, relying on the shear force and pre-tightening force of the bolts to resist the radial impact. However, the integrated design of sealing and fixing functions has been a technical difficulty in improving the durability of the equipment in the industry.

[0003] In the prior art, the fixing method of the sealing end cover of the locking cylinder has the following structural defects: first, four circumferentially distributed bolts are used to directly fix the end cover, and the bolts simultaneously bear the axial pre-tightening force and the radial impact force. However, the tensile strength of the bolt material is much higher than the shear strength, and the radial impact easily leads to bolt fatigue fracture. Second, the end cover, the cylinder body and the guide sleeve are in a plane fitting structure, and lack mechanical interlocking design. The radial force generated by the collision directly acts on the bolts and the edge of the end cover, causing the end cover to deform and the sealing element to fall off. Third, the sealing ring is only positioned by the end cover plane, without an independent positioning structure. A small amount of displacement of the end cover will cause sealing failure, and further cause a chain of failures such as dust intrusion and lubricating oil leakage.

[0004] In summary, due to uneven stress and poor structural compatibility, the existing fixing method leads to an increased failure rate of the locking cylinder under frequent impact working conditions. It not only increases the equipment maintenance frequency, but also shortens the overall service life of the locking cylinder due to sealing failure. Therefore, there is an urgent need for a locking cylinder sealing and fixing method that can optimize the force transmission path and strengthen the structural interlocking to realize the synergistic effect of sealing and fixing functions, in order to solve the inherent defects of the prior art. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and provide a locking cylinder sealing and fixing method. The method can form a three-level load bearing system through the radial interlocking of the end cover inner wall annular groove and the cylinder body radial boss, the circumferential interlocking of the end cover second annular boss and the guide sleeve stepped slot, and the force guiding effect of the chamfered bevel. When subjected to radial impact, the impact force is first converted into an axial component by the bevel, then the main load is borne by the meshing structure of the radial boss and the groove, and finally the end cover rotational displacement is limited by the circumferential slot, so that the radial load completely avoids the bolts and is only transmitted to the cylinder body and the guide sleeve by the rigid interlocking structure, avoiding the shear fracture of the bolts and solving the design defect of the bolts directly subjected to force.

[0006] The application provides the following technical scheme to solve the above technical problems: a locking cylinder sealing and fixing method, the specific steps of which are as follows:

[0007] S100, designing a three-stage interlocking structure: a first annular groove is processed on the inner wall of the end cover, which is used to form a first-stage radial interlocking with the radial boss at the end of the locking cylinder body;

[0008] A second annular boss is processed on the inner wall of the end cover near the edge, forming a second-stage circumferential rotation interlocking;

[0009] A 15°-30° chamfered surface is processed on the outer edge of the end cover, which is used to convert the vertical impact force of a falling object into an axial component along the chamfered surface, reducing the radial impact;

[0010] S200, installing a guide sleeve and positioning: the guide sleeve is pressed into the end of the locking cylinder body in a transition fit, so that the stepped clamping groove on the end face of the guide sleeve is in the same axial plane as the radial boss of the locking cylinder body;

[0011] S300, assembling a sealing ring: the double-lip dustproof sealing ring is embedded in the sealing ring positioning boss on the inner wall of the end cover, so that the inner side of the sealing ring is completely attached to the boss and the outer side is in close contact with the outer wall of the guide sleeve;

[0012] S400, rotating and clamping the end cover: the first annular groove of the end cover is aligned with the radial boss of the locking cylinder body, the end cover is pushed in the axial direction until the end face of the end cover is flush with the end face of the locking cylinder body and the guide sleeve, the end cover is rotated clockwise by 10°-15°, the second annular boss of the end cover is clamped into the circumferential locking groove of the guide sleeve, forming a two-stage mechanical interlocking of axial positioning and circumferential locking;

[0013] S500, axial auxiliary fixing: four bolts are uniformly distributed in the circumferential direction of the end cover, passing through the axial bolt holes of the end cover, the hole positions are coaxial with the threaded holes of the locking cylinder body, a pre-tightening torque of 150-300 N·m is applied, the end cover is axially fixed on the locking cylinder body, at this time the bolts only bear axial tension, the radial impact load is completely borne by the three-stage interlocking structure, and the final fixing is completed.

[0014] Further, in the S100, the first annular groove has a depth of 5-8 mm, the inner diameter is matched with the outer wall of the locking cylinder body, the radial boss has a height of 5-8 mm, and the outer diameter is matched with the first annular groove with a gap of 0.01-0.05 mm.

[0015] Further, in the S100, the second annular boss has a height of 6-10 mm, the outer diameter is matched with the stepped clamping groove on the end face of the guide sleeve, the stepped clamping groove includes an axial guide groove and a circumferential locking groove, and the depth is 8-12 mm.

[0016] Further, the stepped slot structure is that the width of the axial guide slot is 0.5-1mm larger than the width of the second annular boss, the length of the circumferential locking slot is the arc length corresponding to the rotation angle of 10°-15° of the end cover, and the depth is 1-2mm larger than the height of the second annular boss.

[0017] Further, in the S300, the height of the sealing ring positioning boss is 2-5mm, and the outer diameter is in interference fit with the inner diameter of the sealing ring by -0.02--0.05mm.

[0018] Further, in the S100, the angle of the chamfered bevel is preferably 20°-25°, which has the highest impact force conversion efficiency and does not weaken the edge strength of the end cover, and when the thickness of the end cover is 15-30mm, the width of the bevel is 15-18mm.

[0019] Further, in the S300, the structure of the double-lip dustproof sealing ring comprises:

[0020] The main sealing lip has an inclination angle of 20°±1° and a thickness of 3mm, and bears hydraulic sealing;

[0021] The dust lip has an inclination angle of 45°±1° and a thickness of 2.5mm, and bears particulate matter blocking;

[0022] An oil guide groove is arranged between the two lips, with a depth of 0.5mm and a width of 1mm.

[0023] Further, in the S400, the end cover rotation positioning adopts the following method:

[0024] A positioning mark is marked on the outside of the end cover, and a corresponding mark is marked on the end face of the guide sleeve, the end cover is rotated until the two marks are aligned, and it is ensured that the second annular boss is completely clamped into the circumferential locking slot.

[0025] Further, in the S500, the bolt torque is applied in three stages:

[0026] Stage one: 50% target torque, 75-150N·m, eliminate assembly gap;

[0027] Stage two: 80% target torque, 120-240N·m, pressure for 1 minute;

[0028] Stage three: 100% target torque, 150-300N·m, final locking,

[0029] Further, the stress distribution of the three-stage mechanical interlocking is:

[0030] The first stage, the groove-boss of the end cover and the locking cylinder body: bears 60%-70% of the radial impact load;

[0031] The second stage, the stepped clamping groove of the end cover and the guide sleeve: bearing 20%-30% of the radial impact load;

[0032] The third stage, the impact force conversion of the chamfered inclined surface: reducing 10%-20% of the vertical impact force, the axial fixing bolt only bears the weight of the end cover and the axial vibration load.

[0033] Compared with the prior art, the sealing and fixing method of the locking cylinder has the following beneficial effects:

[0034] Firstly, the sealing and fixing method of the locking cylinder forms a three-stage load bearing system through the radial interlocking of the annular groove in the inner wall of the end cover and the radial boss of the cylinder body, the circumferential interlocking of the second annular boss of the end cover and the stepped clamping groove of the guide sleeve, and the force guiding effect of the chamfered inclined surface. When subjected to radial impact, the impact force is first converted into axial component force through the inclined surface, then the main load is borne by the meshing structure of the radial boss and the groove, and finally the rotation displacement of the end cover is limited by the circumferential clamping groove, so that the radial load completely avoids the bolt and is only transmitted to the cylinder body and the guide sleeve by the rigid interlocking structure, thereby avoiding the shearing fracture of the bolt and solving the design defect that the bolt is directly stressed.

[0035] Secondly, the sealing ring is positioned by interference fit through the positioning boss of the end cover inner wall. The axial limiting and radial holding effects of the boss make the sealing ring and the outer wall of the guide sleeve always maintain stable contact. Even if the end cover is slightly displaced due to impact, the meshing structure of the boss and the sealing ring can still maintain the relative position of the sealing element, avoiding the sealing gap caused by the deformation of the end cover in the traditional plane extrusion type sealing. At the same time, the double-lip structure of the sealing ring can form two sealing barriers with the outer wall of the guide sleeve and the end face of the cylinder body, respectively, and cooperate with the anti-displacement function of the interlocking structure to realize the bidirectional guarantee of sealing performance and structural stability, thereby fundamentally solving the problem that the sealing element fails with the end cover.

[0036] Other advantages, objects, and features of the present application will be apparent to those skilled in the art in view of the following detailed description and drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any inventive labor.

[0038] Figure 1 Flowchart of the sealing and fixing method of the locking cylinder;

[0039] Figure 2 It is a structure schematic diagram of a locking cylinder sealing and fixing mode.

[0040] In the figure: 1, end cover; 2, locking cylinder body; 3, guide sleeve; 4, sealing ring. DETAILED DESCRIPTION

[0041] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined application purposes, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with the drawings and preferred embodiments.

[0042] Example one

[0043] This embodiment is aimed at the rolling mill core replacement scene (impact load 15-20kN), and sealing and fixing is realized through a three-stage interlocking structure. During assembly, the precisely processed annular groove and the radial boss form radial interlocking, the second annular boss and the guide sleeve clamping groove constitute circumferential locking, the impact force is decomposed by the 15° chamfered bevel, the bolt is axially fixed with a 200N・m pre-tightening torque, only axial force is borne, and test shows that 886kN peak impact can be borne, the bolt torque attenuation is ≤5% after 100,000 cycles, there is no sealing leakage, the dustproof effect is remarkable, and the double protection of impact load grading transmission and sealing reliability is realized, as shown in Figure 2 The specific structure is as follows:

[0044] (1) Component parameter design:

[0045] This embodiment is aimed at the working condition of frequently bearing radial impact during rolling mill core replacement, and the three-stage interlocking structure parameters are as follows:

[0046] End cover 1: 42CrMo alloy structural steel is adopted, the thickness is 25mm, the edge chamfered bevel angle is 20°, the bevel width is 16mm; the first annular groove depth of the inner wall is 6mm, the gap between the outer diameter and the outer wall of the locking cylinder body 2 is 0.03mm; the second annular boss height is 8mm, and the width is 5mm.

[0047] Locking cylinder body 2: forged steel material is selected, the end radial boss height is 6mm, the gap between the outer diameter and the first annular groove is 0.02mm, 4 M16 threaded holes are uniformly distributed in the circumference, and the hole depth is 30mm.

[0048] Guide sleeve 3: the width of the stepped clamping groove axial guide groove is 5.5mm, which is 0.5mm wider than the second annular boss, the circumferential locking groove length corresponds to the arc length of 12° rotation of the end cover (arc length = π × guide sleeve outer diameter × 12° / 360°), and the depth is 9mm (1mm higher than the second annular boss).

[0049] Double-lip dustproof sealing ring 4: main sealing lip angle 20°, thickness 3mm; dustproof lip angle 45°, thickness 2.5mm; oil guide groove depth 0.5mm, width 1mm; sealing ring positioning boss height 3mm, interference fit with sealing ring inner diameter -0.03mm.

[0050] Bolt: high-strength bolt, diameter 16mm, pre-tightening torque 200N・m.

[0051] (2) As shown in Figure 1 , the step-by-step assembly process is as follows:

[0052] S100 Three-stage interlocking structure processing: using a numerical control lathe to turn the first annular groove in the inner wall of the end cover, ensuring the groove bottom roughness Ra1.6μm, verifying the matching degree of the inner diameter of the groove and the outer wall of the locking cylinder body by a three-coordinate measuring instrument, ensuring that the radial clearance is stable at 0.02mm, this design makes the first annular groove and the radial boss form a precise fit, when subjected to radial impact, the boss can slide along the inner wall of the groove and transfer more than 90% of the radial force, avoiding the force acting directly on the bolt, the second annular boss is processed on the inner wall edge of the end cover, using wire cutting process to ensure that the boss side is perpendicular ≤0.01mm, and the circumferential locking groove of the guide sleeve forms a gapless fit, after the boss is rotated and clamped, it can limit the circumferential rotation of the end cover through side contact, and cooperate with the first-stage radial interlocking to form "radial + circumferential" double restraint, the chamfer slope of the end cover edge is processed by a grinding machine, ensuring that the angle error between the slope and the axis is ≤0.5°, when the machine core falls vertically, the slope can decompose the vertical force F=20kN into axial component F1=F×sin20°≈6.84kN and radial component F2=F×cos20°≈18.79kN, where the axial component is offset by the bolt pre-tightening force, and the radial component is completely borne by the three-stage interlocking structure.

[0053] S200 Guide sleeve installation and positioning: the guide sleeve and the locking cylinder body adopt a transition fit, using a hydraulic press to press the guide sleeve into the end of the cylinder body with a pressure of 50kN, monitoring the axial position of the end face of the guide sleeve and the radial boss of the cylinder body by a dial gauge, ensuring that they are in the same plane (error ≤0.02mm), this design makes the guide sleeve and the cylinder body form a rigid whole, which can deform synchronously when subjected to impact in the future, avoiding local stress concentration.

[0054] S300 sealing ring assembly details: before assembly, the sealing ring positioning boss is degreased, and when the double-lip dustproof sealing ring is embedded in the boss, a special tool is used to ensure that the inner side of the sealing ring is completely attached to the boss (attachment surface ≥ 95%), the contact pressure between the main sealing lip and the outer wall of the guide sleeve is realized through interference fit, and the initial contact pressure is measured by a pressure sensor, reaching 0.8 MPa, which meets the sealing requirements of the hydraulic system 31.5 MPa, the guide oil groove is pre-coated with lithium-based lubricating grease, and when the cylinder body expands and contracts, the lubricating grease can move into the sealing lip gap with the piston rod, reducing friction and wear, and preventing dust from entering. The contact pressure between the dustproof lip and the guide sleeve is 0.3 MPa, which can effectively intercept iron oxide dust (particle size ≤ 50 μm) in the rolling mill working environment.

[0055] S400 end cover rotating and clamping operation: when the end cover is pushed axially, the guide cone surface (taper 1:50) on the outer wall of the guide sleeve guides the end cover to smoothly enter until the three end faces are flush (the flatness is checked with a straightedge ≤ 0.05 mm), and the end cover is rotated clockwise by 12°, at which time the positioning mark on the outer side of the end cover is aligned with the end face mark of the guide sleeve. The rotation resistance torque is measured by a torque wrench to ensure that the second annular boss is completely clamped into the locking groove (the resistance torque is stable at 50-60 N·m). The secondary mechanical interlocking formed in this step makes the axial displacement of the end cover ≤ 0.01 mm and the circumferential rotation angle error ≤ 0.5°. Through finite element analysis verification, the maximum stress of the end cover in this state is 280 MPa, which is much lower than the yield strength of 42CrMo, which is 835 MPa.

[0056] S500 axial auxiliary fixation: before bolt installation, a torque multiplier is used to apply pre-tightening force in three stages: first stage 100 N·m (50% of target value), pressure holding for 30 seconds to eliminate thread gap; second stage 160 N·m (80% of target value), pressure holding for 1 minute to make the bolt plastically deform; third stage 200 N·m (100% of target value), the bolt elongation is measured by a strain gauge to ensure uniform pre-tightening force (elongation error of 4 bolts ≤ 0.01 mm), at which time the bolt only bears axial tension (calculated tension F = 200 N·m / (0.16 × 0.2) ≈ 6250 N, where 0.16 is the bolt diameter and 0.2 is the thread friction coefficient), and the radial impact shear force of the bolt is 0, completely solving the problem of bolt shear fracture in traditional structure.

[0057] (3) Working condition simulation and stress analysis:

[0058] Radial impact test: a drop hammer impact testing machine is used to simulate the drop collision of the machine core, the hammer head mass is 2 t, the drop height is 1 m, the impact speed v = √(2gh) = 4.43 m / s, the impact time is 0.01 s, and the impact force F = mv / t = 2000 kg × 4.43 m / s ÷ 0.01 s ≈ 886 kN (peak value).

[0059] During the impact process, the first level of radial interlocking bears 65% of the load (575.9 kN), which is monitored by strain gauges, and the maximum deformation of the radial boss is 0.12 mm, which is within the elastic deformation range; the second level of circumferential interlocking bears 25% of the load (221.5 kN), and the stress on the side surface of the guide sleeve clamping groove is 320 MPa, which meets the allowable stress requirement of tin bronze, and the chamfered inclined surface decomposes 10% of the load (88.6 kN), which is balanced by the bolt pre-tightening force after being converted into an axial component.

[0060] Sealing performance verification: After the impact test, the sealing effect is verified by the following methods:

[0061] Hydraulic system pressure maintenance test: Apply a pressure of 31.5 MPa and maintain it for 1 hour, with a pressure drop of ≤0.5 MPa, which is much lower than the requirement of 1 MPa.

[0062] Dustproof performance test: Place the locking cylinder in an environment with a dust concentration of 50 mg / m³ and run 1000 extension and contraction cycles. After disassembly, check the inner wall of the cylinder body, and there is no visible dust adhesion, which proves that the dustproof lip effectively blocks the intrusion of particulate matter.

[0063] Long-term reliability test: Perform impact cycle tests on a rolling mill simulation platform with an impact load of 15-20 kN each time. After the test, the bolt pre-tightening torque attenuation is ≤5% (from 200 N・m to 190 N・m), which still meets the use requirements, the gap between the end cover and the cylinder body does not change significantly (maintained at 0.02-0.03 mm), the wear of the main sealing lip of the sealing ring is ≤0.1 mm, and it still maintains effective sealing.

[0064] In summary, the embodiment realizes force transmission by a three-level interlocking structure, the impact load is first converted into an axial component by the chamfered inclined surface to reduce radial impact; the remaining radial force is borne by the first level of annular groove and boss, which disperses the force to the cylinder body through precise fitting; the interlocking of the circumferential boss and the clamping groove limits the rotation of the end cover to avoid the failure of the sealing element due to displacement. The bolt only plays an axial fixing role, completely avoiding the risk of shearing, and the double-lip sealing ring still maintains stable contact under long-term impact through double sealing and the constraint of the positioning boss, achieving the synergistic effect of "structural interlocking to prevent failure and sealing positioning to maintain performance".

[0065] Example Two

[0066] This embodiment adapts to the metallurgical environment of high dust at-10℃~80℃, uses stainless steel end cover, heat-resistant steel cylinder body and fluorine rubber sealing ring, 25° chamfered slope to improve axial force ratio, pre-heat expansion gap to prevent jamming, aluminum bronze guide sleeve and bolt metal gasket to ensure stable locking at high temperature. Test shows that there is no leakage after 500 times of high-low temperature cycle, the dust lip effectively prevents dust at 5000 times of high dust cycle, can withstand 25kN impact at 80℃, and the sealing performance is stable after 1000 hours of high temperature operation, which meets the dual needs of force transmission and sealing in extreme environment

[0067] (1) Component parameter adjustment and environmental adaptation design:

[0068] This embodiment optimizes the component parameters for the high temperature and high dust environment in the metallurgical workshop:

[0069] End cover (1): made of stainless steel (rust resistant), thickness 30mm, chamfered slope angle 25°, slope width 18mm; first annular groove depth 8mm, radial gap 0.05mm (heat expansion and cold contraction space reserved); second annular boss height 10mm, width 6mm.

[0070] Locking cylinder body (2): made of heat-resistant steel, radial boss height 8mm, threaded hole pretreated with high-temperature resistant thread glue (temperature resistant 150℃).

[0071] Guide sleeve (3): made of aluminum bronze (high temperature wear resistant), stepped clamping groove axial guide groove width 7mm (1mm wider than boss), circumferential locking groove depth 12mm (2mm higher than boss), corresponding to 15° arc length of end cover rotation.

[0072] Double-lip dustproof sealing ring (4): made of fluorine rubber material (temperature resistant-20℃~200℃), main sealing lip and dust lip hardness 60±5 Shore A, positioning boss height 5mm, interference fit-0.05mm (enhance high temperature sealing).

[0073] Bolt: high-temperature alloy bolt, pre-tightening torque 300N・m, metal toothed gasket to prevent loosening.

[0074] (2) Step-by-step assembly and environmental adaptability design:

[0075] S100 Structure processing environmental considerations: end cover chamfer angle increased to 25°, in high temperature environment can be the vertical impact force axial force ratio to improve sin25°≈42.26%, reduce radial load, through thermodynamic simulation, 30mm thickness of end cover at 80℃ thermal expansion amount is 0.15mm, the reserved 0.05mm radial clearance can avoid the jam caused by thermal expansion, the first ring groove and radial boss cooperation surface using nitriding treatment (hardness ≥60HRC), improve wear resistance, reduce the metal debris generated by friction in the dust environment.

[0076] S200 temperature compensation of guide sleeve installation: the transition fit of guide sleeve and cylinder uses H7 / m6 (looser than normal temperature), at 80℃ working temperature, thermal expansion makes the fit clearance shrink to 0.01-0.02mm, which ensures the centering accuracy and avoids loosening when cold shrinking. During installation, the cylinder temperature is monitored by infrared thermometer to ensure assembly at 25℃ normal temperature, reducing temperature stress.

[0077] S300 high temperature sealing design of sealing ring: fluororubber sealing ring is preheated at 120℃ for 30 minutes before assembly, so that it generates thermal shrinkage in advance. After cooling, the interference amount with the positioning boss increases to 0.08mm. The sealing ring expands when working at high temperature, which can maintain stable contact pressure. The oil guide groove is filled with high temperature lubricating grease (drop point ≥200℃) to prevent grease loss at high temperature.

[0078] S400 anti-jamming design of end cover rotation: the rotation angle of end cover is increased to 15°, which increases the contact area of the second annular boss with the locking groove by 30%. At high temperature, it can disperse the contact stress. High temperature molybdenum-based lubricating grease is applied during rotation to reduce the friction coefficient to below 0.15, avoiding jamming caused by temperature rise. Positioning marks at high temperature are marked on the end cover and guide sleeve by laser marking machine (considering the position offset after thermal expansion), to ensure the rotation accuracy.

[0079] S500 anti-loosening measure of axial fixation: the bolt hole is processed by hot drilling process to ensure that the hole coaxiality is ≤0.03mm at 80℃. When applying a pre-tightening torque of 300N・m, the bolt axial stress reaches 800MPa monitored by ultrasonic bolt stress meter. The tooth height of the metal tooth-shaped gasket is 0.3mm, and the tooth shape is completely flattened after assembly, forming a mechanical anti-loosening, and the torque attenuation is ≤3% in a vibrating environment.

[0080] (3) Extreme working condition test and principle verification

[0081] High-low temperature cycle test: 500 cycles (8 hours per cycle) in a temperature chamber from -10℃ to 80℃, after the test: at low temperature -10℃, the hardness of the fluorine rubber seal ring increases to 65 Shore A, but the interference fit still ensures that the contact pressure is ≥0.6MPa, and there is no leakage after 2 hours of hydraulic pressure retention; at high temperature 80℃, the radial gap between the end cover and the cylinder body is reduced to 0.01mm due to thermal expansion, and the first level interlocking can still transmit radial force, which can withstand 25kN radial load without plastic deformation after testing;

[0082] High dust wear test: run 5000 extension and contraction cycles in an environment with a dust concentration of 100mg / m³ (containing 50% iron oxide particles), each cycle at a speed of 0.5m / s: the wear amount of the guide sleeve surface is ≤0.05mm, due to the use of aluminum bronze material, the oxide film formed can reduce further wear, and the amount of dust captured by the dust lip reaches 5g, but there is no dust intrusion on the inner side of the main sealing lip, and the oil film formed by the lubricating grease in the oil guide groove effectively blocks the migration of particulate matter.

[0083] Impact and high temperature combined test: apply 25kN radial impact (1000 times) at 80℃: the maximum deformation of the end cover is 0.2mm, after impact, check the flatness of the end face by dial gauge, the error is ≤0.05mm, the sealing element does not fail due to deformation, the pre-tightening torque of the bolt is reduced from 300N・m to 290N・m, and the metal tooth-shaped gasket does not loosen, proving that the anti-loose effect is reliable.

[0084] Seal life test: run continuously at 80℃ and 31.5MPa pressure for 1000 hours: the wear amount of the main sealing lip is 0.2mm, which still maintains sealing performance (pressure drop ≤0.8MPa / hour), the bonding surface of the sealing ring and the positioning boss is not peeled off, and the interference fit effectively prevents the creep of the sealing ring at high temperature.

[0085] This embodiment optimizes parameters to make the three-level interlocking structure still maintain functionality in extreme environments, the thermal expansion gap at high temperature avoids structural jamming, the fluorine rubber seal ring and high temperature lubricating grease ensure sealing and movement reliability, in high dust environment, the synergistic effect of double-lip seal and oil guide groove forms multiple barriers, the strong interference fit of the positioning boss prevents displacement of the sealing ring, and the combination of the bolt and the metal gasket maintains stable pre-tightening force in temperature cycling, the entire structure realizes the functions of "graded transmission of force, environmental adaptation of sealing, and anti-loose and temperature-resistant fixation", and is especially suitable for severe working conditions in the metallurgical industry.

[0086] In summary, through example one and example two, the principle of the sealing and fixing method of the locking cylinder is that the force transmission path is constructed in a three-level interlocking structure, so that the radial load completely avoids the bolt; through the independent positioning and double-lip design of the sealing ring, the bidirectional guarantee of sealing and structure is realized; according to the adjustment parameters (such as angle, interference amount, material) of different working conditions, a variety of application scenes can be adapted, and the stress defects and sealing failure problems of the bolt connection are fundamentally solved.

[0087] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A locking cylinder sealing and fixing method, characterized by, The specific steps of the method are: S100, designing a three-stage interlocking structure: a first annular groove is processed on the inner wall of the end cover, which is used to form a first-stage radial interlocking with a radial boss at the end of the locking cylinder body; A second annular boss is processed on the inner wall of the end cover near the edge to form a second-stage circumferential rotation interlocking; A 15°-30° chamfered slope is processed on the outer edge of the end cover, which is used to convert the vertical impact force of a falling object into an axial component along the slope, thereby reducing the radial impact; S200, installing a guide sleeve and positioning: the guide sleeve is pressed into the end of the locking cylinder body in a transition fit, so that the stepped clamping groove on the end face of the guide sleeve is in the same axial plane as the radial boss of the locking cylinder body; S300, assembling a sealing ring: the double-lip dustproof sealing ring is embedded in the sealing ring positioning boss on the inner wall of the end cover, so that the inner side of the sealing ring is completely attached to the boss and the outer side is in close contact with the outer wall of the guide sleeve; S400, rotating and clamping the end cover: the first annular groove of the end cover is aligned with the radial boss of the locking cylinder body, the end cover is pushed in the axial direction until the end face of the end cover is flush with the end face of the locking cylinder body and the guide sleeve, the end cover is rotated clockwise by 10°-15°, the second annular boss of the end cover is clamped into the circumferential locking groove of the guide sleeve, forming a two-stage mechanical interlocking of axial positioning and circumferential locking; S500, axial auxiliary fixation: four bolts are uniformly distributed in the circumferential direction of the end cover, passing through the axial bolt holes of the end cover, the hole positions are coaxial with the threaded holes of the locking cylinder body, a pre-tightening torque of 150-300 N·m is applied, the end cover is axially fixed on the locking cylinder body, at this time the bolts only bear axial tension, the radial impact load is completely borne by the three-stage interlocking structure, and the final fixation is completed.

2. The locking cylinder sealing and fixing method according to claim 1, characterized in that, In the S100, the first annular groove has a depth of 5-8 mm, the inner diameter matches the outer wall of the locking cylinder body, the radial boss has a height of 5-8 mm, and the outer diameter has a gap of 0.01-0.05 mm from the first annular groove.

3. The locking cylinder sealing and fixing method according to claim 1, characterized in that, In the S100, the second annular boss has a height of 6-10 mm, the outer diameter matches the stepped clamping groove on the end face of the guide sleeve, and the stepped clamping groove includes an axial guide-in groove and a circumferential locking groove, with a depth of 8-12 mm.

4. The locking cylinder sealing and fixing method according to claim 3, characterized in that, The structure of the stepped clamping groove is that the width of the axial guide-in groove is 0.5-1 mm larger than the width of the second annular boss, the length of the circumferential locking groove is the arc length corresponding to the rotation angle of the end cover of 10°-15°, and the depth is 1-2 mm larger than the height of the second annular boss.

5. The locking cylinder sealing and fixing method according to claim 1, wherein In the S300, the sealing ring positioning boss has a height of 2-5 mm and an outer diameter that is in interference fit of -0.02--0.05 mm with the inner diameter of the sealing ring.

6. The locking cylinder sealing and securing method of claim 1, wherein, In the S100, the angle of the chamfered slope is preferably 20°-25°, which has the highest impact force conversion efficiency and does not weaken the edge strength of the end cover, and when the thickness of the end cover is 15-30 mm, the width of the slope is 15-18 mm.

7. The locking cylinder sealing and securing method of claim 1, wherein, In the S300, the structure of the double-lip dustproof sealing ring includes: A main sealing lip with an inclination angle of 20°±1° and a thickness of 3 mm, which bears hydraulic sealing; A dust lip with an inclination angle of 45°±1° and a thickness of 2.5 mm, which bears particulate matter blocking; An oil guide groove between the two lips with a depth of 0.5 mm and a width of 1 mm.

8. The locking cylinder sealing and securing method of claim 1, wherein, In the S400, the end cover rotation positioning is performed in the following manner: Mark the positioning mark on the outside of the end cover, mark the corresponding mark on the end face of the guide sleeve, rotate the end cover until the two marks are aligned, and ensure that the second annular boss is completely clamped into the circumferential locking groove.

9. The locking cylinder sealing and securing method of claim 1, wherein, In the S500, the bolt torque is applied in three stages: Stage one: 50% target torque, 75-150 N·m, eliminate assembly gap; Stage two: 80% target torque, 120-240 N·m, pressure for 1 minute; Stage three: 100% target torque, 150-300 N·m, final locking.

10. The locking cylinder sealing and securing method according to any one of claims 1-9, wherein, The force distribution of the three mechanical interlocks is: First level, the groove-convexity of the end cover and the locking cylinder body: bearing 60%-70% of the radial impact load; Second level, the stepped clamping groove of the end cover and the guide sleeve: bearing 20%-30% of the radial impact load; Third level, the impact force conversion of the chamfered bevel: reducing 10%-20% of the vertical impact force, the axial fixing bolt only bears the weight of the end cover and the axial vibration load.

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