Machining method for high-quality stainless steel assembly type hoistway of home elevator

Abstract

The invention relates to the technical field of elevator assembly shaftways, and discloses a processing method of a household elevator high-quality stainless steel assembly type shaftway, which comprises the following steps of digital design and material optimization, prefabrication processing of high-precision section bars and plates, processing of high-precision stainless steel assembly type shaftways, processing of high-precision stainless steel assembly type shaftways, processing of high-precision stainless steel assembly type shaftways and processing of high-precision stainless steel assembly type shaftways. The construction of a modular connection system, on-site assembly and precision regulation and control, comprehensive performance verification and long-term protection are performed, and after the overall assembly of the shaft is completed, the sealing performance and operation stability test is performed. According to the construction method, through digital design, modular prefabrication and a rapid mechanical connection system, the construction process of a traditional civil engineering shaft and the welding operation of a field welding type shaft are thoroughly abandoned, high-precision prefabrication of components in a factory is achieved, only modular assembly is conducted on the field, and the construction method is particularly suitable for later-stage installation of an existing house; the problems that a traditional method is long in construction period and high in dependence on an existing building structure are solved.

Description

Technical Field

[0001] This invention relates to the field of elevator shaft assembly technology, specifically a processing method for a high-quality stainless steel assembled shaft for home elevators. Background Technology

[0002] Home elevators, as a vertical transportation tool that enhances the convenience and comfort of life, are becoming increasingly popular in residential environments such as villas and duplexes. The elevator shaft, as the core load-bearing and safety protection structure, is of paramount importance in terms of performance and quality. The manufacturing and installation of home elevator shafts mainly take the following forms: traditional civil engineering shafts and on-site welded metal shafts.

[0003] The applicant discovered during the implementation of existing solutions that traditional civil engineering shafts are constructed using materials such as bricks and concrete during building construction or later renovations. This results in long construction cycles and difficulties in ensuring internal flatness and verticality, making it particularly unsuitable for later additions to existing residential buildings. While on-site welded metal shafts, using ordinary carbon steel profiles measured, cut, and welded on-site, reduce reliance on civil engineering to some extent, they heavily depend on the welder's skill level, leading to inconsistent welding quality and potential issues such as incomplete welds, leaks, and deformation, affecting structural strength. Furthermore, the welded shafts require on-site rust prevention treatment, but poor paint adhesion not only affects aesthetics but also makes it difficult to guarantee long-term rust prevention. Therefore, this invention designs a processing method for high-quality stainless steel assembled shafts for home elevators to solve the aforementioned problems. Summary of the Invention

[0004] The purpose of this invention is to provide a processing method for a high-quality stainless steel assembled shaft for home elevators, which solves the problems of long cycle time of traditional civil engineering shafts and the impact of on-site welded metal shafts on structural strength in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A method for processing a high-quality stainless steel assembled shaft for a home elevator, the method comprising the following steps:

[0007] Step S1, Digital Design and Material Selection: Based on the elevator's rated load, operating speed, shaft dimensions, and building environment data, three-dimensional parametric modeling and static and modal finite element analysis are performed to determine the structural form, material thickness, and strength requirements of each component of the shaft. High corrosion-resistant austenitic stainless steel is selected as the main material of the shaft, and its corrosion resistance is quantitatively controlled by the PREN value (presumably referring to a pitting corrosion resistance equivalent).

[0008] Where %Cr is the mass percentage of chromium, %Mo is the mass percentage of molybdenum, and %N is the mass percentage of nitrogen, and the PREN value of the selected stainless steel material is not less than 25;

[0009] Step S2 involves the prefabrication of high-precision profiles and plates. A multi-pass precision cold-bending process is used to manufacture shaft frame profiles with specific cross-sectional shapes. Laser cutting technology is employed for material preparation, and a CNC bending center is used to precisely bend the wall panels. During the bending process, a springback angle prediction and compensation model based on material mechanical properties is introduced. The expression of this model is:

[0010]

[0011] Where Δα is the springback angle of the sheet metal after bending, K is a correction factor related to the work hardening properties of the material, and σ s Let E be the yield strength of the material, R be the elastic modulus of the material, R be the inner radius of the bend in the sheet metal, and T be the thickness of the sheet metal; and the angle of the bending die is pre-compensated based on this model.

[0012] Step S3: Construction of the modular connection system. A rapid mechanical connection system based on a male-female mortise and tenon structure and an eccentric cam locker is designed and manufactured. The male-female mortise and tenon structure enables initial positioning and load-bearing of the components, while the eccentric cam locker enables final locking and prestress retention after connection, thereby achieving weldless assembly of the shaft frame and wall panels. The minimum preload required by the locker is calculated using the following formula:

[0013]

[0014] F min The minimum preload required for a single eccentric cam locker, M is the maximum mass of the elevator car system, g is the acceleration due to gravity, and S is the maximum preload required for a single eccentric cam locker. f The preset safety factor is n, which is the number of locking devices involved in the main force connection on a single-sided shaft frame, and μ is the friction coefficient between the connection interfaces; and the design is checked and performed in conjunction with the formula.

[0015] Step S4, on-site assembly and precision control: On the construction site, modular assembly is carried out in the order of foundation leveling, frame three-dimensional assembly and wall panel hanging; During the frame assembly stage, a total station is used to track and measure the verticality of the shaft guide rail mounting surface in real time, and dynamic correction is performed by an adjustable anchor bolt system set at the bottom of the shaft to ensure that the verticality of the shaft meets the preset dynamic precision control requirements throughout its entire height range.

[0016] Step S5, Comprehensive performance verification and long-term protection: After the overall assembly of the wellbore is completed, the sealing performance and operational stability are tested; elastic sealant is applied to all modular joints for continuous sealing, and a high-performance protective coating is applied to the inner and outer surfaces of the wellbore structure.

[0017] Preferably, in step S1, the finite element analysis includes static strength analysis and dynamic characteristic analysis; the static strength analysis is used to check the stress level of the shaft structure under extreme working conditions such as rated load and safety clamp action load, to ensure that the maximum equivalent stress is lower than the allowable stress of the material; the dynamic characteristic analysis is used to calculate the natural frequency and mode shape of the shaft structure, to ensure that its natural frequency can effectively avoid the excitation frequency of the elevator operation and prevent resonance.

[0018] Preferably, in step S2, the laser cutting process parameters are optimized and controlled using a specific energy model, wherein the specific energy model is:

[0019]

[0020] E v ρ is the specific energy of laser cutting, expressed in joules per cubic millimeter; P is the output power of the laser; v is the moving speed of the laser cutting head; and t is the thickness of the material being cut.

[0021] Preferably, in step S3, the mating of the male and female tenon and mortise structure adopts a micro-interference fit design, and the minimum interference amount δ is determined by calculation based on the thermal expansion properties of the material and the expected temperature difference of the working environment, as follows:

[0022]

[0023] Where δ is the minimum interference required to ensure connection reliability, α is the linear expansion coefficient of stainless steel, ΔT is the maximum ambient temperature difference expected to operate in the wellbore, and D is the nominal diameter of the tenon and mortise mating surface.

[0024] Preferably, in step S4, the adjustable anchor bolt system includes a threaded adjusting rod, a locking nut, and a load-bearing base plate; the elevation of the four corner points at the bottom of the shaft can be precisely adjusted by rotating the adjusting rod, and the dynamic accuracy control requirement refers to the allowable value of the shaft verticality deviation as the height changes; the total station is used for measurement, and the iterative adjustment algorithm is used to quickly converge to the accuracy requirement range.

[0025] The iterative adjustment algorithm includes: measuring verticality deviation, adjusting by rotating the adjustment rod, and repeating the measurement-adjustment steps until the deviation converges, with a maximum of 3 iterations.

[0026] Preferably, in step S5, the high-performance protective coating is a titanium nitride coating prepared by physical vapor deposition.

[0027] Preferably, the coating introduces residual compressive stress on the surface of the wellbore substrate, which is calculated using the following formula:

[0028]

[0029] σ c E represents the residual compressive stress present in the coating. c v is the elastic modulus of the coating. c Let Δα be the Poisson's ratio of the coating material. c ΔT represents the difference in thermal expansion coefficients between the coating material and the stainless steel substrate. c This is the difference between the coating deposition process temperature and the normal operating temperature of the wellbore.

[0030] Preferably, after step S5, an additional step is included:

[0031] A sound-absorbing and noise-reducing layer made of composite material is fixedly attached to the inner wall of the shaft. The sound-absorbing and noise-reducing layer consists of a closed-cell aluminum foam substrate and a non-woven fabric layer covering its surface. It is bonded to the stainless steel inner wall of the shaft by a high-temperature pressure-sensitive adhesive.

[0032] Preferably, the bottom of the shaft is equipped with a bottom support frame, which is an independent modular component; the bottom support frame is fixed to the building foundation by the adjustable anchor bolt system and serves as the reference plane for the three-dimensional assembly of the entire shaft; the first standardized shaft segment module is aligned and connected to the bottom support frame by the male and female tenon structure at its bottom and is fastened by the eccentric cam locker.

[0033] Preferably, the shaft is assembled on site from several standardized shaft segment modules. Each shaft segment module includes four columns, a crossbeam connecting the columns, and a wall panel installed in the frame. The columns and crossbeams, as well as adjacent segment modules, are positioned by the male and female tenon and mortise structure and fastened by the eccentric cam locker.

[0034] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0035] 1. In this invention, through digital design, modular prefabrication and rapid mechanical connection system, the traditional masonry process of civil engineering shaft and the welding operation of on-site welded shaft are completely eliminated. The components are prefabricated with high precision in the factory and only modular assembly is carried out on site, which greatly shortens the construction time. It is particularly suitable for the later addition of existing residential buildings and solves the problems of long construction cycle and strong dependence on existing building structure in traditional methods.

[0036] 2. In this invention, by introducing precision manufacturing technologies such as springback compensation model and laser cutting energy control, the processing accuracy of components is guaranteed. During the on-site assembly stage, the total station is used for real-time measurement and the adjustable anchor bolt system for dynamic correction, ensuring the verticality and flatness of the shaft throughout the entire height range, effectively overcoming the defects of traditional civil engineering shafts where the flatness and verticality are not easy to guarantee.

[0037] 3. In this invention, a weldless connection scheme based on male and female tenon and mortise positioning and eccentric cam locking is adopted. The preload and interference are determined by theoretical calculation, realizing high-precision positioning and reliable prestress retention of the connection interface. In addition, high corrosion-resistant austenitic stainless steel is selected and its pitting corrosion resistance is quantitatively controlled. At the same time, a high-performance protective coating prepared by physical vapor deposition process is applied to the surface. This coating has strong adhesion, wear resistance and corrosion resistance, which fundamentally solves the technical pain points of difficult on-site rust prevention treatment of carbon steel wellbore, poor paint film adhesion and difficulty in maintaining rust prevention effect. Attached Figure Description

[0038] Figure 1 This is a flowchart of the overall processing method of the present invention;

[0039] Figure 2 This is a structural diagram of the modular connection system of the present invention;

[0040] Figure 3 This is a schematic diagram of the assembly of the well section module of the present invention;

[0041] Figure 4 This is a flowchart of the precision control system of the present invention;

[0042] Figure 5 This is a flowchart of the material and protective treatment process of the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0044] Example 1;

[0045] Please see Figures 1-5 In this embodiment of the invention, a method for processing a high-quality stainless steel assembled shaft for a home elevator includes the following steps:

[0046] Step S1, Digital Design and Material Selection: Based on the elevator's rated load, operating speed, shaft dimensions, and building environment data, three-dimensional parametric modeling and static and modal finite element analysis are performed to determine the structural form, material thickness, and strength requirements of each component of the shaft. High corrosion-resistant austenitic stainless steel is selected as the main material of the shaft, and its corrosion resistance is quantitatively controlled by the pitting resistance equivalent PREN value.

[0047] Where %Cr is the mass percentage of chromium, %Mo is the mass percentage of molybdenum, and %N is the mass percentage of nitrogen, and the PREN value of the selected stainless steel material is not less than 25.

[0048] Step S2 involves the prefabrication of high-precision profiles and plates. A multi-pass precision cold-bending process is used to manufacture shaft frame profiles with specific cross-sectional shapes. Laser cutting technology is employed for material preparation, and a CNC bending center is used to precisely bend the wall panels. During the bending process, a springback angle prediction and compensation model based on material mechanical properties is introduced. The model's expression is:

[0049]

[0050] Where Δα is the springback angle of the sheet metal after bending, K is a correction factor related to the work hardening properties of the material, and σ s E is the yield strength of the material, R is the elastic modulus of the material, R is the inner radius of the bend in the sheet metal, and T is the thickness of the sheet metal; and the angle of the bending die is pre-compensated based on this model.

[0051] Step S3: Construction of the modular connection system. Design and manufacture a rapid mechanical connection system based on a male-female tenon and mortise structure and an eccentric cam locker. The male-female tenon and mortise structure enables the initial positioning and load-bearing of components, while the eccentric cam locker enables the final locking and prestress retention after connection, thereby achieving weldless assembly of the shaft frame and wall panel. The minimum preload required by the locker is calculated using the following formula:

[0052]

[0053] F min The minimum preload required for a single eccentric cam locker, M is the maximum mass of the elevator car system, g is the acceleration due to gravity, and S is the maximum preload required for a single eccentric cam locker. f The safety factor is defined as n, the number of locking devices involved in the main load-bearing connection on a single-sided shaft frame, and μ, the coefficient of friction between the connection interfaces. The design is verified using a formula derived from the principle of static equilibrium, ensuring the reliability of the connection system under dynamic loads and avoiding potential problems such as incomplete welding and deformation common in traditional welding methods.

[0054] Step S4, on-site assembly and precision control: On the construction site, modular assembly is carried out in the order of foundation leveling, frame three-dimensional assembly and wall panel hanging; During the frame assembly stage, a total station is used to track and measure the verticality of the shaft guide rail mounting surface in real time, and dynamic correction is performed by an adjustable anchor bolt system set at the bottom of the shaft to ensure that the verticality of the shaft meets the preset dynamic precision control requirements throughout its entire height range.

[0055] Step S5, Comprehensive performance verification and long-term protection: After the overall assembly of the wellbore is completed, the sealing performance and operational stability are tested; elastic sealant is applied to all modular joints for continuous sealing, and a high-performance protective coating is applied to the inner and outer surfaces of the wellbore structure.

[0056] In step S1, the finite element analysis includes static strength analysis and dynamic characteristic analysis. Static strength analysis is used to check the stress level of the shaft structure under extreme working conditions such as rated load and safety clamp action load, to ensure that the maximum equivalent stress is lower than the allowable stress of the material. Dynamic characteristic analysis is used to calculate the natural frequency and mode shape of the shaft structure, to ensure that its natural frequency can effectively avoid the excitation frequency during elevator operation and prevent resonance.

[0057] In step S2, the laser cutting process parameters are optimized and controlled using a specific energy model, which is as follows:

[0058]

[0059] E v ρ is the specific energy of laser cutting, expressed in joules per cubic millimeter, P is the output power of the laser, v is the moving speed of the laser cutting head, and t is the thickness of the material being cut. This model is based on the principle of energy density. By adjusting the power and speed, the specific energy is kept within the optimal range to ensure a smooth cut surface without a heat-affected zone, thus avoiding the burrs and deformation problems in traditional cutting.

[0060] In step S3, the male and female tenon and mortise structure adopts a slight interference fit design. The minimum interference amount δ is determined by calculation based on the thermal expansion properties of the material and the expected temperature difference of the working environment, as follows:

[0061]

[0062] Where δ is the minimum interference required to ensure connection reliability, α is the linear expansion coefficient of stainless steel, ΔT is the maximum ambient temperature difference expected to operate in the wellbore, and D is the nominal diameter of the tenon and mortise mating surface. This formula is based on the theory of thermal expansion and takes into account the influence of temperature changes on the mating clearance, ensuring that the connection remains tight under ambient temperature differences and preventing loosening.

[0063] In step S4, the adjustable anchor bolt system includes a threaded adjusting rod, a locking nut, and a load-bearing base plate; the elevation of the four corner points at the bottom of the shaft can be precisely adjusted by rotating the adjusting rod. The dynamic accuracy control requirement refers to the allowable value of the shaft verticality deviation as the height changes; a total station is used for measurement, and the iterative adjustment algorithm is used to quickly converge to the accuracy requirement range.

[0064] In step S5, the high-performance protective coating is a titanium nitride coating prepared by physical vapor deposition.

[0065] The coating introduces residual compressive stress on the surface of the wellbore substrate, which is calculated using the following formula:

[0066]

[0067] σ c E represents the residual compressive stress present in the coating. c v is the elastic modulus of the coating. c Let Δα be the Poisson's ratio of the coating material. c ΔT represents the difference in thermal expansion coefficients between the coating material and the stainless steel substrate. c This is the difference between the coating deposition process temperature and the normal operating temperature of the wellbore.

[0068] The working principle of this invention is as follows: In terms of material selection, highly corrosion-resistant austenitic stainless steel is chosen. Its corrosion resistance is quantitatively controlled using the Pren (Prep) formula, where %Cr is the mass percentage of chromium, %Mo is the mass percentage of molybdenum, and %N is the mass percentage of nitrogen. The PREN value is not less than 25 to ensure that the material still has excellent pitting corrosion resistance in harsh environments. This formula originates from the standardized assessment of the corrosion resistance of stainless steel in the field of materials science. Chromium, molybdenum, and nitrogen can form a dense oxide film, improving corrosion resistance.

[0069] In the prefabrication of high-precision profiles and plates, this step manufactures shaft frame profiles through a multi-pass precision cold bending forming process, and uses laser cutting and CNC bending technology for material cutting and forming. In the bending process, a springback angle prediction and compensation model is introduced.

[0070]

[0071] In this formula, Δα is the springback angle of the sheet metal after bending, K is a correction coefficient related to the work hardening characteristics of the material, and σ is determined experimentally. sLet E be the yield strength of the material, E be the elastic modulus of the material, R be the inner radius of the bend in the sheet metal, and T be the thickness of the sheet metal. This model is based on the springback theory in mechanics of materials, taking into account the influence of material properties and geometric parameters on springback. By predicting the springback angle and pre-compensating for the bending die angle, it ensures bending accuracy, solves the dimensional deviation problem caused by springback in traditional bending, and improves component interchangeability and assembly efficiency.

[0072] In step S4, modular assembly is carried out on the construction site. A total station is used to measure the verticality of the shaft guide rail mounting surface in real time, and dynamic correction is performed using an adjustable anchor bolt system. The adjustable anchor bolt system includes a threaded adjusting rod, a locking nut, and a load-bearing base plate. The elevation of the bottom corner point of the shaft is precisely adjusted by rotating the adjusting rod. The allowable value of verticality deviation varying with height is quickly converged through an iterative adjustment algorithm, ensuring that the verticality meets the requirements throughout the entire height range of the shaft. This design solves the problem of difficulty in ensuring the flatness and verticality of traditional civil engineering shafts, improving installation accuracy and efficiency.

[0073] In step S5, after the wellbore assembly is completed, sealing performance and operational stability tests are performed. Elastic sealant is applied to all joints for continuous sealing to prevent air leakage and noise. A high-performance protective coating, such as a titanium nitride coating, is prepared using a physical vapor deposition process, and its residual compressive stress is calculated using a formula based on thermal mismatch theory. This formula can inhibit crack propagation, enhance coating adhesion and wear resistance, and solve the problems of poor adhesion and inadequate rust prevention in traditional paint films.

[0074] Example 2;

[0075] Please see Figures 1-5 In this embodiment of the invention, after step S5, a further step is included:

[0076] A sound-absorbing and noise-reducing layer made of composite material is fixedly attached to the inner wall of the shaft. The sound-absorbing and noise-reducing layer consists of a closed-cell aluminum foam substrate and a non-woven fabric layer covering its surface. It is bonded to the stainless steel inner wall of the shaft by a high-temperature pressure-sensitive adhesive.

[0077] The bottom of the shaft is equipped with a bottom support frame, which is an independent modular design. The bottom support frame is fixed to the building foundation by an adjustable anchor bolt system and serves as the reference plane for the three-dimensional assembly of the entire shaft. The first standardized shaft segment module is aligned and connected to the bottom support frame by the male and female tenon structure at its bottom and is fastened by an eccentric cam locker.

[0078] The shaft is assembled on site from several standardized shaft segment modules. Each shaft segment module includes four columns, crossbeams connecting the columns, and wall panels installed in the frame. The columns and crossbeams, as well as adjacent segment modules, are positioned by a male and female tenon and mortise structure and fastened by an eccentric cam locker.

[0079] The working principle of this invention is as follows: After step S5, a sound-absorbing and noise-reducing layer composed of closed-cell aluminum foam substrate and non-woven fabric layer is fixedly attached to the inner wall of the shaft and bonded with high-temperature pressure-sensitive adhesive. Closed-cell aluminum foam has a porous structure, which can effectively absorb sound wave energy and reduce noise propagation; the non-woven fabric layer further suppresses high-frequency vibrations. This design solves the noise problem during elevator operation and improves the comfort of the home environment. Its working principle is based on acoustic impedance matching theory; the composite material layer can effectively dissipate sound energy, and the high-temperature adhesive ensures that it remains firmly attached under temperature changes.

[0080] The bottom of the shaft is equipped with an independent modular bottom support frame, which is fixed to the building foundation via an adjustable anchor bolt system, serving as the reference plane for the entire shaft's three-dimensional assembly. The first standardized shaft segment module is aligned and connected to the bottom support frame via a male-female tenon joint structure at its bottom, and secured with an eccentric cam locker. This design ensures the accuracy and stability of the assembly reference, solving the problem of verticality deviation caused by on-site measurement errors. Its working principle is based on modular theory, achieving rapid and weld-free assembly through standardized interfaces and mechanical locking.

[0081] The shaft is assembled on-site from several standardized shaft segment modules. Each module includes four columns, beams, and wall panels. The columns and beams, as well as adjacent segment modules, are positioned by a male and female tenon and mortise structure and fastened by an eccentric cam locker. This design realizes the scalability and repeatability of the shaft and solves the problems of long construction cycle and high customization cost of traditional civil engineering shafts.

[0082] Example 3;

[0083] Please see Figures 1-5 This paper provides a specific embodiment of a residential elevator shaft. Based on the elevator's rated load of 400 kg, operating speed of 0.4 m / s, and shaft dimensions of 1600 mm × 1500 mm, a three-dimensional parametric model is constructed. Static finite element analysis is used to verify the stress level of the shaft under 1.5 times the rated load and the safety clamp operation condition, ensuring that the maximum equivalent stress does not exceed 125 MPa. Dynamic characteristic analysis calculates that the first natural frequency of the shaft structure is 18 Hz, effectively avoiding the common excitation frequency range of 3 to 15 Hz during elevator operation, thus preventing resonance.

[0084] The material is austenitic stainless steel, with a chemical composition that meets the requirements of 18.2% chromium, 2.1% molybdenum, and 0.2% nitrogen by mass. Calculated according to the pitting resistance equivalent formula, the PREN value is 25.5, which is higher than the minimum requirement of 25, ensuring high corrosion resistance.

[0085] The shaft support column profile is manufactured through a five-stage precision cold bending process, with a cross-sectional shape of 50 mm × 50 mm square tube and a wall thickness of 2.0 mm. The wall panel is made of 1.5 mm thick stainless steel plate, cut by laser cutting. The laser output power is 4000 watts, and the cutting head movement speed is 20 mm per second. According to the specific energy model, the specific energy is calculated to be 133.3 joules per cubic millimeter, ensuring cutting quality.

[0086] The panel was bent at a CNC bending center with a bending radius of 3.0 mm. Based on the springback angle prediction model, the material yield strength was taken as 205 MPa, the elastic modulus as 195 GPa, and the correction factor as 0.85, resulting in a calculated springback angle of 0.8 degrees. The bending die angle was pre-compensated accordingly, and the actual bending angle was set to 89.2 degrees. After bending, the springback returned to the designed angle of 90 degrees, ensuring forming accuracy.

[0087] The male and female mortise and tenon structure adopts a slight interference fit design, with a nominal tenon diameter of 30 mm. Based on the material's linear expansion coefficient of 1.7 × 10⁻⁶, this is suitable for applications where the tenon has a nominal diameter of 30 mm. -5 For each degree Celsius, the expected temperature difference in the working environment is 40 degrees Celsius. The calculated minimum interference δ is 0.0204 mm, and the actual design interference is 0.025 mm, ensuring that the connection does not loosen under high temperature conditions.

[0088] The minimum preload of the eccentric cam locker is calculated based on the maximum mass of the car system (600 kg), a safety factor of 2.0, four lockers on one side, and a friction coefficient of 0.15. The calculated minimum preload required for a single locker is 4905 N. The selected locker provides a preload of 5000 N, which meets the safety requirements.

[0089] At the construction site, the foundation was first leveled using an adjustable anchor bolt system with a 2mm pitch, and the elevation was precisely adjusted by rotating the bolts. A total station was used to measure the shaft guide rail mounting surface in real time. Within a 12-meter height, the verticality deviation was controlled within 5mm. Through an iterative adjustment algorithm, the deviation was converged to 3mm within three adjustments, meeting the dynamic accuracy control requirements.

[0090] After the hoistway was assembled, an airtightness test was conducted, and the leakage was less than 5 cubic meters per hour under a pressure difference of 100 Pa. In the operational stability test, the car's vibration acceleration was less than 0.15 m / s². Silicone elastic sealant was applied to all joints for continuous sealing. A titanium nitride coating with a thickness of 3 micrometers was prepared on the inner and outer surfaces of the hoistway using physical vapor deposition. Based on the residual compressive stress formula, the coating's elastic modulus was taken as 250 GPa, Poisson's ratio as 0.25, and the coefficient of thermal expansion difference as 4.2 × 10⁻⁶. -6 For every degree Celsius difference in process temperature (300 degrees Celsius), the calculated residual compressive stress is -1.26 gigapascals, which effectively improves surface hardness and wear resistance.

[0091] A sound-absorbing and noise-reducing layer was fixedly attached to the inner wall of the shaft. This layer, made of closed-cell aluminum foam substrate, was 10 mm thick and covered with a 0.5 mm thick non-woven fabric layer. It was then bonded using a high-temperature pressure-sensitive adhesive with a 0.1 mm thick adhesive layer. Testing showed that the noise level inside the shaft was reduced to below 45 decibels.

[0092] An independent modular support frame is installed at the bottom of the shaft, serving as the assembly reference plane. The first standardized shaft segment module is aligned and connected to the support frame via a bottom tenon and mortise structure, and secured with an eccentric cam locker. The entire shaft is assembled on-site from eight standard segment modules. Each module is 1.5 meters high and includes four columns, four crossbeams, and four wall panels, achieving rapid, weld-free assembly. The total installation time is controlled within eight hours.

[0093] Working Principle: This invention provides a systematic processing method for high-quality stainless steel assembled shafts for home elevators. Its core working principle lies in achieving structural optimization and scientific material selection through digital design and finite element analysis; ensuring component forming accuracy by introducing precision processing technologies such as springback angle prediction and compensation models and laser cutting specific energy control; achieving highly reliable modular assembly without welding through a mechanical connection system composed of male and female tenons and eccentric cam lockers; and finally ensuring the long-term operational stability and durability of the shaft through high-precision on-site control and high-performance coating protection.

[0094] A composite sound-absorbing and noise-reducing layer made of closed-cell aluminum foam and non-woven fabric is added inside the shaft to effectively reduce operating noise through the principle of sound energy dissipation. At the same time, an independent modular bottom support frame is introduced as a precise benchmark for the three-dimensional assembly of the entire shaft. Through quick alignment and connection with the first standard module, the initial installation accuracy and stability of the overall structure are ensured. This design enhances the comfort of using the shaft and further improves the standardization and efficiency of on-site modular assembly.

[0095] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A processing method for a high-quality stainless steel assembled shaft for home elevators, characterized in that, The method includes the following steps: Step S1, Digital Design and Material Selection: Based on the elevator's rated load, operating speed, shaft dimensions, and building environment data, three-dimensional parametric modeling and static and modal finite element analysis are performed to determine the structural form, material thickness, and strength requirements of each component of the shaft. High corrosion-resistant austenitic stainless steel is selected as the main material of the shaft, and its corrosion resistance is quantitatively controlled by the PREN value (presumably referring to a pitting corrosion resistance equivalent). Where %Cr is the mass percentage of chromium, %Mo is the mass percentage of molybdenum, and %N is the mass percentage of nitrogen, and the PREN value of the selected stainless steel material is not less than 25; Step S2 involves the prefabrication of high-precision profiles and plates. A multi-pass precision cold-bending process is used to manufacture shaft frame profiles with specific cross-sectional shapes. Laser cutting technology is employed for material preparation, and a CNC bending center is used to precisely bend the wall panels. During the bending process, a springback angle prediction and compensation model based on material mechanical properties is introduced. The expression of this model is: Where Δα is the springback angle of the sheet metal after bending, K is a correction factor related to the work hardening characteristics of the material, determined through tensile and bending tests, with a typical range of 0.8-1.2, and σ s Let E be the yield strength of the material, R be the elastic modulus of the material, R be the inner radius of the bend in the sheet metal, and T be the thickness of the sheet metal; and the angle of the bending die is pre-compensated based on this model. Step S3: Construction of the modular connection system. A rapid mechanical connection system based on a male-female mortise and tenon structure and an eccentric cam locker is designed and manufactured. The male-female mortise and tenon structure enables initial positioning and load-bearing of the components, while the eccentric cam locker enables final locking and prestress retention after connection, thereby achieving weldless assembly of the shaft frame and wall panels. The minimum preload required by the locker is calculated using the following formula: F min The minimum preload required for a single eccentric cam locker, M is the maximum mass of the elevator car system, g is the acceleration due to gravity, and S is the maximum preload required for a single eccentric cam locker. f The preset safety factor is determined according to elevator safety standards and is set to 2.0-3.

0. n is the number of locking devices on a single-sided shaft frame that participate in the main load-bearing connection, and μ is the friction coefficient between the connection interfaces, which is determined through material pairing tests. The design is then checked and verified in conjunction with the formula. Step S4, on-site assembly and precision control: On the construction site, modular assembly is carried out in the order of foundation leveling, frame three-dimensional assembly and wall panel hanging; During the frame assembly stage, a total station is used to track and measure the verticality of the shaft guide rail mounting surface in real time, and dynamic correction is performed by an adjustable anchor bolt system set at the bottom of the shaft to ensure that the verticality of the shaft meets the preset dynamic precision control requirements throughout its entire height range. Step S5, Comprehensive performance verification and long-term protection: After the overall assembly of the wellbore is completed, the sealing performance and operational stability are tested; elastic sealant is applied to all modular joints for continuous sealing, and a high-performance protective coating is applied to the inner and outer surfaces of the wellbore structure.

2. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that: In step S1, the finite element analysis includes static strength analysis and dynamic characteristic analysis. The static strength analysis is used to check the stress level of the shaft structure under extreme conditions of rated load and safety clamp action load, to ensure that the maximum equivalent stress is lower than the allowable stress of the material. The dynamic characteristic analysis is used to calculate the natural frequency and mode shape of the shaft structure, to ensure that its natural frequency can effectively avoid the excitation frequency of the elevator operation and prevent resonance.

3. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that: In step S2, the laser cutting process parameters are optimized and controlled using a specific energy model, which is: E v ρ is the specific energy of laser cutting, expressed in joules per cubic millimeter; P is the output power of the laser; v is the moving speed of the laser cutting head; and t is the thickness of the material being cut.

4. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that: In step S3, the male and female tenon and mortise structure adopts a micro-interference fit design. The minimum interference amount δ is calculated and determined based on the thermal expansion properties of the material and the expected temperature difference of the working environment using the following formula: Where δ is the minimum interference required to ensure connection reliability, α is the linear expansion coefficient of stainless steel, ΔT is the maximum ambient temperature difference expected to operate in the wellbore, and D is the nominal diameter of the tenon and mortise mating surface.

5. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that: In step S4, the adjustable anchor bolt system includes a threaded adjusting rod, a locking nut, and a load-bearing base plate; the elevation of the four corner points at the bottom of the shaft can be precisely adjusted by rotating the adjusting rod; the dynamic accuracy control requirement refers to the allowable value of the shaft verticality deviation as the height changes; the total station is used for measurement, and the iterative adjustment algorithm is used to quickly converge to the accuracy requirement range.

6. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that, In step S5, the high-performance protective coating is a titanium nitride coating prepared by physical vapor deposition.

7. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 6, characterized in that: The coating introduces residual compressive stress on the surface of the wellbore substrate, which is calculated using the following formula: σ c E represents the residual compressive stress present in the coating. c v is the elastic modulus of the coating. c Let Δα be the Poisson's ratio of the coating material. c ΔT represents the difference in thermal expansion coefficients between the coating material and the stainless steel substrate. c This is the difference between the coating deposition process temperature and the normal operating temperature of the wellbore.

8. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that, Following step S5, the following step is also included: A sound-absorbing and noise-reducing layer made of composite material is fixedly attached to the inner wall of the shaft. The sound-absorbing and noise-reducing layer consists of a closed-cell aluminum foam substrate and a non-woven fabric layer covering its surface. It is bonded to the stainless steel inner wall of the shaft by a high-temperature pressure-sensitive adhesive.

9. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that, The bottom of the shaft is equipped with a bottom support frame, which is an independent modular structure. The bottom support frame is fixed to the building foundation by the adjustable anchor bolt system and serves as the reference plane for the three-dimensional assembly of the entire shaft. The first standardized shaft segment module is aligned and connected to the bottom support frame by the male and female tenon structure at its bottom and is fastened by the eccentric cam locker.

10. The processing method of a high-quality stainless steel assembled shaft for a home elevator according to claim 1, characterized in that: The shaft is assembled on site from several standardized shaft segment modules. Each shaft segment module includes four columns, a crossbeam connecting the columns, and a wall panel installed in the frame. The columns and crossbeams, as well as adjacent segment modules, are positioned by the male and female tenon and mortise structure and fastened by the eccentric cam lock.

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