Elevator guide rail surface finishing process based on sound wave assistance

Abstract

The invention discloses an elevator guide rail surface finishing process based on sound wave assistance, and belongs to the technical field of precision machining, the elevator guide rail surface finishing process based on sound wave assistance is characterized in that a guide rail is positioned through an adjustable V-shaped clamp, and a Venturi nozzle is mixed with nanometer aluminum oxide abrasive particles to form a gas-solid two-phase flow for surface impact; the ultrasonic vibration system is synchronously activated to enhance the impact uniformity of the abrasive particles, the laser displacement sensor is used for detecting and dynamically adjusting the concentration of the abrasive particles in real time, and finally the abrasive particles are recycled through the three-stage recovery system. Through high-precision positioning, multi-parameter closed-loop control and resource recycling, the machining quality and stability are remarkably improved, and the method is suitable for carbon steel, stainless steel and composite guide rails and has the advantages of being efficient, environmentally friendly and low in energy consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision machining, and specifically relates to a surface finishing process for elevator guide rails assisted by acoustic waves. Background Art

[0002] As a core guiding component for elevator operation, the surface roughness and straightness of elevator guide rails directly affect the smoothness, safety, and service life of elevator operation; with the popularization of high-rise buildings, the market demand for high-precision guide rails is increasing day by day, and the quality of the guide rail surface finishing process has become a key factor restricting the improvement of elevator performance. However, the current traditional finishing processes have the following problems: low efficiency, relying on manual parameter adjustment, and it is difficult to meet the processing requirements of different material guide rails such as carbon steel, stainless steel, and composite materials; insufficient precision, uneven abrasive particle distribution in the traditional gas-solid flow impact process, which is likely to cause rough surface topography or local over-grinding; serious pollution, ineffective recovery of dry processing dust, high waste rate of nano-abrasive particles, and excessive emission concentration, and a large amount of industrial wastewater is generated in wet processing, and the treatment cost of the waste liquid containing abrasive particles accounts for 15%-20% of the total processing cost; lack of dynamic control, unable to monitor the roughness in real time and dynamically adjust parameters, resulting in poor processing consistency.

[0003] Therefore, there is an urgent need for a surface finishing process that can take into account high precision, high efficiency, low pollution, and has dynamic feedback and automatic control to break through the limitations of traditional technologies. Summary of the Invention

[0004] In view of the above pain points, the present invention provides a surface finishing process for elevator guide rails assisted by acoustic waves, which realizes high-precision, low-pollution, and fully automated guide rail surface processing through the synergistic impact of ultrasonic vibration and gas-solid two-phase flow, real-time roughness feedback regulation, and efficient dust recovery.

[0005] The solution of the present invention is as follows:

[0006] A surface finishing process for elevator guide rails assisted by acoustic waves, characterized by comprising the following steps:

[0007] S1. Fix the elevator guide rail through an adjustable V-shaped fixture, read the guide rail material label and automatically retrieve the corresponding processing parameters;

[0008] S2. Start the compressed air system, mix with nano-aluminum oxide abrasive particles through a Venturi nozzle to form a gas-solid two-phase flow, and use it to impact the guide rail surface to achieve initial surface flattening;

[0009] S3. While the gas-solid flow impacts the guide rail surface, activate the ultrasonic vibration system to make the ultrasonic vibration and the gas-solid two-phase flow act synergistically, enhance the frequency and uniformity of the abrasive particle impact through high-frequency vibration, and further improve the surface processing precision and refine the surface topography;

[0010] S4. Real - time scan the surface roughness through a laser displacement sensor and adjust the processing parameters to ensure that the surface accuracy always meets the process requirements;

[0011] S5. Recycle the dust generated during processing. Extract reusable nano - abrasive grains from the dust through cyclone separation, filtration, and magnetic separation technologies. After screening and regeneration, they are recycled;

[0012] S6. After the surface roughness and straightness meet the standards, cut the guide rail.

[0013] Preferably, the adjustable V - type fixture uses the bottom surface and side guiding surface of the guide rail as the positioning reference, drives the positioning block to move through a servo - motor, adapts to T - type solid guide rails and J - type hollow guide rails, and the positioning accuracy is ±0.03 mm.

[0014] Preferably, the inner wall of the Venturi nozzle is provided with spiral diversion grooves with a pitch of 1 - 3 mm and a depth of 0.3 - 0.7 mm, which are mixed with nano - alumina abrasive grains with a particle size ≤50 nm. The abrasive grain concentration is controlled by a servo - screw feeder to be 10 - 50 g / m 3 , and the feeding accuracy is ±0.5 g / min.

[0015] Preferably, the Venturi nozzle moves along the axis of the guide rail at a speed of 0.3 - 0.8 m / min, and at the same time activates the ultrasonic vibration system.

[0016] Preferably, the ultrasonic vibration system includes a piezoelectric ceramic transducer and a tapered conical horn. The transducer generates high - frequency vibrations of 20 - 30 kHz, and the horn amplifies the amplitude to 5 - 10 μm. The air - solid flow impact frequency is dynamically matched through a bolt pre - tightening force adjustment device, and the frequency difference ≤0.5 kHz.

[0017] Preferably, the accuracy of the laser displacement sensor is ≤±1 μm, the scanning interval is 50 - 100 mm, and the detection density can be automatically switched according to the guide rail material label to detect the surface roughness Ra in real - time; each time the surface scan is triggered, based on the formula:

[0018]

[0019] Dynamically adjust the abrasive grain concentration; where C is the real - time abrasive grain concentration, unit, g / m 3 , C0 is the initial concentration, v0 is the reference speed, unit, m / min, v is the real - time feed speed, and ΔRa is the roughness deviation value, unit, μm.

[0020] Preferably, when the real - time detected surface roughness Ra is greater than the preset value, the compensation term (1 + 0.1×ΔRa) in the formula will make the abrasive grain concentration increase linearly with the increase of the roughness deviation value ΔRa, realizing the dynamic compensation of the material removal efficiency.

[0021] Preferably, the dust recovery treatment includes: a primary cyclone separator, a secondary bag filter, and a tertiary activated carbon adsorption. After magnetic separation and screening regeneration of the abrasive grains, the recycling rate is ≥ 85%, and the emission concentration is < 10 mg / m 3 .

[0022] Preferably, the processing environment of the gas-solid two-phase flow is a dry environment without liquid medium, and the guide rail material includes carbon steel, stainless steel, or composite material.

[0023] Preferably, the adjustable V-type fixture, Venturi nozzle, ultrasonic vibration system, and dust recovery treatment system are integrated on the same processing platform, and the whole process is automated through the PLC control system.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] (1) Process automation: The adjustable V-type fixture uses the bottom surface and side guide surface of the guide rail as the positioning reference, and drives the positioning block to move through the servo motor, accurately adapting to the T-shaped solid guide rail and J-shaped hollow guide rail, with a positioning accuracy of ±0.05 mm; The PLC control system integrates a laser displacement sensor, which can automatically retrieve parameters, switch the detection density according to the guide rail material label, and dynamically adjust the abrasive grain concentration based on the real-time roughness deviation, realizing the full-process automation from positioning, processing to detection, with a short changeover time and high processing consistency;

[0026] (2) Dry and environmentally friendly processing: Adopting a gas-solid two-phase flow processing environment without liquid medium, thoroughly avoiding the wastewater pollution problem of traditional wet processes; The dust recovery system realizes an emission concentration of < 10 mg / m 3 through primary cyclone separation, secondary bag filtration, and tertiary activated carbon adsorption. At the same time, the recycling rate of nano-abrasive grains is ≥ 85% after magnetic separation and screening regeneration, greatly reducing material consumption and environmental burden;

[0027] (3) Multi-material adaptability and efficient resource utilization: The inner wall of the Venturi nozzle is provided with spiral diversion grooves with a pitch of 1 - 3 mm and a depth of 0.3 - 0.7 mm, which are mixed with nano-aluminum oxide abrasive grains with a particle size of ≤ 50 nm to form a gas-solid two-phase flow. The abrasive grain concentration is controlled at 10 - 50 g / m 3 by the servo spiral feeder, which can adapt to various guide rail materials such as carbon steel, stainless steel, and composite materials; The abrasive grain recycling and regeneration technology significantly improves resource utilization rate, reduces processing costs, and enhances process applicability at the same time. Description of the Drawings

[0028] Figure 1 It is a process flow schematic diagram of the elevator guide rail surface finishing process based on acoustic wave assistance. Detailed Embodiments

[0029] The technical solutions of the embodiments of the present invention will be explained and described below. However, the following embodiments are only the preferred embodiments of the present invention, not all of them. Based on the embodiments in the implementation manners, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present invention.

[0030] Embodiment 1

[0031] I. Application Scenario

[0032] For a carbon steel guide rail with a specification of 125T: the material is Q235, the initial roughness is Ra 3.2 μm, surface finishing is carried out, and the target roughness is Ra ≤ 0.4 μm, and the straightness is ≤ 0.5 mm / m.

[0033] II. Detailed Process Steps

[0034] S1. Guide Rail Positioning and Parameter Retrieval

[0035] Place the 125T carbon steel guide rail on an adjustable V-shaped fixture, with the bottom width of 125 mm and the side guide surface height of 14 mm as the positioning reference. The servo motor drives the positioning block to move, and the axis of the guide rail is calibrated by a laser alignment instrument, with a positioning accuracy of ±0.05 mm; after the fixture reads the guide rail material label, it automatically retrieves the preset parameters: the pitch of the Venturi nozzle is 2 mm, the depth is 0.5 mm, the initial concentration of abrasive grains C0 = 20 g / m 3 , the ultrasonic vibration frequency is 25 kHz, and the reference feed speed v0 = 0.5 m / min.

[0036] S2. Initial Flattening Processing of Gas-Solid Two-Phase Flow

[0037] Start the compressed air system. Air with a pressure of 0.6 MPa forms a high-speed air flow of 80 m / s through the Venturi nozzle, and is mixed with 30 nm nano-aluminum oxide abrasive grains to form a gas-solid two-phase flow; the servo screw feeder controls the abrasive grain concentration at 20 g / m with an accuracy of ±0.5 g / min 3 , the nozzle moves along the axis of the guide rail at a speed of 0.5 m / min, impacts for 3 minutes to remove the surface oxide scale, and the initial roughness is reduced to Ra 1.6 μm.

[0038] S3. Ultrasonic Vibration-Assisted Strengthening Processing

[0039] The piezoelectric ceramic transducer generates high-frequency vibration of 25 kHz, and the amplitude is amplified to 8 μm through a tapered horn; through the bolt pre-tightening force adjustment device, the difference between the ultrasonic vibration frequency and the gas-solid flow impact frequency is controlled within 0.2 kHz to form a resonance effect, so that the abrasive grain impact frequency is increased to 50 kHz to refine the surface texture.

[0040] S4. Laser Real-Time Detection and Parameter Adjustment

[0041] Laser displacement sensor, with the precision set to ±1μm; Scanning at intervals of 75mm, the local Ra = 0.6μm is detected for the first time, and the roughness deviation ΔRa = 0.2μm is calculated. Based on the dynamic adjustment formula for abrasive concentration:

[0042]

[0043] In the formula, C is the real-time abrasive concentration, unit: g / m 3 , C0 is the initial concentration, v0 is the reference speed, unit: m / min, v is the real-time feed speed, and ΔRa is the roughness deviation value, unit: μm;

[0044] This formula is based on the theory of gas-solid two-phase flow impact machining, and realizes dynamic parameter compensation by establishing the coupling relationship between abrasive concentration, feed speed, and roughness deviation: When the feed speed becomes faster, the impact time of the abrasive on the guide rail will decrease, so the abrasive concentration needs to be increased in the opposite proportion of the speed to compensate; At the same time, if the surface roughness exceeds the target value by 1 micron, the abrasive concentration needs to be increased by an additional 10%. This 10% compensation ratio is determined through multiple experiments. Combining the adjustment logics of these two aspects forms the dynamic adjustment formula;

[0045] Since the current feed speed v = 0.5m / min is the same as the reference speed v0, substituting ΔRa = 0.2μm into the calculation gives the real-time concentration C = 20×1×(1 + 0.1×0.2) = 20.4g / m 3 ; The servo feeder completes the concentration adjustment within 10 seconds. After continuous processing for 2 minutes, the secondary scan shows that Ra drops to 0.35μm.

[0046] S5. Dust recovery and abrasive regeneration

[0047] The processing dust is treated in three stages: The first-stage cyclone separator separates particles larger than 5μm, the second-stage bag filter intercepts dust with a size of 0.1 - 5μm, and the third-stage activated carbon adsorbs to purify the gas. The measured emission concentration is 8mg / m 3 ; The magnetic separation device removes iron filings from the abrasive. After screening, 90% of the nano-aluminum oxide abrasives can be recycled, and the recycling rate reaches 85%.

[0048] S6. Qualified blanking

[0049] Finally, the surface roughness Ra of the detected guide rail is 0.32μm, and the straightness is 0.3mm / m, both of which are better than the process requirements; The processing cycle is 8 minutes, and the abrasive consumption is reduced by 35% compared with the traditional process.

[0050] Example 2

[0051] I. Application scenario

[0052] For austenitic stainless steel guide rails with the specification of T89B: the material is 06Cr19Ni10, the initial roughness Ra is 2.5μm, and surface finishing is carried out. The target roughness Ra ≤ 0.2μm and the straightness ≤ 0.3mm / m to meet the low-noise operation requirements of high-speed elevators at 4.0m / s.

[0053] II. Detailed process steps

[0054] S1. Guide rail positioning and parameter retrieval

[0055] Place the T89B stainless steel guide rail on an adjustable V-shaped fixture, with the bottom surface and the side guiding surface as the positioning reference. Calibrate the axis of the guide rail through a laser alignment instrument, and the positioning accuracy reaches ±0.03mm. After the fixture reads the material label of the guide rail, it automatically retrieves the preset parameters: the pitch of the Venturi nozzle is 1.5mm, the depth is 0.4mm, the initial concentration C0 of nano-aluminum oxide abrasive grains is 20g / m 3 , the ultrasonic vibration frequency is 30kHz, and the reference feed speed v0 = 0.4m / min.

[0056] S2. Initial flat processing of gas-solid two-phase flow

[0057] Start the compressed air system. The air with a pressure of 0.7MPa forms a high-speed air flow of 90m / s through the Venturi nozzle and mixes with 30nm nano-aluminum oxide abrasive grains to form a gas-solid two-phase flow. The servo screw feeder controls the abrasive grain concentration at 20g / m with an accuracy of ±0.3g / min 3 , and the nozzle moves along the axis of the guide rail at a speed of 0.4m / min, impacts for 2.5 minutes to remove the surface oxide layer, and the initial roughness is reduced to Ra1.2μm.

[0058] S3. Ultrasonic vibration assisted strengthening processing

[0059] The piezoelectric ceramic transducer generates high-frequency vibration of 30kHz, and the amplitude is amplified to 8μm through a tapered horn. Through the phase modulation system, the difference between the ultrasonic vibration frequency and the impact frequency of the gas-solid flow is controlled within 0.3kHz to form a resonance effect, so that the impact frequency of the abrasive grains is increased to 60kHz to refine the surface texture.

[0060] S4. Laser real-time detection and parameter adjustment

[0061] The laser displacement sensor has an accuracy set at ±0.5μm; it scans at intervals of 50mm. When it first detects that the local Ra = 0.35μm, calculate the roughness deviation ΔRa = 0.15μm. Based on the dynamic adjustment formula of abrasive grain concentration:

[0062]

[0063] Since the current feed rate v = 0.4 m / min is consistent with the reference speed v0, substituting ΔRa = 0.15 μm into the calculation gives the real-time concentration C = 20×1×(1 + 0.1×0.15) = 20.3 g / m 3 ; The servo feeder completes the concentration adjustment within 8 seconds. After continuous processing for 1.5 minutes, the secondary scanned Ra drops to 0.18 μm.

[0064] S5. Dust recovery and abrasive regeneration

[0065] The processing dust is treated in three stages: the first-stage cyclone separator separates particles larger than 5 μm, the second-stage bag filter intercepts dust with a size of 0.1 - 5 μm, and the third-stage activated carbon adsorber purifies the gas. The measured emission concentration is 5 mg / m 3 ; The magnetic separation device removes iron filings from the abrasives. After screening, 90% of the nano-aluminum oxide abrasives can be recycled, and the recycling rate reaches 85%.

[0066] S6. Qualified blanking

[0067] Finally, the measured surface roughness Ra of the guide rail is 0.18 μm, and the straightness is 0.25 mm / m, both of which are better than the process requirements; the processing cycle is 7 minutes, and the abrasive consumption is reduced by 40% compared with the traditional process.

[0068] Example 3

[0069] I. Application scenario

[0070] A certain high-end elevator enterprise performs surface finishing on a carbon fiber reinforced composite (CFRP) guide rail: the material is T700 / epoxy resin, and the initial roughness Ra is 3.8 μm; the target roughness is Ra ≤ 0.6 μm, and the surface hardness is ≥ 300 HV to meet the requirements of lightweight and high wear resistance.

[0071] II. Detailed process steps

[0072] S1. Guide rail positioning and parameter retrieval

[0073] Place the CFRP guide rail on an adjustable V-shaped fixture, use the bottom surface and the side guiding surface as the positioning reference, and calibrate the guide rail axis through a machine vision system with a positioning accuracy of ±0.02 mm; after the fixture reads the guide rail material label, it automatically retrieves the preset parameters: the pitch of the Venturi nozzle is 2.5 mm, the depth is 0.6 mm, the initial concentration C0 of nano-aluminum oxide abrasives is 20 g / m 3 , the ultrasonic vibration frequency is 22 kHz, and the reference feed rate v0 = 0.3 m / min.

[0074] S2. Initial planar processing of gas-solid two-phase flow

[0075] Start the compressed air system. Air with a pressure of 0.5 MPa forms a high-speed air flow of 70 m / s through a Venturi nozzle and mixes with 30 nm nano-aluminum oxide abrasive grains to form a gas-solid two-phase flow. The servo screw feeder controls the abrasive grain concentration at 20 g / m with an accuracy of ±0.2 g / min 3 , and the nozzle moves along the axis of the guide rail at a speed of 0.3 m / min and impacts for 4 minutes to remove surface burrs, reducing the initial roughness to Ra 2.0 μm.

[0076] S3. Ultrasonic vibration assisted strengthening machining

[0077] The piezoelectric ceramic transducer generates a high-frequency vibration of 22 kHz, and the amplitude is amplified to 8 μm through a tapered horn. Through the frequency modulation system, the ultrasonic vibration frequency changes periodically in the range of 22 - 23 kHz to form a beat frequency effect, making the impact energy distribution of the abrasive grains more uniform and avoiding local overheating damage to the composite material matrix.

[0078] S4. Laser real-time detection and parameter adjustment

[0079] The laser displacement sensor has an accuracy set to ±1 μm; it scans at intervals of 100 mm. When it first detects that the local Ra = 0.8 μm, the roughness deviation ΔRa = 0.2 μm is calculated. Based on the dynamic adjustment formula for abrasive grain concentration:

[0080]

[0081] Since the current feed speed v = 0.3 m / min is the same as the reference speed v, substituting ΔRa = 0.2 μm into the calculation gives the real-time concentration C = 20×1×(1 + 0.1×0.2) = 20.4 g / m 3 ; the servo feeder completes the concentration adjustment within 10 seconds, and at the same time locks the ultrasonic frequency at 22.5 kHz to enhance the removal efficiency. After continuous machining for 3 minutes, the secondary scan shows that Ra drops to 0.55 μm.

[0082] S5. Dust recovery and abrasive grain regeneration

[0083] The machining dust undergoes three-stage treatment: the first-stage cyclone separator separates particles larger than 5 μm, the second-stage bag filter intercepts dust with a size of 0.1 - 5 μm, and the third-stage activated carbon adsorption purifies the gas. The measured emission concentration is 3 mg / m 3 ; the magnetic separation device removes iron filings from the abrasive grains. After screening, 90% of the nano-aluminum oxide abrasive grains can be recycled, and the recycling rate reaches 85%.

[0084] S6. Qualified blanking

[0085] The final inspection shows that the surface roughness Ra of the guide rail is 0.55 μm, and the surface hardness is 320 HV, both of which are better than the process requirements; the processing cycle is 12 minutes, the retention rate of the interlaminar bonding strength of the composite material is ≥ 98%, and there are no defects such as fiber pull-out or matrix cracking.

[0086] Example 4

[0087] I. Application Scenario

[0088] For a carbon steel guide rail with a length of 12 m: the material is Q345, and the initial roughness Ra is 4.0 μm; surface finishing is carried out, with the target roughness Ra ≤ 0.4 μm and the full-length straightness ≤ 0.8 mm. It is necessary to overcome the processing non-uniformity caused by the self-weight deformation of the long guide rail.

[0089] II. Detailed Process Steps

[0090] S1. Guide Rail Positioning and Parameter Retrieval.

[0091] Place the 12 m ultra-long guide rail on an adjustable V-shaped fixture, use the bottom surface and the side guide surface as the positioning reference, calibrate the axis of the guide rail segment by segment through a laser tracker, and the positioning accuracy reaches ±0.05 mm. After the fixture reads the material label of the guide rail, it automatically retrieves the preset parameters: the pitch of the Venturi nozzle is 3 mm, the depth is 0.7 mm, the initial concentration c0 of nano-aluminum oxide abrasive is 20 g / m 3 , the ultrasonic vibration frequency is 28 kHz, and the reference feed speed v0 = 0.5 m / min.

[0092] S2. Initial Planarization Processing of Gas-Solid Two-Phase Flow

[0093] Divide the guide rail into 6 segments, each 2 m long; start the compressed air system, and the air with a pressure of 0.65 MPa forms a high-speed air flow of 85 m / s through the Venturi nozzle, which is mixed with 30 nm nano-aluminum oxide abrasive to form a gas-solid two-phase flow; the servo screw feeder controls the abrasive concentration at 20 g / m with an accuracy of ±0.4 g / min 3 , and the nozzle processes each segment at a speed of 0.5 m / min. The processing time for each segment is 1.5 minutes, and the initial roughness is reduced to Ra 1.8 μm.

[0094] S3. Ultrasonic Vibration-Assisted Strengthening Processing.

[0095] The piezoelectric ceramic transducer generates a high-frequency vibration of 28 kHz, and the amplitude is amplified to 8 μm through a tapered horn; in the middle section where the self-weight deformation of the guide rail is the largest, the 3rd - 4th segments, the vibration frequency is fine-tuned to 28.5 kHz to enhance the impact effect of the abrasive on the concave surface and compensate for the uneven contact caused by the deformation.

[0096] S4. Laser Real-Time Detection and Parameter Adjustment.

[0097] Laser displacement sensor, with the precision set to ±1μm; Scanning each section of the guide rail at 1m intervals, it is detected that Ra of the 3rd section is 0.6μm and Ra of the 5th section is 0.5μm. Based on the dynamic adjustment formula of abrasive concentration:

[0098] For the 3rd section: At the same time, reduce the feed speed to 0.4m / min to extend the processing time;

[0099] For the 5th section: At the same time, increase the feed speed to 0.6m / min to improve efficiency;

[0100] The servo feeder adjusts the concentration of the two sections respectively.

[0101] S5, Dust recovery and abrasive regeneration.

[0102] The processing dust is treated in three stages: the first-stage cyclone separator separates particles larger than 5μm, the second-stage bag filter intercepts dust with a size of 0.1 - 5μm, and the third-stage activated carbon adsorption purifies the gas. The measured emission concentration is 7mg / m 3 ; The magnetic separation device removes iron filings from the abrasives. After screening, 90% of the nano-aluminum oxide abrasives can be recycled, and the recycling rate reaches 85%.

[0103] S6, Qualified blanking.

[0104] Finally, it is detected that the surface roughness Ra of the entire length of the guide rail is 0.38μm, and the straightness is 0.7mm, both of which are better than the process requirements; the processing cycle is 15 minutes, and the deviation of the processing quality consistency of each section is ≤5%.

[0105] Comparative Example 1

[0106] I. Application scenario

[0107] Traditional wet grinding equipment processes 125T carbon steel guide rails identical to those in Example 1: The material is Q235, and the initial roughness is Ra3.2μm; This process relies on emulsion cooling and mechanical grinding with silicon carbide grinding wheels, representing the mainstream processing method in current small and medium-sized elevator parts factories.

[0108] II. Detailed process steps

[0109] S1, Guide rail fixation: Clamp both sides of the guide rail using a general-purpose hydraulic vise, with only the bottom surface as the single positioning reference, and without calibrating the side guiding surface; The operator aligns the guide rail axis visually, and the positioning accuracy is significantly affected by the wear of the fixture, with the measured deviation reaching ±0.15mm.

[0110] S2. Rough grinding process: Use a silicon carbide grinding wheel with a diameter of 300 mm, a grit size of 200 μm, a grinding wheel speed of 2000 r / min, a feed rate of 0.2 m / min, and spray emulsified liquid for cooling at a flow rate of 20 L / min; Remove the surface oxide scale in this stage, and the roughness is reduced to Ra1.6 μm after rough grinding, which takes 8 minutes.

[0111] S3. Semi-finish grinding process: Replace it with an alumina grinding wheel with a grit size of 100 μm, reduce the feed rate to 0.1 m / min, continue grinding for 6 minutes, and the roughness is reduced to Ra0.8 μm; During this process, the emulsified liquid is mixed with the grinding chips to form a paste-like waste liquid, and the machine tool workbench needs to be cleaned regularly during downtime.

[0112] S4. Finish grinding process: Use a diamond grinding wheel with a grit size of 50 μm, grind at a low speed of 0.05 m / min for 11 minutes, and try to further refine the surface. However, due to the insufficient accuracy of the equipment spindle, the runout error is ±0.03 mm, and finally the roughness only reaches Ra0.6 μm, and wavy defects appear in local areas due to grinding wheel clogging.

[0113] S5. Waste liquid treatment: The mixture of emulsified liquid and grinding chips is directly discharged into the industrial wastewater pipe network, and the abrasive grains are not recovered. About 50 L of waste liquid is generated per ton of guide rail processing.

[0114] III. Comparison table of key indicators

[0115]

[0116]

[0117] Comparative Example 2

[0118] I. Application scenario

[0119] A certain factory uses the processing equipment - the 2020 model to process the same T89B stainless steel guide rail as in Example 2: The material is 06Cr19Ni10, and the initial roughness is Ra2.5 μm; This equipment only has the function of gas-solid two-phase flow impact and does not have an ultrasonic vibration system.

[0120] II. Detailed process steps

[0121] S1. Guide rail positioning: Use a simple V-block structure, clamp the bottom surface of the guide rail by manually rotating the screw, and no positioning elements are set on the side guide surface. The positioning accuracy depends on the operator's experience, and the measured deviation is ±0.1 mm; The fixture does not integrate the function of reading the material label, and the processing parameters need to be manually input.

[0122] S2. Gas-solid flow generating device: The inner wall of the Venturi nozzle is a smooth cylindrical surface, the compressed air pressure is 0.7 MPa, the air flow velocity is 90 m / s, and it is mixed with 50 nm nano-aluminum oxide abrasive grains; The abrasive grain concentration is manually set to 25 g / m 3, conveyed by a positive displacement feeder, with a feeding accuracy of ±2 g / min.

[0123] S3. Processing process: The nozzle is fixed at the end of the cantilever beam and moves unidirectionally at a speed of 0.6 m / min to impact the surface of the guide rail once; the impact frequency of the abrasive grains is only the frequency of the gas-solid flow itself, about 20 kHz, and the impact angle has a deviation of ±15° due to the uneven movement speed of the nozzle.

[0124] S4. Detection and adjustment: After each section of the guide rail (about 2 m) is processed, the operator uses a handheld roughness meter with an accuracy of ±5 μm for manual detection. When it is found that the local roughness exceeds the standard, the abrasive grain concentration is manually adjusted through a knob, and the single adjustment takes about 2 minutes.

[0125] S5. Dust treatment: A primary cyclone separator is configured to separate particles with a particle size > 10 μm. The nano-sized abrasive grains are discharged with the waste gas, and the recycling rate of the abrasive grains is only 65%, and the emission concentration reaches 50 mg / m 3 .

[0126] III. Comparison table of key indicators

[0127] Index Example 2 Comparative Example 2 Performance Difference Ultrasonic Vibration Frequency 30 kHz None Impact Frequency Increased by 100% Final Roughness Ra 0.18 μm (Meeting Standard) 0.35 μm (Exceeding Standard by 75%) Roughness Reduced by 49% Dynamic Adjustment Response Time 8 seconds 120 seconds Adjustment Speed Increased by 93% Processing Cycle 7 minutes 12 minutes Efficiency Increased by 71% Emission Concentration <![CDATA[5mg / m 3 > <![CDATA[50mg / m 3 > Pollution Reduced by 90%

[0128] Comparative Example 3

[0129] I. Application scenario

[0130] Traditional sandblasting equipment processes the same carbon fiber reinforced composite (CFRP) guide rail as in Example 3: the material is T700 / epoxy resin, and the initial roughness is Ra 3.8 μm; this process uses quartz sand as the abrasive.

[0131] II. Detailed process steps

[0132] S1. Guide rail fixation: A top surface pressing type hydraulic fixture is used. The guide rail top surface is vertically pressed down by 4 hydraulic cylinders, and the side guiding surface does not contact any positioning elements, and the axis deviation of the guide rail reaches ±0.2 mm; the fixture does not consider the brittle characteristics of the composite material, and the excessive pressing force causes local indentations on the guide rail.

[0133] S2. Sandblasting parameters: Quartz sand with a particle size of 100 μm is used, with a Mohs hardness of 7, the compressed air pressure is 0.3 MPa, the sandblasting gun is 100 mm away from the guide rail surface, and it is sprayed obliquely at an angle of 30°; due to insufficient pressure and abrasive grain dispersion, it takes 5 minutes of repeated sandblasting to remove the surface burrs; the phenomenon of quartz sand fragmentation is observed during the process, and the fragmentation rate is about 30%.

[0134] S3. Processing defect treatment: After sandblasting, it is found that there are fiber pull-out and resin cracking phenomena on the guide rail surface, and manual sandpaper polishing is used for 4 minutes to remove the protruding fibers.

[0135] S4. Detection and Testing: The surface hardness was detected by a microhardness tester, with an average value of 260 HV; the interlayer bonding strength was tested by the short beam shear method, with a retention rate of 85%.

[0136] III. Key Index Comparison Table

[0137] Index Example 3 Comparative Example 3 Performance Difference Fixture Positioning Method Adjustable V-Type Top Surface Hydraulic Interlayer Damage Reduced by 90% Final Roughness Ra 0.55 μm (Meeting Standard) 1.2 μm (Exceeding Standard by 100%) Roughness Reduced by 54% Interlayer Bonding Strength 98% Retention Rate 85% Retention Rate Strength Increased by 13% Abrasive Grain Type / Grain Size 30 nm Alumina 100 μm Quartz Sand Surface Hardness Increased by 23% Fiber Pull-Out Density <![CDATA[< 5 per mm 2 > <![CDATA[50 per mm 2 > Damage Reduced by 90%

[0138] Comparative Example 4

[0139] I. Application Scenario

[0140] Ultra-long guide rail processing technology, processing the same 12m carbon steel guide rail as in Example 4: The material is Q345, and the initial roughness is Ra4.0μm; this process relies on manual segmented calibration and parameter adjustment, representing a traditional process without automation.

[0141] II. Detailed Process Steps

[0142] S1. Guide Rail Support: A fixed support bracket was set every 2m on the processing platform, and the height of the guide rail was adjusted section by section using a hydraulic jack; the operator manually calibrated the axis through a laser collimator and a micrometer, and each section of calibration required repeated adjustment 3 - 5 times, with a cumulative time consumption of 30 minutes, and the final positioning accuracy was ±0.1mm.

[0143] S2. Segmented Machining: The guide rail was divided into 6 sections, each 2m long. The nozzle was fixed above the processing area, and the guide rail was moved by a crane to achieve segmented machining; before each section of machining, the operator set the abrasive concentration according to experience, usually between 25 - 30g / m 3 There is no formulaic calculation basis.

[0144] S3. Parameter Adjustment: When machining the 3rd section, it was found by manual touch detection that the surface was relatively rough, and the concentration was increased from 25g / m 3 to 30g / m 3 based on experience. However, due to the response delay of the feeding system, about 1.5 minutes, the first half of this section was over-machined, and the roughness dropped to Ra0.3μm, and there were pits in the second half due to excessive concentration.

[0145] S4. Straightness Compensation: In the middle section, the 3rd - 4th sections, due to the self-weight of the guide rail sagging by 0.5mm, the dynamic frequency adjustment function was not enabled, and only the machining time was extended from 1.5 minutes to 2 minutes for compensation. However, due to the fixed impact angle of the gas-solid flow, the concave surface could not be effectively corrected, and the measured straightness deviation reached 1.2mm.

[0146] S5. Post-processing: The difference in machining parameters for each section resulted in a roughness fluctuation range of 0.45 - 0.7μm, and an additional 20 minutes were required for global homogenization processing.

[0147] III. Key Index Comparison Table

[0148] Index Example 4 Comparative Example 4 Performance Difference Full-Length Straightness 0.7 mm (Meeting Standard) 1.2 mm (Exceeding Standard by 50%) Straightness Increased by 42% Roughness Deviation of Each Section ≤5％ 18％ Consistency Increased by 72% Processing Cycle 15 minutes 40 minutes Efficiency Increased by 167% Manual Intervention Fully Automated 2-Person Cooperative Operation Labor Cost Reduced by 100% Dynamic Compensation Response Time Real-Time Adjustment Lag of 1.5 minutes Error Correction Speed Increased by 95%

[0149] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and the descriptions in the specification are only preferred examples of the present invention, and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. The surface finishing process of elevator guide rails based on acoustic wave assistance, characterized in that, It includes the following steps: S1. Fix the elevator guide rail with an adjustable V-shaped fixture, read the material label of the guide rail and automatically retrieve the corresponding processing parameters; S2. Start the compressed air system, mix with nano-aluminum oxide abrasive grains through a Venturi nozzle to form a gas-solid two-phase flow, and use it to impact the surface of the guide rail to achieve initial surface leveling; S3. While the gas-solid flow impacts the surface of the guide rail, activate the ultrasonic vibration system to make the ultrasonic vibration cooperate with the gas-solid two-phase flow. Enhance the frequency and uniformity of the abrasive grain impact through high-frequency vibration, further improve the surface processing accuracy and refine the surface topography; S4. Real-time scan the surface roughness through a laser displacement sensor and adjust the processing parameters to ensure that the surface accuracy always meets the process requirements; S5. Recycle the dust generated during processing. Extract reusable nano-abrasive grains from the dust through cyclone separation, filtration and magnetic separation technologies, and recycle them after screening and regeneration; S6. After the surface roughness and straightness meet the standards, cut the guide rail.

2. The surface finishing process of an elevator guide rail based on acoustic wave assistance according to claim 1, characterized in that, The adjustable V-shaped fixture takes the bottom surface and side guiding surface of the guide rail as the positioning reference, drives the positioning block to move through a servo motor, adapts to T-shaped solid guide rails and J-shaped hollow guide rails, and the positioning accuracy is ±0.03mm.

3. The sonic-assisted elevator guide rail surface finishing process according to claim 1, wherein, The inner wall of the Venturi nozzle is provided with spiral guide grooves with a pitch of 1-3 mm and a depth of 0.3-0.7 mm, which are mixed with nano-alumina abrasive grains with a particle size ≤ 50 nm. The abrasive grain concentration is controlled by a servo spiral feeder to be 10-50 g / m 3 , and the feeding accuracy is ±0.5 g / min.

4. The surface finishing process of an elevator guide rail based on acoustic wave assistance according to claim 3, characterized in that, The Venturi nozzle moves along the axis of the guide rail at a speed of 0.3-0.8m / min, and at the same time activates the ultrasonic vibration system.

5. The sonic-assisted elevator guide rail surface finishing process according to claim 1, wherein, The ultrasonic vibration system includes a piezoelectric ceramic transducer and a tapered conical horn. The transducer generates high-frequency vibrations of 20-30kHz, and the horn amplifies the amplitude to 5-10μm. Dynamically match the gas-solid flow impact frequency through a bolt pre-tightening force adjustment device, and the frequency difference ≤0.5kHz.

6. The surface finishing process of an elevator guide rail based on acoustic wave assistance according to claim 1, wherein The accuracy of the laser displacement sensor is ≤±1μm, the scanning interval is 50-100mm, and the detection density can be automatically switched through the material label of the guide rail to detect the surface roughness Ra in real time; every time the surface scan is triggered, based on the formula: Dynamically adjust the abrasive concentration; where C is the real-time abrasive concentration, unit: g / m 3 , C0 is the initial concentration, v0 is the reference speed, unit: m / min, v is the real-time feed speed, and ΔRa is the roughness deviation value, unit: μm.

7. The sonic-assisted elevator guide rail surface finishing process according to claim 6, characterized in that When the real-time detected surface roughness Ra is greater than the preset value, the compensation term (1 + 0.1×ΔRa) in the formula will make the abrasive grain concentration increase linearly with the increase of the roughness deviation value ΔRa, realizing dynamic compensation of the material removal efficiency.

8. The surface finishing process of an elevator guide rail based on acoustic wave assistance according to claim 1, characterized in that, The dust recovery treatment includes: a primary cyclone separator, a secondary bag filter, and a tertiary activated carbon adsorption. After magnetic separation and screening regeneration of the abrasive particles, the recycling rate is ≥85%, and the emission concentration is <10 mg / m 3 .

9. The surface finishing process of an elevator guide rail based on acoustic wave assistance according to claim 1, wherein The processing environment of the gas-solid two-phase flow is a dry environment without liquid medium, and the guide rail materials include carbon steel, stainless steel or composite materials.

10. The elevator guide rail surface finishing process based on acoustic wave assistance according to claim 1, characterized in that, The adjustable V-shaped fixture, Venturi nozzle, ultrasonic vibration system and dust recycling and treatment system are integrated on the same processing platform, and the whole process is automated through a PLC control system.

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