CN112024799A - Automobile electronic water pump bearing machining method - Google Patents
Automobile electronic water pump bearing machining method Download PDFInfo
- Publication number
- CN112024799A CN112024799A CN202010879580.1A CN202010879580A CN112024799A CN 112024799 A CN112024799 A CN 112024799A CN 202010879580 A CN202010879580 A CN 202010879580A CN 112024799 A CN112024799 A CN 112024799A
- Authority
- CN
- China
- Prior art keywords
- mandrel
- bearing
- forging
- treatment
- polishing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/002—Hybrid process, e.g. forging following casting
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D10/00—Modifying the physical properties by methods other than heat treatment or deformation
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
- C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
- C23F11/18—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using inorganic inhibitors
- C23F11/181—Nitrogen containing compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
- Rolling Contact Bearings (AREA)
Abstract
The invention discloses a processing method of an automobile electronic water pump bearing, which comprises the following steps: s1, carrying out heat treatment on the mandrel, forging and forming the mandrel through a finish forging machine, immediately transmitting the mandrel to a quenching tank for quenching after the forging is finished, and putting the mandrel into a tempering furnace for tempering after the mandrel is quenched; s2, polishing the mandrel, polishing the outer diameter of the mandrel through a grinding machine after straightening, polishing the outer diameter of the mandrel to a required range, and polishing a ball raceway through the grinding machine; s3, performing outer ring heat treatment; s4, polishing the outer ring; s5, assembling a bearing, namely, assembling balls and a retainer into raceways of a core shaft and an outer ring through a bearing assembling machine for assembly; s6, carrying out demagnetization treatment on the bearing through an R-L-C demagnetization circuit; and S7, performing antirust treatment, namely spraying an antirust agent through a sprayer to perform surface treatment on the bearing, and then coating antirust oil. The invention has the advantages of excellent antirust performance, thereby increasing the stability of the product and prolonging the service life.
Description
Technical Field
The invention relates to the technical field of water pump bearing processing, in particular to a processing method of an automobile electronic water pump bearing.
Background
The automobile water pump shaft connecting bearing is a bearing, and the steel (comprising a shaft, an outer ring and a steel ball roller) selected by the conventional shaft connecting bearing is high-carbon chromium bearing steel (GCr 15). Because the smelting of the high-quality bearing steel is performed through vacuum deoxidation and electromagnetic stirring, the content of oxides is less, the bearing steel can bear larger contact pressure stress and higher high tensile stress, and the hardness of the raceway of the shaft is 58-62HRC after heat treatment. The hardness of the raceway of the lower ring is 60-64HRC, and the hardness of the steel ball and the roller is 61-65 HRC. When the shaft and the outer ring are made of carburizing bearing steel, the hardness of the raceway is 60-64 HRC. The material of the retainer is reinforced nylon 66 generally, the material of the sealing ring is nitrile rubber generally, and when the requirement is higher, the sealing ring can also be a fluororubber sealing ring. The development speed of the bearing industry is high, but the bearing is easy to rust at the present stage, and the precision of the bearing is influenced, so that the product is poor in stability, low in reliability and short in service life.
Disclosure of Invention
The invention aims to provide a processing method of an automobile electronic water pump bearing, which has the advantages of excellent antirust performance, product stability increase and service life prolonging, and solves the problems that the development speed of the bearing industry is high, but the bearing is easy to rust at the present stage, the bearing precision is influenced, and the product stability is poor, the reliability is low and the service life is short.
In order to achieve the purpose, the invention provides the following technical scheme: the processing method of the automobile electronic water pump bearing comprises the following steps:
s1, performing heat treatment on the mandrel, forging and forming the mandrel through a finish forging machine, so that the forged piece has high surface finish, good surface quality and less heat loss in the forging process, meanwhile, an ideal quenching temperature is ensured, the forged piece is immediately transmitted to a quenching tank for quenching water after the forging is finished, and the forged piece is placed into a tempering furnace for tempering treatment after the mandrel is quenched;
s2, polishing the mandrel, straightening the mandrel after tempering, polishing the outer diameter of the mandrel through a grinding machine after straightening, polishing the outer diameter of the mandrel to a required range, and polishing a ball raceway through the grinding machine;
s3, performing outer ring heat treatment, forging and forming the outer ring through a finish forging machine, so that the forged piece is high in surface finish, good in surface quality, low in heat loss in the forging process, and capable of ensuring an ideal quenching temperature, immediately transmitting the forged piece to a quenching tank for quenching water after the forging is finished, and putting the forged piece into a tempering furnace for tempering treatment after the mandrel quenching is finished;
s4, polishing the outer ring, and after tempering, conveying the outer ring to a grinding machine to polish the inner surface of the outer ring to polish a ball raceway;
s5, assembling a bearing, namely, assembling balls and a retainer into raceways of a core shaft and an outer ring through a bearing assembling machine for assembly;
s6, carrying out demagnetization treatment, namely carrying out demagnetization treatment on the bearing through an R-L-C demagnetization circuit, and forming a strong pulse magnetic field in the magnetic induction coil by utilizing instantaneous discharge of a charging capacitor to realize demagnetization of the bearing ring;
and S7, performing antirust treatment, namely spraying an antirust agent through a sprayer to perform surface treatment on the bearing, and then coating antirust oil.
Preferably, the transmission process time in S1 is controlled to be about 8min, the temperature of the forge piece is controlled to be above 850 ℃, the tempering temperature is 500-650 ℃, and the tempering time is about 120 min.
Preferably, before finish forging in S1 and S2, steel ingots are selected according to product structures, a free forging machine is used for cogging the steel ingots to 2j400mmx4150mm, after blank hydrogen diffusion treatment, the steel ingots are transferred to a finish forging machine for forming, the finish forging temperature is 1110 ℃, the forming process of the finish forging machine is carried out in three passes, and the deformation of each pass is 25-34%.
Preferably, both the outer ring and the mandrel are finish ground in S5 prior to assembly.
Preferably, the rust inhibitor in S7 is a solution containing 8% to 10% of sodium nitrite and 2% to 3% of sodium carbonate as the balance.
Compared with the prior art, the invention has the beneficial effects that: the mandrel and the outer ring are forged by the precision forging machine, so that the process is simplified, the strength is improved by 10%, the plasticity and the toughness are improved, compared with the original process, the production process is greatly simplified, and the energy consumption is reduced; the bearing is demagnetized by the R-L-C demagnetization circuit, so that the bearing can be used for on-machine demagnetization, the production link can be reduced, and compared with a power frequency alternating-current demagnetization device, the device has low power loss and good demagnetization quality; by using the antirust agent prepared from the sodium nitrite, the antirust effect is best when the pH value of the sodium nitrite is 8-10 under the alkalescent general state, therefore, the sodium nitrite anode type corrosion inhibitor needs to be mixed with sodium carbonate for use, has strong oxidizing property to passivate the metal surface, is convenient for the adhesion of rust preventive oil, and the surface of the bearing is coated with anti-rust oil which has the function of isolating the metal surface from the environment so as to protect the metal from being influenced by corrosive media in the environment, thereby preventing metal corrosion, the action mechanism of the anti-rust oil is that various anti-rust additives are added into the basic components, forming a dense adsorption film arranged orderly on the metal surface, or trapping and dispersing polar substances such as water and acidic substances in oil, and coating and dissolving the polar substances in micelles or micelles, and replacing water films or water drops on the metal surface, thereby preventing oxygen, moisture and acidic substances in the air from corroding the metal surface and playing a role of rust prevention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The embodiment provided by the invention comprises the following steps: the processing method of the automobile electronic water pump bearing comprises the following steps:
s1, performing heat treatment on the mandrel, forging and forming the mandrel through a finish forging machine, so that the forged piece has high surface finish, good surface quality and less heat loss in the forging process, and simultaneously an ideal quenching temperature is ensured, the forged piece is immediately transmitted to a quenching tank for quenching water after the forging is finished, the mandrel is put into a tempering furnace for tempering treatment after the quenching is finished, the transmission process time in S1 is controlled to be about 8min, the temperature of the forged piece is controlled to be above 850 ℃, the tempering temperature is 500-650 ℃, and the tempering time is about 120 min;
s2, polishing the mandrel, straightening the mandrel after tempering, polishing the outer diameter of the mandrel through a grinding machine after straightening, polishing the outer diameter of the mandrel to a required range, polishing a ball raceway through the grinding machine, selecting a steel ingot according to a product structure before finish forging in S1 and S2, cogging the steel ingot to 2j400mmx4150mm by using a free forging machine, transferring the billet to a finish forging machine for forming after hydrogen diffusion treatment, wherein the finish forging temperature is 1110 ℃, the forming process of the finish forging machine is carried out in three passes, and the deformation of each pass is 25% -34%;
s3, performing heat treatment on the outer ring, forging and forming the outer ring through a precision forging machine, so that the forged piece has high surface finish, good surface quality and less heat loss in the forging process, and simultaneously ensures an ideal quenching temperature, the forged piece is immediately transmitted to a quenching tank for quenching water after the forging is finished, the mandrel is put into a tempering furnace for tempering after the quenching is finished, and the mandrel and the outer ring are forged through the precision forging machine, so that the process is simplified, the strength is improved by 10 percent, the plasticity and the toughness are improved, compared with the original process, the production process is greatly simplified, and the energy consumption is reduced;
s4, polishing the outer ring, and after tempering, conveying the outer ring to a grinding machine to polish the inner surface of the outer ring to polish a ball raceway;
s5, assembling a bearing, namely, assembling balls and a retainer into raceways of a core shaft and an outer ring through a bearing assembling machine for assembling, wherein the outer ring and the core shaft are subjected to fine grinding treatment before assembling in S5;
s6, demagnetization processing, namely, carrying out demagnetization processing on the bearing through an R-L-C demagnetization circuit, forming a strong pulse magnetic field in a magnetic induction coil by utilizing instant discharge of a charging capacitor, realizing demagnetization of a bearing ring, carrying out demagnetization processing on the bearing through the R-L-C demagnetization circuit, being capable of being used for on-machine demagnetization, reducing production links, and compared with a power frequency alternating current demagnetization device, the device has low power supply loss and good demagnetization quality;
s7, performing anti-rust treatment, spraying an anti-rust agent by a sprayer to perform surface treatment on the bearing, and then coating anti-rust oil, wherein the anti-rust agent in S7 is a solution containing 8% -10% of sodium nitrite and 2% -3% of sodium carbonate with the balance, the anti-rust agent prepared by using the sodium nitrite has the best anti-rust effect when the pH value is 8-10 under a alkalescent general state, so that the anti-rust oil is required to be mixed with sodium carbonate for use, the sodium nitrite belongs to an anode type corrosion inhibitor and has strong oxidizing property to passivate the metal surface, so that the anti-rust oil is convenient to adhere to the bearing, the anti-rust oil is coated on the bearing surface, the anti-rust oil has the function of isolating the metal surface from the environment to protect the metal from being influenced by a corrosion medium in the environment, so as to prevent the metal from being rusted, the anti-rust oil has the action mechanism that various anti-rust additives are added into, or trapping and dispersing polar substances such as water and acidic substances in the oil, coating and dissolving the polar substances in micelles or micelles, and replacing water films or water drops on the metal surface, thereby preventing oxygen, moisture and acidic substances in the air from corroding the metal surface to play a role in rust prevention.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (5)
1. The processing method of the automobile electronic water pump bearing is characterized by comprising the following steps:
s1, performing heat treatment on the mandrel, forging and forming the mandrel through a finish forging machine, so that the forged piece has high surface finish, good surface quality and less heat loss in the forging process, meanwhile, an ideal quenching temperature is ensured, the forged piece is immediately transmitted to a quenching tank for quenching water after the forging is finished, and the forged piece is placed into a tempering furnace for tempering treatment after the mandrel is quenched;
s2, polishing the mandrel, straightening the mandrel after tempering, polishing the outer diameter of the mandrel through a grinding machine after straightening, polishing the outer diameter of the mandrel to a required range, and polishing a ball raceway through the grinding machine;
s3, performing outer ring heat treatment, forging and forming the outer ring through a finish forging machine, so that the forged piece is high in surface finish, good in surface quality, low in heat loss in the forging process, and capable of ensuring an ideal quenching temperature, immediately transmitting the forged piece to a quenching tank for quenching water after the forging is finished, and putting the forged piece into a tempering furnace for tempering treatment after the mandrel quenching is finished;
s4, polishing the outer ring, and after tempering, conveying the outer ring to a grinding machine to polish the inner surface of the outer ring to polish a ball raceway;
s5, assembling a bearing, namely, assembling balls and a retainer into raceways of a core shaft and an outer ring through a bearing assembling machine for assembly;
s6, carrying out demagnetization treatment, namely carrying out demagnetization treatment on the bearing through an R-L-C demagnetization circuit, and forming a strong pulse magnetic field in the magnetic induction coil by utilizing instantaneous discharge of a charging capacitor to realize demagnetization of the bearing ring;
and S7, performing antirust treatment, namely spraying an antirust agent through a sprayer to perform surface treatment on the bearing, and then coating antirust oil.
2. The automobile electronic water pump bearing processing method according to claim 1, characterized in that: in the S1, the transmission process time is controlled to be about 8min, the temperature of the forge piece is controlled to be above 850 ℃, the tempering temperature is 500-650 ℃, and the tempering time is about 120 min.
3. The automobile electronic water pump bearing processing method according to claim 1, characterized in that: selecting a steel ingot according to a product structure before finish forging in S1 and S2, cogging the steel ingot to 2j400mmx4150mm by using a free forging machine, transferring to a finish forging machine for forming after the blank is subjected to hydrogen diffusion treatment, wherein the finish forging temperature is 1110 ℃, and the forming process of the finish forging machine is carried out in three passes, and the deformation of each pass is 25-34%.
4. The automobile electronic water pump bearing processing method according to claim 1, characterized in that: s5 where the outer ring and the mandrel are both finish ground prior to assembly.
5. The automobile electronic water pump bearing processing method according to claim 1, characterized in that: the antirust agent in S7 is a solution containing 8% -10% of sodium nitrite and 2% -3% of sodium carbonate, and the balance is water.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010879580.1A CN112024799A (en) | 2020-08-27 | 2020-08-27 | Automobile electronic water pump bearing machining method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010879580.1A CN112024799A (en) | 2020-08-27 | 2020-08-27 | Automobile electronic water pump bearing machining method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112024799A true CN112024799A (en) | 2020-12-04 |
Family
ID=73585971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010879580.1A Pending CN112024799A (en) | 2020-08-27 | 2020-08-27 | Automobile electronic water pump bearing machining method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112024799A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1966767A (en) * | 2006-02-09 | 2007-05-23 | 人本集团有限公司 | Blueing anti-rust treatment process for chamfer and capped edge of bearing ring |
| CN101817141A (en) * | 2010-04-22 | 2010-09-01 | 江苏迪邦三星轴承有限公司 | Processing technique for bearing of megawatt wind power speed increasing gear box |
| CN106799566A (en) * | 2017-01-22 | 2017-06-06 | 杭州华博汽车零部件有限公司 | Integrated low-noise automobile hub-bearing unit and preparation method thereof |
| CN108500568A (en) * | 2018-04-09 | 2018-09-07 | 张家港市海工船舶机械制造有限公司 | A kind of rolling bearing processing technology |
| CN109536689A (en) * | 2018-12-28 | 2019-03-29 | 洛阳轴承研究所有限公司 | A kind of heat working technological process of bearing steel components |
-
2020
- 2020-08-27 CN CN202010879580.1A patent/CN112024799A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1966767A (en) * | 2006-02-09 | 2007-05-23 | 人本集团有限公司 | Blueing anti-rust treatment process for chamfer and capped edge of bearing ring |
| CN101817141A (en) * | 2010-04-22 | 2010-09-01 | 江苏迪邦三星轴承有限公司 | Processing technique for bearing of megawatt wind power speed increasing gear box |
| CN106799566A (en) * | 2017-01-22 | 2017-06-06 | 杭州华博汽车零部件有限公司 | Integrated low-noise automobile hub-bearing unit and preparation method thereof |
| CN108500568A (en) * | 2018-04-09 | 2018-09-07 | 张家港市海工船舶机械制造有限公司 | A kind of rolling bearing processing technology |
| CN109536689A (en) * | 2018-12-28 | 2019-03-29 | 洛阳轴承研究所有限公司 | A kind of heat working technological process of bearing steel components |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2014378B1 (en) | Process for producing stainless-steel pipe | |
| CN103290306B (en) | Wear, corrosion and rust resistant metal pipeline | |
| CN103602920A (en) | Bearing steel and manufacturing process of wear-resistant bearing | |
| CN103276282A (en) | Fabrication method of anti-corrosive and wear-resistant pipeline for delivering minerals | |
| CN114990447B (en) | Alloy material, hole expanding die and processing technology | |
| CN112024799A (en) | Automobile electronic water pump bearing machining method | |
| CN113789479A (en) | Corrosion-resistant high-strength stainless steel and preparation process thereof | |
| CN113122771B (en) | High-performance friction welding steel piston and preparation method thereof | |
| EP2140949B1 (en) | Process for producing unidirectionally grain oriented electromagnetic steel sheet | |
| CN106498304B (en) | A kind of corrosion resisting bearing and preparation method thereof | |
| CN103276283B (en) | A kind of anticorrosion antiwear pipeline of conveying mineral | |
| CN108950417A (en) | A kind of processing technology of tap special stainless steel material | |
| CN105063588B (en) | A kind of metal surface composite phosphate membrane preparation method for adapting to Warm Extrusion | |
| CN112281158A (en) | Treatment process of high-hardness bearing steel pipe | |
| CN108505025B (en) | Manganese phosphating solution and application thereof | |
| KR100675213B1 (en) | Sliding parts with excellent performance in seizure resistance and the making process | |
| JP4078689B2 (en) | Lubrication method for high strength bolt base material | |
| CN100423856C (en) | Method for improving binding strength of coating on internal multiple keys | |
| CN114774784B (en) | Large-caliber alloy steel pipe fitting and processing technology thereof | |
| CN115547668B (en) | Circular ring magnetic steel processing technology | |
| CN102912102A (en) | Manufacturing method of GCr15 coiled cold-drawn material for cold extrusion of metal structural part | |
| CN115094317B (en) | High-wear-resistance high-toughness steel and preparation method thereof | |
| CN112501522B (en) | High-temperature-resistant piercing plug and preparation method thereof | |
| CN107355382A (en) | Compressor slide plate and rotary compressor | |
| CN116623097A (en) | C75S steel belt for clamp spring and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201204 |