CN111425310B - Control method for preventing EGR system from freezing - Google Patents
Control method for preventing EGR system from freezing Download PDFInfo
- Publication number
- CN111425310B CN111425310B CN202010242882.8A CN202010242882A CN111425310B CN 111425310 B CN111425310 B CN 111425310B CN 202010242882 A CN202010242882 A CN 202010242882A CN 111425310 B CN111425310 B CN 111425310B
- Authority
- CN
- China
- Prior art keywords
- temperature
- egr
- whole vehicle
- control method
- egr system
- 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.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/0077—Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- F02M26/17—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system
- F02M26/18—Thermal insulation or heat protection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- F02M26/17—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories in relation to the intake system
- F02M26/19—Means for improving the mixing of air and recirculated exhaust gases, e.g. venturis or multiple openings to the intake system
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/52—Systems for actuating EGR valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M2026/001—Arrangements; Control features; Details
- F02M2026/004—EGR valve controlled by a temperature signal or an air/fuel ratio (lambda) signal
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust-Gas Circulating Devices (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
Abstract
The invention discloses a control method for preventing an EGR (exhaust gas recirculation) system from being frozen, relates to the EGR system, and solves the technical problem of freezing of the existing EGR system, and the method comprises the following steps: s1, acquiring the idle time of a whole vehicle, the temperature of mixed gas in an air inlet main pipe and the ambient temperature; s2, if the temperature of mixed gas in the air inlet main pipe is lower than a first calibration temperature value, the ambient temperature is lower than a second calibration temperature value and the idling time of the whole vehicle exceeds a first calibration time value, jumping to the step S3; otherwise, returning to the step S1; s3, acquiring the operation state of the whole vehicle, and if the whole vehicle has no corresponding operation, jumping to the step S4; otherwise, returning to the step S1; s4, increasing the rotating speed and the load of the engine to open the EGR valve, and mixing the engine exhaust gas with cold air through a mixer until the temperature of mixed gas in the air inlet main pipe is higher than a third calibrated temperature value; and S5, recovering the normal idling working condition of the whole vehicle after delaying the second calibration time value, and returning to the step S1. The method can effectively reduce the potential safety hazard that the EGR system cannot be started or shut down due to icing.
Description
Technical Field
The present invention relates to EGR systems, and more particularly, it relates to a control method for preventing EGR systems from freezing.
Background
In order to meet the national six-emission regulations, the internal combustion engine adopts a technical route of equivalent combustion, but because the combustion temperature in a cylinder is higher in the technical route, EGR (exhaust gas recirculation) gas must be introduced to reduce the combustion temperature in the cylinder and improve the reliability of the engine. EGR gas composition consisting mainly of CO2And H2O composition wherein H2O is present mainly in gaseous form. Since the EGR valve is physically constructed as a poppet valve, the valve plate and valve seat cannot be completely sealed, and there is a slight leakage in the closed state. In cold regions, when there is a slight leak in the EGR valve, the gas enters the EGR mixer to mix with fresh air, because the temperature of the air is low, and the moisture in the EGR condenses into water upon condensation. Under a small-load working condition, particularly a long-time idling working condition, condensed water cannot be brought into a cylinder due to small air flow in the EGR, so that the condensed water is attached to an EGR mixer to form ice. EGR mixers can become clogged as the amount of ice build upThe formed air can not enter the cylinder through the mixer to be combusted, so that the power of the engine is insufficient or the flameout fault is caused, and the driving safety is influenced.
The mainstream internal combustion engine control system adopting the EGR technology for the current six gas engines is shown in FIG. 1. A portion of the exhaust gas combusted from the engine cylinder a passes through the EGR cooler B and the EGR valve C into the mixer D. The main problems of the current mainstream EGR (exhaust gas recirculation) control system are:
the ECU can calculate the opening degree of the EGR valve according to the EGR rate target under different working conditions, and when the engine is in a small load or idling working condition, because the combustion stability of the small load and the idling working condition is poor, if the EGR is introduced, the problems of unstable combustion, rotation speed fluctuation and the like can be caused. The EGR rate target for the low load or idle condition is generally set to 0, and therefore the EGR valve opening degree is 0. Under the condition of cold weather, a driver usually uses warm air for heating under an in-situ idling working condition in the process of waiting for loading and unloading goods, if the EGR valve has slight leakage, the hot combustion exhaust gas in the exhaust gas pipeline behind the EGR cooler B, the EGR valve C and the connecting pipeline of the mixer D is more easily frozen under the long-time condition, and a series of fault conditions such as flameout or incapability of starting the engine in the running process are caused.
Disclosure of Invention
The present invention is directed to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a control method capable of effectively preventing an EGR system from being frozen.
The technical scheme of the invention is as follows: a control method of preventing EGR system icing, the method comprising:
s1, acquiring the idle time of a whole vehicle, the temperature of mixed gas in an air inlet main pipe and the ambient temperature;
s2, if the temperature of mixed gas in the air inlet main pipe is lower than a first calibration temperature value, the ambient temperature is lower than a second calibration temperature value and the idling time of the whole vehicle exceeds a first calibration time value, jumping to the step S3; otherwise, returning to the step S1;
s3, acquiring the operation state of the whole vehicle, and if the whole vehicle has no corresponding operation, jumping to the step S4; otherwise, returning to the step S1;
s4, increasing the rotating speed and the load of the engine, enabling the EGR valve to be opened according to the EGR rate target, and enabling the exhaust gas of the engine to be mixed with cold air through a mixer until the temperature of the mixed gas in the air inlet main pipe is higher than a third calibrated temperature value;
and S5, recovering the normal idling working condition of the whole vehicle after delaying the second calibration time value, and returning to the step S1.
As a further improvement, the corresponding operation includes at least one of a throttle signal, a brake signal, a clutch signal, and a PTO signal.
Further, when the step S4 is skipped, the user is reminded that the EGR system is operating the anti-icing function.
Further, the first calibration temperature value is 0-5 ℃.
Further, the second calibration temperature value is 0-5 ℃.
Further, the third calibration temperature value is 20-25 ℃.
Further, the first calibration time value is 10-15 min.
Further, the second calibration time value is 3-5 min.
Further, the temperature and the ambient temperature of mixed gas in the air inlet manifold are obtained through a temperature pressure sensor and an engine ambient temperature sensor which are arranged on an engine air inlet pipe, the rotating speed and the load of the engine are improved through an engine ECU, and the EGR valve is opened according to an EGR rate target.
Advantageous effects
Compared with the prior art, the invention has the advantages that: according to the invention, by acquiring the idling time of the whole vehicle, the temperature of the mixed gas in the air inlet main pipe and the ambient temperature, when the temperature of the mixed gas in the air inlet main pipe is lower than a first calibration temperature value, the ambient temperature is lower than a second calibration temperature value and the idling time of the whole vehicle exceeds a first calibration time value, the rotating speed and the load of the engine are increased, the EGR valve is opened according to an EGR rate target, the exhaust gas of the engine is mixed with cold air through the mixer until the temperature of the mixed gas in the air inlet main pipe is higher than a third calibration temperature value, the normal idling working condition of the whole vehicle is recovered after the second calibration time value is delayed, the potential safety hazard that the EGR system cannot be started or shut down due to icing can be effectively reduced by repeating the actions, and the running reliability of the EGR system is improved. The invention can achieve the anti-icing effect of the EGR system only by optimizing the application program without increasing the cost of parts, thereby saving the cost and being easy to popularize.
Drawings
FIG. 1 is a schematic diagram of a prior art structure;
fig. 2 is a schematic diagram of a control structure of the present invention.
Wherein: 1-engine, 2-exhaust manifold, 3-EGR gas pipe, 4-EGR cooler, 5-EGR valve, 6-mixer, 7-temperature pressure sensor, 8-intake pipe and 9-environment temperature sensor.
Detailed Description
The invention will be further described with reference to specific embodiments shown in the drawings.
Referring to fig. 2, a portion of exhaust gas discharged from the engine 1 into the exhaust manifold 2 passes through the EGR pipe 3, sequentially passes through the EGR cooler 4, the EGR valve 5, and reaches the mixer 6, and the exhaust gas is mixed with cool air in the mixer 6 and then enters the engine 1 through the intake pipe 8.
A control method for preventing EGR system icing, the method comprising the steps of:
s1, an engine ECU acquires the idling time of a whole vehicle, the engine ECU acquires the temperature of mixed gas in an air inlet main pipe through a temperature and pressure sensor 7 arranged on an air inlet pipe 8 of the engine, and the engine ECU acquires the ambient temperature through an engine ambient temperature sensor 9;
s2, if the temperature of mixed gas in the air inlet main pipe is lower than a first calibration temperature value, the ambient temperature is lower than a second calibration temperature value and the idling time of the whole vehicle exceeds a first calibration time value, jumping to the step S3; otherwise, returning to the step S1;
s3, acquiring the operation state of the whole vehicle, and if the whole vehicle has no corresponding operation, jumping to the step S4; otherwise, returning to the step S1;
s4, the engine ECU increases the engine speed and load, so that the EGR valve 5 is opened according to the EGR rate target, and the engine exhaust gas is mixed with cold air through the mixer 6 until the temperature of the mixed gas in the air inlet manifold is higher than a third calibrated temperature value, thereby effectively preventing icing or deicing;
and S5, recovering the normal idling working condition of the whole vehicle after delaying the second calibration time value, and returning to the step S1.
The corresponding operation comprises at least one of an accelerator signal, a brake signal, a clutch signal and a PTO signal, and the steps S4 and S5 can be executed to prevent icing only when the whole vehicle does not perform the operation.
When the step S4 is skipped, the engine ECU sends out a reminding message to remind the user that the EGR system is running the anti-icing function, so that the user is informed that the function is normal when the function is started, and the anti-icing function is not necessary to be panic and to be operated.
The specific values of the first calibration temperature value, the second calibration temperature value, the third calibration temperature value, the first calibration time value and the second calibration time value can be set according to specific vehicle types or specific working environments. In this embodiment, the first calibration temperature value is 0-5 ℃, the second calibration temperature value is 0-5 ℃, the third calibration temperature value is 20-25 ℃, the first calibration time value is 10-15 min, and the second calibration time value is 3-5 min.
According to the invention, by acquiring the idling time of the whole vehicle, the temperature of the mixed gas in the air inlet main pipe and the ambient temperature, when the temperature of the mixed gas in the air inlet main pipe is lower than a first calibration temperature value, the ambient temperature is lower than a second calibration temperature value and the idling time of the whole vehicle exceeds a first calibration time value, the rotating speed and the load of the engine are increased, the EGR valve is opened according to an EGR rate target, the exhaust gas of the engine is mixed with cold air through the mixer until the temperature of the mixed gas in the air inlet main pipe is higher than a third calibration temperature value, the normal idling working condition of the whole vehicle is recovered after the second calibration time value is delayed, the potential safety hazard that the EGR system cannot be started or shut down due to icing can be effectively reduced by repeating the actions, and the running reliability of the EGR system is improved. The invention can achieve the anti-icing effect of the EGR system only by optimizing the application program without increasing the cost of parts, thereby saving the cost and being easy to popularize.
The above is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that several variations and modifications can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the utility of the patent.
Claims (9)
1. A control method for preventing EGR system icing, the method comprising the steps of:
s1, acquiring the idle time of a whole vehicle, the temperature of mixed gas in an air inlet main pipe and the ambient temperature;
s2, if the temperature of mixed gas in the air inlet main pipe is lower than a first calibration temperature value, the ambient temperature is lower than a second calibration temperature value and the idling time of the whole vehicle exceeds a first calibration time value, jumping to the step S3; otherwise, returning to the step S1;
s3, acquiring the operation state of the whole vehicle, and if the whole vehicle has no corresponding operation, jumping to the step S4; otherwise, returning to the step S1;
s4, increasing the rotating speed and the load of the engine, enabling the EGR valve to be opened according to the EGR rate target, and enabling the exhaust gas of the engine to be mixed with cold air through a mixer until the temperature of the mixed gas in the air inlet main pipe is higher than a third calibrated temperature value;
and S5, recovering the normal idling working condition of the whole vehicle after delaying the second calibration time value, and returning to the step S1.
2. The control method of claim 1, wherein the corresponding operation comprises at least one of a throttle signal, a brake signal, a clutch signal, and a PTO signal.
3. The control method for preventing the EGR system from being frozen as claimed in claim 1, wherein when the step S4 is skipped, the user is reminded that the EGR system is running the anti-freezing function.
4. The control method for preventing the EGR system from being frozen according to claim 1, wherein the first calibrated temperature value is 0-5 ℃.
5. The control method for preventing the EGR system from being frozen according to claim 1, wherein the second calibrated temperature value is 0-5 ℃.
6. The control method for preventing the EGR system from being frozen according to claim 1, wherein the third calibrated temperature value is 20-25 ℃.
7. The control method for preventing the EGR system from being frozen according to claim 1, wherein the first calibration time value is 10-15 min.
8. The control method for preventing the EGR system from being frozen according to claim 1, wherein the second calibration time value is 3-5 min.
9. The control method for preventing the EGR system from being frozen according to any one of claims 1-8, characterized in that the temperature of the mixed gas in the intake manifold and the ambient temperature are respectively obtained through a temperature pressure sensor and an engine ambient temperature sensor which are arranged on an engine intake pipe, the engine ECU is used for increasing the engine speed and the engine load, and the EGR valve is opened according to the EGR rate target.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010242882.8A CN111425310B (en) | 2020-03-31 | 2020-03-31 | Control method for preventing EGR system from freezing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010242882.8A CN111425310B (en) | 2020-03-31 | 2020-03-31 | Control method for preventing EGR system from freezing |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111425310A CN111425310A (en) | 2020-07-17 |
CN111425310B true CN111425310B (en) | 2022-02-22 |
Family
ID=71551730
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202010242882.8A Active CN111425310B (en) | 2020-03-31 | 2020-03-31 | Control method for preventing EGR system from freezing |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN111425310B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113686588B (en) * | 2021-07-16 | 2023-06-16 | 东风汽车集团股份有限公司 | Test method and device for EGR system in cold environment |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56118529A (en) * | 1980-02-22 | 1981-09-17 | Nippon Denso Co Ltd | Rotational speed controlling method for engine |
JPH10159661A (en) * | 1996-11-28 | 1998-06-16 | Mazda Motor Corp | Abnormality detecting device for communication and shutting-off of passage |
JP3792506B2 (en) * | 2000-12-01 | 2006-07-05 | 本田技研工業株式会社 | Control device for internal combustion engine |
KR20030048749A (en) * | 2001-12-13 | 2003-06-25 | 현대자동차주식회사 | Exhaust gas recirculation system and it's control method for rising defrosting efficiency of automobile |
US8209102B2 (en) * | 2010-01-18 | 2012-06-26 | GM Global Technology Operations LLC | Accelerator pedal torque request systems and methods |
JP5793294B2 (en) * | 2010-12-06 | 2015-10-14 | 日野自動車株式会社 | EGR valve operation availability determination device |
US8585547B2 (en) * | 2011-03-21 | 2013-11-19 | GM Global Technology Operations LLC | System and method for preventing icing in positive crankcase ventilation systems |
EP2710240B1 (en) * | 2011-05-02 | 2021-04-14 | Volvo Truck Corporation | Method and internal combustion engine system for keeping an exhaust gas aftertreatment system within its working temperature range |
JP5936321B2 (en) * | 2011-09-05 | 2016-06-22 | 日野自動車株式会社 | Freezing prevention device for EGR device |
JP5965343B2 (en) * | 2013-03-28 | 2016-08-03 | ヤンマー株式会社 | engine |
US9175619B2 (en) * | 2013-07-11 | 2015-11-03 | Ford Global Technologies, Llc | Method of inferring start-up misfires due to the build-up of ice and melt water in the intake system of a vehicle engine |
JP2015161227A (en) * | 2014-02-27 | 2015-09-07 | マツダ株式会社 | Engine with turbo supercharger |
CN105332802B (en) * | 2015-10-26 | 2019-01-15 | 潍柴动力股份有限公司 | The method and apparatus for preventing spark plug icing |
CN106930868B (en) * | 2015-12-29 | 2020-02-25 | 联创汽车电子有限公司 | Cold end EGR valve protection system of vehicle-mounted diesel engine exhaust gas recirculation system and protection method thereof |
CN107542555B (en) * | 2016-06-28 | 2019-10-25 | 上汽通用汽车有限公司 | Vehicle exhaust recirculating system ice-breaking mode control method |
US10100751B2 (en) * | 2016-08-17 | 2018-10-16 | Ford Global Technologies, Llc | Methods and systems for clearing throttle obstruction |
TR201619065A2 (en) * | 2016-12-21 | 2018-07-23 | Ford Otomotiv Sanayi As | A MOTOR CYCLE WITH DIRECTIONABLE HEATING |
DE102017200800B4 (en) * | 2017-01-19 | 2018-09-20 | Ford Global Technologies, Llc | Method for operating a supercharged internal combustion engine with intercooling |
US10125702B2 (en) * | 2017-03-07 | 2018-11-13 | GM Global Technology Operations LLC | Method of operating an internal combustion engine having a turbocharger |
CN110454268A (en) * | 2019-07-16 | 2019-11-15 | 玉柴联合动力股份有限公司 | A kind of engine and cooler for recycled exhaust gas parallel connection cooling system |
-
2020
- 2020-03-31 CN CN202010242882.8A patent/CN111425310B/en active Active
Also Published As
Publication number | Publication date |
---|---|
CN111425310A (en) | 2020-07-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7469691B2 (en) | Exhaust gas recirculation cooler bypass | |
CN109139307B (en) | EGR valve flow diagnosis method | |
JP6049577B2 (en) | Exhaust gas recirculation system for turbocharged engines | |
US9151207B2 (en) | Distinguishing between EGR valve and oxygen sensor degradation | |
CN107542555B (en) | Vehicle exhaust recirculating system ice-breaking mode control method | |
WO2012077183A1 (en) | Control device for internal combustion engine | |
EP2317100A1 (en) | Method and system to control an engine shut-down for a vehicle | |
US20150211447A1 (en) | Control device for internal combustion engine | |
US8316638B2 (en) | Control system for a particulate matter filter | |
CN109441671B (en) | Diagnosis system and method for low-desorption pipeline of engine | |
US20130180508A1 (en) | System and method of controlling an amount of condensation in an engine air intake system | |
CN111425310B (en) | Control method for preventing EGR system from freezing | |
JP2010285937A (en) | Blow-by gas processing device for internal combustion engine | |
US20160097319A1 (en) | Control apparatus of engine | |
US20070043498A1 (en) | Learned egr valve position control | |
CN209704669U (en) | A kind of crankcase ventilation system and vehicle for vehicle | |
JP5999150B2 (en) | Control method for internal combustion engine | |
CN111322178B (en) | An EGR mixer heating system | |
EP2354507B1 (en) | A method of controlling a diesel engine | |
EP2221464A1 (en) | Control unit for internal combustion engine | |
CN105545501B (en) | A kind of full working scope reduction diesel engine NOxThe control method of emission control systems | |
CN113187632B (en) | Natural gas engine, air inlet system thereof, and anti-icing device and method for air inlet system | |
JP2008063976A (en) | Exhaust gas recirculating device of engine | |
CN115016571B (en) | Temperature control method and device of CCSCR (semiconductor control rectifier) equipment, vehicle and storage medium | |
CN216811971U (en) | Engine air intake system and engine |
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 | ||
GR01 | Patent grant | ||
GR01 | Patent grant |