CN112211761A - Adjustable 1/4 wave tube, method and control system - Google Patents
Adjustable 1/4 wave tube, method and control system Download PDFInfo
- Publication number
- CN112211761A CN112211761A CN202011079935.5A CN202011079935A CN112211761A CN 112211761 A CN112211761 A CN 112211761A CN 202011079935 A CN202011079935 A CN 202011079935A CN 112211761 A CN112211761 A CN 112211761A
- Authority
- CN
- China
- Prior art keywords
- sealing plate
- length
- cylinder body
- connecting rod
- adjustable
- 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
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000007789 sealing Methods 0.000 claims abstract description 70
- 238000006073 displacement reaction Methods 0.000 claims description 23
- 238000005457 optimization Methods 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 2
- 239000002994 raw material Substances 0.000 claims description 2
- 230000008030 elimination Effects 0.000 description 4
- 238000003379 elimination reaction Methods 0.000 description 4
- 230000005855 radiation Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000030279 gene silencing Effects 0.000 description 1
Images
Classifications
-
- 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
- F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
- F02M35/12—Intake silencers ; Sound modulation, transmission or amplification
- F02M35/1205—Flow throttling or guiding
- F02M35/1222—Flow throttling or guiding by using adjustable or movable elements, e.g. valves, membranes, bellows, expanding or shrinking elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K13/00—Arrangement in connection with combustion air intake or gas exhaust of propulsion units
- B60K13/02—Arrangement in connection with combustion air intake or gas exhaust of propulsion units concerning intake
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Transportation (AREA)
- Characterised By The Charging Evacuation (AREA)
Abstract
The invention discloses an adjustable 1/4 wavelength tube, a method and a control system, wherein the adjustable 1/4 wavelength tube comprises a cylinder body, a sealing plate, a connecting rod and a driving assembly, wherein one end of the cylinder body is communicated with an air inlet pipe; the sealing plate is arranged in the cylinder body and is connected with the cylinder body in a sliding and sealing manner; the sliding direction of the sealing plate is consistent with the length direction of the cylinder body; one end of the connecting rod is connected with the sealing plate, and the other end of the connecting rod is connected with the driving assembly, so that the driving assembly can drive the sealing plate to move along the length direction of the cylinder body through the connecting rod. The invention can optimize the frequency of the air inlet system according to different engine rotating speeds and corresponding requirements, thereby enabling the adjustable 1/4 wave tube to optimize the air inlet noise with different frequencies.
Description
Technical Field
The invention relates to the technical field of automobile air intake noise elimination, in particular to an adjustable 1/4 wave pipe, a method and a control system.
Background
The 1/4 wave pipe is a closed pipe mounted on the main pipe, as shown in fig. 1. When the sound wave enters the side branch pipe from the main pipe, the sound wave is reflected to the main pipe by the closed end, and the sound wave of certain frequency and the sound wave of the same frequency in the main pipe are mutually offset due to opposite phases, so that the aim of silencing is fulfilled.
The existing air intake system 1/4 wavelength pipe noise elimination frequency is fixed because of the fixed length, so the noise elimination frequency is also fixed. Once the length of the wavelength tube of the existing air inlet system 1/4 is determined, the corresponding noise elimination frequency is fixed and cannot be changed. In the case of intake, the frequency of intake noise varies depending on the engine speed.
Disclosure of Invention
The invention aims to provide an adjustable 1/4 wave tube, a method and a system, which are used for solving the defects in the prior art, and can optimize the frequency of an air inlet system according to different engine rotating speeds and corresponding requirements, so that the adjustable 1/4 wave tube can optimize air inlet noise with different frequencies.
The invention provides an adjustable 1/4 wave tube, which comprises a cylinder, a sealing plate, a connecting rod and a driving assembly, wherein one end of the cylinder is communicated with an air inlet pipe;
the sealing plate is arranged in the cylinder body and is connected with the cylinder body in a sliding and sealing manner; the sliding direction of the sealing plate is consistent with the length direction of the cylinder body;
one end of the connecting rod is connected with the sealing plate, and the other end of the connecting rod is connected with the driving assembly, so that the driving assembly can drive the sealing plate to move along the length direction of the cylinder body through the connecting rod.
The adjustable 1/4 wave tube as described above, further comprising a displacement sensor for detecting the position of the sealing plate within the cylinder to enable the driving assembly to drive the sealing plate to a set target position.
The adjustable 1/4 wave tube as described above, wherein, optionally, the driving assembly is a motor, and the connecting rod is a lead screw or a rod with two ends hinged to an eccentric disc on the motor and the sealing plate respectively.
The invention also proposes a method for adjusting an adjustable 1/4 wave tube as defined in any one of the above, characterized in that it comprises the following steps:
s1, obtaining an engine speed signal and a displacement sensor signal;
s2, acquiring a target length according to the engine speed signal;
s3, judging whether the displacement sensor signal is equal to the target length, if so, keeping the current state; if not, the position of the sealing plate is adjusted until the signal of the displacement sensor is equal to the target length.
The method as described above, wherein optionally, in step S2, the method for obtaining the target length according to the engine speed signal is:
s21, presetting the air intake system optimization frequency corresponding to different engine speeds;
s22, taking the air intake system optimization frequency corresponding to the engine speed signal as a target frequency;
and S23, calculating the effective length of the corresponding 1/4 wave tube according to the target frequency, and taking the effective length as the target length.
The method as described above, wherein optionally, in step S23, the calculation formula of the effective length is as follows:
wherein L is the effective length, c is the sound velocity, and n is a positive integer.
The invention also provides a control system for the adjustable 1/4 wave tube, which is characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,
a rotational speed sensor for detecting a rotational speed of the engine;
a displacement sensor mounted on the sealing plate for acquiring the position of the sealing plate to obtain the effective length of the cylinder,
a controller electrically connected to the rotational speed sensor, the displacement sensor and the drive assembly;
the controller is internally pre-stored with air intake system optimization frequencies corresponding to different engine rotating speeds; the controller is used for acquiring the current engine speed, acquiring system optimization frequency according to the engine speed and calculating a target length according to the optimization frequency;
the controller is also used for controlling the driving assembly to work according to the target length so as to enable the sealing plate to move to the corresponding position.
The control system as described above, wherein optionally the controller is an ECU.
The control system as described above, wherein optionally, the formula for calculating the target length according to the optimized frequency is:
wherein L is the effective length, c is the sound velocity, and n is a positive integer.
Compared with the prior art, the sealing plate is arranged in the cylinder body, and the sealing plate is connected in the cylinder body in a sliding and sealing manner, so that the effective length of the 1/4 wave-length tube can be adjusted by adjusting the position of the sealing plate, and the aim of eliminating air inlet noise with different frequencies is fulfilled. Research shows that the intake noise frequency and the engine speed have a relationship, and the intake noise at different engine speeds can be specifically eliminated by presetting the intake noise frequencies corresponding to different engine speeds.
Drawings
Fig. 1 is a schematic structural diagram of an adjustable 1/4 wave tube proposed by the present invention;
FIG. 2 is a flow chart of the steps of the method proposed by the present invention;
fig. 3 is a block diagram of a control system according to the present invention.
Description of reference numerals: the device comprises a cylinder 1, a sealing plate 2, a connecting rod 3, a driving assembly 4, a displacement sensor 5, a controller 6 and a rotating speed sensor 7.
Detailed Description
The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.
In the case of the example 1, the following examples are given,
referring to fig. 1, the present embodiment provides an adjustable 1/4 wave tube, which includes a tube body 1, a sealing plate 2, a connecting rod 3, and a driving assembly 4, wherein one end of the tube body 1 is used for communicating with an air inlet pipe, and in a specific implementation, the tube body 1 may be a tube with a circular cross section or a square cross section, or of other shapes, but in which shape, an inner cavity of the tube body 1 should be a cylinder with a uniform cross section. When in use, the central line of the cylinder body 1 is vertical to the central line of the air inlet pipe.
Specifically, the sealing plate 2 is installed in the cylinder 1, and the sealing plate 2 is connected with the cylinder 1 in a sliding and sealing manner; the sliding direction of the sealing plate 2 is identical to the length direction of the cylinder 1. When in implementation, at least one sealing ring is arranged between the sealing plate and the cylinder body 1, namely, a sealing groove is arranged on the periphery of the sealing plate 2, and the sealing ring is arranged in the sealing groove.
More specifically, one end of the connecting rod 3 is connected to the sealing plate 2, and the other end of the connecting rod is connected to the driving assembly 4, so that the driving assembly 4 can drive the sealing plate 2 to move along the length direction of the cylinder 1 through the connecting rod 3.
In specific implementation, the driving assembly 4 is a motor, and the connecting rod 3 is a screw rod or a rod piece with two ends respectively hinged to the eccentric disc on the motor and the sealing plate 2. Specifically, the connecting rod 3 may be a telescopic member, such as a pneumatic rod, a hydraulic rod, an electric telescopic rod, or the like. Of course, it can also be a rod, when the connecting rod 3 is a rod, an eccentric disc should be connected to the motor, and one end of the connecting rod 3 is hinged with the eccentric disc, and the other end is hinged with the sealing plate 2, forming a piston connecting rod structure similar to that of the engine. Thereby converting the rotational motion of the motor into the reciprocating motion of the sealing plate 2.
In order to realize accurate adjustment of the sealing plate 2, the sealing plate sealing device further comprises a displacement sensor 5, wherein the displacement sensor 5 is used for detecting the position of the sealing plate 2 in the cylinder body 1, so that the driving assembly 4 can drive the sealing plate 2 to a set target position.
When the sealing plate is used specifically, when air inlet noise of a certain frequency needs to be eliminated, the sealing plate 2 is moved to a corresponding position. In this way, intake noise of different frequencies can be eliminated as needed.
Specifically, it is determined to optimize a particular frequency bin: the test confirms that the influence of the intake radiation noise on the noise in the vehicle is larger in the frequency ranges which are the specific frequency ranges needing to be optimized, namely the optimized frequency of the intake system, and records the corresponding rotating speed when the vehicle runs.
According to the determined specific frequency band, the effective length of the 1/4 wavelength tube corresponding to the specific frequency band is determined through a calculation formula, the length of the adjustable 1/4 wavelength tube is designed, and the corresponding rotating speed is stored in the ECU together.
When the vehicle is started and the ECU monitors an engine speed signal, the signal is transmitted to the motor to drive the motor to push the connecting rod, and whether the adjusting connecting rod pushes the sealing plate to reduce the length of the 1/4 wavelength tube or pulls the connecting rod to increase the length of the 1/4 wavelength tube is adjusted. When the linkage is pushed, the displacement sensor will send a signal to the ECU, and until the sealing plate moves to a set position, the ECU will signal the motor to stop working, reaching the expected length of 1/4 wave tube.
Example 2
Referring to fig. 2, the present embodiment provides a method for adjusting an adjustable 1/4 wave tube according to embodiment 1, which includes the following steps:
s1, obtaining an engine speed signal and a displacement sensor 5 signal;
s2, acquiring a target length according to the engine speed signal;
in specific implementation, the method specifically comprises the following steps: s21, presetting the air intake system optimization frequency corresponding to different engine speeds; the corresponding relation between the engine speed and the optimization frequency of the air intake system is set in advance and can be prestored in a comparison table mode. S22, taking the air intake system optimization frequency corresponding to the engine speed signal as a target frequency; and S23, calculating the effective length of the corresponding 1/4 wave tube according to the target frequency, and taking the effective length as the target length. The calculation formula of the effective length is as follows:
wherein L is the effective length, c is the sound velocity, and n is a positive integer.
S3, judging whether the signal of the displacement sensor 5 is equal to the target length, if so, keeping the current state; if not, the position of the sealing plate 2 is adjusted until the signal of the displacement sensor 5 is equal to the target length.
By the above steps, the specific frequency of the inlet radiation noise can be more accurately optimized according to different engine speeds, and the number of 1/4 wave tubes can be saved.
Example 3
Referring to fig. 3, the present embodiment provides a control system for the embodiment 1, which includes a rotation speed sensor 7 for detecting a rotation speed of an engine;
a displacement sensor 5 mounted on the sealing plate 2 for acquiring the position of the sealing plate 2 to obtain the effective length of the cylinder 1,
the controller 6 is electrically connected with the rotating speed sensor 7, the displacement sensor 5 and the driving assembly, and the controller 6 is electrically connected with the driving assembly; specifically, the controller 6 receives the signal of the rotating speed sensor 7 and is used for receiving the signal of the rotating speed sensor 7
The controller 6 is internally pre-stored with air intake system optimization frequencies corresponding to different engine rotating speeds; the controller 6 is used for acquiring the current engine speed, acquiring system optimization frequency according to the engine speed, and calculating a target length according to the optimization frequency; wherein, the formula for calculating the target length according to the optimized frequency is as follows:
wherein L is the effective length, c is the sound velocity, and n is a positive integer.
The controller 6 is further configured to control the driving assembly to operate according to the target length, so as to move the sealing plate 2 to a corresponding position. In practice, the controller 6 is an ECU.
When the device is used specifically, the influence of the intake radiation noise on the noise in the vehicle in which frequency sections is large is confirmed through testing when the vehicle runs, the frequency sections are specific frequency sections needing to be optimized, namely the optimized frequency of an intake system, and the corresponding rotating speed is recorded.
According to the determined specific frequency band, the effective length of the 1/4 wavelength tube corresponding to the specific frequency band is determined through a calculation formula, the length of the adjustable 1/4 wavelength tube is designed, and the corresponding rotating speed is stored in the ECU together.
When the vehicle is started and the ECU monitors an engine speed signal, the signal is transmitted to the motor to drive the motor to push the connecting rod, and whether the adjusting connecting rod pushes the sealing plate to reduce the length of the 1/4 wavelength tube or pulls the connecting rod to increase the length of the 1/4 wavelength tube is adjusted. When the linkage is pushed, the displacement sensor will send a signal to the ECU, and until the sealing plate moves to a set position, the ECU will signal the motor to stop working, reaching the expected length of 1/4 wave tube.
The construction, features and functions of the present invention are described in detail in the embodiments illustrated in the drawings, which are only preferred embodiments of the present invention, but the present invention is not limited by the drawings, and all equivalent embodiments modified or changed according to the idea of the present invention should fall within the protection scope of the present invention without departing from the spirit of the present invention covered by the description and the drawings.
Claims (9)
1. An adjustable 1/4 wave tube, characterized by: comprises a cylinder body (1) with one end communicated with an air inlet pipe, a sealing plate (2), a connecting rod (3) and a driving component (4);
the sealing plate (2) is arranged in the cylinder body (1), and the sealing plate (2) is connected with the cylinder body (1) in a sliding and sealing manner; the sliding direction of the sealing plate (2) is consistent with the length direction of the cylinder (1);
one end of the connecting rod (3) is connected with the sealing plate (2), and the other end of the connecting rod is connected with the driving component (4), so that the driving component (4) can drive the sealing plate (2) to move along the length direction of the cylinder body (1) through the connecting rod (3).
2. The adjustable 1/4 wave tube of claim 1, wherein: the sealing device is characterized by further comprising a displacement sensor (5), wherein the displacement sensor (5) is used for detecting the position of the sealing plate (2) in the cylinder body (1) so that the driving assembly (4) can drive the sealing plate (2) to a set target position.
3. The adjustable 1/4 wave tube of claim 2, wherein: the driving assembly (4) is a motor, and the connecting rod (3) is a screw rod or a rod piece with two ends respectively hinged with the eccentric disc on the motor and the sealing plate (2).
4. A method for adjusting an adjustable 1/4 wave tube according to any one of claims 1-3, comprising the steps of:
s1, obtaining an engine speed signal and a displacement sensor (5) signal;
s2, acquiring a target length according to the engine speed signal;
s3, judging whether the signal of the displacement sensor (5) is equal to the target length, if so, keeping the current state; if not, the position of the sealing plate (2) is adjusted until the signal of the displacement sensor (5) is equal to the target length.
5. The method of claim 4, wherein: in step S2, the method for obtaining the target length according to the engine speed signal is:
s21, presetting the air intake system optimization frequency corresponding to different engine speeds;
s22, taking the air intake system optimization frequency corresponding to the engine speed signal as a target frequency;
and S23, calculating the effective length of the corresponding 1/4 wave tube according to the target frequency, and taking the effective length as the target length.
6. The method of claim 5, wherein: in step S23, the effective length is calculated as follows:
wherein L is the effective length, c is the sound velocity, and n is a positive integer.
7. A control system for the adjustable 1/4 wave tube of claim 1, characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,
a rotational speed sensor (7) for detecting the rotational speed of the engine;
a displacement sensor (5) arranged on the sealing plate (2) and used for acquiring the position of the sealing plate (2) so as to obtain the effective length of the cylinder body (1),
a controller (6), wherein the controller (6) is electrically connected with the rotating speed sensor (7), the displacement sensor (5) and the driving component;
the controller (6) is internally pre-stored with air intake system optimization frequencies corresponding to different engine rotating speeds; the controller (6) is used for acquiring the current engine speed, acquiring system optimization frequency according to the engine speed and calculating a target length according to the optimization frequency;
the controller (6) is also used for controlling the driving assembly to work according to the target length so as to enable the sealing plate (2) to move to the corresponding position.
8. The control system according to claim 7, characterized in that the controller (6) is an ECU.
9. The control system of claim 7, wherein the formula for calculating the target length from the optimized frequency is:
wherein L is the effective length, c is the sound velocity, and n is a positive integer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011079935.5A CN112211761A (en) | 2020-10-10 | 2020-10-10 | Adjustable 1/4 wave tube, method and control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011079935.5A CN112211761A (en) | 2020-10-10 | 2020-10-10 | Adjustable 1/4 wave tube, method and control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112211761A true CN112211761A (en) | 2021-01-12 |
Family
ID=74053155
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011079935.5A Pending CN112211761A (en) | 2020-10-10 | 2020-10-10 | Adjustable 1/4 wave tube, method and control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112211761A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115751379A (en) * | 2022-09-27 | 2023-03-07 | 南京航空航天大学 | Quarter wave tube for suppressing combustion instability and control method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5317112A (en) * | 1991-10-16 | 1994-05-31 | Hyundai Motor Company | Intake silencer of the variable type for use in motor vehicle |
| CN203532117U (en) * | 2013-07-31 | 2014-04-09 | 重庆长安汽车股份有限公司 | Frequency adjustable one-fourth wavelength pipe mounted to air inlet pipe |
| CN104832327A (en) * | 2014-11-25 | 2015-08-12 | 北汽福田汽车股份有限公司 | Air inlet pipe assembly for vehicle engine air inlet system and vehicle adopting air inlet pipe assembly |
| CN207847826U (en) * | 2017-12-14 | 2018-09-11 | 郑州宇通客车股份有限公司 | Sound attenuation assembly and the engine system with the sound attenuation assembly, vehicle |
-
2020
- 2020-10-10 CN CN202011079935.5A patent/CN112211761A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5317112A (en) * | 1991-10-16 | 1994-05-31 | Hyundai Motor Company | Intake silencer of the variable type for use in motor vehicle |
| CN203532117U (en) * | 2013-07-31 | 2014-04-09 | 重庆长安汽车股份有限公司 | Frequency adjustable one-fourth wavelength pipe mounted to air inlet pipe |
| CN104832327A (en) * | 2014-11-25 | 2015-08-12 | 北汽福田汽车股份有限公司 | Air inlet pipe assembly for vehicle engine air inlet system and vehicle adopting air inlet pipe assembly |
| CN207847826U (en) * | 2017-12-14 | 2018-09-11 | 郑州宇通客车股份有限公司 | Sound attenuation assembly and the engine system with the sound attenuation assembly, vehicle |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115751379A (en) * | 2022-09-27 | 2023-03-07 | 南京航空航天大学 | Quarter wave tube for suppressing combustion instability and control method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112211761A (en) | Adjustable 1/4 wave tube, method and control system | |
| KR100504084B1 (en) | Device for contactlessly measuring the distance | |
| US20070286730A1 (en) | Device for Measuring the Displacement Travel of a Hydraulic Displacement Mechanism | |
| US6199846B1 (en) | Electric power operated clamp with spring lock | |
| CN110116601A (en) | A kind of air-conditioning duct silencer | |
| CN110770427A (en) | Method for detecting a current correction value of an inlet section of a combustion motor during operation | |
| US6347573B1 (en) | Piston cylinder unit having an adjustable stroke length | |
| CN106482318B (en) | A kind of adjustable air-conditioning duct muffler | |
| GB1580759A (en) | Braking apparatus for an internal combustion engine | |
| CN116557978A (en) | Air conditioner external unit pipeline fixing device, control method thereof and air conditioner | |
| US4483179A (en) | Method of and device for detection of knocking for internal combustion engine | |
| CN216788664U (en) | Constant temperature control device for air inlet system of air compressor of air source unit | |
| CN208672452U (en) | It is a kind of for testing the test device of automotive components rigidity | |
| US20150167654A1 (en) | Variable capacity compressor | |
| CN113567618B (en) | Gas concentration detection device | |
| US7321822B2 (en) | Device and method for estimation of an engine torque | |
| CN219775885U (en) | Air conditioner external machine pipeline fixing device and air conditioner | |
| CN1576588A (en) | Screw compressor | |
| US20190017447A1 (en) | Internal combustion engine, in particular as drive engine for a vehicle | |
| CN201896678U (en) | Forklift liquefied gas engine with electromagnetic type sensor bracket | |
| CN101315079A (en) | Silencer with adjustable noise elimination frequency band | |
| CN210464767U (en) | Torque measuring device of automobile air conditioner compressor | |
| WO2017118168A1 (en) | Control method and system for engine | |
| CN215109359U (en) | Air compressor machine amortization structure | |
| CN218376659U (en) | Protection system, engine and vehicle of engine booster subassembly |
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 |
Application publication date: 20210112 |
|
| RJ01 | Rejection of invention patent application after publication |