CN110310851B - Arc extinguish chamber corrugated pipe machining method - Google Patents
Arc extinguish chamber corrugated pipe machining method Download PDFInfo
- Publication number
- CN110310851B CN110310851B CN201910517411.0A CN201910517411A CN110310851B CN 110310851 B CN110310851 B CN 110310851B CN 201910517411 A CN201910517411 A CN 201910517411A CN 110310851 B CN110310851 B CN 110310851B
- Authority
- CN
- China
- Prior art keywords
- corrugated pipe
- extinguish chamber
- arc extinguish
- hydraulic forming
- cavity
- 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
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000003754 machining Methods 0.000 title claims abstract description 9
- 230000003068 static effect Effects 0.000 claims abstract description 36
- 230000002093 peripheral effect Effects 0.000 claims abstract description 26
- 230000008569 process Effects 0.000 claims abstract description 7
- 238000012545 processing Methods 0.000 claims description 8
- 238000000465 moulding Methods 0.000 abstract description 2
- 238000004880 explosion Methods 0.000 description 8
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000013475 authorization Methods 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000008358 core component Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H11/00—Apparatus or processes specially adapted for the manufacture of electric switches
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Abstract
The invention relates to the technical field of circuit breakers, and provides a machining method for an arc extinguish chamber corrugated pipe, which can solve the problems that the corrugated pipe is easy to fatigue crack and has short service life in the prior art. The machining method of the arc extinguish chamber corrugated pipe comprises the following steps: placing the bobbin blank in a cavity of a hydraulic forming die, and obtaining an arc extinguish chamber corrugated pipe through a hydraulic forming process; during hydraulic forming, the distance between the outer peripheral surface of the whole bobbin blank and a cavity of a hydraulic forming die is gradually increased from a movable end to a static end, so that the thickness of the tube wall of the arc extinguish chamber corrugated tube obtained by the bobbin blank forming is gradually increased from the static end to the movable end; or the distance between the peripheral surface of at least one section of the bobbin blank and the cavity of the hydraulic forming die is gradually increased from the movable end to the static end, so that the thickness of the tube wall of the corresponding section of the arc extinguish chamber corrugated tube obtained by molding the bobbin blank is gradually increased from the static end to the movable end.
Description
Technical Field
The invention relates to the technical field of circuit breakers, in particular to a machining method of an arc extinguish chamber corrugated pipe.
Background
The vacuum interrupter is a core component in the circuit breaker, and the service life and reliability of the vacuum interrupter are very important for the whole circuit breaker. Patent documents with an authorization announcement number of CN206225281U and an authorization announcement date of 2017.06.06 disclose a magnetic arc-extinguishing chamber for a high-voltage vacuum circuit breaker, which includes a ceramic shell, openings at two ends of the ceramic shell are respectively covered with a movable end cover and a stationary end cover, the movable end cover and the stationary end cover are respectively mounted on the two end covers in a penetrating manner, a movable contact and a stationary contact are arranged on the end portions of the movable and stationary contact, which are close to each other, and the movable end assembly is composed of the movable contact and the movable contact. The movable conducting rod is sleeved with a cylindrical corrugated pipe with the same diameter, one end of the corrugated pipe is connected with the movable end cover, and the other end of the corrugated pipe is connected with the movable conducting rod. The outer surface of the corrugated pipe is provided with U-shaped single waves with the same shape and size, and a plurality of single waves are connected to form a corrugated structure.
With the development of the corrugated pipe processing technology, a hydroformed corrugated pipe with gradually changing radial dimensions appears, for example, a reducing corrugated pipe and a forming method thereof disclosed in patent application publication No. CN106090453A and application publication No. 2016.11.09, the reducing corrugated pipe comprises a small-diameter straight-edge conical pipe section, a large-diameter straight-edge conical pipe section and a conical corrugated section located between the small-diameter straight-edge conical pipe section and the large-diameter straight-edge conical pipe section, and both the wave crest and the wave trough of the conical corrugated section gradually increase from the small-diameter straight-edge conical pipe section to the large-diameter straight-edge conical pipe section, so that the corrugated pipe is integrally conical. When the reducing corrugated pipe is processed, a conical blank is put into a die and is obtained through a hydraulic forming process. When the variable-diameter corrugated pipe is applied to a vacuum arc extinguish chamber, the variable-diameter corrugated pipe is sleeved on the peripheral surface of a movable conducting rod, one end of the corrugated pipe is welded with a movable contact at the end part of the movable conducting rod, the other end of the corrugated pipe is welded with a movable end cover to keep the corrugated pipe sealed, the end of the corrugated pipe welded with the movable conducting rod is a movable end, the end connected with the movable end cover is a static end, when the movable conducting rod moves, the movable contact is driven to be in contact with or separated from a static contact, and the acting force for driving the movable conducting rod to move is also transmitted to the corrugated pipe.
The reducing corrugated pipe has the following problems in use: because of the time delay of the acting force, when the movable conducting rod acts, the movable end of the corrugated pipe always acts before the static end, because the corrugated structure on the corrugated pipe has a buffer effect, the acting force is different in magnitude on different positions when being transmitted along the direction from the movable end to the static end, the distribution of the acting force on the corrugated pipe is uneven, the stress and the deformation of the movable end are large when the movable end moves, and the movable end is easy to fatigue crack.
Disclosure of Invention
The invention aims to provide a machining method of an arc extinguish chamber corrugated pipe, and the arc extinguish chamber corrugated pipe obtained by the method can solve the problem that a corrugated pipe is easy to fatigue crack in the prior art.
In order to achieve the purpose, the machining method of the arc extinguish chamber corrugated pipe adopts the following technical scheme:
the machining method of the arc extinguish chamber corrugated pipe comprises the following steps: placing the bobbin blank in a cavity of a hydraulic forming die, and obtaining an arc extinguish chamber corrugated pipe through a hydraulic forming process; during hydraulic forming, the distance between the outer peripheral surface of the whole bobbin blank and a cavity of a hydraulic forming die is gradually increased from a movable end to a static end, so that the thickness of the tube wall of the arc extinguish chamber corrugated tube obtained by the bobbin blank forming is gradually increased from the static end to the movable end; or the distance between the peripheral surface of at least one section of the bobbin blank and the cavity of the hydraulic forming die is gradually increased from the movable end to the static end, so that the thickness of the tube wall of the corresponding section of the arc extinguish chamber corrugated tube obtained by molding the bobbin blank is gradually increased from the static end to the movable end.
The beneficial effects are that: the distance between the whole peripheral surface or at least one section of peripheral surface of the bobbin blank and the cavity of the hydraulic forming die is gradually increased from a movable end to a static end, the distance between the peripheral surface and the cavity, close to the movable end, of the whole bobbin blank or a variable section of the bobbin blank is smaller than the distance between the peripheral surface and the cavity, close to the static end, of the bobbin blank, the movable end of the bobbin blank is the movable end of the molded arc extinguish chamber corrugated pipe, the static end of the bobbin blank is the static end of the molded arc extinguish chamber corrugated pipe, the distance between the peripheral surface and the cavity of the static end of the bobbin blank is larger, the static end of the bobbin blank has a larger deformation space in the radial direction, the static end of the bobbin blank can be extruded to be thinner by applying hydraulic pressure to the inner wall surface of the bobbin blank, and therefore the aim of gradually changing the wall thickness of the arc extinguish chamber corrugated pipe along the axial direction is achieved. The parts with different pipe wall thicknesses have different rigidities, so that the possibility of cracking can be reduced, and the service life of the whole corrugated pipe is prolonged.
Furthermore, a hydraulic forming die with a frustum-shaped cavity is adopted during hydraulic forming, and the diameter of the end part of the cavity corresponding to the movable end of the arc extinguish chamber corrugated pipe is smaller than the diameter of the end part corresponding to the static end of the arc extinguish chamber corrugated pipe.
The beneficial effects are that: the die cavity of the hydraulic forming die is of a frustum structure, so that the arc extinguish chamber corrugated pipe with the radial size change can be conveniently obtained in hydraulic forming, the diameter of the corresponding part of the wave crest in the arc extinguish chamber corrugated pipe is arranged in a gradually increasing mode, the corresponding part of the wave crest of the arc extinguish chamber corrugated pipe is in a frustum shape along the axial direction, and the problem that the corrugated pipe is locally distorted and cracked due to axial deflection in the telescopic deformation process can be effectively solved.
Further, the bobbin blank adopts a frustum-shaped pipe body, and the inclination of the bobbin blank is set to be smaller than that of a cavity of the hydraulic forming die.
The beneficial effects are that: the tube blank is of a frustum-shaped structure, and is convenient to be matched with a hydraulic forming die to obtain the arc extinguish chamber corrugated tube with the radial size changing.
Further, the waveform on the outer peripheral surface of the arc extinguish chamber corrugated pipe is set to be arranged with the waveform symmetry axis perpendicular to the outer peripheral surface.
The beneficial effects are that: the symmetrical axis of the waveform is perpendicular to the outer peripheral surface, and when the arc extinguish chamber corrugated pipe is stretched and deformed, the deformation direction of the waveform is parallel to the outer peripheral surface of the arc extinguish chamber corrugated pipe, so that the arc extinguish chamber corrugated pipe can be deformed better.
Drawings
FIG. 1 is a schematic structural diagram of a vacuum interrupter according to the present invention;
FIG. 2 is a schematic structural diagram of an arc extinguishing chamber bellows according to the present invention;
fig. 3 is a schematic diagram of a process for forming the bellows for the arc extinguishing chamber according to the present invention.
In the figure: 10-a housing; 11-moving end cover; 12-a static end cap; 13-moving contact; 14-a static contact; 15-a movable conducting rod; 16-arc chute bellows; 161-waveform; 162-a moving end; 163-a dead end; 20-a hydraulic forming die; 30-tube blank.
Detailed Description
The following describes a specific embodiment of a method for processing an arc extinguishing chamber corrugated pipe according to the present invention with reference to the accompanying drawings.
As shown in fig. 1 to 3, which are an embodiment of a method for processing an arc extinguish chamber bellows according to the present invention, the arc extinguish chamber bellows obtained by the method is used in a vacuum arc extinguish chamber, as shown in fig. 1, the vacuum arc extinguish chamber comprises a housing 10, mounting ports are respectively formed at two ends of the housing 10, and an operator sets a movable contact 13 and a fixed contact 14 in the housing 10 through the mounting ports. A movable end cover 11 and a static end cover 12 are respectively arranged at the mounting opening, a through hole is arranged on the movable end cover 11, a movable conducting rod 15 extends into the shell, and a movable contact 13 is arranged at the end part of the movable conducting rod 15. An arc extinguish chamber corrugated pipe 16 is sleeved on the movable conducting rod 15, one end of the arc extinguish chamber corrugated pipe 16 is welded with the movable end cover 11, the other end of the arc extinguish chamber corrugated pipe 16 is welded with the movable contact 13, and when the movable conducting rod 15 drives the movable contact 13 to act, the arc extinguish chamber corrugated pipe 16 can stretch and deform along with the movable conducting rod 15.
As shown in fig. 2, the arc extinguish chamber corrugated pipe 16 is formed by processing a bobbin blank through a hydroforming process, the end of the arc extinguish chamber corrugated pipe 16, which is used for being matched with the movable conducting rod 15, is a movable end 162, the end matched with the movable end cover 11 is a stationary end 163, the wall thickness of the arc extinguish chamber corrugated pipe 16 is changed along the axial direction, that is, the wall thickness of the arc extinguish chamber corrugated pipe 16 is gradually reduced along the direction from the movable end 162 to the stationary end 163, and the wall thickness of the arc extinguish chamber corrugated pipe 162 is larger so as to ensure the rigidity of the movable end. Not only the tube wall thickness of explosion chamber bellows 16 can be along axial continuous variation, the external diameter of explosion chamber bellows 16 also can be along axial continuous variation, the external diameter of 16 quiet end departments of explosion chamber bellows will be greater than the external diameter of 16 movable end departments of explosion chamber bellows, the external diameter of explosion chamber bellows refers to the diameter that corresponds the department with the crest, the wave form of explosion chamber bellows is the U-shaped, the external diameter between 16 both ends of explosion chamber bellows wholly presents the trend of following the directional quiet end 163 of movable end 162 and increase gradually, and explosion chamber bellows 16 wholly is the frustum shape structure that one end is big one end is little. The waveform 161 disposed on the outer peripheral surface of the arc extinguishing chamber bellows 16 is perpendicular to the outer peripheral surface of the arc extinguishing chamber bellows, and the symmetry axis of the waveform 161 is parallel to the perpendicular line of the outer peripheral surface of the arc extinguishing chamber bellows.
For the arc extinguish chamber corrugated pipe, the arc extinguish chamber corrugated pipe in other embodiments has a variable wall thickness section with a pipe wall thickness changing along the axial direction in the axial direction, and also has a part with the same pipe wall thickness connected with the variable wall thickness section, and at the moment, the variable wall thickness section in the arc extinguish chamber corrugated pipe is gradually reduced from a movable end to a static end and is in a continuous change form.
In other embodiments, the arc chute bellows may be provided in a constant diameter configuration.
In other embodiments, the wave shape on the outer circumference of the arc extinguish chamber corrugated pipe can be arranged in a mode of being perpendicular to the axis of the arc extinguish chamber corrugated pipe, and when the wave shape is arranged in such a mode, the wave shape is arranged in an inclined mode with the outer circumference of the arc extinguish chamber corrugated pipe.
As shown in fig. 3, when the arc extinguish chamber corrugated tube is processed, a plate material with uniform thickness needs to be rolled into a frustum-shaped bobbin blank 30 with two different end diameters, and in order to ensure that different tube wall thicknesses can be processed when the tube blank 30 is matched with the hydroforming die 20, when the tube blank 30 is placed in a die cavity, the distance between the whole outer peripheral surface of the bobbin blank 30 and the die cavity of the hydroforming die 20 is gradually increased from a moving end to a static end, that is, the distance between the outer peripheral surface of the moving end of the bobbin blank 30 and the die cavity is smaller than the distance between the outer peripheral surface of the static end of the bobbin blank 30 and the die cavity. The moving end of the tube blank 30 is the moving end of the molded arc extinguishing chamber corrugated tube 16, and the static end of the tube blank 30 is the static end of the molded arc extinguishing chamber corrugated tube 16.
The distance between the outer peripheral surface of the stationary end of the bobbin blank 30 and the cavity is large, the stationary end of the bobbin blank 30 has a larger deformation space in the radial direction, and the stationary end of the bobbin blank 30 can be extruded to be thinner by applying hydraulic pressure to the inner wall surface of the bobbin blank 30, so that the purpose that the wall thickness of the arc extinguishing chamber corrugated pipe 16 gradually and continuously changes along the axial direction is achieved.
In this embodiment, a cavity of the hydraulic forming mold is of a frustum structure, and a radial dimension of an end portion of the cavity corresponding to the movable end is smaller than a radial dimension of an end portion corresponding to the stationary end. When the size of the bobbin blank is set by an operator, the difference between the outer diameter of the static end of the bobbin blank and the radial size of the large end of the cavity is larger than the difference between the outer diameter of the dynamic end of the bobbin blank and the radial size of the small end of the cavity. The tube blank 30 is of a frustum-shaped structure, and the inclination of the tube blank 30 is smaller than that of a cavity of the hydraulic forming die. And the axis of the forming space for forming the waveform in the cavity is perpendicular to the peripheral surface of the bobbin blank 30, so the waveform symmetric axis on the obtained arc extinguish chamber corrugated pipe is perpendicular to the peripheral surface of the arc extinguish chamber corrugated pipe, the waveform symmetric axis is in an oblique upward form, in order to facilitate demoulding, a split die can be adopted for hydraulic forming processing, and during demoulding, the die is split and taken down.
Specifically, the distance between the static end of the bobbin blank and the large end of the cavity is set to be 0.5mm, and the distance between the movable end of the bobbin blank and the small end of the cavity is set to be 0.1 mm. After hydraulic forming, the thickness of the static end of the arc extinguish chamber corrugated pipe is 80% of the thickness of the static end of the original bobbin blank, and the thickness of the moving end of the corrugated pipe is 95% of the thickness of the moving end of the original bobbin blank.
In other embodiments, the distance between a part of the tube blank, i.e. a variable section of which the wall thickness needs to be changed, and the cavity of the hydroforming die can be gradually increased from the movable end to the static end, and the obtained arc extinguish chamber corrugated tube has a variable section of which the wall thickness is changed, i.e. a variable wall thickness section.
In other embodiments, the bobbin blank may be a cylindrical bobbin blank, and the cylindrical bobbin blank may be processed by matching with a hydraulic forming die with a frustum-shaped cavity, and the cylindrical bobbin blank may be processed by punching the blank.
The above-mentioned embodiments, the objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (4)
1. The machining method of the arc extinguish chamber corrugated pipe comprises the following steps:
placing the bobbin blank in a cavity of a hydraulic forming die, and obtaining an arc extinguish chamber corrugated pipe through a hydraulic forming process;
the method is characterized in that:
during hydraulic forming, the distance between the whole peripheral surface of the bobbin blank and a cavity of a hydraulic forming die is gradually increased from a movable end to a static end, so that the thickness of the tube wall of the arc extinguish chamber corrugated tube obtained by the bobbin blank forming is gradually increased from the static end to the movable end.
2. The method for processing the arc extinguish chamber corrugated pipe according to claim 1, is characterized in that: the hydraulic forming die with the die cavity of a frustum structure is adopted during hydraulic forming, and the diameter of the end part, corresponding to the movable end of the arc extinguish chamber corrugated pipe, in the die cavity is smaller than the diameter of the end part, corresponding to the static end of the arc extinguish chamber corrugated pipe.
3. The method for processing the arc extinguish chamber corrugated pipe as recited in claim 2, wherein the method comprises the following steps: the bobbin blank adopts a frustum-shaped pipe body, and the inclination of the bobbin blank is set to be smaller than that of a cavity of the hydraulic forming die.
4. The method for processing the arc extinguish chamber corrugated pipe according to claim 3, wherein the method comprises the following steps: the waveform on the outer peripheral surface of the arc extinguish chamber corrugated pipe is set to be arranged with the waveform symmetry axis vertical to the outer peripheral surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910517411.0A CN110310851B (en) | 2019-06-14 | 2019-06-14 | Arc extinguish chamber corrugated pipe machining method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910517411.0A CN110310851B (en) | 2019-06-14 | 2019-06-14 | Arc extinguish chamber corrugated pipe machining method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110310851A CN110310851A (en) | 2019-10-08 |
| CN110310851B true CN110310851B (en) | 2021-11-05 |
Family
ID=68077176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910517411.0A Active CN110310851B (en) | 2019-06-14 | 2019-06-14 | Arc extinguish chamber corrugated pipe machining method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110310851B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009052628A (en) * | 2007-08-24 | 2009-03-12 | Nissin Electric Co Ltd | Using method of molded bellows and vacuum valve |
| CN205248179U (en) * | 2015-12-02 | 2016-05-18 | 北京京森源电器有限公司 | Vacuum arc -extinguishing chamber contact |
| CN106090453B (en) * | 2016-08-30 | 2018-02-23 | 洛阳双瑞特种装备有限公司 | A kind of variable-diameter corrugated pipe and its forming method |
| CN206742142U (en) * | 2017-06-02 | 2017-12-12 | 成都旭光电子股份有限公司 | A kind of bellows of vacuum interrupter |
-
2019
- 2019-06-14 CN CN201910517411.0A patent/CN110310851B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110310851A (en) | 2019-10-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101644282B1 (en) | Press molding method and bottomed container | |
| US7516634B1 (en) | Electrohydraulic forming tool | |
| CN110310859B (en) | Vacuum arc extinguish chamber and arc extinguish chamber corrugated pipe thereof | |
| CN106270104B (en) | A kind of magnetic field impulse hole flanging formation method of housing component | |
| CN205551242U (en) | Mould | |
| CN102430652A (en) | Composite mould for machining parts such as short flanged washers | |
| CN110400712B (en) | Machining method for arc extinguish chamber corrugated pipe | |
| CN110310851B (en) | Arc extinguish chamber corrugated pipe machining method | |
| BR0308688B1 (en) | PROCESS TO PRODUCE A CAN COVER CASE AND APPARATUS TO PRODUCE A CAN COVER CASE | |
| CN105682823A (en) | Method for forming closed-bottom cylindrical container | |
| KR100215142B1 (en) | Resilent support with at least two cylindrical sleves sleeves for same and method for manufacturing said support with said sleeves | |
| JPH07111851B2 (en) | Method for manufacturing thimbles of contact fingers and thimbles manufactured by the method | |
| CN117174526A (en) | Vacuum arc-extinguishing chamber with prolonged service life | |
| CN109277445B (en) | Fluid pressure forming device and method for metal corrugated pipe | |
| JP2007125585A (en) | Molding method and molding die | |
| CN202721076U (en) | 12kV vacuum switch tube for vacuum circuit breaker | |
| CN101770893A (en) | Bushing terminal of vacuum circuit breaker and method thereof | |
| JP2007015006A (en) | Apparatus and method for drawing/ironing forming | |
| CN210091979U (en) | Vacuum arc-extinguishing chamber of circuit breaker | |
| JP5152106B2 (en) | Hydroform processing apparatus and hydroform processing method | |
| CN217252247U (en) | Aluminum pipe flaring forming die assembly | |
| CN219873301U (en) | Vacuum switch tube | |
| CN215791379U (en) | Spacer ring ultrasonic lower die structure | |
| CN203253896U (en) | Aluminum bronze porcelain bushing flange centrifugation casting mold | |
| KR101841233B1 (en) | Press die for forming a bolt portion or a nut portion on products |
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 | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20200727 Address after: South East of Pingdingshan city in Henan province 467001 No. 22 Applicant after: PINGGAO GROUP Co.,Ltd. Applicant after: STATE GRID CORPORATION OF CHINA Applicant after: State Grid Liaoning Electric Power Co., Ltd. Electric Power Research Institute Address before: South East of Pingdingshan city in Henan province 467001 No. 22 Applicant before: PINGGAO GROUP Co.,Ltd. Applicant before: STATE GRID CORPORATION OF CHINA |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |