CN112008085B - Universal part preheating device and preheating method thereof - Google Patents
Universal part preheating device and preheating method thereof Download PDFInfo
- Publication number
- CN112008085B CN112008085B CN202010770490.9A CN202010770490A CN112008085B CN 112008085 B CN112008085 B CN 112008085B CN 202010770490 A CN202010770490 A CN 202010770490A CN 112008085 B CN112008085 B CN 112008085B
- Authority
- CN
- China
- Prior art keywords
- coils
- workpiece
- coil
- alternating current
- current power
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
- B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
- B22F7/062—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
- B33Y40/10—Pre-treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
- B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
- B22F7/062—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts
- B22F2007/068—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts repairing articles
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Mechanical Engineering (AREA)
- General Induction Heating (AREA)
Abstract
The invention discloses a general part preheating device, which comprises a forming cylinder, wherein a Z-axis lifting device is arranged below the forming cylinder, the upper part of the Z-axis lifting device is arranged in the forming cylinder, the upper surface of the lifting device is connected with a base material, a workpiece is connected to the base material, a plurality of coils which are matched with the outline of the workpiece are sleeved on the workpiece from top to bottom, an alternating current power supply interface is arranged on the forming cylinder, the coils are respectively connected with the alternating current power supply interface and form an electric loop, and backfill powder is filled above the base material in the forming cylinder. The universal part preheating device solves the problems that internal stress is easy to generate in the non-preheating repair process and induction heating preheating is uneven in the prior art. The invention also discloses a general part preheating method.
Description
Technical Field
The invention belongs to the technical field of 3D printing equipment, relates to a universal part preheating device and also relates to a preheating method by adopting the universal part preheating device.
Background
The metal 3D forming technology realizes the forming processing of parts by adding materials, and can quickly, directly and accurately convert the design idea into a physical model with a certain function. The performance of the processed part can replace the traditional processed part; the method can shorten the product design and manufacturing period, promote the competitive capacity of enterprises, enhance the profitability of the enterprises, and establish a brand-new product development mode for design developers of industrial products. Compared with the traditional processing method, the metal 3D forming technology can form parts with any complex shape, and the mechanical properties of the formed parts are superior to those of the parts processed by the traditional method. At present, various technologies for 3D forming of metal exist, such as SLM, LSF, EBM, etc., SLM equipment is mainly used for forming of parts, and heating wires are arranged below a base material of the SLM equipment for heating, so that cracking caused by internal stress during forming is reduced; LSF and EBM can also be used for part forming, but are often used for part repair because their forming quality is not as good as that of SLM devices.
The prior repair process of the part is not preheated, the temperature difference of two sides of the repair surface of the part is large, internal stress is easy to generate, the combination between the repair surface of the part and the first layer of molding surface can be influenced, the performance of the repair part of the part is influenced, and the risk of cracking exists. The existing induction heating generally adopts a single coil and directly adopts out-of-cylinder heating, so that uneven preheating of different parts can be caused.
Disclosure of Invention
The invention aims to provide a universal part preheating device, which solves the problems that internal stress is easy to generate and induction heating preheating is uneven in the non-preheating repair process in the prior art.
It is another object of the present invention to provide a universal part preheating method.
The technical scheme includes that the universal part preheating device comprises a forming cylinder, a Z-axis lifting device is arranged below the forming cylinder, a base material is connected to the upper surface of the Z-axis lifting device, a workpiece is connected to the base material, a plurality of coils which are matched with the outline of the workpiece are sleeved on the workpiece from top to bottom, an alternating current power supply interface is arranged on the forming cylinder, the coils are respectively connected with the alternating current power supply interface to form an electric loop, and backfill powder is filled above the base material in the forming cylinder.
The first aspect of the present invention is also characterized in that,
a gap exists between the inner side of the coil and the corresponding position of the workpiece.
The plurality of coils are fixed at different heights of the workpiece by filling with backfill powder.
The coils are respectively connected with the alternating current power supply interface through wires to form an electric loop, and the length of the wires for connecting each coil with the alternating current power supply interface is larger than the moving stroke of each coil when the Z-axis lifting device lifts.
The alternating current power supply interface is arranged as an alternating current guide rail, one side of each coil, which is close to the alternating current guide rail, is provided with an opening, two sides of the opening are respectively connected with conducting strips, and the two conducting strips are respectively connected with two electrode ends of the alternating current guide rail.
The gaps between the plurality of coils and the outer contours at the corresponding workpiece are equal.
The two adjacent coils are arranged in parallel and distributed at equal intervals in the vertical direction or in a regular gradient or irregular distribution.
The other technical scheme adopted by the invention is that a universal part preheating method is adopted, and the universal part preheating device is implemented according to the following steps:
step 1, selecting proper arrangement positions and quantity of coils according to the outline shape of a workpiece to be preheated;
step 2, preparing coils according to the quantity and the arrangement positions selected in the step 1 and the outer contour shape of the preheated workpiece, so that each coil is identical to the outer contour shape of the corresponding workpiece;
step 3, sleeving the prepared coils at the corresponding outer contours of the workpieces in sequence from bottom to top, filling backfill powder into the forming cylinder to the height of the current coil by each coil, connecting the current coil with an alternating current power interface and forming an electric loop until all the coils are completely installed;
and 4, supplying alternating current to the alternating current power supply interface, supplying power to the Z-axis lifting device, lifting the coil and the workpiece along with the Z-axis lifting device, and generating an alternating magnetic field around the workpiece by the alternating current power supply through the coil, so that the workpiece generates eddy current to realize heating.
When the coils are sleeved in the step 3, two adjacent coils are arranged in parallel and distributed at equal intervals or in regular gradient or irregular distribution in the vertical direction.
The beneficial effects of the invention are as follows:
the invention adopts in-cylinder heating, preheats the repair part through the coil, so that the part is heated uniformly, and internal stress generated by temperature difference in the process of repairing the part is avoided, thereby reducing the cracking problem of the repair part, improving the repair and molding quality of the part, being suitable for repairing or repairing the part and bringing benefit to customers.
Drawings
FIG. 1 is a schematic diagram of a general part preheating device according to the present invention;
fig. 2 is a top view of fig. 1.
In the figure, a 1.Z shaft lifting device, a cooling plate, a base material, a forming cylinder, a workpiece, backfill powder, a forming chamber, an alternating current power supply interface and a coil, wherein the cooling plate, the base material, the forming cylinder and the forming chamber are respectively arranged in sequence, and the forming chamber, the alternating current power supply interface and the coil are respectively arranged in sequence;
8-1, an alternating current guide rail, 8-2, an opening and 8-3, a conducting strip.
Detailed Description
The invention will be described in detail below with reference to the drawings and the detailed description.
The invention relates to a general part preheating device, the structure of which is shown in fig. 1-2, and the general part preheating device comprises a forming cylinder 4, a Z-axis lifting device 1 is arranged below the forming cylinder 4, the upper part of the Z-axis lifting device 1 is arranged in the forming cylinder 4, the upper surface of the lifting device 1 is connected with a base material 3, a workpiece 5 is connected on the base material 3, a plurality of coils 9 which are matched with the outer contour of the workpiece 5 are sleeved on the workpiece 5 from top to bottom, an alternating current power interface 8 is arranged on the forming cylinder 4, the coils 9 are respectively connected with the alternating current power interface 8 to form an electric loop, and backfill powder 6 is filled in the forming cylinder 4 above the base material 3.
A gap exists between the inner side of the coil 9 and the corresponding position of the workpiece 5.
A cooling plate 2 is connected between the upper surface of the Z-axis lifting device 1 and the substrate 3.
A forming chamber 7 is also arranged above the forming cylinder 4.
The plurality of coils 9 are fixed at different heights of the workpiece 5 by filling of the backfill powder 6.
The coils 9 are respectively connected with the alternating current power supply interface 8 through wires to form an electric loop, and the length of the wires for connecting each coil 9 with the alternating current power supply interface 8 is longer than the moving stroke of each coil 9 when the Z-axis lifting device 1 is lifted.
The alternating current power supply interface 8 is arranged as an alternating current guide rail 8-1, an opening 8-2 is arranged on one side, close to the alternating current guide rail 8-1, of each coil 9, conducting strips 8-3 are respectively connected to two sides of the opening 8-2, and two conducting strips 8-3 are respectively connected to two electrode ends of the alternating current guide rail 8-1.
The gaps between the plurality of coils 9 and the outer contours at the corresponding workpiece 5 are equal.
The adjacent two coils 9 are arranged in parallel and distributed at equal intervals in the vertical direction or in a regular gradient or irregular distribution.
The invention relates to a general part preheating device, which has the working principle that:
the cooling plate 2 is added below the base material 3 of the SLM equipment, the workpiece 5 is connected to the base material 3 by the Z-axis lifting device 1, the base material is connected to the Z-axis lifting device 1, a plurality of coils 9 with the same section as the workpiece 5 are placed at different heights of the workpiece 5 and cannot be in contact with the workpiece in the backfilling process of the backfilling powder 6, the coils 9 are compacted and fixed through the backfilling powder 6, the backfilling powder 6 is nonconductive, therefore, the backfilling powder 6 also serves as an insulating part between the workpiece 5 and the coils 9, then the coils 9 after being connected are connected to the alternating current power interface 8 on the forming cylinder 4, the coils 9 after being connected can be lifted along with the Z-axis lifting device 11, the coils 9 are always connected with the power interface 8 and form a loop in the lifting process, and alternating current power generates alternating magnetic fields around the workpiece through the coils 9, so that the workpiece is heated by eddy currents.
The conductive sheets 8-3 at two sides of each coil 9 slide in the alternating current guide rail 8-1, and two electrode ends of the alternating current guide rail 8-1 are respectively connected to form an electric loop formed between each coil 9 and the alternating current power supply interface 8.
The invention discloses a general part preheating method, which adopts the general part preheating device and is implemented according to the following steps:
step 1, selecting proper arrangement positions and number of coils 9 according to the outline shape of a workpiece 5 to be preheated;
step 2, preparing coils 9 according to the number and arrangement positions selected in the step 1 and then preheating the outer contour shape of the workpiece 5, so that each coil 9 is identical to the outer contour shape of the corresponding workpiece 5;
step 3, sleeving the prepared coils 9 at the corresponding outer contour of the workpiece 5 in sequence from bottom to top, filling backfill powder 6 into the forming cylinder 4 to the height of the current coil 9 by each coil 9, and connecting the current coil 9 with an alternating current power interface 8 to form an electric loop until all the coils 9 are completely installed;
and 4, supplying alternating current to the alternating current power supply interface 8, supplying power to the Z-axis lifting device 1, lifting the coil 9 and the workpiece 5 along with the Z-axis lifting device 1, and generating an alternating magnetic field around the workpiece 5 by the alternating current power supply through the coil 9, so that the workpiece 5 generates eddy current to realize heating.
When the coils 9 are sleeved in the step 3, two adjacent coils 9 are arranged in parallel and distributed at equal intervals in the vertical direction or in regular gradient or irregular distribution.
The invention can make the coil 9 into different shapes according to different heating objects, then the coil 9 is connected with the alternating current power interface 8, the alternating current power interface 8 supplies alternating current to the coil 9, and the alternating current of the coil 9 generates an alternating magnetic field passing through the workpiece, and the magnetic field enables the workpiece 5 to generate eddy current for heating.
According to the invention, the repair part is preheated through the coils 9 (the same as the cross section of the part) with different shapes, so that the cross section temperature of the repair part is uniform when the repair part is heated, and the generation of internal stress is avoided; the repair parts are heated uniformly by sectionally heating the parts at different heights through a plurality of coils.
Claims (6)
1. The utility model provides a general part preheating device, its characterized in that includes shaping jar (4), shaping jar (4) below is provided with Z axle elevating gear (1), in Z axle elevating gear (1) top is located shaping jar (4), elevating gear (1) upper surface is connected with substrate (3), be connected with work piece (5) on substrate (3), be equipped with a plurality of coils (9) that suit its outline from top to bottom on work piece (5), be provided with on shaping jar (4) alternating current power interface (8), a plurality of coils (9) respectively with alternating current power interface (8) are connected and form the electric circuit, be located in shaping jar (4) substrate (3) top and fill backfill powder (6); a gap exists between the inner side of the coil (9) and the corresponding position of the workpiece (5); the plurality of coils (9) are fixed at different heights of the workpiece (5) through filling of backfill powder (6); the coils (9) are respectively connected with the alternating current power supply interface (8) through wires to form a circuit, and the length of the wires connecting each coil (9) with the alternating current power supply interface (8) is larger than the moving stroke of each coil (9) when the Z-axis lifting device (1) is lifted.
2. A universal part preheating device according to claim 1, characterized in that the ac power supply interface (8) is arranged as an ac power guide rail (8-1), one side of each coil (9) close to the ac power guide rail (8-1) is provided with an opening (8-2), two sides of the opening (8-2) are respectively connected with a conductive sheet (8-3), and two conductive sheets (8-3) are respectively connected with two electrode ends of the ac power guide rail (8-1).
3. A universal part preheating arrangement according to claim 1, characterized in that the gaps between the plurality of coils (9) and the outer contours at the corresponding work pieces (5) are equal.
4. A universal part preheating device according to claim 1, characterized in that two adjacent coils (9) are arranged in parallel and distributed equally spaced apart in the vertical direction or in a regular gradient or irregular distribution.
5. A method for preheating universal parts, characterized in that a universal part preheating device according to claim 1 is used, which is implemented in particular according to the following steps:
step 1, selecting proper arrangement positions and number of coils (9) according to the outline shape of a workpiece (5) to be preheated;
step 2, preparing coils (9) according to the number and arrangement positions selected in the step 1 and preheating the outer contour shape of the workpiece (5) so that each coil (9) is identical to the outer contour shape of the corresponding workpiece (5);
step 3, sleeving the prepared coils (9) at the corresponding outer contour of the workpiece (5) in sequence from bottom to top, filling backfill powder (6) into the forming cylinder (4) to the height of the current coil (9) by each coil (9), and connecting the current coil (9) with the alternating current power interface (8) to form an electric loop until all the coils (9) are completely installed;
and 4, alternating current is supplied to an alternating current power supply interface (8), the Z-axis lifting device (1) is electrified, the Z-axis lifting device (1) is lifted, the coil (9) and the workpiece (5) are lifted together with the Z-axis lifting device (1), and an alternating current power supply generates an alternating magnetic field around the workpiece (5) through the coil (9), so that the workpiece (5) generates vortex flow to realize heating.
6. The method according to claim 5, wherein when the coils (9) are sleeved in the step 3, two adjacent coils (9) are arranged in parallel and distributed at equal intervals or in regular gradient or irregular distribution in the vertical direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010770490.9A CN112008085B (en) | 2020-08-04 | 2020-08-04 | Universal part preheating device and preheating method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010770490.9A CN112008085B (en) | 2020-08-04 | 2020-08-04 | Universal part preheating device and preheating method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112008085A CN112008085A (en) | 2020-12-01 |
| CN112008085B true CN112008085B (en) | 2023-09-05 |
Family
ID=73500069
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010770490.9A Active CN112008085B (en) | 2020-08-04 | 2020-08-04 | Universal part preheating device and preheating method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112008085B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4788394A (en) * | 1985-03-06 | 1988-11-29 | N.V. Bekaert S.A. | Multi-wire induction heating |
| CN101125394A (en) * | 2007-06-13 | 2008-02-20 | 华中科技大学 | Automatic powder feeding laser induction composite coating method and device |
| CN103100713A (en) * | 2013-01-23 | 2013-05-15 | 西安铂力特激光成形技术有限公司 | Preheat device and preheat method of selective laser selection area melting subscriber loop multiplex (SLM) equipment powder feeding barrel |
| DE102012012344A1 (en) * | 2012-03-21 | 2013-09-26 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method for manufacturing workpiece e.g. three-dimensional object, involves preheating material adjacent to storage chamber located in process chamber before removing stock material from chamber and transferring to process chamber |
| JP2018003087A (en) * | 2016-06-30 | 2018-01-11 | キヤノン株式会社 | Three-dimensional molding apparatus, and method for manufacturing three-dimensionally molded article |
| CN109822091A (en) * | 2019-03-01 | 2019-05-31 | 西安科技大学 | The molding rapid molding device of close said magnetic powder material adsorption plane and method |
| CN212634320U (en) * | 2020-08-04 | 2021-03-02 | 西安铂力特增材技术股份有限公司 | Universal part preheating device |
-
2020
- 2020-08-04 CN CN202010770490.9A patent/CN112008085B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4788394A (en) * | 1985-03-06 | 1988-11-29 | N.V. Bekaert S.A. | Multi-wire induction heating |
| CN101125394A (en) * | 2007-06-13 | 2008-02-20 | 华中科技大学 | Automatic powder feeding laser induction composite coating method and device |
| DE102012012344A1 (en) * | 2012-03-21 | 2013-09-26 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method for manufacturing workpiece e.g. three-dimensional object, involves preheating material adjacent to storage chamber located in process chamber before removing stock material from chamber and transferring to process chamber |
| CN103100713A (en) * | 2013-01-23 | 2013-05-15 | 西安铂力特激光成形技术有限公司 | Preheat device and preheat method of selective laser selection area melting subscriber loop multiplex (SLM) equipment powder feeding barrel |
| JP2018003087A (en) * | 2016-06-30 | 2018-01-11 | キヤノン株式会社 | Three-dimensional molding apparatus, and method for manufacturing three-dimensionally molded article |
| CN109822091A (en) * | 2019-03-01 | 2019-05-31 | 西安科技大学 | The molding rapid molding device of close said magnetic powder material adsorption plane and method |
| CN212634320U (en) * | 2020-08-04 | 2021-03-02 | 西安铂力特增材技术股份有限公司 | Universal part preheating device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112008085A (en) | 2020-12-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102658618B (en) | Method and device for vulcanizing inner mold and outer mold of tire through direct voltage electromagnetic heating | |
| CN113709994B (en) | Production equipment and method for forming conducting layer on resistance welding surface of circuit board | |
| CN212634320U (en) | Universal part preheating device | |
| CN112008085B (en) | Universal part preheating device and preheating method thereof | |
| CN103464564A (en) | Electromagnetic forming device and forming method for aluminum alloy rib plate | |
| CN110918739B (en) | Rapid heating-forming device and method for aluminum alloy vehicle body component | |
| CN204565022U (en) | The all solid state variable frequency induction heater of isothermal forging upper/lower die | |
| CN100490591C (en) | Vulcanizer and melamine ware former electromagnetic heating method and apparatus | |
| CN108284146A (en) | The electromagnetism progressive molding system and method for aluminum alloy curved part local induction heating | |
| CN203235930U (en) | Induction heating device for riser of steel ingot | |
| JP2001032016A (en) | High frequency induction heating apparatus | |
| CN211240158U (en) | High-frequency induction heating device for preheating raw materials | |
| CN108012358A (en) | A kind of electromagnetic induction heating 3D printing formation system | |
| CN212885032U (en) | 3D printing device for parts needing high-temperature preheating | |
| CN215404357U (en) | High-frequency induction quenching inductor for powder metallurgy VVT pressing plate sprocket lock pin hole | |
| CN211868414U (en) | Plastic mold pressing mould heating device | |
| CN104690204B (en) | Isothermal forging upper/lower die all solid state variable frequency induction heater and heating means | |
| CN2798486Y (en) | Electromagnetic heating apparatus for vulcanizer and vessel former | |
| CN112024874A (en) | 3D printing part temperature gradient control device and method | |
| CN219214167U (en) | Electromagnetic induction heating coil plate and equipment for hot plate of tire vulcanizer | |
| US20190289682A1 (en) | Inductors and inductor extraction assemblies | |
| CN108495725B (en) | Device and method for forming a workpiece by means of magnetic pulse forming | |
| CN204504127U (en) | Isothermal forging φ 900-2000mm upper/lower die closed assembly induction heater | |
| CN202684323U (en) | High frequency pressure welding device | |
| CN118106672B (en) | Large steel structure welding preheating device |
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 |