Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a welding method and a welding structure of a titanium-steel composite pipe, so as to avoid forming a brittle joint at the welding end of the titanium-steel composite pipe and promote the application and development of the titanium-steel composite pipe.
The technical scheme adopted by the invention is as follows:
a welding method of a titanium steel composite pipe comprises the following steps:
A. processing a pipe layer at a pipe opening to be welded of the titanium steel composite pipe, sequentially exposing all inner pipe layers in the outer pipe layer and respectively forming inner pipe layer reserved sections;
B. b, welding the pipe orifice to be welded after the treatment of the step A; the inner pipe layer reserved section of the innermost layer of the pipe orifice to be welded is welded with the inner pipe layer reserved section of the innermost layer of the other pipe orifice to be welded, and the outer pipe layer of the pipe orifice to be welded and the reserved sections of the other inner pipe layers are welded with the outer pipe layer of the other pipe orifice to be welded and the reserved sections of the other inner pipe layers in a one-to-one correspondence mode through corresponding connecting pieces.
Preferably, the titanium-steel composite pipe is of an outer-layer steel-inner-layer titanium structure; the welding method comprises the following steps:
A. cutting the pipe layer of the pipe orifice to be welded of the titanium-steel composite pipe, exposing the titanium pipe layer in the steel pipe layer and forming a reserved section of the titanium pipe layer;
B. b, welding the reserved section of the titanium pipe layer of the pipe orifice to be welded treated in the step A with the reserved section of the titanium pipe layer of the other pipe orifice to be welded;
C. and sleeving a connecting piece outside the reserved section of the titanium pipe layer of the pipe orifice to be welded, and respectively welding two ends of the connecting piece with the steel pipe layer at the pipe orifice to be welded and the steel pipe layer at the other pipe orifice to be welded.
Preferably, the connecting piece comprises a semi-annular first supporting block and a semi-annular second supporting block, and the first supporting block and the second supporting block are spliced into an annular shape; the inner diameter of the connecting piece is matched with the outer diameter of the reserved section of the titanium pipe layer, and two end faces of the connecting piece are respectively attached to the section faces of the steel pipe layer at the corresponding ends.
Preferably, the inner annular surfaces of the first supporting block and the second supporting block are respectively provided with a groove for accommodating a welding seam; the cross sections of the first supporting block and the second supporting block are hexagonal; the profile surface of the steel pipe layer is an inclined plane matched with the two end surfaces of the connecting piece, the bottom waist of the connecting piece is attached to the inclined plane, and the top waist of the connecting piece and the inclined plane form a triangular welding groove.
Preferably, the titanium-steel composite pipe is an outer layer titanium-inner layer steel structure, and the welding method comprises the following steps:
A. cutting the pipe layer of the pipe orifice to be welded of the titanium-steel composite pipe, exposing the steel pipe layer in the titanium pipe layer and forming a reserved steel pipe layer section;
B. b, welding the steel pipe layer reserved section of the pipe orifice to be welded processed in the step A with the steel pipe layer reserved section of the other pipe orifice to be welded;
C. and sleeving a connecting piece outside the reserved section of the steel pipe layer of the pipe orifice to be welded, and respectively welding two ends of the connecting piece with the titanium pipe layer at the pipe orifice to be welded and the titanium pipe layer at the other pipe orifice to be welded.
Preferably, the connector is a hollow sleeve; the inner diameter of the sleeve is matched with the outer diameter of the titanium tube layer, two ends of the sleeve are respectively welded with the outer surface of the titanium tube layer at the corresponding end, and the section surface of the titanium tube layer is positioned in the sleeve.
Preferably, the sleeve is a titanium sleeve.
Preferably, the titanium-steel composite pipe is of an outer-layer titanium-middle-layer steel-inner-layer titanium structure; the welding method comprises the following steps:
A. cutting the pipe layer of the pipe orifice to be welded of the titanium-steel composite pipe, sequentially exposing the middle-layer steel pipe layer and the inner-layer titanium pipe layer in the outer-layer titanium pipe layer and respectively forming a middle-layer steel pipe layer reserved section and an inner-layer titanium pipe layer reserved section;
B. b, welding the reserved section of the inner titanium pipe layer of the pipe orifice to be welded, which is processed in the step A, with the reserved section of the inner titanium pipe layer of the other pipe orifice to be welded;
C. sleeving a first connecting piece outside the reserved section of the inner titanium pipe layer of the pipe orifice to be welded, and respectively welding two ends of the first connecting piece with the reserved section of the middle steel pipe layer at the pipe orifice to be welded and the reserved section of the middle steel pipe layer at the other pipe orifice to be welded;
D. and sleeving a second connecting piece outside the first connecting piece, and respectively welding two ends of the second connecting piece with the outer titanium tube layer at the pipe orifice to be welded and the outer titanium tube layer at the other pipe orifice to be welded.
Preferably, the first connecting piece is annular in shape; the inner diameter of the first connecting piece is matched with the outer diameter of the reserved section of the inner-layer titanium pipe layer, and two end faces of the first connecting piece are respectively attached to the section opening face of the reserved section of the middle-layer steel pipe layer at the corresponding end; the first connecting piece comprises a semi-annular first supporting block and a semi-annular second supporting block, and grooves for accommodating welding seams are formed in the inner annular surfaces of the first supporting block and the second supporting block respectively;
the second connecting piece is a hollow sleeve; the inner diameter of the sleeve is matched with the outer diameter of the outer titanium tube layer, two ends of the sleeve are respectively welded with the outer surface of the outer titanium tube layer at the corresponding end, and the section surface of the outer titanium tube layer is positioned in the sleeve.
Based on the welding method of the titanium-steel composite pipe, the invention also provides a welding structure of the titanium-steel composite pipe, which comprises the following steps: a first welding nozzle and a second welding nozzle; the first welding pipe orifice and the second welding pipe orifice are respectively provided with an outer pipe layer and reserved sections of the inner pipe layers which are exposed in sequence;
the inner pipe layer reserved section on the innermost layer of the first welding pipe orifice is welded with the inner pipe layer reserved section on the innermost layer of the second welding pipe orifice, and the outer pipe layer and the rest of the inner pipe layer reserved sections of the first welding pipe orifice are correspondingly welded with the outer pipe layer and the rest of the inner pipe layer reserved sections of the second welding pipe orifice through corresponding connecting pieces one by one.
The invention has the beneficial effects that:
according to the welding method and the welding structure of the titanium-steel composite pipe, provided by the invention, the reserved section of the inner pipe layer at the innermost layer of the pipe layer is directly welded, and the outer pipe layer and the reserved sections of the other inner pipe layers are respectively welded one by one through the corresponding connecting pieces, so that the welding ends of the pipe layers made of different materials are separately welded, and a brittle joint formed by directly welding the titanium-steel composite pipe is avoided, therefore, the welding strength is improved, the reliable welding of the titanium-steel composite pipe is realized, and the application and development of the titanium-steel composite pipe are promoted.
Detailed Description
Example 1
The embodiment provides a welding method of a titanium steel composite pipe with an inner layer titanium-outer layer steel structure, which comprises the following steps:
processing a to-be-welded pipe orifice of the titanium steel composite pipe: and (3) machining the pipe openings to be welded at the two ends to be butted of the titanium steel composite pipe, exposing the inner titanium pipe layer in the outer steel pipe layer 2 and forming an inner titanium pipe layer reserved section 1. Preferably, the section surface of the outer steel pipe layer 2 is an inclined plane with an angle of 120 degrees; 5-10 mm is reserved in the inner layer titanium pipe layer reserved section 1, and the surface of the inner layer titanium pipe layer reserved section 1 is machined to be 0.1-0.15 mm below the combined surface of the titanium pipe layer and the steel pipe layer.
Processing a supporting block: the supporting blocks are two, are first supporting block and second supporting block respectively, and first supporting block and second supporting block's structure is the same, adopts the mode processing of machining two can splice and form annular semi-annular supporting blocks. Preferably, the cross sections of the two supporting blocks are hexagonal, the wall thickness of the supporting blocks is the same as that of the steel-coated tube layer, and the inner diameter of the supporting blocks is equal to the outer diameter R + (0-0.02) mm of the tube of the reserved section 1 of the inner titanium tube layer; the included angles between the inner ring surfaces 4 of the two supporting blocks and the two bottom waists 6 on the two sides of the supporting blocks are both 120 degrees, the included angles between the outer ring surfaces of the two supporting blocks and the two top waists 7 on the two sides of the supporting blocks are both 120 degrees, and the waist edge at the joint of the bottom waists 6 and the top waists 7 of the supporting blocks is positioned at 1/3 of the wall thickness of the outer steel pipe layer 2. Meanwhile, the inner ring surfaces 4 of the two supporting blocks are provided with grooves 5 distributed along the circumferential direction of the ring for accommodating the weld reinforcement of the butt joint end of the reserved section 1 of the inner titanium pipe layer.
Through the supporting block, the outer steel pipe layer 2 can be connected, and the pipe-pipe butt joint strength is ensured; and the supporting block has the binding power to the reserved section 1 of the inner-layer titanium tube layer, and the pressure can be borne at the reserved section 1 of the welded inner-layer titanium tube layer.
Welding an inner titanium pipe layer: firstly, assembling pipe orifices of two pipe orifices to be welded and ensuring that the two pipes are concentric; and welding the butt joint ends of the reserved sections 1 of the inner titanium tube layers of the two pipe orifices to be welded by adopting plasma welding, argon arc welding or friction stir welding to complete the welding of the inner titanium tube layers.
Welding a support block: sleeving two supporting blocks on the outer sides of the reserved sections 1 of the inner titanium tube layers of the two pipe orifices to be welded, and splicing the supporting blocks into a ring; inner ring surfaces 4 of the two supporting blocks are attached to the outer surface of the reserved end of the inner titanium pipe layer, bottom waists 6 on two sides of the inner ring surfaces 4 of the two supporting blocks are respectively attached to the corresponding section surfaces of the outer steel pipe layer 2, top waists 7 on two sides of the outer ring surfaces of the two supporting blocks are respectively formed into a triangular welding groove with the corresponding section surfaces of the outer steel pipe layer 2, and manual electric arc welding, carbon dioxide gas shielded welding or submerged arc welding is adopted at the welding groove for welding.
As shown in fig. 1 to 3, based on the welding method, the present embodiment further provides a welded structure of a titanium steel composite pipe with an inner layer titanium-outer layer steel structure, which includes: a first welding nozzle and a second welding nozzle; the first welding pipe orifice and the second welding pipe orifice are respectively provided with an outer steel pipe layer 2 and an exposed inner titanium pipe layer reserved section 1.
Preferably, the section surface of the outer steel pipe layer 2 is an inclined plane with an angle of 120 degrees; the reserved length of the reserved section 1 of the inner titanium tube layer is 5-10 mm; the surface of the reserved section 1 of the inner titanium tube layer is located 0.1-0.15 mm below the titanium steel joint surface.
The first welding pipe orifice is in butt joint with the second welding pipe orifice, the reserved section 1 of the inner layer titanium pipe layer of the first welding pipe orifice is welded with the reserved section 1 of the inner layer titanium pipe layer of the second welding pipe orifice, and the outer steel pipe layer 2 of the first welding pipe orifice is welded with the outer steel pipe layer 2 of the second welding pipe orifice through corresponding connecting pieces.
Preferably, the connecting piece is two semicircular supporting blocks which can be spliced to form a ring, the cross sections of the two supporting blocks are hexagonal, the wall thickness of the supporting blocks is the same as that of the outer-layer steel pipe layer 2, and the inner diameter of the supporting blocks is the pipe outer diameter R + (0-0.02) mm of the inner-layer titanium pipe layer reserved section 1; the included angles between the inner ring surfaces 4 of the two supporting blocks and the two bottom waists 6 on the two sides of the supporting blocks are both 120 degrees, the included angles between the outer ring surfaces of the two supporting blocks and the two top waists 7 on the two sides of the supporting blocks are both 120 degrees, and the waist edge at the joint of the bottom waists 6 and the top waists 7 of the supporting blocks is positioned at 1/3 of the wall thickness of the outer steel pipe layer 2. Meanwhile, the inner ring surfaces 4 of the two supporting blocks are provided with grooves 5 distributed along the circumferential direction of the ring for accommodating the weld reinforcement of the butt joint end of the reserved section 1 of the inner titanium pipe layer.
The first supporting block 3 and the second supporting block are spliced into a ring shape and sleeved on the outer surfaces of the inner titanium pipe layer reserved sections 1 of the first welding pipe orifice and the second welding pipe orifice; the inner ring surfaces 4 of the first supporting block 3 and the second supporting block are attached to the outer surface of the inner titanium pipe layer reserved section 1, the bottom waists 6 of the first supporting block 3 and the second supporting block are attached to the section surfaces of the outer steel pipe layers 2 of the corresponding ends, the top waists 7 are attached to the section surfaces of the outer steel pipe layers 2 of the corresponding ends to form triangular welding grooves, and welding is conducted at the welding grooves.
Example 2
The embodiment provides a welding method of a titanium steel composite pipe with an inner layer steel-outer layer titanium structure, which comprises the following steps:
processing a to-be-welded pipe orifice of the titanium steel composite pipe: and machining the pipe openings to be welded at the two ends to be butted of the titanium-steel composite pipe, removing the outer titanium pipe layer 9, exposing the inner steel pipe layer in the outer titanium pipe layer 9 and forming an inner steel pipe layer reserved section 8. Preferably, the reserved length of the reserved section 8 of the inner steel pipe layer is 15-20 mm; meanwhile, a 30-degree groove 10 is processed on the end face of the reserved section 8 of the inner steel pipe layer, so that a triangular welding groove is formed in the outer side of the butt joint end after the two reserved sections 8 of the inner steel pipe layer are in butt joint, welding is facilitated, and the welding effect can be improved.
Processing the titanium sleeve 11: and selecting a titanium sleeve 11 made of the same material as the outer titanium tube layer 9 for processing, wherein the inner diameter of the titanium sleeve 11 is matched with the outer diameter of the outer titanium tube layer 9, the wall thickness of the titanium sleeve 11 is consistent with the thickness of the outer titanium tube layer 9, and the length of the titanium sleeve 11 is 50 +/-5 mm.
Butt welding: firstly, sleeving a titanium sleeve 11 on one side of a titanium steel composite pipe in advance, and then pairing pipe orifices of two pipe orifices to be welded to ensure that the pipes are concentric; the butt joint end of the reserved section 8 of the inner steel pipe layer is welded by adopting manual arc welding, carbon dioxide gas shielded welding or submerged arc welding, and the residual height of a welded seam after welding is smaller than the thickness of the outer titanium pipe layer 9.
And moving the titanium sleeve 11 to enable the titanium sleeve 11 to be positioned at the outer sides of the inner steel pipe layer reserved sections 8 of the two pipe orifices to be welded, and welding two ends of the titanium sleeve 11 and the outer surface of the corresponding outer titanium pipe layer 9 respectively by adopting plasma welding, argon arc welding or friction stir welding to form fillet welds.
As shown in fig. 4, based on the welding method, the present embodiment further provides a welded structure of a titanium steel composite pipe with an inner layer steel-outer layer titanium structure, which includes: a first welding nozzle and a second welding nozzle; the first welding pipe orifice and the second welding pipe orifice are respectively provided with an outer titanium pipe layer 9 and an exposed inner steel pipe layer reserved section 8. Preferably, the reserved length of the reserved section 8 of the inner steel pipe layer is 15-20 mm; and the end surface of the reserved section 8 of the inner steel pipe layer is provided with a 30-degree groove 10.
The inner steel pipe layer reserved section 8 of the first welding pipe orifice is welded with the inner steel pipe layer reserved section 8 of the second welding pipe orifice, and a welding joint is positioned at a triangular welding groove formed by the two grooves 10; the outer titanium tube layer 9 of the first welding pipe orifice and the outer titanium tube layer 9 of the second welding pipe orifice are welded through corresponding connecting pieces.
Preferably, the connecting piece is a titanium sleeve 11, and two ends of the titanium sleeve 11 are respectively welded with the outer surfaces of the outer titanium tube layers 9 of the first welding pipe orifice and the second welding pipe orifice, and a fillet weld is formed at the welding end. The inner diameter of the titanium sleeve 11 is matched with the outer diameter of the outer titanium tube layer 9, the wall thickness of the titanium sleeve 11 is consistent with the thickness of the outer titanium tube layer 9, and the length of the titanium sleeve 11 is 50 +/-5 mm.
In the present embodiment, including but not limited to the titanium sleeve 11, it may also be a hollow tube made of other welding materials without Fe, Mn, Ni, etc. elements, so as to avoid forming intermetallic brittle compounds during welding with the outer titanium tube layer 9.
Example 3
The embodiment provides a welding method of a titanium steel composite pipe with an outer layer titanium-middle layer steel-inner layer titanium structure, which comprises the following steps:
processing a to-be-welded pipe orifice of the titanium steel composite pipe: and (3) machining two pipe orifices to be welded of the titanium-steel composite pipe to be butted, and sequentially exposing the middle-layer steel pipe layer and the inner-layer titanium pipe layer in the outer-layer titanium pipe layer 9 to respectively form a middle-layer steel pipe layer reserved section 12 and an inner-layer titanium pipe layer reserved section 1.
Preferably, the section surface of the end surface of the middle steel pipe layer reserved section 12 is an inclined plane with an angle of 120 degrees, and the reserved length of the middle steel pipe layer reserved section 12 is 15-20 mm; 5-10 mm is reserved in the inner layer titanium tube layer reserved section 1, and the surface of the inner layer titanium tube layer reserved section 1 is machined to be 0.1-0.15 mm below the joint surface of the middle steel tube layer and the inner layer titanium tube layer.
Processing a supporting block: two semi-annular supporting blocks which can be spliced to form a ring are processed in a mechanical processing mode. Preferably, the cross sections of the two supporting blocks are regular hexagons, the wall thickness of the two supporting blocks is the same as that of the middle-layer steel pipe layer reserved section 12, and the inner diameter of the two supporting blocks is equal to the outer diameter R + (0-0.02) mm of the pipe of the inner-layer titanium pipe layer reserved section 1; the included angles between the inner ring surfaces 4 of the two supporting blocks and the two bottom waists 6 on the two sides of the inner ring surfaces are 120 degrees, the included angles between the outer ring surfaces of the two supporting blocks and the two top waists 7 on the two sides of the outer ring surfaces of the two supporting blocks are 120 degrees, and the waist edge at the joint of the bottom waists 6 and the top waists 7 of the supporting blocks is positioned at 1/3 of the wall thickness of the middle-layer steel pipe layer reserved section 12. Meanwhile, the inner ring surfaces 4 of the two supporting blocks are provided with grooves 5 distributed along the circumferential direction of the ring for accommodating the weld reinforcement of the butt joint end of the inner layer titanium pipe layer reserved section 1.
Processing the titanium sleeve 11: and selecting a titanium sleeve 11 made of the same material as the outer titanium tube layer 9 for processing, wherein the inner diameter of the processed titanium sleeve 11 is matched with the outer diameter of the outer titanium tube layer 9, and the wall thickness of the titanium sleeve 11 is consistent with that of the outer titanium tube layer 9.
Welding an inner titanium pipe layer: firstly, assembling two pipe orifices to be welded and ensuring the concentricity of the two pipes; and then butting the reserved sections 1 of the inner titanium tube layers of the two pipe orifices to be welded, and welding by adopting plasma welding, argon arc welding or friction stir welding.
Welding a middle steel pipe layer: sleeving two supporting blocks on the outer sides of the middle steel pipe layer reserved sections 12 of the two pipe orifices to be welded, and splicing the two supporting blocks into a ring; the inner ring surfaces 4 of the two supporting blocks are attached to the outer surface of the reserved end of the inner titanium pipe layer, the bottom waists 6 on the two sides of the inner ring surfaces 4 of the two supporting blocks are respectively attached to the section surfaces of the reserved sections 12 of the middle steel pipe layer at the corresponding ends, the top waists 7 on the two sides of the outer ring surfaces of the two supporting blocks are respectively attached to the section surfaces of the reserved sections 12 of the middle steel pipe layer at the corresponding ends to form a triangular welding groove, and manual electric arc welding, carbon dioxide vapor shield welding or submerged arc welding is adopted to weld at the welding groove.
Welding an outer titanium tube layer 9: moving the titanium sleeve 11 to enable the titanium sleeve 11 to be positioned at the outer side of the middle steel pipe layer reserved section 12 of the two pipe orifices to be welded, and welding two ends of the titanium sleeve 11 and the outer surface of the outer titanium pipe layer 9 at the corresponding ends respectively by adopting plasma welding, argon arc welding or friction stir welding to form fillet welds; wherein, the distance between the two end surfaces of the titanium sleeve 11 and the section surface of the outer titanium tube layer 9 at the corresponding end is preferably 30 +/-5 mm.
As shown in fig. 5, based on the welding method, the present embodiment further provides a welded structure of a titanium steel composite pipe with an outer layer titanium-middle layer steel-inner layer titanium structure, which includes: a first welding nozzle and a second welding nozzle; the first welding pipe orifice and the second welding pipe orifice are respectively provided with an outer titanium pipe layer 9, and a middle steel pipe layer reserved section 12 and an inner titanium pipe layer reserved section 1 which are exposed in sequence.
Preferably, the section surface of the end surface of the middle steel pipe layer reserved section 12 is an inclined plane with an angle of 120 degrees, and the reserved length of the middle steel pipe layer reserved section 12 is 15-20 mm; 5-10 mm is reserved in the inner layer titanium tube layer reserved section 1, and the surface of the inner layer titanium tube layer reserved section 1 is machined to be 0.1-0.15 mm below the joint surface of the middle steel tube layer and the inner layer titanium tube layer. Meanwhile, the end face of the reserved section 1 of the inner titanium tube layer is provided with a 30-degree groove 10.
Welding the inner titanium tube layer reserved section 1 of the first welding pipe orifice and the inner titanium tube layer reserved section 1 of the second welding pipe orifice, wherein a welding joint is positioned at a triangular welding groove formed by the two grooves 10; the middle-layer steel pipe layer reserved section 12 of the first welding pipe orifice is welded with the middle-layer steel pipe layer reserved section 12 of the second welding pipe orifice through corresponding supporting blocks; the outer titanium tube layer 9 of the first welding pipe orifice and the outer titanium tube layer 9 of the second welding pipe orifice are welded through corresponding titanium sleeves 11.
The supporting blocks comprise two semicircular supporting blocks which can be spliced to form a ring, the cross sections of the two supporting blocks are hexagonal, the wall thickness of the supporting blocks is the same as that of the middle-layer steel pipe layer reserved section 12, and the inner diameter of the supporting blocks is the pipe outer diameter R + (0-0.02) mm of the inner-layer titanium pipe layer reserved section 1; the included angles between the inner ring surfaces 4 of the two supporting blocks and the two bottom waists 6 on the two sides of the inner ring surfaces are both 120 degrees, the included angles between the outer ring surfaces of the two supporting blocks and the two top waists 7 on the two sides of the outer ring surfaces of the two supporting blocks are both 120 degrees, and waist edges at the connection parts of the bottom waists 6 and the top waists 7 of the supporting blocks are positioned at 1/3 of the wall thickness of the middle-layer steel pipe layer reserved section 12; meanwhile, the inner ring surfaces 4 of the two supporting blocks are provided with grooves 5 distributed along the circumferential direction of the ring for accommodating the weld reinforcement at the butt joint end of the inner layer titanium pipe layer reserved section 1.
The inner diameter of the titanium sleeve 11 is matched with the outer diameter of the outer titanium tube layer 9, and the wall thickness of the titanium sleeve 11 is consistent with that of the outer titanium tube layer 9.
The first supporting block 3 and the second supporting block are spliced into a ring shape and sleeved on the outer surfaces of the inner titanium pipe layer reserved sections 1 of the first welding pipe orifice and the second welding pipe orifice; the inner ring surfaces 4 of the first supporting block 3 and the second supporting block are attached to the outer surface of the inner layer titanium pipe layer reserved section 1, the bottom waists 6 of the first supporting block 3 and the second supporting block are both attached to the section surfaces of the middle layer steel pipe layer reserved sections 12 of the corresponding ends, and the top waists 7 are both attached to the section surfaces of the middle layer steel pipe layer reserved sections 12 of the corresponding ends to form triangular welding grooves and are welded through the welding grooves.
The two ends of the titanium sleeve 11 are respectively welded with the outer surfaces of the outer titanium tube layers 9 of the first welding tube opening and the second welding tube opening, fillet welds are formed at the welding ends, and the distance between the two ends of the titanium sleeve 11 and the section surface of the outer titanium tube layer 9 of the corresponding end is 30 +/-5 mm.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.