Summary of the invention
The embodiment of the present invention provides a kind of ferromagnetic concentrator and powder bed electron beam selective melting former, existing to solveThe congregational rate of ferromagnetic concentrator lead to problems such as beam spot focusing delay and focus coil generate heat with the increase of frequency.
The embodiment of the present invention provides a kind of ferromagnetic concentrator, comprising: at least one main coil and at least one auxiliary winding；
The main coil and the auxiliary winding are individually powered, and main coil input electric current is constant and current directionConstant, the size of current of the auxiliary winding input and direction change.
Preferably, when the quantity of the main coil be even number when, the winding mode for having 50% main coil be it is counterclockwise,The winding mode for having 50% main coil is clockwise.
Preferably, when the quantity of the main coil is odd number, the number of the main coil with anti-clockwise windings modeAmount than have winding mode clockwise the main coil quantity more than 1.
Preferably, the axis of the axis of the main coil and the auxiliary winding is overlapped；
And the auxiliary winding is located at the inside of the main coil, external, front, any one position in rear portion.
Preferably, when the auxiliary winding is located at the inside of the main coil, the coil outer diameter of the auxiliary winding is equal to instituteThe internal diameter of main coil is stated, and the length of the auxiliary winding is equal to the length of the main coil.
Preferably, when the auxiliary winding is located at the front of the main coil, the internal diameter of the auxiliary winding is equal to the masterThe internal diameter for the auxiliary winding that coil inside includes, and the axial length of the auxiliary winding is the axial length of the main coilBetween 1/3~1/2；Or
When the auxiliary winding is located at the rear portion of the main coil, the internal diameter of the auxiliary winding is equal to inside the main coilIncluding the auxiliary winding internal diameter, and the axial length of the auxiliary winding be the main coil axial length 1/3~1/2Between；Or
When the auxiliary winding is located at the outside of the main coil, the internal diameter of the auxiliary winding is equal to inside the main coilIncluding the auxiliary winding internal diameter, and the axial length of the auxiliary winding be the main coil axial length 1/3~1/2Between.
Preferably, the number of ampere turns of the main coil is 3~7 times of the number of ampere turns of the auxiliary winding.
Preferably, the number of ampere turns of the main coil nearest with forming face distance successively successively decreases trapezoidal point from top to bottomCloth, wherein the distance between described trapezoidal upper bottom and forming face are greater than the distance between the trapezoidal bottom and forming face；The angle formed between the trapezoidal bottom and the trapezoidal waist is between 70-90 degree.
Preferably, the distance between end face of two adjacent main coils is the 1/5 of the main coil axial lengthBetween~1/2；Or
The distance between end face of two adjacent auxiliary windings be the main coil axial length 1/5~1/2 itBetween；Or
The distance between end face of two adjacent main coils and an auxiliary winding is the main coilBetween the 1/5~1/2 of axial length.
The embodiment of the invention also provides a kind of powder bed electron beam selective melting formers, which is characterized in that including appointingFerromagnetic concentrator described in item one by one；
When the quantity for the main coil for including in the ferromagnetic concentrator is even number, the forming of powder bed electron beam selective melting is setIt is standby to be scanned preheating and fusing by linear of Electron Beam shape of spot；Or
When the quantity for the main coil for including in the ferromagnetic concentrator is odd number, powder bed electron beam selective melting formerPreheating and fusing are scanned by circle of Electron Beam shape of spot.
The embodiment of the invention provides a kind of ferromagnetic concentrators and powder bed electron beam selective melting former, the coil to includeAt least one main coil and at least one auxiliary winding, the main coil and the auxiliary winding are individually powered, and the main coil is defeatedThe electric current entered is constant and current direction is constant, and the size of current of the auxiliary winding input and direction change.The present invention is implementedThe ferromagnetic concentrator that example provides is combined by multiple groups main coil and auxiliary winding, since the electric current of main coil input is constant and current directionIt is constant, it can determine that main coil generates constant high-intensity magnetic field and can be reduced magnetic field fever；Furthermore auxiliary winding can be defeated with flexible modulationEnter current value to adjust congregational rate.It is poor that the ferromagnetic concentrator that this method provides solves Electron Beam Focusing effect from structure, depositsIn the serious problem of spherical aberration, furthermore, which is applied in powder bed electron beam selective melting former, it is determined that electricityBeamlet beam spot scans shape, and can improve forming accuracy, so that the forming efficiency of electron beam selective melting be greatly improved.The congregational rate of existing ferromagnetic concentrator is further solved as the increase of frequency leads to beam spot focusing delay and focus coilThe problems such as fever.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, completeSite preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based onEmbodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every otherEmbodiment shall fall within the protection scope of the present invention.
Fig. 1 illustratively shows ferromagnetic concentrator structural schematic diagram provided in an embodiment of the present invention, as shown in Figure 1, the magneticFocalizer mainly includes at least one main coil and at least one auxiliary winding.
It should be noted that ferromagnetic concentrator may include the coil cluster being made of multiple main coils and multiple auxiliary windings,The coil cluster that a main coil and an auxiliary winding form can be only included includes to coil cluster in embodiments of the present inventionThe quantity of main coil and auxiliary winding is without limitation.
In practical applications, main coil is mainly used for guaranteeing electron gun focusing effect, keep before Electron Beam Focusing with it is poly-Defocused beam spot shape and orientation consistency, and reduce the spherical aberration in traditional focus device, auxiliary winding is primarily to realize large areaHigh-precision focusing effect, and reduce the fever of focalizer.
Specifically, main coil and auxiliary winding are individually powered.In embodiments of the present invention, the number of turns of main coil compared withMore, inductance value is big, in order to determine that main coil generates constant high-intensity magnetic field and high-intensity magnetic field reduces heat, so keeping main coil inputElectric current it is constant and sense of current is constant；Further, since the number of turns of auxiliary winding is fewer, inductance value is small, it is possible toThe input current value of flexible modulation auxiliary winding, and then adjustable focusing effect.It should be noted that in the embodiment of the present inventionIn, auxiliary winding input electric current size and sense of current be it is adjustable, and auxiliary winding input electric current sizeSpecific restriction is not done with sense of current.
In practical applications, the conducting wire being arranged on main coil and auxiliary winding can choose diameter be 0.3mm to 0.8mm itBetween high temperature resistant enamel covered wire, be based on this, input current value range can be in 0-10A on each coil, it should be noted that alsoIt can be ensuring in the case where the ampere-turn numerical value of main coil and auxiliary winding is constant, to the number of turns and input of main coil and auxiliary windingCurrent value is changed.
In embodiments of the present invention, control magnetic field is distinguished for convenience, the winding method of auxiliary winding can be uniformly set toCoiling clockwise or coiling counterclockwise.In practical applications, it is selected in order to ensure the ferromagnetic concentrator is applied to powder bed electron beamArea is melted in former, and the preheating of electronics beam scanning and melting method are to be scanned using Electron Beam shape of spot as linearPreheating and fusing, it is preferable that the total quantity of main coil needs for even number, and it is inverse for needing for even number main coil to be divided into halfHour hands coiling, the other half is coiling clockwise；Further, it is also necessary to ensure that whole main coils are passed through sense of current and electric currentSize is consistent.
In practical applications, in order to ensure ferromagnetic concentrator to be applied in powder bed electron beam selective melting former, andThe preheating of electronics beam scanning and melting method are that preheating and fusing are scanned by circle of Electron Beam shape of spot, it is preferable that mainThe total quantity of coil needs for odd number, and the quantity of the main coil with coiling counterclockwise is than with winding mode clockwiseThe quantity of main coil is 1 more, further, it is also necessary to ensure that whole main coils are passed through sense of current and size of current is uniformIt causes.
When main coil and auxiliary winding are installed, therefore, to assure that the axis of the coil cluster of main coil and auxiliary winding compositionAlways it is overlapped, i.e. the axis of main coil and the axis of auxiliary winding is overlapped.
Specifically, when auxiliary winding is integrally located at the inside of main coil, the coil outer diameter of auxiliary winding is equal to the interior of main coilDiameter, and the length of auxiliary winding is equal to the length of main coil；When auxiliary winding is located at the front of main coil, the internal diameter of auxiliary winding is equal toThe internal diameter for the auxiliary winding for including inside main coil, and the axial length of auxiliary winding be the axial length of main coil 1/3~1/2 itBetween；When auxiliary winding is located at the rear portion of main coil, the internal diameter of auxiliary winding is equal to the internal diameter for the auxiliary winding for including inside main coil, andThe axial length of auxiliary winding is between the 1/3~1/2 of the axial length of main coil；When auxiliary winding is located at the outside of main coil,The internal diameter of auxiliary winding is equal to the internal diameter for the auxiliary winding for including inside main coil, and the axial length of auxiliary winding is the axial direction of main coilBetween the 1/3~1/2 of length.
In embodiments of the present invention, include at least one main coil and at least one auxiliary winding in coil cluster, work as coilWhen in cluster including two adjacent main coils, the distance between end face of main coil is the 1/5~1/2 of main coil axial lengthBetween；When including two adjacent auxiliary windings in coil cluster, the distance between end face of auxiliary winding is that main coil is axially longBetween the 1/5~1/2 of degree；When in coil cluster including two adjacent main coils and an auxiliary winding, main coil andThe distance between end face of auxiliary winding is between the 1/5~1/2 of main coil axial length.
In embodiments of the present invention, guarantee that each main coil and the number of ampere turns of each auxiliary winding are consistent, and at least oneThe number of ampere turns of a main coil is 3~7 times of the number of ampere turns of at least one auxiliary winding.
As shown in Figure 1, in figure the number of turns of main coil be respectively be 900-1500 circle, the number of turns of all auxiliary windings is respectively 100-350 circles, conducting wire are the high temperature resistant enamel covered wire of diameter 0.6mm.Diameter D is 30-60mm in Fig. 1, in order to enable two neighboring lineThe magnetic field influence of circle is smaller, so determining that the distance of two neighboring coil is D/3, a height of 1.25D of main coil 1, auxiliary windingA height of 0.5D.
In practical applications, electron beam is when perpendicular end surface is down through first end face in magnetic focusing coil, electron beamDue to the effect by uneven distribution magnetic field, spiral advance integrally will do it, and electronic beam radius can be gradually reduced, whenWhen electron beam is pierced by another end face, the non-uniform magnetic field of magnetic focusing coil end face can make electron beam have lesser drag effect,In embodiments of the present invention, in order to enhance the focusing effect of magnetic focusing coil, so by whole coil the number of turns of magnetic focusing coilDistribution carries out trapezoidal distribution as shown in Figure 1, i.e. forming number of ampere turns of the identity distance from nearest main coil successively successively decreases from top to bottomTrapezoidal distribution, wherein the distance between trapezoidal upper bottom and forming face are greater than the distance between trapezoidal bottom and forming face；The embodiment of the present invention this, for the angle formed between trapezoidal bottom and trapezoidal waist between 70-90 degree or so, Fig. 1 is this hairThe preferred embodiment that bright embodiment provides, i.e., the angle formed between trapezoidal bottom and trapezoidal waist is 85 degree.
The embodiment of the invention also provides a kind of powder bed electron beam selective melting former, which includes above-mentioned retouchThe ferromagnetic concentrator stated.
Conditional electronic rifle ferromagnetic concentrator and other critical components limit powder bed electron beam due to the deficiency of coil itselfThe forming area of selective melting, so the production for high-volume part, the quantity processed every time can all be limited, in addition,For Investigation of Large Area Electron Beam selective melting forming technique, the sewwp beam spot shape of electron beam should become into a line, rather than passThe sewwp beam spot of one point of system.The focalizer provided through the embodiment of the present invention, since focalizer includes right-handed screw and inverse spiral shellTwo kinds of focusing effects are revolved, ensure that beam spot shape of the electron beam before focusing, specific beam spot shape can pass through stigmatorIt realizes, and the selection to beam spot position after focusing, it can be determined by specific requirements, in the embodiment of the present invention, it is determined thatElectron beam spot scans shape, and can improve forming accuracy, so that the forming effect of electron beam selective melting be greatly improvedRate.
Specifically, in powder bed electron beam selective melting former provided in an embodiment of the present invention, when being wrapped in ferromagnetic concentratorThe quantity of the main coil included be even number when, powder bed electron beam selective melting former using Electron Beam shape of spot as linear intoRow scanning preheating and fusing；When the quantity for the main coil for including in ferromagnetic concentrator be odd number when, powder bed electron beam selective melting atShape equipment is scanned preheating and fusing by circle of Electron Beam shape of spot.
In Fig. 1 when the winding mode of two main coils, size of current are consistent with current direction, Distribution of Magnetic Field such as Fig. 2Shown, Fig. 2 is Distribution of Magnetic Field schematic diagram provided in an embodiment of the present invention, as shown in Figure 2, when the coiling side of two main coilsWhen formula, size of current are consistent with current direction, this distribution that magnetic field is formed, it is ensured that rotation when electron beam is threadingly advancedThe characteristics of adjustability in direction, finally achievable beam spot rotation angle is zero.
Fig. 3 be in the prior art beam spot forming and scanning theory figure, Fig. 4 be the embodiment of the present invention in beam spot atShape and scanning theory figure.In the prior art, the direction of harness shape when beam spot enters magnetic focusing coil as shown in a in Fig. 3,Then certain angle generally can be will form as shown in b in Fig. 3 by the shape after two magnetic focusing coils between a and b in Fig. 3.In embodiments of the present invention, in order to ensure the direction of the object of beam spot and the direction of picture are consistent to improve electronics beam shapingEfficiency, thus determine winding mode one of two main lines be it is counterclockwise, another be it is clockwise, when input coil electric current sideTo on the contrary, and the size of electric current is 2 ampere-hours, if a in the direction of harness shape when beam spot enters magnetic focusing coil such as Fig. 4It is shown, then it can generally be formed between b in a and Fig. 4 in Fig. 4 as shown in b in Fig. 4 by the shape after two magnetic focusing coilsAngle is close to 0 degree.In embodiments of the present invention, when the angle between a and b in Fig. 4 is 0, so that it may pass through line scanning sideFormula preheats electron beam powder bed, is scanned, and not only substantially increases production efficiency, but also increase processing technology mode.
In practical applications, Investigation of Large Area Electron Beam selective melting, since the image distance of electron beam is becoming always, so needing notThe magnetic field strength of the change coil stopped is quickly focused, institute with reaching best focusing effect in order to reduce coil heating and realizeIt is changed with the current value only to auxiliary focus coil, change frequency can reach 9000HZ.And Investigation of Large Area Electron Beam constituencyThe preheating of fusing and fusing scanning strategy need to be become line by point, in this way to improve preheating and melting rate and to forming bottom plateLasting heat preservation.
In embodiments of the present invention, in order to reduce the distance of focalizer vertical axial and keep realize focus before beam spot shapeFig. 1 can be carried out structure optimization by shape function.In practical applications, can according to different requirements, to the vertical dimension of focalizer intoRow change, in order to meet the needs of various electron guns, in embodiments of the present invention, additionally provides two embodiments, respectively Fig. 5Shown in ferromagnetic concentrator structural schematic diagram in ferromagnetic concentrator structural schematic diagram and embodiment shown in fig. 62 in embodiment 1.
Specifically, the function for the ferromagnetic concentrator that Fig. 1 is provided equally can be achieved in the ferromagnetic concentrator provided in Fig. 5, but in Fig. 5Change frequency, that is, speed of ferromagnetic concentrator can decrease, while the size of focalizer entirety can be reduced, so that magneticThe structure of focalizer is relatively easy compared with the structure that Fig. 1 is provided；The magnetic that Fig. 1 is provided equally can be achieved in the ferromagnetic concentrator provided in Fig. 6The function of focalizer, but change frequency, that is, speed of the ferromagnetic concentrator in Fig. 6 can reduce more, while can reduce focusingThe overall dimensions of device, so that the structure of ferromagnetic concentrator is simpler, it should be noted that the ferromagnetic concentrator that Fig. 6 is provided only hasReduce the function of electron beam spherical aberration.
In conclusion the embodiment of the invention provides a kind of ferromagnetic concentrator and powder bed electron beam selective melting former,Ferromagnetic concentrator provided in an embodiment of the present invention is combined by multiple groups main coil and auxiliary winding, due to main coil input electric current it is constant withAnd current direction is constant, can determine that main coil generates constant high-intensity magnetic field and can be reduced magnetic field fever；Furthermore auxiliary winding can be withFlexible modulation input current value adjusts congregational rate.The ferromagnetic concentrator that this method provides solves Electron Beam Focusing from structureEffect is poor, there is a problem of that spherical aberration is serious, furthermore, which is applied to powder bed electron beam selective melting formerIn, it is determined that electron beam spot scans shape, and can improve forming accuracy, so that electron beam selective melting be greatly improvedForming efficiency.The congregational rate of existing ferromagnetic concentrator is further solved as the increase of frequency leads to beam spot focusing delayThe problems such as with focus coil fever.
It should be understood by those skilled in the art that, the embodiment of the present invention can provide as method, system or computer programProduct.Therefore, complete hardware embodiment, complete software embodiment or reality combining software and hardware aspects can be used in the present inventionApply the form of example.Moreover, it wherein includes the computer of computer usable program code that the present invention, which can be used in one or more,The computer program implemented in usable storage medium (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.) producesThe form of product.
The present invention be referring to according to the method for the embodiment of the present invention, the process of equipment (system) and computer program productFigure and/or block diagram describe.It should be understood that every one stream in flowchart and/or the block diagram can be realized by computer program instructionsThe combination of process and/or box in journey and/or box and flowchart and/or the block diagram.It can provide these computer programsInstruct the processor of general purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices to produceA raw machine, so that being generated by the instruction that computer or the processor of other programmable data processing devices execute for realThe device for the function of being specified in present one or more flows of the flowchart and/or one or more blocks of the block diagram.
These computer program instructions, which may also be stored in, is able to guide computer or other programmable data processing devices with spyDetermine in the computer-readable memory that mode works, so that it includes referring to that instruction stored in the computer readable memory, which generates,Enable the manufacture of device, the command device realize in one box of one or more flows of the flowchart and/or block diagram orThe function of being specified in multiple boxes.
These computer program instructions also can be loaded onto a computer or other programmable data processing device, so that countingSeries of operation steps are executed on calculation machine or other programmable devices to generate computer implemented processing, thus in computer orThe instruction executed on other programmable devices is provided for realizing in one or more flows of the flowchart and/or block diagram oneThe step of function of being specified in a box or multiple boxes.
Although preferred embodiments of the present invention have been described, it is created once a person skilled in the art knows basicProperty concept, then additional changes and modifications may be made to these embodiments.So it includes excellent that the following claims are intended to be interpreted asIt selects embodiment and falls into all change and modification of the scope of the invention.
Obviously, various changes and modifications can be made to the invention without departing from essence of the invention by those skilled in the artMind and range.In this way, if these modifications and changes of the present invention belongs to the range of the claims in the present invention and its equivalent technologiesWithin, then the present invention is also intended to include these modifications and variations.