CN108621429B - A kind of three-dimensional printer screw extrusion system of changeable print head - Google Patents

Abstract

The invention discloses a kind of three-dimensional printer screw extrusion systems of changeable print head, including fixing printing head component and the orientable active print head assembly between at least first state and the second state；When active print head assembly is located in first state, the nozzle of active print head assembly is lower than the nozzle of fixing printing head component；When active print head assembly is located in the second state, the nozzle of active print head assembly is higher than the nozzle of fixing printing head component.Two printing extruder heads of present invention design " one is dynamic certain ", only pass through the height of switching activity print head, the difference in height switching between two print heads can be realized, be easily guaranteed that the precision of two print heads switching.

Description

A kind of three-dimensional printer screw extrusion system of changeable print head

Technical field

The present invention relates to the three-dimensional printers based on melting fused deposition rapid moulding technique, and in particular to the changeable printing of one kind The three-dimensional printer screw extrusion system of head.

Background technique

Three-dimensional printer based on melting fused deposition rapid moulding technique is the plastics silk for the use of diameter being 1~2mm or so, Plastics silk melt extruded is printed at the filament of 0.2~0.4mm or so and successively by the printing extruder head that computer controls It is piled into three-dimension object.In general, melting fused deposition rapid moulding technique needs to add support when manufacture has the object of cantilever design. If three-dimensional printer extruder head only has single melting Channel design structure, the object of printing and support can only be with same materials come structure It builds.Although support section can be made to become more loose to reach by controlling the method for operation of extruder head in print procedure To the purpose convenient for removing, but due to being to be difficult to recognize on the boundary of object and support after the completion of printing using same material Cause removing difficult, support also be easy to cause object fine structure to damage when removing.In order to solve this problem, currently, based on molten The three-dimensional printer printing extruder head for melting accumulation quick shaping process mostly uses dual channel structure, and one of runner is for melting The model formings materials such as ABS plastic are squeezed out, another runner can be easy the branch of physics removing or chemical stripping for melting extrusion Timbering material, when removing, will not damage molded model.

Patent of invention (ZL200780020529.8) discloses a kind of monomotor extruder head with multiple extrusion line, makes With a driving motor, keep melting extrusion head and passive material feeding pressing wheel real in an oscillatory manner by the mechanical mechanism of a set of complexity The print head channels of existing two kinds of silks of moulding material and backing material and feeding drive switching control, and switching mechanism is complicated and increases The weight for squeezing out head assembly is added, has been unfavorable for the flying print campaign of extruder head, when printing short segment, is easy to make extruder head Positioning is inaccurate, and error is big.

Utility model patent (ZL 200820206342.9) discloses a kind of micro-column for melting fused deposition rapid moulding Plug extrusion system is respectively operated alone moulding material and backing material by two driving motors, and is moved with mechanical elevating Dynamic mode realizes the switching control of Channels.Required driving force is larger when due to high polymer molding, the big electricity of driving force Machine volume and weight is larger, increases the cost for squeezing out head assembly, volume and weight；Secondly, Channels switching mode and Effect places one's entire reliance upon silk to the thrust of runner, the processing of mechanical part and assembly precision etc., in addition, two nozzles are printing When different materials, different materials are different the thrust of runner, certainly will influence the precision of two nozzle switching height, simultaneously also It is acted upon by temperature changes.

When carrying out the switching of extruder head runner, the mechanical location of two nozzles requires to move for two kinds of designs disclosed above Dynamic and reset, moving process generates machinery positioning error easily to influence the dimensional accuracy of printing objects, or even waste product occurs. In addition to the deficiency of above-mentioned printing extruder head switching construction, there is also following disadvantages:

(1) runner in liquefier is longer, is easy to appear the uneven phenomenon of heating, increases the resistance that silk enters runner Also easily there is overflow phenomena in power.In addition, viscosity is big when the high polymer moldings such as ABS, poor fluidity, silk to be made can smoothly enter into stream Road and extrusion molding, silk will have enough frictional force, and propose high requirement to driving motor, it is made both to have had larger drive Power has lesser volume and weight again, and the two is contradictory.

(2) driving wheel is round and has " V " type dentalation, and the tooth contacted with silk is less, silk to be made smoothly into Air stream enter runner and extrusion molding, need to have biggish frictional force, must just increase the pressing force F on follower, when F reaches certain value When, the dentalation on driving wheel, which will be weighed wounded seriously, even scratches silk, destroys driving motor revolving speed and squeezes out silk volume Matching, the silk powder scraped can also trickle down on molding model, seriously affect the formed precision of model.When F is not achieved When particular value, silk will not be pushed into runner.So in this working principle, the smooth extrusion molding of silk and reduction silk It is contradictory that material, which scratches,.

The design for also having dual channel printing extruder head contour at present, two extruder heads avoid extruder head and cut without switching It changes and leads to the problem of the dimensional accuracy that machinery positioning is not allowed and influences printing objects.But two printing extruder heads of this structure level Difficulty is easy to scratch the model of printing, and the salivation of nozzle can seriously affect the surface quality of workpiece.

Summary of the invention

In view of the above shortcomings of the prior art, the three-dimensional printer screw that the present invention provides a kind of changeable print head squeezes System out is printing raw material with two kinds of filamentary materials, can simply, accurately switch print head, and silk can be made smoothly liquefy, is crowded Out and precise forming.

To achieve the above object, the technical solution of the present invention is as follows:

A kind of three-dimensional printer screw extrusion system of changeable print head, including fixing printing head component and extremely Orientable active print head assembly between few print state and non-printing status；When active print head assembly is located in printing shape When state, active print head assembly is lower than fixing printing head component；When active print head assembly is located in non-printing status, activity Print head assembly is higher than fixing printing head component.

When carrying out print head assembly switching, fixing printing head component is fixed always, only to active print head assembly Carry out whole switching can effectively avoid two print heads and is both needed to move so that two print head assemblies realize certain difference in height The problem of caused positioning accuracy difference, so as to effectively improve the dimensional accuracy of printing objects.

As an improvement of the present invention, the active print head assembly includes motor, feeding spiro rod, pinch roller, pinch roller Regulating device and liquefier, the axial parallel silk direction of feed of feeding spiro rod, the axially vertical silk direction of feed of pinch roller, pinch roller phase Adjacent feeding spiro rod setting, pinch roller regulating device adjusting pinch roller is silk to be pressed on feeding spiro rod, motor driven feeding spiro rod Rotation drives silk to enter liquefier.Using screw feeding mode, silk and feeding spiro rod are arranged in parallel, and contact area is big, Feeding friction power is increased, the requirement to motor driving force is reduced, the motor for selecting volume and weight little, which can meet, to be wanted It asks.

Further, the pinch roller is equipped with the V-type groove for constraining, being oriented to silk, and the depth of the V-type groove is greater than The radius of silk, and it is less than the diameter of silk.Silk is compressed and is oriented to using V-type groove, it can be accurately by silk pressure Tightly on feeding spiro rod surface, the accuracy of feeding ensure that.

Further, the pinch roller regulating device include pinch roller mounting rod, pinch roller pressure regulating screw, pinch roller pressure spring and Pinch roller mounting rod adjusting screw, pinch roller mounting rod can be rotated around wherein one end, and pinch roller is mounted in the middle part of pinch roller mounting rod, pinch roller tune The other end of pinch roller mounting rod, pinch roller pressure regulating screw is arranged in pressure screw, pinch roller pressure spring and pinch roller mounting rod adjusting screw With pinch roller pressure spring for adjusting pinch roller to the pressure of silk, pinch roller mounting rod adjusting screw is sent for adjusting pinch roller with described Expect the gap between screw rod.

Further, the liquefier includes melting runner and heating wire, melts the adjacent pinch roller of entrance of runner, The outlet for melting runner forms nozzle to contract, and heating wire is evenly arranged in the outer wall of melting runner.Melting runner can be made fast Speed, uniform heating, can shorten the length of melting runner, reduce the resistance that silk squeezes out.

It further include at least rotating active print between print state and non-printing status as another improvement of the invention The changeover module of head assembly.

Further, the changeover module is included in and the orientable changer lever of second point at least first point, is mounted on Switching locating piece in active print head assembly and the resilient mounting being connect with active print head assembly；Changer lever direction is living The side of dynamic print head assembly is equipped with ladder ramp, and switching locating piece is equipped with the switching wheel rolled along ladder ramp；Work as switching When bar is moved at first, switching wheel is rolled to the bottom surface in ladder ramp, and active print head assembly is under the pulling force of resilient mounting Turn to print state；When changer lever is moved to second point, switching wheel is rolled to the top surface in ladder ramp, active print head group Part overcomes the pulling force of resilient mounting to turn to non-printing status.

The rotation of active print head assembly is realized by moving horizontally changer lever, resilient mounting is remained to active print On the one hand the tensile force of head assembly provides active print head assembly and is reset to the pulling force of print state, while activity can be made to beat Print head assembly is attached on changer lever, realizes positioning；On the other hand, after active print head assembly turns to non-printing status, rebound The tightening force that device provides increases, and active print head assembly can be tightly fitted on changer lever, prevent fixing printing head group When part works, the raw vibration of active print hair.

Further, the switching locating piece is equipped with slot, and changer lever is equipped with the inserted block to match with slot, when When changer lever is moved at first, inserted block is just inserted into slot.It, can be effective by the further positioning of inserted block and slot It prevents active print head assembly to be displaced in print procedure, ensure that the precision of printing.

Further, the changeover module further includes a fixed changer lever retainer, and changer lever, which is slidedly assemblied in, to be cut It changes in bar retainer, an elastic locking hoodle is set on changer lever, interval setting and locking hoodle on changer lever retainer The left lock slots and right lock slots to match, when changer lever is moved at first, locking hoodle is caught in left lock slots；Work as switching When bar is moved to second point, locking hoodle is caught in right lock slots.Rod lock will be switched by locking hoodle, prevent active print head It is inaccurate that vibration when component operation causes changer lever to position.

Further, the resilient mounting includes a fixed rebound bracket, rebound adjusting screw and rebound spring, is returned It plays after adjusting screw passes through rebound bracket and is spirally connected with active print head assembly, rebound spring covers in rebound adjusting screw, and position Between the head of screw and rebound bracket of rebound adjusting screw.Rebound spring is adjusted to active print head by rebound adjusting screw The tensile force of component, it is ensured that the positioning performance of active print head assembly.

Compared with the prior art, the invention has the following advantages: the present invention is suitable for using two feeding driving motors realities The three-dimensional printer extruder head design that existing two print heads alternately switch, realizes three-dimensional printer two in a kind of method of simplicity The accurate switching of print head, and the stamp with the size precision of object will not be influenced because switching print head.

1, two printing extruder heads of design " one is dynamic certain ", only pass through the height of switching activity print head, can be realized two Difference in height switching between a print head, is easily guaranteed that the precision of two print heads switching, meanwhile, switching device is simple and reliable, The measures such as positioning, locking, rebound are provided for active print head, ensure that the reliability when precision and work of its positioning.

2, using screw feeding mode, feeding spiro rod is linear type and screw pitch is smaller, easy processing, silk and thread contact It is more, stress is more uniform；Furthermore the pinch roller of adjustable pressure with V-type groove structure is compressed and is oriented to silk, both for Silk provides biggish driving force, and avoids weighing wounded and even scratch silk, ensure that the accuracy of feeding, biggish to improve The stamp with the size precision of three-dimension object.

3, liquefier uses heating wire uniform winding in melting runner outer wall, and melting runner can be made quickly, uniformly to heat up, The length of melting runner can be shortened, the resistance that silk squeezes out is reduced, using the lesser motor of driving force, volume and weight Enough power is provided for silk, alleviates the volume and weight of entire extrusion system.

Detailed description of the invention

Fig. 1 is the overall structure diagram of extrusion system forward direction；

Fig. 2 is the overall structure diagram of extrusion system backwards；

Fig. 3 is the structural schematic diagram of active print head assembly；

Fig. 4 is the enlarged view at pinch roller, silk and the feeding spiro rod cooperation of active print head assembly；

Fig. 5 is the cross-sectional view of liquefier；

Fig. 6 is the structural schematic diagram of switching device；

Fig. 7 is the back side partial view that active print head assembly switches to print state；

Fig. 8 is the sectional view of T-T in Fig. 7；

Fig. 9 is the back side partial view that active print head assembly switches to non-printing status；

Figure 10 is the dextrad view of Fig. 9；

Figure 11 is the sectional view of H-H in Fig. 9.

Specific embodiment

In order to make the foregoing objectives, features and advantages of the present invention clearer and more comprehensible, with reference to the accompanying drawing and specific real Applying mode, the present invention is described in further detail.

As depicted in figs. 1 and 2, the three-dimensional printer screw extrusion system of a kind of changeable print head, including pedestal 7, Fixing printing head component 8, active print head assembly 12 and changeover module 13.Two print head assembly one for moulding material Wire feed, melting and extrusion molding, wire feed, melting and an extrusion molding for being used to support material.

Fixing printing head component 8 is fixedly mounted on pedestal 7, and position is constant always, and active print head assembly 12 is mounted on It in active print head rotary shaft 10, can be rotated, active print head rotary shaft 10 and be mounted on pedestal 7 by bearing 11 Active print head link block 9 is fixed, and changeover module 13 is mounted on the back side of pedestal 7, for drive active print head assembly 12 around Active print head rotary shaft 10 rotates, to realize the difference in height with fixing printing head component 8, to realize two print head assemblies The function of printing alternate.8 symmetrical configuration of active print head assembly 12 and fixing printing head component, only installation site is different, and And working principle is identical, only introduces the structure and working principle of active print head assembly 12 below.

As shown in Figures 3 to 5, active print head assembly 12 include mounting plate 14, small synchronizing wheel 16, motor mount 17, Motor 18, pinch roller 23, pinch roller regulating device, feeding mounting base 27, liquefier 30, feeding spiro rod lower mounting seat 31, go out fiber tube 32, Out fiber tube fixing piece 33, feeding spiro rod 35, into fiber tube fixing piece 36, into fiber tube 37, feeding spiro rod upper mounting seat 38, feeding spiro rod Upper mounting seat bearing (ball) cover 39, synchronous belt 40, big synchronizing wheel 41, feeding spiro rod locking nut 42.

14 upper end of mounting plate is equipped with axis hole 15, and active print head assembly 12 is rotatably installed in active print head by axis hole 15 In rotary shaft 10.Motor 18 is mounted on the back side of mounting plate 14, the small synchronization being mounted on motor 18 by motor mount 17 Wheel 16 is connected by synchronous belt 40 and big synchronizing wheel 41, and big synchronizing wheel 41 is then mounted on the upper end of feeding spiro rod 35, and motor 18 is logical The deceleration device driving feeding spiro rod 35 that too small synchronizing wheel 16, synchronous belt 40 and big synchronizing wheel 41 form rotates, feeding spiro rod 35 Then pass through feeding spiro rod lower mounting seat 31, feeding spiro rod upper mounting seat 38, feeding spiro rod upper mounting seat bearing (ball) cover 39, feeding spiral shell The components such as stem jam nut 42 and matched bearing are vertically installed on mounting plate 14, guarantee the rotation that feeding spiro rod 35 can be stable Turn.

Feeding mounting base 27 is mounted on mounting plate 14, and fiber tube fixing piece 33 is common right into fiber tube fixing piece 36 and out Fiber tube 32 is fixed into fiber tube 37 and out, and the two ensure that silk 34 is suitable on a straight line parallel with feeding spiro rod 35 Benefit is into silk and wire vent.Pinch roller 23 is located at into fiber tube 37 and out between fiber tube 32, and the thread segment 43 at 35 middle part of adjacent feeding spiro rod Setting, pinch roller 23 are equipped with the V-type groove 24 towards thread segment 43, and the depth of V-type groove 24 is greater than the radius of silk 34, and small Silk 34 is pressed on thread segment 43 for constraining, being oriented to silk 34 in the diameter of silk 34.

Pinch roller regulating device includes pinch roller pressure regulating screw 19, pinch roller pressure spring 20, pinch roller mounting rod 21, pinch roller mounting rod Adjusting screw 22, pinch roller 23, anti-friction washers 25 and pinch roller mounting rod shaft 26.Feeding mounting base 27 is also installed simultaneously for pinch roller Bar shaft 26 provides mounting hole 28, and pinch roller mounting rod shaft 26 is pressed into 28 mounting holes, and one end of pinch roller mounting rod 21 passes through 25 slide fit of anti-friction washers is mounted in pinch roller mounting rod shaft 26, and can be rotated around it.Pinch roller 23 is mounted on pinch roller mounting rod 21 middle parts, the other end of pinch roller mounting rod 21 are equipped with the through-hole passed through for pinch roller pressure regulating screw 19, and 20 sets of pinch roller pressure spring exists On pinch roller pressure regulating screw 19, pinch roller pressure regulating screw 19 passes through pinch roller mounting rod 21 and is spirally connected with feeding mounting base 27, is supplied by rotation Pinch roller pressure regulating screw 19 and pinch roller pressure spring 20 finely tune the deflection angle of pinch roller mounting rod 21, to realize that adjusting pinch roller 23 is right The pressure of silk 34, to guarantee that silk 34 has suitable feeding friction power, pinch roller pressure regulation near pinch roller mounting rod adjusting screw 22 Screw 19 is screwed on pinch roller mounting rod 21, after pinch roller mounting rod 21 is stretched out in bottom, can be contradicted feeding mounting base 27, be passed through tune The workplace between its extension elongation adjusting pinch roller 23 and 35 thread segment 43 of feeding spiro rod is saved away to adapt to the silk of different-diameter 34。

Thread segment 43 uses common triangle thread or saw-tooth thread, and is set as fine pitch, when pinch roller 23 is silk When material 34 is pressed on thread segment 43, there are multiple screw threads and silk 34 to contact, silk stress is more uniform, will not damage silk.When sending When expecting that screw rod 35 rotates, thread segment 43 can drive silk 34 to move down under the guiding of the V-type groove 24 of pinch roller 23, be sent into out In fiber tube 32, and then push into melt in the liquefier 30 being connected with fiber tube 32 out and extrusion molding.

Liquefier 30 includes melting runner locking nut 45, heating wire 49, mounting base 50 and melting runner 51.Mounting base 50 It is mounted on mounting plate 14, melting runner 51 is fixed in mounting base 50 by locking nut 45, and the upper end of melting runner 51 is The feed inlet 44 connecting with fiber tube 32 out, for silk 34 to be smoothly sent into melting runner 51, melting 51 lower end of runner goes out Mouth forms nozzle 48 to contract, and 49 uniform winding of heating wire melts silk 34, after melting in melting 51 outer wall of runner Silk squeezed out by nozzle 48.Mounting base 50 uses partiting thermal insulation material, and such as phenolic materials are provided with fever in mounting base 50 Silk electric source line interface 46 and temperature sensor fixing hole 47, temperature sensor fixing hole 47, can promptly and accurately close to nozzle 48 The extrusion temperature at nozzle 48 is monitored and controlled, make to squeeze out more smooth and ensure that molding precision.

Active print head assembly 12 of the invention, motor 18 pass through small synchronizing wheel 16, synchronous belt 40 and big 41 groups of synchronizing wheel At deceleration device driving feeding spiro rod 35 rotate, biggish driving force can be brought using small motor for feeding spiro rod 35, Simultaneously because wire feed screw rod 35 is in printhead prints, direction of rotation is constant always, and deceleration device is not in reversed diastema, protects The precision of wire feed is demonstrate,proved.Silk 34 and feeding spiro rod 35 are arranged in parallel, and pinch roller 23 is pressed in silk 34 on the screw thread of feeding spiro rod 35 When in section 43, there are multiple screw threads and silk 34 to contact, 34 stress of silk is more uniform, will not damage silk, while also increasing and sending Expect frictional force, enters under the driving of feeding spiro rod 35 and complete melting in liquefier 30, feeding spiro rod 35 is constantly silk 34 It is sent into liquefier 30 via fiber tube 32 out, plays the role of a piston to the material of molten condition in liquefier 30, melting The material of state is printed from the extrusion of nozzle 48.Liquefier 30 is melting 51 outer wall of runner using 49 uniform winding of heating wire, can Make to melt runner 51 quickly, uniform heating, melting runner 51 can uniformly melt silk 34 in very short distance, significantly The length for shortening melting runner 51, reduces the propelling resistance of silk 34, thereby reduces the demand to 18 driving force of motor, Be conducive to further decrease the volume and weight of motor 18.

As shown in Fig. 6 to Figure 11, changeover module 13 include switching locating piece 29, rebound spring 53, rebound adjusting screw 55, Changer lever retainer 56, locking hoodle 57, locking hoodle set 58, changer lever 60 and rebound bracket 61.

Rebound 61 one end of bracket is fixed on pedestal 7, and the other end extends to 14 back of mounting plate, and rebound adjusting screw 55 is worn It is spirally connected after crossing rebound bracket 61 with mounting plate 14,53 sets of rebound spring is compressed in rebound adjustment in rebound adjusting screw 55 Between the head of screw and rebound bracket 61 of screw 55, rebound spring 53 is in confined state always, there is mounting plate 14 around work The trend that dynamic print head rotary shaft 10 rotates backward.

Changer lever retainer 56 is mounted on pedestal 7, and 60 slide fit of changer lever is mounted in retainer 56 and pastes with pedestal 7 It closes.Changer lever 60 is equipped with locking hoodle and covers mounting hole 59, and for installing locking hoodle set 58, locking hoodle 57 is pacified by spring It, can the inside and outside movement under locking hoodle set 58 and internal spring constraint when stress in locking hoodle set 58.Changer lever is protected The left lock slots 69 and right lock slots 70 for being arranged at intervals on frame 56 and being caught in for locking hoodle 57 are held, changer lever 60 is completed to cut every time Move when making, locking hoodle 57 is constrained in the left lock slots 69 or right lock slots 70 of changer lever retainer 56, realizes switching The locking of bar 60 prevents changer lever 60 from moving due to vibrating, to influence printing precision.

Switching locating piece 29 is mounted on 14 back side of mounting plate, including switching wheel 67 and slot 68.Changer lever 60 is towards installation The one side of plate 14 is equipped with the ladder ramp 66 rolled for switching wheel 67, and switching wheel 67 is rolled from 66 bottom surface of ladder ramp to top surface During, mounting plate 14 rotates forward around active print head rotary shaft 10, and top surface herein refers to close to the face of mounting plate 14. Inserted block 54 is additionally provided on changer lever 60, when switching wheel 67 is located at 66 bottom surface of ladder ramp, inserted block 54 is just inserted in slot 68 In.

The specific work process of changeover module 13 is illustrated below:

Referring to Fig. 7 and Fig. 8, when extrusion system is fixed except extrusion system with direction A movement and by being mounted on When changer lever 60 is switched to position shown in Fig. 8 by left block 65, active print head assembly 12 is beaten around the rotation of bearing 11 to fixation The parallel position of head assembly 8 is printed, generates difference in height 64 between nozzle 48,63, active print head 12 is in running order.Switching In the process, switching wheel 67 is rolled from 66 top surface of ladder ramp to 66 bottom surface of ladder ramp, springs back adjusting screw 55 in rebound spring There is pulling force effect backward always to mounting plate 14 under 53 elastic force, makes the rotation of mounting plate 14 to positioning section 62, then changer lever In the slot 68 of 60 54 slide fit of inserted block insertion switching locating piece 29, the accurate positionin to active print head assembly 12 is completed, At the same time, the locking hoodle 57 on changer lever 60 moves in left lock slots 69, completes the locking to changer lever 60, ensure that The reliability of accuracy and work that active print head assembly 12 switches.

Referring to Fig. 9 to Figure 11, when extrusion system is fixed except extrusion system with direction B movement and by being mounted on When changer lever 60 is switched to position shown in Fig. 9 by right block 71, active print head assembly 12 is rotated around bearing 11 to the position Figure 10, Difference in height 72 is generated between nozzle 48,63, fixing printing head component 8 is in running order.Since fixing printing head component 8 is solid It is fixed motionless, so the nozzle 63 of fixing printing head component 8 can be positioned accurately.In handoff procedure, switching takes turns 67 from ladder slope 66 bottom surface of road is rolled to 66 top surface of ladder ramp, and spring back adjusting screw 55 has pulling force effect backward to mounting plate 14 always, and With the increase of rotational angle, pulling force is also increasing, when switching to 66 top surface of ladder ramp, what rebound spring 53 was subject to Compressing force is maximum, also maximum to the pulling force of mounting plate 14 backward, ensure that when fixing printing head component 8 works, active print Head assembly 12 is tightly pressed on changer lever 60, will not influence the printing of fixing printing head component 8, when on changer lever 60 When locking hoodle 57 is moved in right lock slots 70, the locking to changer lever 60 is also completed, ensure that active print head assembly The reliability of 12 switchings.

Changeover module 13 of the invention is in such a way that external block pushes changer lever 60 to translate, so that active print head group Part 12 generates rotation, so that the difference in height for realizing fixing printing head component 8 and active print head assembly 12 switches, meanwhile, it is living Dynamic print head assembly 12 is whole to be switched over, and ensure that the precision of two print head assemblies switching.

It is to be appreciated that term " on ", "lower" in the present embodiment, "front", "rear", "left", "right", "vertical", " water It is flat ", "inner", "outside", "top", the instructions such as "bottom" orientation or positional relationship be to be based on the orientation or positional relationship shown in the drawings, It is merely for convenience of description embodiments of the present invention and simplifies description, rather than the device or element of indication or suggestion meaning must There must be specific orientation, be constructed and operated in a specific orientation, therefore should not be understood as the limit to embodiments of the present invention System.

Simply to illustrate that technical concepts and features of the invention, its purpose is allows in the art above-described embodiment Those of ordinary skill cans understand the content of the present invention and implement it accordingly, and it is not intended to limit the scope of the present invention.It is all It is the equivalent changes or modifications that the essence of content according to the present invention is made, should be covered by the scope of protection of the present invention.

Claims (9)

1. a kind of three-dimensional printer screw extrusion system of changeable print head, it is characterised in that: including fixing printing head group Part (8) and in active print head assembly (12) orientable at least between print state and non-printing status；Work as active print When head assembly (12) is located in print state, active print head assembly (12) is lower than fixing printing head component (8)；Work as active print When head assembly (12) is located in non-printing status, active print head assembly (12) is higher than fixing printing head component (8)；The work Dynamic print head assembly (12) include motor (18), feeding spiro rod (35), pinch roller (23), pinch roller regulating device and liquefier (30), Axial parallel silk (34) direction of feed of feeding spiro rod (35), pinch roller (23) axially vertical silk (34) direction of feed, pinch roller (23) adjacent feeding spiro rod (35) setting, pinch roller regulating device adjust pinch roller (23) so that silk (34) is pressed on feeding spiro rod (35) on, motor (18) drives feeding spiro rod (35) rotation, and silk (34) is driven to enter liquefier (30).

2. the three-dimensional printer screw extrusion system of changeable print head according to claim 1, it is characterised in that: institute The pinch roller (23) stated is equipped with the V-type groove (24) for constraining, being oriented to silk, and the depth of the V-type groove (24) is greater than silk (34) radius, and it is less than the diameter of silk (34).

3. the three-dimensional printer screw extrusion system of changeable print head according to claim 1, it is characterised in that: institute The pinch roller regulating device stated includes pinch roller mounting rod (21), pinch roller pressure regulating screw (19), pinch roller pressure spring (20) and pinch roller peace It fills bar adjusting screw (22), pinch roller mounting rod (21) can be rotated around wherein one end, and pinch roller (23) is mounted on pinch roller mounting rod (21) Middle part, pinch roller pressure regulating screw (19), pinch roller pressure spring (20) and pinch roller mounting rod adjusting screw (22) setting are installed in pinch roller The other end of bar (21), pinch roller pressure regulating screw (19) and pinch roller pressure spring (20) are for adjusting pinch roller (23) to silk (34) Pressure, pinch roller mounting rod adjusting screw (22) are used to adjust the gap between pinch roller (23) and the feeding spiro rod (35).

4. the three-dimensional printer screw extrusion system of changeable print head according to claim 1, it is characterised in that: institute The liquefier (30) stated includes melting runner (51) and heating wire (49), melts the adjacent pinch roller of entrance of runner (51) (23), the outlet for melting runner (51) forms nozzle (48) to contract, and heating wire (49) is evenly arranged in melting runner (51) Outer wall.

5. the three-dimensional printer screw extrusion system of changeable print head according to claim 1, it is characterised in that: also It include the changeover module (13) that active print head assembly (12) are rotated at least between print state and non-printing status.

6. the three-dimensional printer screw extrusion system of changeable print head according to claim 5, it is characterised in that: institute The changeover module (13) stated is included in and the orientable changer lever of second point (60) at least first point, is mounted on active print head group Switching locating piece (29) on part (12) and the resilient mounting being connect with active print head assembly (12)；Changer lever (60) court Ladder ramp (66) are equipped with to the side of active print head assembly (12), switching locating piece (29) is equipped with along ladder ramp (66) The switching wheel (67) of rolling；When changer lever (60) is moved at first, switching wheel (67) is rolled to the bottom of ladder ramp (66) Face, active print head assembly (12) turn to print state under the pulling force of resilient mounting；When changer lever (60) is moved to second When point, switching wheel (67) is rolled to the top surface of ladder ramp (66), and active print head assembly (12) overcomes the pulling force of resilient mounting Turn to non-printing status.

7. the three-dimensional printer screw extrusion system of changeable print head according to claim 6, it is characterised in that: institute The switching locating piece (29) stated is equipped with slot (68), and changer lever (60) is equipped with the inserted block (54) to match with slot (68), When changer lever (60) is moved at first, inserted block (54) is just inserted into slot (68).

8. the three-dimensional printer screw extrusion system of changeable print head according to claim 6, it is characterised in that: institute The changeover module (13) stated further includes a fixed changer lever retainer (56), and changer lever (60) is slidedly assemblied in changer lever holding In frame (56), an elastic locking hoodle (57) is set on changer lever (60), on changer lever retainer (56) interval setting with The left lock slots (69) and right lock slots (70) that locking hoodle (57) matches, when changer lever (60) is moved at first, lock Determine hoodle (57) and is caught in left lock slots (69)；When changer lever (60) is moved to second point, locking hoodle (57) is caught in right locking Slot (70).

9. the three-dimensional printer screw extrusion system of changeable print head according to claim 6, it is characterised in that: institute The resilient mounting stated includes a fixed rebound bracket (61), rebound adjusting screw (55) and rebound spring (53), rebound adjustment Screw (55) passes through rebound bracket (61) and is spirally connected afterwards with active print head assembly (12), and rebound spring (53), which is covered, adjusts spiral shell in rebound It follows closely on (55), and is located between the head of screw of rebound adjusting screw (55) and rebound bracket (61).