CN110614767B

CN110614767B - Solid-liquid material combined type double-nozzle 3D printer and printing method thereof

Info

Publication number: CN110614767B
Application number: CN201910758604.5A
Authority: CN
Inventors: 侯有军
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2024-02-20
Anticipated expiration: 2039-08-16
Also published as: CN110614767A; WO2021031444A1

Abstract

The invention discloses a solid-liquid material combined double-nozzle 3D printer and a printing method thereof; the double-nozzle 3D printer comprises a frame, an XY surface movement module, a Z-axis movement module, a carrying plate, a solid material printing unit, a liquid material printing unit and a master control module, wherein the solid material printing unit comprises a solid printing head module and a wire feeding module, the upper end of a wire feeding throat pipe of the solid printing head module passes through a fixed plate of a cooling module to be communicated with a wire feeding channel in an XY surface movement sliding block, and the lower end of the wire feeding throat pipe extends into a circular through hole of a metal heating block and is communicated with a solid nozzle; the invention can print the article combining the solid material and the liquid material, or print the solid material or the liquid material article singly and the mixed article of the two-component liquid material; the invention can flexibly control the feeding mode and the printing speed of the liquid material, and is suitable for 3D printing of various materials including heat-sensitive or thermosetting liquid materials.

Description

Solid-liquid material combined type double-nozzle 3D printer and printing method thereof

Technical Field

The invention relates to 3D printing equipment and a printing method, in particular to a solid-liquid material combined double-nozzle 3D printer and a printing method thereof, and belongs to the technical field of 3D printing.

Background

3D printing is a rapid prototyping technique for building objects by printing solid powder, liquid material or polymer melt material layer by layer on the basis of digital model files. Currently available 3D printing techniques are numerous, including extrusion molding (fused deposition FDM and liquid direct writing LDW), photo-curing molding (laser scanning SLA, projection curing DLP or polymer jet type polymet), powder spreading molding (laser sintering SLS/SLM or inkjet bonding 3 DP), etc., wherein extrusion 3D printing is one of the earliest and most widely used.

In the traditional extrusion type 3D printing technology, a single spray head is mainly designed, and the technology is mature. With the development of 3D printing technology for multiple colors and multiple materials, more and more 3D printing devices begin to adopt dual-jet or multiple-jet designs. However, whether in a single-jet, dual-jet, or multiple-jet design, most existing extrusion 3D printers print only a single item of material, such as thermoplastic material items using FDM printers or liquid material items using LDW printers, and cannot print composite material items comprising thermoplastic solid materials and liquid materials, such as liquid silicone items comprising plastic support structures or biomaterial items comprising elastomeric skeletal structures, etc. Moreover, the majority of the prior art spray head positions and nozzle heights are fixed, and this conventional design presents problems: when the single nozzle moves rapidly in a non-printing interval, the nozzle of the single nozzle often scratches a printing model, and under the conditions of double nozzles or multiple nozzles, one nozzle can scratch the model when working because the heights of the nozzles are the same, so that the printing quality is affected. Although various approaches have been taken in the prior art to address the above problems, there are a number of drawbacks.

Chinese patent application CN106626388A discloses a dual-nozzle device of a 3D printer, chinese patent application CN108790145A discloses an electromagnetically controlled telescopic dual-nozzle FDM-3D printer nozzle assembly, and both mainly control the expansion and contraction of the dual nozzle by switching on and off of an electromagnet; chinese patent No. CN206781005U discloses a dual spray for a 3D printer with automatic height adjustment, chinese patent No. CN206926264U discloses a dual spray assembly for a 3D printer, chinese patent No. CN207549494U discloses an adjustable dual spray for 3D printing, chinese patent No. CN207682959U discloses a dual spray switching device for a 3D printer, and the four utility models drive the dual spray to move up and down mainly by the reciprocating rotation of a motor. The Chinese patent No. 207105636U discloses a pneumatic double nozzle for FFF printer, which mainly realizes the expansion and contraction of the double nozzle by adding an extra pneumatic unit on the double nozzle of FFF printer (namely FDM). The prior art adopts an additional electromagnetic unit, a motor unit or a pneumatic unit to realize automatic expansion and contraction of the double spray heads, so that the printing spray head assembly has a complex structure, large volume and large weight, the rapid movement of the printing head is influenced, and unnecessary energy consumption is generated; meanwhile, none of the above prior arts relates to 3D printing of liquid materials and telescoping control of printheads thereof.

Chinese patent application CN107053662a discloses a photo-curing silica gel 3D printing device and printing method thereof, chinese patent application CN109016070a discloses a double-nozzle extrusion type ceramic 3D printer and printing method thereof, chinese patent application CN109203174A discloses an extrusion type 3D printing double-nozzle device, and the three patent application technologies respectively realize double-nozzle printing of photo-curing silica gel material, ceramic slurry and concrete slurry; chinese utility model patent CN108391844a discloses a multifunctional 3D printer, chinese utility model patent CN208164300U discloses a dual-nozzle 3D printer with combined soft and hard materials, and the two prior arts respectively realize dual-nozzle printing of solid wire and liquid material; the Chinese patent No. 208020765U discloses a material supply system for biological 3D printing, which utilizes an electromagnetic pneumatic reversing valve to switch the working states of double spray heads of different biological materials, thereby avoiding the damage to the biological materials caused by a screw extrusion mode. Although the prior art relates to 3D printing of liquid materials and double-nozzle design, the nozzle height cannot be automatically adjusted, so that the printing quality is affected, and popularization of the 3D printing technology of the extrusion type liquid materials and the 3D printing technology of the combined double-nozzle of solid and liquid materials are restricted.

Although the prior art relates to more schemes of 3D printing, the prior art does not have a dual-nozzle 3D printing device and a printing method thereof, wherein solid materials and liquid materials can be printed at the same time, and the nozzles can automatically stretch and retract, which restricts the application of 3D printing, which needs to print the solid materials and the liquid materials at the same time and ensures the printing quality, to a certain extent.

Disclosure of Invention

In order to solve the problems in the prior art, the technical problem to be solved by the invention is to provide the solid-liquid material combined double-nozzle 3D printer and the printing method thereof, by means of automatic expansion and material breaking and back suction of the liquid printing head, the interference of the non-working nozzle on a printing model in the printing process is effectively avoided, the printing quality is improved, the printing device can print composite material articles simultaneously containing solid materials and liquid material model structures, can print solid materials or liquid material articles independently, can also perform mixed printing of double-component liquid materials, and has wide application range.

The invention aims at realizing the following technical scheme:

a solid-liquid material combined double-spray-head 3D printer comprises a frame, an XY plane movement module, a Z axis movement module, a carrier plate, a solid material printing unit, a liquid material printing unit and a master control module;

The frame is of a tetragonal frame structure; the XY plane movement module is horizontally arranged at the upper part of the frame; the Z-axis movement module is arranged at the rear part of the frame, and the carrying plate is arranged on a Z-axis lifting frame of the Z-axis movement module;

the first rod piece and the second rod piece of the XY-plane movement module are oppositely arranged at intervals along the Y-axis direction; the third rod piece and the fourth rod piece are oppositely arranged at intervals along the X-axis direction; the X-axis first synchronous belt and the X-axis second synchronous belt are oppositely arranged at intervals along the X-axis direction and are respectively positioned beside the third rod piece and the fourth rod piece; the Y-axis first synchronous belt and the Y-axis second synchronous belt are oppositely arranged at intervals along the Y-axis direction and are respectively positioned beside the second rod piece and the first rod piece; the X-axis motor synchronous belt is respectively connected with the X-axis motor and the first rod piece through two synchronous wheels, and the Y-axis motor synchronous belt is respectively connected with the Y-axis motor and the third rod piece through two synchronous wheels; two ends of the first rod piece are respectively connected with two ends of the second rod piece through an X-axis first synchronous belt and an X-axis second synchronous belt; two ends of the third rod piece are respectively connected with two ends of the fourth rod piece through a Y-axis first synchronous belt and a Y-axis second synchronous belt; the first X-axis sliding block and the second X-axis sliding block are respectively connected with the third rod piece and the fourth rod piece in a sliding way through linear bearings, and the first Y-axis sliding block and the second Y-axis sliding block are respectively connected with the second rod piece and the first rod piece in a sliding way through linear bearings; two ends of the fifth rod piece are fixedly connected with the X-axis first sliding block and the X-axis second sliding block respectively, and two ends of the sixth rod piece are fixedly connected with the Y-axis first sliding block and the Y-axis second sliding block respectively; the X-axis first sliding block and the X-axis second sliding block are respectively and fixedly connected with the X-axis first synchronous belt and the X-axis second synchronous belt; the Y-axis first sliding block and the Y-axis second sliding block are respectively fixedly connected with the Y-axis first synchronous belt and the Y-axis second synchronous belt; the XY surface moving slide block is provided with through holes in the X axis direction and the Y axis direction respectively, and linear bearings are arranged in the through holes and are respectively connected with the sixth rod piece and the fifth rod piece in a sliding manner through the linear bearings; the XY surface moving slide block is provided with a wire feeding channel in the Z axis direction;

The Z-axis movement module comprises a Z-axis motor, a screw rod and a Z-axis lifting frame; the screw rod is fixed at the rear part of the frame; the bottom of the screw rod is connected with a spindle of the Z-axis motor; the Z-axis lifting frame is connected with the screw rod through a screw rod nut;

the carrying plate comprises a hot bed plate with a heating element, a first temperature sensor and a panel; the hot bed board is fixedly connected with the Z-axis lifting frame; the first temperature sensor is fixed at the bottom of the hot bed plate; the panel is adhered and fixed on the hot bed board;

the solid material printing unit comprises a solid printing head module and a wire feeding module; the wire feeding gear and the driven roller of the wire feeding module are arranged at intervals, the intervals are wire feeding gaps, and the wire feeding gaps are smaller than the diameter of the solid wire; the wire feeding gap is positioned right above a wire feeding channel of the XY-plane moving slide block; the wire feeding gear is connected with a wire feeding motor; the wire feeding motor and the driven roller are fixed on a wire feeding bracket, and the wire feeding bracket is fixed on the upper end surface of the XY surface moving slide block; the solid printing head module comprises a solid printing head and a cooling module; the solid printing head consists of a heating module, a wire feeding throat pipe and a solid nozzle; the solid printing head module is arranged on the XY surface moving sliding block; the upper end of the wire feeding throat pipe passes through the fixed plate of the cooling module to be communicated with the wire feeding channel in the XY-surface moving slide block, and the lower end of the wire feeding throat pipe stretches into the circular through hole of the metal heating block and is communicated with the solid nozzle;

The liquid material printing unit comprises a liquid printing head module, a pressure charging barrel and an air source; the air inlet of the pressure charging barrel is communicated with an air source; the liquid printing head module is arranged on the XY surface moving sliding block;

the main control module is mainly formed by connecting a data input module, a data acquisition module, a display control module and an output control module with a central processing module respectively, wherein the data acquisition module is connected with the object carrying plate and the solid material printing unit respectively; the output control module is respectively connected with the XY plane movement module, the Z axis movement module, the object carrying plate, the solid material printing unit and the liquid material printing unit.

To further achieve the object of the present invention, preferably, the heating module includes a metal heating block, a heating rod and a second temperature sensor, wherein the heating rod is transversely embedded in the metal heating block; the circular through hole is arranged in the metal heating block along the Z-axis direction; the solid nozzle is communicated with the circular through hole of the metal heating block.

Preferably, the cooling module comprises a fixed plate with a unidirectional heat dissipation groove, an upper cooling fan, a lower cooling fan and a lower cooling air duct, wherein the upper cooling fan and the lower cooling fan are respectively arranged on the upper side and the lower side of one end of the fixed plate, and the lower cooling air duct is positioned at the bottom of the lower cooling fan and provided with a double air outlet; the other end of the fixed plate is positioned above the heating module and is fixed on the lower end surface of the XY-surface moving slide block; the air outlet of the upper cooling fan faces downwards and is communicated with the unidirectional heat dissipation groove of the fixed plate; the air outlet of the lower cooling fan faces downwards and is communicated with the air inlet of the lower cooling air duct; the lower cooling air duct is of a hollow cylindrical structure, the upper end of the lower cooling air duct is provided with an air inlet matched with the air outlet of the lower cooling fan, the lower end of the lower cooling air duct is provided with a first air outlet and a second air outlet, the first air outlet faces the solid nozzle, and the second air outlet faces the liquid nozzle.

Preferably, the liquid printing head module comprises a pneumatic electromagnetic valve and a liquid printing head; the pneumatic electromagnetic valve is provided with an air inlet, a normally closed air outlet and a normally open air outlet, the air inlet is communicated with an air source, and the normally closed air outlet and the normally open air outlet are respectively communicated with a first air inlet and a second air inlet of the liquid printing head;

the liquid printing head mainly comprises a cylinder part, a connecting component and a charging barrel part which are sequentially connected from top to bottom; the cylinder part comprises a cylinder body, a piston body, a valve rod, a first air inlet and a second air inlet; the cylinder body is cylindrical; a piston body in sealing sliding fit with the wall of the air chamber is arranged in the air chamber of the air cylinder body; the piston body is fixedly connected with the upper end of the valve rod, and the side walls of the air chambers above and below the piston body are respectively provided with a first air inlet and a second air inlet;

the connecting component mainly comprises a connecting bracket and a valve needle clamp; a valve needle clamp is arranged in the connecting support, the upper end of the valve needle clamp forms a distance with the lower surface of the upper end of the connecting support, and the bottom of the valve needle clamp forms a distance with the upper surface of the bottom of the connecting support; the bottom of the cylinder body is provided with a sealing sleeve which is in sealing sliding fit with the valve rod; the upper end of the sealing sleeve is connected with the bottom of the cylinder body, and the lower end of the sealing sleeve stretches into the connecting bracket and is connected with the connecting bracket;

The charging barrel part comprises a guide sleeve, a charging barrel valve, a liquid spray head and a sleeve locknut; the guide sleeve is fixedly connected with the connecting bracket; the guide sleeve is of a stepped hollow cylindrical structure, the hollow diameter of the upper end is smaller than that of the lower end, a first limit is formed at the stepped position, the cylinder valve is of a peripheral stepped cylindrical structure, the peripheral diameter of the upper end cylinder is small, the peripheral diameter of the lower end cylinder is large, and a second limit is formed at the peripheral stepped position; the cylinder valve is arranged in the guide sleeve, the diameter of the periphery of the cylinder at the lower end of the cylinder valve is the same as the diameter of the hollow at the lower end of the guide sleeve, and the diameter of the periphery of the cylinder at the upper end of the cylinder valve is the same as the diameter of the hollow at the upper end of the guide sleeve; the outer wall of the charging barrel valve is in sliding fit with the inner wall of the guide sleeve; the top end of the inner cavity of the guide sleeve is provided with a spring, the lower end of the guide sleeve is provided with an axial long and narrow opening and a circumferential external thread, and the lower end of the guide sleeve is connected with a sleeve locknut through the external thread; the lower end of the feed cylinder valve is provided with a feed chamber, the lower end of the feed chamber is provided with a feed outlet of the feed cylinder valve, and the lateral direction of the feed chamber is communicated with the feed inlet of the feed cylinder valve extending out of the outer cylinder at the lower end of the feed cylinder valve; the feed inlet of the feed cylinder valve is transversely arranged in the long and narrow opening; the width of the long and narrow opening is equal to the outer diameter of the feed inlet of the feed cylinder valve; the upper end of the material chamber of the material cylinder valve is provided with a top pinhole; the lower end of the valve needle is provided with a sealing valve head, and the valve needle passes through a discharge hole of the charging barrel valve, a material cavity, a top needle hole and a spring from bottom to top and is connected with a valve needle clamp; the sealing valve head is positioned in the discharge hole of the charging barrel valve; the diameter of the sealing valve head is equal to the diameter of the inner cavity of the discharge hole of the charging barrel valve and is larger than the diameter of the inner cavity at the lower end of the charging cavity; the valve needle is in sealing sliding interference fit with the top needle hole; the liquid spray head comprises a spray head feeding hole, a spray head material cavity and a liquid spray nozzle, wherein the spray head feeding hole is positioned at the upper end of the spray head material cavity, is mutually nested with the discharge hole of the feed cylinder valve and is in tight interference fit, the liquid spray nozzle is of a tubular flat structure, and the upper end of the liquid spray nozzle is communicated with the spray head material cavity; the sleeve locknut is of a cavity structure, the upper part of the cavity is cylindrical and is provided with internal threads which are in clearance-free close fit with external threads at the lower end of the guide sleeve, the lower part of the cavity is conical, and the bottom of the cavity is provided with an opening; the liquid nozzle is positioned in the cavity of the sleeve locknut, and the lower end of the liquid nozzle extends out of the bottom opening of the sleeve locknut.

Preferably, the connecting bracket is of an open frame structure and comprises an upper end face and a lower end face which are parallel to each other and a middle fixing plate connected with the upper end face and the lower end face; a valve needle clamp is arranged in the frame-shaped structure of the opening; the upper end of the valve needle clamp is provided with a threaded hole, and the lower end of the valve needle clamp is provided with an opening; the lower end of the valve rod passes through the upper end surfaces of the sealing sleeve and the connecting bracket and stretches into the threaded hole at the upper end of the valve needle clamp; the upper end of the valve needle extends into the lower end opening of the valve needle clamp;

the connecting assembly further comprises a first locking nut, a second locking nut, lateral locking screws, a damping ring and a damping piece; the sealing sleeve is connected with the connecting bracket in a way that a mounting round hole is formed in the upper end face of the connecting bracket, the lower end of the sealing sleeve penetrates through the mounting round hole, a first locking nut is arranged on the periphery of the sealing sleeve positioned at the lower part of the upper end face of the connecting bracket, and the sealing sleeve is fixed with the upper end face of the connecting bracket through the first locking nut; the lower end of the valve rod is provided with an external thread which is connected with the upper end of the valve needle clamp through threads; the periphery of a valve rod on the valve needle clamp is provided with a second locking nut, and the lower end of the valve rod is fixed with the upper end of the valve needle clamp through the second locking nut; the upper end of the valve needle is fixed in the lower end opening of the valve needle clamp through a lateral locking screw which is arranged on the side wall of the lower end of the valve needle clamp; -

A movable C-shaped or O-shaped damping ring which is easy to detach and replace is sleeved on a valve rod between the first locking nut and the second locking nut, and a damping piece is stuck on the lower end face of the valve needle clamp;

four round holes are formed in the middle fixing plate and fixedly connected with the front side face of the XY-face moving shaft sliding block through screws.

Preferably, the discharge hole of the feed cylinder valve is provided with embedded double threads, the outer side of the feed hole of the spray head of the liquid spray head is provided with a bayonet or a screw, and the discharge hole of the feed cylinder valve is tightly matched with the feed hole of the spray head through the embedded double threads to form firm connection;

the inner cavity of the discharge hole of the charging barrel valve and the sealing valve head are both cone-shaped with narrow upper part and wide lower part; the feed inlet of the feed cylinder valve is connected with the feed module through a hose; -

The mode of fixed connection of the guide sleeve and the connecting bracket is that the lower end face of the connecting bracket is provided with a connecting round hole, the top of the guide sleeve is positioned in the connecting round hole, one side of the lower end face of the connecting bracket is provided with a threaded hole, a lateral positioning screw is arranged in the threaded hole, and the lower end of the connecting bracket is fixed with the guide sleeve through the lateral positioning screw.

Preferably, the liquid material printing unit further comprises a feeding module, the feeding module and the wire feeding module are arranged on the upper end face of the XY-plane moving slide block side by side, and the feeding module comprises a feeding mechanism and at least one three-way valve suite; the feeding mechanism comprises a feeding motor, a peristaltic cavity shell, more than two peristaltic rollers and at least one peristaltic hose, wherein a peristaltic hose feeding port and a peristaltic hose discharging port are respectively arranged at two ends of the peristaltic hose, the feeding motor is in driving connection with the peristaltic rollers, and the peristaltic rollers are arranged on the peristaltic hose at intervals;

Each three-way valve sleeve mainly comprises a feeding three-way valve and a discharging three-way valve; the feeding three-way valve is provided with a three-way valve sleeve feeding port, a first discharging port and a second discharging port; the discharging three-way valve is provided with a three-way valve sleeve piece discharging port, a first feeding port and a second feeding port; the first discharge port and the first feed port are respectively communicated with the peristaltic rubber pipe feed port and the peristaltic rubber pipe discharge port, the second discharge port is communicated with the second feed port, the three-way valve sleeve feed port is communicated with the discharge port of the pressure feed cylinder, and the three-way valve sleeve feed port is communicated with the feed cylinder valve feed port.

The feeding module is provided with two feeding modes of mechanism feeding and direct feeding, and the two feeding modes can be switched by adjusting the valve direction of the three-way valve suite.

Preferably, the three-way valve sleeve is provided with two pressure feed cylinders, and the two pressure feed cylinders are respectively communicated with the two three-way valve sleeve members; the two peristaltic rubber tubes are arranged in the peristaltic cavity shell side by side and are respectively communicated with the two three-way valve sleeve pieces; the mixing pipe assembly comprises a static mixing pipe and a mixing pipe tee fitting, a discharge port of the static mixing pipe is communicated with a feed inlet of the feed cylinder valve, two feed inlets of the mixing pipe tee fitting are respectively communicated with two tee valve assemblies, and a feed inlet of the static mixing pipe is communicated with a discharge port of the mixing pipe tee fitting.

Preferably, the solid material printing unit further comprises a wire tray filled with solid wires, and the wire tray is connected with the solid printing head module through a wire feeding module; the wire tray and the pressure charging barrel are respectively fixed on the outer side of the frame;

the Z-axis motion module further comprises a Z-axis first guide rod and a Z-axis second guide rod; the Z-axis first guide rod and the Z-axis second guide rod are arranged at two sides of the screw rod at intervals along the Z-axis direction and are fixed at the rear part of the frame, and the Z-axis first guide rod and the Z-axis second guide rod are respectively connected with the Z-axis lifting frame through linear bearings;

the hot bed board is fixedly connected with the Z-axis lifting frame through leveling screws.

The printing method of the solid-liquid material combined double-nozzle 3D printer comprises the following steps:

1) Respectively designing a solid material three-dimensional digital model, a liquid material three-dimensional digital model and an assembly model of the solid material three-dimensional digital model and the liquid material three-dimensional digital model by using computer software, inputting three-dimensional coordinate deviations dX, dY and dZ of solid-liquid double nozzles and required digital model files into printing software for slicing treatment, and obtaining slice files with partition information of two model materials or slice files with structural information of a single model material;

2) Preheating a carrying plate and a solid printing head according to the need, loading solid wires, selecting a feeding mode of a feeding module, accessing a mixing pipe assembly, adding liquid materials into a pressure charging barrel, communicating all pipelines, adjusting the output pressure of an air source, leveling and correcting the carrying plate to a zero position, and guiding corresponding slice files into a master control module;

3) Printing a bottom layer, wherein the bottom layer is a printed front k layer, k > =0 and is a base part of the three-dimensional model; under the control of the master control module, the liquid printing head is in a stop position, the solid printing head returns to a zero position, then moves to a working area to print and discharge, and moves according to a planned path of the slice file until all bottom layers are printed;

4) Printing a solid layer, wherein the solid layer is positioned above the bottom surface layer, is a solid part of a three-dimensional model, has partition information of solid materials and liquid materials and is used for constructing composite structures with different materials; under the control of a master control module, a solid printing head prints a solid material structure of a k+1th layer according to a planned path, then a carrying plate descends dZ, a liquid printing head descends to a working position and prints and discharges, the liquid material structure of the layer is printed according to the planned path, after the printing of the k+1th layer is finished, the carrying plate descends by a slice thickness h, the liquid printing head continues to print the liquid material structure of the k+2th layer, then ascends to a stop position, and meanwhile the carrying plate ascends dZ, the solid printing head is switched to continue to print the solid material structure of the k+2th layer, and the printing process of the rest layers is repeated continuously until the whole solid layer is printed;

5) And stripping the printing model from the carrier plate, and drying or heating and solidifying the liquid material part of the model at normal temperature according to the requirement, removing the solid material supporting structure or carrying out surface treatment on the model to finally obtain the model printing part.

Compared with the prior art, the invention has the advantages that:

1) According to the invention, a design scheme of solid-liquid material combined double-nozzle 3D printing is adopted, so that a composite structure article containing solid materials and liquid materials can be printed at the same time, and an article made of a single material can be printed, thereby realizing multiple purposes of one machine; when the composite structure article is printed, the solid material part can be used as a detachable supporting structure of the liquid material part, so that 3D printing of the liquid material article with a complex bottom surface shape is realized, and also can be used as a framework structure inside the liquid material part, so that 3D printing of the multi-material article is realized.

2) The XY surface movement module adopted by the invention does not need to move an X-axis motor and a Y-axis motor when in XY surface movement, reduces the movement resistance of the XY surface movement sliding block and the solid-liquid material double spray heads in all directions of the XY surface, reduces or avoids the vibration of the double spray heads when the double spray heads move at high speed to work, and effectively improves the printing speed and the printing quality.

3) The liquid material printing spray head adopted by the invention can automatically stretch and retract without external force when the liquid material printing spray head is started and stopped, the function can not only avoid the damage of the spray head to the model when the liquid material structure is independently printed and rapidly moved in a non-printing area, but also avoid the interference between the double spray heads when the composite structure article combined by the solid material and the liquid material is printed, and the printing quality is effectively improved.

4) The invention adds the mode-adjustable feeding module (namely short-range feeding) near the liquid material printing nozzle, and when the feeding mechanism mode is selected, the feeding mechanism has the functions of pressurizing and controlling speed, thereby not only improving the printing speed and stability, but also reducing the output pressure of an air source and improving the safety; when the ultrahigh-viscosity liquid material or the biological liquid material sensitive to high-shear pressure is used, a feeding pipe mode can be directly selected, so that the damage of ultrahigh-pressure and high-shear to peristaltic hoses and biological materials is avoided; in addition, compared with long-distance feeding, the short-distance feeding design scheme adopted by the invention can greatly reduce the pressure drop of the long-distance feeding pipe and remarkably improve the printing speed of the liquid material printing nozzle.

5) According to the invention, the material mixing pipe assembly is additionally arranged in the material feeding module, and the number of the pressure material barrels, the peristaltic rubber pipes and the three-way valves is correspondingly increased, so that 3D printing of the two-component liquid material and 3D printing of a mixed structure object combined with the solid material can be conveniently realized, and the application range of the invention is greatly widened.

6) The cooling module adopted by the invention can cool the upper module and the lower module of the solid material printing spray head simultaneously, and can cool the liquid material printing spray head simultaneously, thereby avoiding the serious consequences that the heat-sensitive liquid material in the nozzle is influenced by a heat field and can be thermally solidified or thermally degenerated and block the nozzle, and effectively improving the printing stability and the printing quality.

Drawings

Fig. 1 is a schematic structural diagram of a solid-liquid material combined dual-nozzle 3D printer provided in embodiment 1;

fig. 2 is a schematic diagram of the structure of an XY-plane movement module provided in embodiment 1;

FIG. 3 is a schematic view of the structure of the Z-axis motion module provided in embodiment 1;

FIG. 4 is a schematic diagram of a solid-liquid material combined dual spray module according to embodiment 1;

FIG. 5A is a front view of the liquid printhead provided in example 1;

FIG. 5B is a left side view of the liquid printhead provided in example 1;

FIG. 6 is a schematic view of the cartridge valve of FIG. 5;

FIG. 7A is a schematic view of the liquid printhead of example 1 in a stopped position with the discharge port closed;

FIG. 7B is a schematic view of the liquid printhead of example 1 in the working position with the discharge port closed;

FIG. 7C is a schematic view of the liquid printhead of example 1 in the working position with the discharge port open;

FIG. 8A is a schematic view of the feeding module according to embodiment 1;

FIG. 8B is a schematic diagram of the feeding module according to embodiment 2;

FIG. 9 is a block diagram showing the composition and control flow of the master control module provided in embodiment 1;

FIG. 10A is a schematic diagram of a solid-liquid material combined dual spray module according to example 1 when printing solid materials;

fig. 10B is a schematic diagram of the solid-liquid material combined type dual spray module provided in embodiment 1 when printing a liquid material.

Detailed Description

The invention is further described below with reference to the drawings and examples; it should be noted that the detailed description is merely for explaining the present invention and is not intended to limit the scope of the present invention.

The structures, proportions, sizes, positions, etc. shown in the drawings are used for matching with the disclosure of the specification, and are not intended to limit the applicable conditions of the invention, so that the invention has no technical significance, and any structural modification, change of proportion, size or position adjustment should fall within the scope of the disclosure of the invention without affecting the efficacy and achievement of the object of the invention. In addition, the terms such as "upper" and "lower" are also used in the present specification for convenience of description, but are not limited to the scope of the present invention, and the changes or modifications of the relative relationship are also considered as the scope of the present invention without any substantial change of technical content.

Example 1

As shown in fig. 1-4, a solid-liquid material combined double-nozzle 3D printer comprises a frame 1, an XY plane movement module 2, a Z axis movement module 3, a carrier plate 4, a solid material printing unit 5, a liquid material printing unit 6 and a master control module 7; the frame 1 is a tetragonal frame structure; the XY plane movement module 2 is horizontally arranged at the upper part of the frame 1; the Z-axis movement module 3 is arranged at the rear part of the frame 1, and the carrying plate 4 is arranged on a Z-axis lifting frame 35 of the Z-axis movement module 3; the solid material printing unit 5 comprises a solid printing head module 51, a wire feeding module 53 and a wire tray 52 filled with solid wires, and the wire tray 52 is connected with the solid printing head module 51 through the wire feeding module 53; the liquid material printing unit 6 includes a liquid printhead module 61, a pressure cylinder 62 containing liquid material, and a gas source 63, the gas inlet of the pressure cylinder 62 being in communication with the gas source 63; the solid print head module 51 and the liquid print head module 61 are mounted on the XY-surface moving slider 23. Preferably, the filament tray 52 and the pressure cylinder 62 are fixed to the outside of the frame 1, respectively.

As shown in fig. 2, the XY-surface movement module 2 includes an X-axis movement module 21, a Y-axis movement module 22, and an XY-surface movement slider 23; the X-axis motion module 21 includes an X-axis motor 211, an X-axis motor timing belt 212, a first lever 213, a second lever 214, an X-axis first timing belt 215, an X-axis second timing belt 216, an X-axis first slider 217, an X-axis second slider 218, a third lever 219, a fourth lever 220, a fifth lever 227, and a sixth lever 228;

The Y-axis motion module 22 includes a Y-axis motor 221, a Y-axis motor timing belt 222, a third bar 219, a fourth bar 220, a Y-axis first timing belt 223, a Y-axis second timing belt 224, a Y-axis first slider 225, a Y-axis second slider 226, a first bar 213, a second bar 214, a fifth bar 227, and a sixth bar 228; -

The first lever 213 and the second lever 214 are disposed at an opposite interval in the Y-axis direction; the third rod 219 and the fourth rod 220 are disposed at opposite intervals in the X-axis direction; the X-axis first synchronous belt 215 and the X-axis second synchronous belt 216 are oppositely arranged at intervals along the X-axis direction and are respectively positioned beside the third rod piece 219 and the fourth rod piece 220; the Y-axis first synchronous belt 223 and the Y-axis second synchronous belt 224 are oppositely arranged at intervals along the Y-axis direction and are respectively positioned beside the second rod piece 213 and the first rod piece 214; the X-axis motor timing belt 212 is connected with the X-axis motor 211 and the first rod 213 via two timing wheels, and the Y-axis motor timing belt 222 is connected with the Y-axis motor 221 and the third rod 219 via two timing wheels, respectively; the two ends of the first rod piece 213 are respectively connected with the two ends of the second rod piece 214 through an X-axis first synchronous belt 215 and an X-axis second synchronous belt 216, so that the power transmission of the X-axis motor 211 is realized; two ends of the third rod piece 219 are respectively connected with two ends of the fourth rod piece 220 through a Y-axis first synchronous belt 223 and a Y-axis second synchronous belt 224, so that power transmission of the Y-axis motor 221 is realized; the X-axis first slider 217 and the X-axis second slider 218 are respectively slidably connected to the third rod 219 and the fourth rod 220 through linear bearings, and the Y-axis first slider 225 and the Y-axis second slider 226 are respectively slidably connected to the second rod 214 and the first rod 213 through linear bearings; two ends of a fifth rod piece 227 are fixedly connected with the X-axis first sliding block 217 and the X-axis second sliding block 218 respectively, and two ends of a sixth rod piece 228 are fixedly connected with the Y-axis first sliding block 225 and the Y-axis second sliding block 226 respectively; the first X-axis sliding block 217 and the second X-axis sliding block 218 are respectively and fixedly connected with the first X-axis synchronous belt 215 and the second X-axis synchronous belt 216, and drive the fifth rod 227 to do linear motion in the X-axis direction; the first Y-axis sliding block 225 and the second Y-axis sliding block 226 are respectively and fixedly connected with the first Y-axis synchronous belt 223 and the second Y-axis synchronous belt 224, and drive the sixth rod 228 to do linear motion in the Y-axis direction; the XY surface moving slide block 23 is arranged at the cross part of the fifth rod member 227 and the sixth rod member 228, the XY surface moving slide block 23 is respectively provided with a through hole in the X axis direction and the Y axis direction, a linear bearing is arranged in the through hole, and the XY surface moving slide block is respectively in sliding connection with the sixth rod member 227 and the fifth rod member 228 through the linear bearing; the XY-surface moving slide 23 is provided with a wire feed passage 231 in the Z-axis direction; under the control of the master control module 7, the X-axis motor 211 and the Y-axis motor 221 respectively drive the fifth rod 227 and the sixth rod 228 to synchronously move in the X-axis direction and the Y-axis direction, so as to push the XY-plane moving slide block 23 to perform two-dimensional movement in the XY plane.

Preferably, the X-axis motor 211, the Y-axis motor 221, the first rod 213, the second rod 214, the third rod 219, and the fourth rod 220 are fixed to the upper portion of the frame 1, respectively.

As shown in fig. 3, the Z-axis movement module 3 includes a Z-axis motor 31, a screw 32, and a Z-axis lifter 35; the screw rod 32 is fixed at the rear part of the frame 1; the bottom of the screw rod 32 is fixedly connected with a main shaft of the Z-axis motor 31 through a coupler; the Z-axis lifting frame 35 is connected with the screw rod 32 through a screw nut; preferably, the Z-axis motion module 3 further comprises a Z-axis first guide bar 33 and a Z-axis second guide bar 34; the Z-axis first guide rod 33 and the Z-axis second guide rod 34 are arranged at two sides of the screw rod 32 at intervals along the Z-axis direction and are fixed at the rear part of the frame 1, and the Z-axis first guide rod 33 and the Z-axis second guide rod 34 are respectively connected with a Z-axis lifting frame 35 through linear bearings; under the control of the master control module 7, the Z-axis motor 31 drives the screw rod 32 to rotate, so that the Z-axis lifting frame 35 is pushed to perform linear motion in the Z-axis direction.

The carrier plate 4 comprises a hot bed plate 41 containing heating elements, a first temperature sensor 42 and a panel 43; the hot bed plate 41 is fixedly connected with the Z-axis lifting frame 35 through leveling screws; the first temperature sensor 42 is fixed at the bottom of the hot bed plate 41; the panel 43 is attached and fixed to the upper surface of the hot bed plate 41 and is easy to detach.

As shown in fig. 4, the wire feeding module 53 mainly comprises a wire feeding motor 56, a wire feeding gear 57, a driven roller 58 and a wire feeding bracket 59, wherein the wire feeding gear 57 is connected with the wire feeding motor 56 through a wire feeding motor spindle; the wire feeding gear 57 and the driven roller 58 are arranged at intervals, the intervals are wire feeding gaps, and the wire feeding gaps are smaller than the diameter of the solid wire; the wire feeding motor 56 and the driven roller 58 are fixed on a wire feeding bracket 59; the wire feeding module 53 drives the wire feeding gear 57 to press the solid wire by using the wire feeding motor 56 and insert or withdraw the solid wire into or from the wire feeding path 231. Preferably, the wire feeding bracket 59 is fixed to the upper end surface of the XY-surface moving slider 23, and the wire feeding gap is located directly above the wire feeding passage 231 of the XY-surface moving slider 23.

As shown in fig. 4, the solid printhead module 51 includes a solid printhead 54 and a cooling module 55; the solid printhead 54 is composed of a heating module 510, a wire feed throat 511, and a solid nozzle 512; wherein the heating module 510 includes a metal heating block 513, a heating rod 514 transversely embedded in the metal heating block 513, and a second temperature sensor 515; a circular through hole in the Z-axis direction is formed in the metal heating block 513; the solid nozzle 512 communicates with a circular through hole of the metal heating block 513; the wire feeding throat 511 is of a hollow tubular structure, the upper end of the wire feeding throat passes through the fixed plate 516 of the cooling module 55 to be communicated with the wire feeding channel 231 in the XY plane movement sliding block 23, and the lower end of the wire feeding throat extends into the circular through hole of the metal heating block 513 and is communicated with the solid nozzle 512; the solid wire is driven by the wire feeding module 53 to sequentially enter the wire feeding channel 231, the wire feeding throat 511 and the heating module 510, heated and melted, extruded and printed and molded by the bottom opening of the nozzle 512 under wire feeding pressure. Preferably, the upper end of the solid nozzle 512 is a hollow cylinder and is provided with external threads, the solid nozzle is fixedly connected with a circular through hole in the metal heating block 513 through threads, the lower end of the solid nozzle is a hollow cone, the cone angle ranges from 15 degrees to 75 degrees, and the bottom of the solid nozzle is provided with an opening.

As shown in fig. 4, the cooling module 55 includes a fixing plate 516 with a unidirectional heat dissipation groove, an upper cooling fan 517 and a lower cooling fan 518 respectively installed at upper and lower sides of one end of the fixing plate, and a lower cooling air duct 519 with a double air outlet at the bottom of the lower cooling fan 518; the other end of the fixing plate 516 is positioned above the heating module 510 and is fixed on the lower end surface of the XY-surface moving slide 23; the air outlet of the upper cooling fan 517 is downward and communicated with the unidirectional heat dissipation groove of the fixed plate 516, so that the upper end of the wire feeding throat 511 and the bottom of the XY-surface moving slide block 23 can be cooled; the air outlet of the lower cooling fan 518 faces downwards and is communicated with the air inlet of the lower cooling air channel 519; the lower cooling air channel 519 is of a hollow cylindrical structure, the upper end of the lower cooling air channel 519 is provided with an air inlet which is matched with the air outlet of the lower cooling fan 518, the lower end of the lower cooling air channel is provided with a first air outlet and a second air outlet, the first air outlet faces the solid nozzle 512, and the second air outlet faces the liquid nozzle 643; the lower cooling fan 518 cools the mold under the solid nozzle 512 and the liquid nozzle 643, respectively, using the double outlets of the lower cooling tunnel 519. Preferably, the first air outlet transversely protrudes out of the outer circumference of the cylinder of the lower cooling air duct and is arranged in a downward inclined manner; the second air outlet transversely protrudes out of the outer circumference of the cylinder of the lower cooling air duct.

As shown in fig. 4, the liquid printhead module 61 includes a pneumatic solenoid valve 64 and a liquid printhead 65; the pneumatic solenoid valve 64 is provided with an air inlet 67, a normally closed air outlet 68 and a normally open air outlet 69, the air inlet 67 being in communication with the air source 63, the normally closed air outlet 68 and the normally open air outlet 69 being in communication with the first air inlet 610 and the second air inlet 611 of the liquid print head 65, respectively. Preferably, the pneumatic solenoid valve 64 and the liquid print head 65 are mounted side by side on the side of the XY-surface moving slider 23.

As shown in fig. 5A, 5B, 6 and 7A, the liquid print head 65 is mainly composed of a cylinder portion 612, a connection assembly 613 and a cartridge portion 614 which are connected in order from top to bottom.

Cylinder portion 612 includes a cylinder block, a piston body 615, a valve stem 616, a first intake port 617, and a second intake port 618; the cylinder body is cylindrical; a piston body 615 which is in sealing sliding fit with the wall of the air chamber is arranged in the air chamber of the air cylinder body; piston body 615 is fixedly coupled to the upper end of valve stem 616, and the sidewalls of the air chamber above and below piston body 615 are provided with a first air inlet 617 and a second air inlet 618, respectively.

The connection assembly 613 basically includes a connection bracket 619 and a needle clamp 620; a valve needle clamp 620 is arranged in the connecting support 619, the upper end of the valve needle clamp 620 and the lower surface of the upper end of the connecting support 619 form a distance, and the bottom of the valve needle clamp 620 and the upper surface of the bottom of the connecting support 619 form a distance; the bottom of the cylinder body is provided with a sealing sleeve which is in sealing sliding fit with the valve rod 616; the upper end of the sealing sleeve is connected with the bottom of the cylinder body, and the lower end of the sealing sleeve stretches into the connecting bracket 619 and is connected with the connecting bracket 619.

Preferably, the connecting bracket 619 is an open frame structure, and includes upper and lower end surfaces parallel to each other and an intermediate fixing plate connected to the upper and lower end surfaces; a valve needle clamp 620 is arranged in the frame structure of the opening; the valve needle clamp 620 is provided with a threaded hole at the upper end for threaded connection with the valve rod 616, and an opening at the lower end; the lower end of the valve rod 616 passes through the upper end surfaces of the sealing sleeve and the connecting bracket 619 and extends into a threaded hole at the upper end of the valve needle clamp 620; the upper end of needle 621 extends into the lower end opening of needle clamp 620.

Preferably, the connection assembly 613 further includes a first lock nut 622, a second lock nut 623, a lateral lock screw 624, a shock ring 625, and a shock absorbing tab 626; the sealing sleeve is connected with the connecting bracket 619 in a manner that a mounting round hole is formed in the upper end face of the connecting bracket 619, the lower end of the sealing sleeve penetrates through the mounting round hole, a first locking nut 622 is arranged on the periphery of the sealing sleeve positioned at the lower part of the upper end face of the connecting bracket 619, and the sealing sleeve is fixed with the upper end face of the connecting bracket 619 through the first locking nut 622; the lower end of the valve rod 616 is provided with external threads which are in threaded connection with the upper end of the valve needle clamp 620; a second locking nut 623 is arranged on the periphery of the valve rod 616 above the valve needle clamp 620, and the lower end of the valve rod 616 is fixed with the upper end of the valve needle clamp 620 through the second locking nut 623; the upper end of the needle 621 is secured within the lower end opening of the needle clamp 620 by a lateral locking screw 624, the lateral locking screw 624 being disposed on a sidewall of the lower end of the needle clamp 620.

Preferably, a movable and easily-detachable C-shaped or O-shaped damping ring 625 is sleeved on the valve rod 616 between the first locking nut 622 and the second locking nut 623, and the stroke upper limit (i.e. stop position) of the valve needle clamp 620 can be adjusted by replacing the damping ring 625 with different heights; the shock absorbing sheet 626 is adhered to the lower end surface of the needle clamp 620, and when the needle clamp 620 moves up to the stop position, the distance between the shock absorbing sheet 626 and the upper end surface of the bottom of the connecting bracket 619 is the stroke H0 of the valve rod 616 and the needle 621.

Preferably, the middle fixing plate is provided with four round holes 627 which can be fixedly connected with the front side surface of the XY-surface moving shaft sliding block 23 through screws.

The cartridge portion 614 includes a guide sleeve 628, a cartridge valve 629, a liquid ejection head 630, and a sleeve locknut 631; wherein the guide sleeve 628 is fixedly connected with the connecting bracket 619; the guide sleeve 628 is a stepped hollow cylinder structure, the upper hollow diameter is smaller than the lower hollow diameter, and a first limit 632 is formed at the step; as shown in fig. 6, the cylinder valve 629 has a cylindrical structure with a stepped outer periphery, the diameter of the outer periphery of the upper cylinder is small, the diameter of the outer periphery of the lower cylinder is large, and a second limit 633 is formed at the stepped outer periphery; a cylinder valve 629 is arranged in the guide sleeve 628, the diameter of the periphery of the cylinder at the lower end of the cylinder valve 629 is the same as the diameter of the hollow at the lower end of the guide sleeve 628, and the diameter of the periphery of the cylinder at the upper end of the cylinder valve 629 is the same as the diameter of the hollow at the upper end of the guide sleeve 628; the outer wall of the cartridge valve 629 is a sliding fit with the inner wall of the guide sleeve 628. The first stop 632 is used to limit upward movement of the second stop 633 of the cartridge valve 629; the top end of the inner cavity of the guide sleeve 628 is provided with a spring 634, the lower end of the guide sleeve 628 is provided with an axial long and narrow opening 635 and a circumferential external thread, and the lower end of the guide sleeve 628 is connected with a sleeve locknut 631 through the external thread; the lower end of the feed cylinder valve 629 is provided with a feed chamber 636, the lower end of the feed chamber 636 is provided with a feed cylinder valve discharge hole 637, and the feed chamber 636 is laterally communicated with a feed cylinder valve feed hole 638 extending out of the lower end of the feed cylinder valve 629; a cartridge valve feed 638 is disposed transversely in the elongated opening 635; the width of the slit 635 is equal to the outer diameter of the cartridge valve feed port 638, allowing the cartridge valve feed port 638 to enter from the bottom and restricting rotation of the cartridge valve 629; the upper end of the feed chamber 636 of the cartridge valve 629 is provided with a top pinhole 639; the lower end of valve needle 621 is provided with a sealing valve head 640, valve needle 621 passing through cartridge valve discharge port 637, cartridge chamber 636, top needle hole 639 and spring 634 from below to above, connected to valve needle clamp 620; the sealing valve head 640 is positioned in the charging barrel valve discharging hole 637; the diameter of the sealing valve head 640 is equal to the diameter of the inner cavity of the discharge hole 637 of the cartridge valve and is larger than the diameter of the inner cavity at the lower end of the material chamber 636; the valve needle 621 is in a sealing sliding interference fit with the top needle bore 639.

The liquid nozzle 630 includes a nozzle feed inlet 641, a nozzle feed chamber 642 and a liquid nozzle 643, wherein the nozzle feed inlet 641 is positioned at the upper end of the nozzle feed chamber 642, is nested with the discharge port 637 of the cartridge valve, and has a tight interference fit, the liquid nozzle 643 is preferably in a tubular flat structure (the flat structure of the liquid nozzle 643 is opposite to the inclined structure), and the upper end is communicated with the nozzle feed chamber 642; the sleeve locknut 631 has a cavity structure, the upper part of the cavity is cylindrical and is provided with internal threads which are in clearance-free close fit with external threads at the lower end of the guide sleeve 628, the lower part of the cavity is conical, and the bottom of the cavity is provided with an opening; the liquid spray head 630 is positioned in the cavity of the sleeve locknut 631, and the lower end of the liquid spray nozzle 643 protrudes out of the bottom opening of the sleeve locknut 631.

Preferably, the cylinder valve discharge hole 637 is provided with an embedded double thread 664, a bayonet or screw is provided on the outer side of the nozzle feed hole 641 of the liquid nozzle 630, and the cylinder valve discharge hole 637 and the nozzle feed hole 641 are tightly matched through the embedded double thread 664 to form a firm connection.

Preferably, the inner cavity of the charging barrel valve discharging hole 637 and the sealing valve head 640 are in cone shapes with narrow upper part and wide lower part, when the valve needle 621 moves upwards, the sealing valve head 640 forms sealing fit with the inner cavity of the charging barrel valve discharging hole 637, the charging barrel valve discharging hole 637 is closed, and when the valve needle 621 moves downwards, the charging barrel valve discharging hole 637 is opened; the sealing valve head 640, when open the cartridge valve discharge port 637, is located within the head material chamber 642 of the liquid head 630, but does not contact the side walls and bottom of the head material chamber 642. The cartridge valve feed port 638 is located within the elongated opening 635 of the guide sleeve 628 and is in sliding engagement with the elongated opening 635; the cartridge valve feed port 638 is connected to the feed module 66 via a hose.

Preferably, the guide sleeve 628 is fixedly connected with the connecting bracket 619 in such a way that a connecting round hole is formed in the lower end face of the connecting bracket 619, the top of the guide sleeve 628 is located in the connecting round hole, a threaded hole is formed in one side of the lower end face of the connecting bracket, a lateral positioning screw 644 is arranged in the threaded hole, and the lower end of the connecting bracket is fixed with the guide sleeve 628 through the lateral positioning screw 644.

In order for the printhead to function properly, the first air inlet 617 and the second air inlet 618 of the cylinder portion 612 are connected to the normally closed air outlet 68 and the normally open air outlet 69 of the pneumatic solenoid valve 64, respectively, through quick-change fittings and air pipes, and the pressure of the air source 63 ranges from 0.1 to 1MPa; simultaneously, the cartridge valve 629 in the closed state is pushed into the guide sleeve 628 to be abutted against two limit positions (a first limit position 632 and a second limit position 633), and the valve needle 621 passes through the spring 634 to be fixedly connected with the valve needle clamp 620 in the stop position; the sleeve locknut 631 is threadably secured in place with the lower end of the guide sleeve 628. When the second air inlet 618 is in air and the first air inlet 617 is out air, the piston body 615 drives the valve rod 616 and the valve needle 621 to move up to the stop position, and vice versa, to move down to the working position.

Fig. 7A, 7B, and 7C are schematic diagrams of the operation of the liquid print head 65. The distance H1 between the top end of the sleeve locknut 631 and the bottom of the feed port 638 of the cartridge valve can be adjusted by rotating the sleeve locknut 631; when H1 is greater than zero and less than the stroke H0 of valve needle 621, cartridge valve 629 and liquid spray head 630 will move downward H1 with downward movement of valve needle 621 by top spring 634 until cartridge valve feed port 638 abuts sleeve locknut 631, where the distance of movement H1 is the stroke H1 of liquid spray head 630 (see fig. 7A and 7B); when the needle 621 continues to descend, the sealing valve head 640 opens the cartridge valve discharge port 637, and the liquid ejection head 630 enters an operating state (see fig. 7C); when the valve needle 621 is up, the sealing valve head 640 closes the cartridge valve discharge port 637, the liquid jet 630 is sucked back and moves up H1 together with the cartridge valve 629 until the second stopper 633 collides with the first stopper 632, and the liquid jet 630 stops working.

Therefore, when the liquid printing head 65 works, the liquid spraying head 630 can be quickly stretched and cut along with the change of the working state, the drawing and dripping of the liquid spraying head are avoided, the model is not scratched, the printing quality is remarkably improved, an additional motor, an electromagnet or other power devices are not required, the size is small, the weight is light, the structure is simple, and the maintenance is convenient.

Preferably, the liquid material printing unit 6 further includes a feeding module 66, as shown in fig. 4 and 8A, the feeding module 66 is mounted on the upper end surface of the XY-surface moving slide 23 side by side with the wire feeding module 53, and the feeding module 66 includes a feeding mechanism 645 and a three-way valve assembly 646; wherein, the feeding mechanism 645 comprises a feeding motor 647, a peristaltic cavity shell 648, more than two peristaltic rollers 649 and a peristaltic hose 650, wherein a peristaltic hose feed inlet 651 and a peristaltic hose discharge outlet 652 are respectively arranged at two ends of the peristaltic hose 650, the feeding motor 647 is in driving connection with the peristaltic rollers 649, and the peristaltic rollers 649 are arranged on the peristaltic hose 650 at intervals; the feeding motor 647 drives a plurality of peristaltic rollers 649 to alternately extrude and release peristaltic hoses 650 in the peristaltic cavity shell 648, so that bidirectional controllable feeding of liquid materials is realized; the three-way valve set 646 consists essentially of a feed three-way valve 653 and a discharge three-way valve 654; the feed three-way valve 653 is provided with a three-way valve sleeve feed port 659, a first discharge port 655 and a second discharge port 657; the discharge three-way valve 654 is provided with a three-way valve sleeve discharge port 660, a first feed port 656 and a second feed port 658; the first outlet 655 and the first inlet 656 are respectively in communication with the peristaltic hose inlet 651 and the peristaltic hose outlet 652, the second outlet 657 is in communication with the second inlet 658, the three-way valve sleeve inlet 659 is in communication with the outlet of the pressure cylinder 62, and the three-way valve sleeve outlet 660 is in communication with the cylinder valve inlet 638. The feed module 66 is provided with two feed modes, a mechanical feed and a direct feed, and can be switched between the two feed modes by adjusting the valve direction of the three-way valve assembly 646.

Preferably, the master control module 7 is fixed at the bottom of the frame 1, as shown in fig. 9, the master control module 7 mainly comprises a data input module 71, a data acquisition module 72, a display control module 73, and an output control module 74 respectively connected with a central processing module 75; the data acquisition module 72 is respectively connected with the first temperature sensor 42 and the second temperature sensor 515; the output control module 74 is respectively connected with the X-axis motor 211, the Y-axis motor 221, the Z-axis motor 31, the wire feeding motor 56, the feeding motor 647, the pneumatic solenoid valve 64, the hot bed plate 41, the heating rod 514, the upper cooling fan 517 and the lower cooling fan 518; the data input module 71 may adopt hardware such as a USB interface, an SD card slot, a WIFI module, a bluetooth module, and an ethernet interface, and is configured to receive model slice data and a control command that are input from the outside, and send the model slice data and the control command to the central processing module 75 for processing; the data acquisition module 72 mainly includes temperature acquisition circuits such as an R-V conversion circuit, a signal amplification circuit, an ADC circuit, etc., and is configured to receive temperature data acquired by the first temperature sensor 42 and the second temperature sensor 515, and send the temperature data to the central processing module 75 for processing; the display control module 73 may adopt an output module such as a liquid crystal screen and an OLDE screen, an input module such as a button and an encoder knob, and a multifunctional module such as a touch screen and a tablet computer with integrated input and output functions, and is used for displaying state information such as temperature and receiving an externally input control command; the output control module 74 mainly includes a motor driving module, an electromagnetic valve control module, a heating device control module, and a fan control module, and is configured to change a control command sent by the central processing module 75 into an executable parameter and send the executable parameter to the X-axis motor 211, the Y-axis motor 221, the Z-axis motor 31, the wire feeding motor 56, the feeding motor 647, the pneumatic electromagnetic valve 64, the hot bed board 41, the heating rod 514, the upper cooling fan 517, and the lower cooling fan 518, respectively; the central processing module 75 mainly includes a main controller based on a single chip Microcomputer (MCU), and is configured to store, analyze and process data and control commands from the data input module 71, the data acquisition module 72 and the display control module 73, output the control commands to the output control module 74, and display printer status information such as temperature and the like on the display control module 73. In general, the master control module 7 is configured to receive slice file data with partition information, and is in communication connection with related components in the X-axis motion module 21, the Y-axis motion module 22, the Z-axis motion module 3, the carrier board 4, the solid printhead module 51, the wire feeding module 53, the liquid printhead module 61, and the feeding module 66, and control each part to work cooperatively according to the partition information of the slice file.

The solid material used in this example was polylactic acid plastic wire (PLA), and the liquid material was thermosetting one-component Liquid Silicone Rubber (LSR). A printing method of a double-nozzle 3D printer using a solid-liquid material combination comprises the following steps:

1) Respectively designing a three-dimensional digital model of a PLA part, a three-dimensional digital model of an LSR part and an assembly model of the two parts by using computer software, inputting three-dimensional coordinate deviations dX, dY and dZ of solid-liquid double nozzles and the assembly model file into printing software for slicing treatment, and obtaining a slicing file with partition information of two model materials;

2) The power supply is switched on, the carrying plate 4 and the solid printing head 54 are preheated, PLA wires are filled, the feeding module 66 is switched into a direct feeding mode, LSR is added into the pressure charging barrel 62, all pipelines are communicated, the output pressure of the air source 63 is regulated to be 0.8MPa, the carrying plate 4 is leveled and the zero position of each shaft is corrected, and corresponding slice files are led into the master control module 7;

3) Printing a bottom layer, wherein the bottom layer is a printed front k layer (k > =0) and is a base part of the three-dimensional model, and can be conveniently stripped from the object carrying plate 4 and the entity layer; under the control of the master control module 7, the upper cooling fan 517 and the lower cooling fan 518 start to work, the liquid printing head 65 is in a stop position, the solid printing head 54 returns to a zero position first, then moves to a working area to print PLA bottom layers, and moves according to a planned path of a slice file until all the bottom layers are printed;

4) Printing a solid layer, wherein the solid layer is positioned above the bottom surface layer, is a solid part of a three-dimensional model, has partition information of solid materials and liquid materials and is used for constructing composite structures of different materials; as shown in fig. 10A and 10B, under the control of the master control module 7, the solid printing head 54 prints the k+1th PLA structure according to the planned path, then the carrying board 4 descends dZ, the liquid printing head 65 descends to the working position, printing and discharging are started under the feeding pressure of the air source 63, the LSR structure of the k+1th layer is printed according to the planned path, after the printing of the k+1th layer is finished, the carrying board 4 descends by a slice thickness h, the liquid printing head 65 continues to print the LSR structure of the k+2th layer, then the carrying board returns to the stop position, and meanwhile, the carrying board 4 ascends dZ, and is switched to the solid printing head 54 to continue printing the k+2th PLA structure; the printing process of the other layers is repeated continuously until the whole entity layer is printed;

5) And (3) detaching the panel 43 from the carrier plate 4, putting the uncured model and the panel 43 together into an oven for post-heating, curing and shaping, and then stripping the cured model and manually removing the PLA support structure to obtain the liquid silica gel printing piece.

Preferably, in the printing process, in order to remove residues at the spray heads and improve printing quality, the printing heads just switched to the working positions are moved to the non-printing area to print a layer of erasing towers before formal printing.

The embodiment can replace at least one of different solid materials and liquid materials at any time according to printing requirements, wherein the solid materials comprise at least one of thermoplastic materials such as ABS, PLA, PA, PS, PMMA, PC, PET, PP, PVA, wood plastic materials and the like, and the liquid materials comprise at least one of reactive high molecular prepolymer (liquid silicone rubber/polyurethane/epoxy resin/polyacrylate/unsaturated polyester/photosensitive prepolymer), liquid high molecular material (polymer solution/emulsion/suspension), liquid biological material (agar/glucose/gelatin/chitosan/collagen/sodium alginate/hydroxyapatite/soybean protein/biological cell solution, emulsion or dispersion), liquid food material (flour/chocolate/vegetable/meat/egg-based solution, emulsion or dispersion) and liquid building material (cement/ceramic/gypsum solution, emulsion or dispersion).

According to the embodiment, according to the characteristics of the liquid material and the printing requirements, the liquid spray heads 630 with different specifications, such as long-tube thin spray heads, are used for printing unsupported three-dimensional models in gel liquid, cone-shaped thick spray heads are used for printing high-viscosity liquid silica gel, and black opaque spray heads are used for printing photosensitive resin and the like.

Example 2

Unlike example 1, this example uses a thermosetting two-component epoxy resin (DEP) as the liquid material, and does not use a solid material. Therefore, on the basis of example 1, this example is modified as follows:

As shown in fig. 8B, in a solid-liquid material combined dual-nozzle 3D printer, two pressure cylinders 62, two peristaltic hoses 650, two three-way valve assemblies 646, and a material mixing pipe assembly 661 are added in the feeding module 66, and the other components are the same as those in embodiment 1;

the pressure feed cylinder 62A and the pressure feed cylinder 62B are respectively provided with two components A and B of DEP and are respectively communicated with two three-way valve sleeve feed inlets 659; two rubber tubes 650 are placed side by side in peristaltic chamber housing 648 and are respectively in communication with two three-way valve assemblies 646; the peristaltic hoses 650 are the same in material, the same in wall thickness, and the same in inside diameter or adjusted accordingly according to the mixing ratio of the two components a and B. The mixing tube assembly 661 comprises a static mixing tube 662 and a mixing tube tee fitting 663, wherein the discharge port of the static mixing tube 662 is communicated with the feed port 638 of the feed cylinder valve, the two feed ports of the mixing tube tee fitting 663 are respectively communicated with the discharge ports 660 of the two tee valve sleeve members, and the feed port of the static mixing tube 662 is communicated with the discharge port of the mixing tube tee fitting 663.

A printing method of a solid-liquid material combined type double-nozzle 3D printer is used for printing a thermosetting double-component epoxy resin (DEP) model and comprises the following printing steps:

Firstly, designing a three-dimensional digital model of a DEP printing piece by using computer software, inputting three-dimensional coordinate deviations dX, dY, dZ of a solid-liquid double-nozzle and a DEP model file into the printing software for slicing processing, and obtaining a slice file with DEP structure information;

step two, switching on a power supply, switching the feeding module 66 into a mechanism feeding mode, respectively adding two components A and B into the two pressure feed cylinders 62, communicating the two components A and B with each pipeline, regulating the output pressure of the air source 63 to be 0.6MPa, leveling the carrying plate 4, correcting zero positions of each shaft, and guiding the corresponding slice files into the master control module 7;

printing an entity layer, wherein the entity layer is an entity part of the three-dimensional model and has DEP structure information; under the control of the master control module 7, the upper cooling fan 517 and the lower cooling fan 518 start to work, the carrier plate 4 firstly descends dZ from the zero position, and the liquid printing head 65 at the stop position moves to the working area and descends to the working position; the two components A and B are uniformly mixed in proportion by a static mixing pipe 662 under the driving pressure of a feeding mechanism, then are printed and discharged, the DEP structure of the 1 st layer is printed according to a planned path, after the 1 st layer is printed, the carrier plate 4 descends by one slice thickness h, and the liquid printing head 65 continuously prints the DEP structure of the 2 nd layer; the printing process of the other layers is repeated continuously until the whole entity layer is printed; in the printing process of each layer, when the liquid printing head 65 moves rapidly in the non-printing area, the feeding mechanism 645 pauses working, the pneumatic electromagnetic valve 64 controls the liquid printing head 65 to suck back in a material breaking way and move upwards to a stop position, and the damage of the liquid nozzle 630 to the current layer of the model is effectively avoided;

And step four, detaching the panel 43 from the carrying plate 4, putting the uncured model and the panel 43 together into an oven for post-heating, curing and shaping, and then stripping the cured model and simply modifying the surface of the model to obtain the epoxy resin printing part.

In summary, the invention effectively overcomes the defects in the prior art, can print multi-material composite articles containing solid materials and liquid materials, such as medical bones and muscles, and can print solid materials or liquid material articles independently, such as industrial handhelds, building models or personalized foods, and the used solid materials and liquid materials have various choices, and are widely used in the technical field of 3D printing in the directions of education, medical treatment, food, building, industrial design and the like.

It should be noted that the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be considered as equivalent alternatives, which are included in the scope of the present invention.

Claims

1. A solid-liquid material combined double-nozzle 3D printer is characterized in that: the device comprises a frame, an XY plane movement module, a Z-axis movement module, a carrying plate, a solid material printing unit, a liquid material printing unit and a master control module;

the liquid printing head module comprises a pneumatic electromagnetic valve and a liquid printing head; the pneumatic electromagnetic valve is provided with an air inlet, a normally closed air outlet and a normally open air outlet, the air inlet is communicated with an air source, and the normally closed air outlet and the normally open air outlet are respectively communicated with a first air inlet and a second air inlet of the liquid printing head;

The charging barrel part comprises a guide sleeve, a charging barrel valve, a liquid spray head and a sleeve locknut; the guide sleeve is fixedly connected with the connecting bracket; the guide sleeve is of a stepped hollow cylindrical structure, the hollow diameter of the upper end is smaller than that of the lower end, a first limit is formed at the stepped position, the cylinder valve is of a peripheral stepped cylindrical structure, the peripheral diameter of the upper end cylinder is small, the peripheral diameter of the lower end cylinder is large, and a second limit is formed at the peripheral stepped position; the cylinder valve is arranged in the guide sleeve, the diameter of the periphery of the cylinder at the lower end of the cylinder valve is the same as the diameter of the hollow at the lower end of the guide sleeve, and the diameter of the periphery of the cylinder at the upper end of the cylinder valve is the same as the diameter of the hollow at the upper end of the guide sleeve; the outer wall of the charging barrel valve is in sliding fit with the inner wall of the guide sleeve; the top end of the inner cavity of the guide sleeve is provided with a spring, the lower end of the guide sleeve is provided with an axial long and narrow opening and a circumferential external thread, and the lower end of the guide sleeve is connected with a sleeve locknut through the external thread; the lower end of the feed cylinder valve is provided with a feed chamber, the lower end of the feed chamber is provided with a feed outlet of the feed cylinder valve, and the lateral direction of the feed chamber is communicated with the feed inlet of the feed cylinder valve extending out of the outer cylinder at the lower end of the feed cylinder valve; the feed inlet of the feed cylinder valve is transversely arranged in the long and narrow opening; the width of the long and narrow opening is equal to the outer diameter of the feed inlet of the feed cylinder valve; the upper end of the material chamber of the material cylinder valve is provided with a top pinhole; the lower end of the valve needle is provided with a sealing valve head, and the valve needle passes through a discharge hole of the charging barrel valve, a material cavity, a top needle hole and a spring from bottom to top and is connected with a valve needle clamp; the sealing valve head is positioned in the discharge hole of the charging barrel valve; the diameter of the sealing valve head is equal to the diameter of the inner cavity of the discharge hole of the charging barrel valve and is larger than the diameter of the inner cavity at the lower end of the charging cavity; the valve needle is in sealing sliding interference fit with the top needle hole; the liquid spray head comprises a spray head feeding hole, a spray head material cavity and a liquid spray nozzle, wherein the spray head feeding hole is positioned at the upper end of the spray head material cavity, is mutually nested with the discharge hole of the feed cylinder valve and is in tight interference fit, the liquid spray nozzle is of a tubular flat structure, and the upper end of the liquid spray nozzle is communicated with the spray head material cavity; the sleeve locknut is of a cavity structure, the upper part of the cavity is cylindrical and is provided with internal threads which are in clearance-free close fit with external threads at the lower end of the guide sleeve, the lower part of the cavity is conical, and the bottom of the cavity is provided with an opening; the liquid spray nozzle is positioned in the cavity of the sleeve locknut, and the lower end of the liquid spray nozzle extends out of the bottom opening of the sleeve locknut;

The main control module is mainly formed by connecting a data input module, a data acquisition module, a display control module and an output control module with a central processing module respectively, wherein the data acquisition module is connected with the object carrying plate and the solid material printing unit respectively; the output control module is respectively connected with the XY plane movement module, the Z axis movement module, the object carrying plate, the solid material printing unit and the liquid material printing unit;

the heating module comprises a metal heating block, a heating rod and a second temperature sensor, and the heating rod is transversely embedded into the metal heating block; the circular through hole is arranged in the metal heating block along the Z-axis direction; the solid nozzle is communicated with the circular through hole of the metal heating block.

2. The solid-liquid material combined dual spray 3D printer of claim 1, wherein: the cooling module comprises a fixed plate with a unidirectional heat dissipation groove, an upper cooling fan and a lower cooling fan which are respectively arranged on the upper side and the lower side of one end of the fixed plate, and a lower cooling air duct with double air outlets which is positioned at the bottom of the lower cooling fan; the other end of the fixed plate is positioned above the heating module and is fixed on the lower end surface of the XY-surface moving slide block; the air outlet of the upper cooling fan faces downwards and is communicated with the unidirectional heat dissipation groove of the fixed plate; the air outlet of the lower cooling fan faces downwards and is communicated with the air inlet of the lower cooling air duct; the lower cooling air duct is of a hollow cylindrical structure, the upper end of the lower cooling air duct is provided with an air inlet matched with the air outlet of the lower cooling fan, the lower end of the lower cooling air duct is provided with a first air outlet and a second air outlet, the first air outlet faces the solid nozzle, and the second air outlet faces the liquid nozzle.

3. The solid-liquid material combined dual spray 3D printer of claim 1, wherein: the connecting bracket is of an open frame structure and comprises an upper end face and a lower end face which are parallel to each other and a middle fixing plate connected with the upper end face and the lower end face; a valve needle clamp is arranged in the frame-shaped structure of the opening; the upper end of the valve needle clamp is provided with a threaded hole, and the lower end of the valve needle clamp is provided with an opening; the lower end of the valve rod passes through the upper end surfaces of the sealing sleeve and the connecting bracket and stretches into the threaded hole at the upper end of the valve needle clamp; the upper end of the valve needle extends into the lower end opening of the valve needle clamp;

the connecting assembly further comprises a first locking nut, a second locking nut, lateral locking screws, a damping ring and a damping piece; the sealing sleeve is connected with the connecting bracket in a way that a mounting round hole is formed in the upper end face of the connecting bracket, the lower end of the sealing sleeve penetrates through the mounting round hole, a first locking nut is arranged on the periphery of the sealing sleeve positioned at the lower part of the upper end face of the connecting bracket, and the sealing sleeve is fixed with the upper end face of the connecting bracket through the first locking nut; the lower end of the valve rod is provided with an external thread which is connected with the upper end of the valve needle clamp through threads; the periphery of a valve rod on the valve needle clamp is provided with a second locking nut, and the lower end of the valve rod is fixed with the upper end of the valve needle clamp through the second locking nut; the upper end of the valve needle is fixed in the lower end opening of the valve needle clamp through a lateral locking screw which is arranged on the side wall of the lower end of the valve needle clamp;

4. The solid-liquid material combined dual spray 3D printer of claim 1, wherein: the discharge port of the feed cylinder valve is provided with embedded double threads, the outer side of the feed port of the spray head of the liquid spray head is provided with a bayonet or a screw, and the discharge port of the feed cylinder valve is tightly matched with the feed port of the spray head through the embedded double threads to form firm connection;

the inner cavity of the discharge hole of the charging barrel valve and the sealing valve head are both cone-shaped with narrow upper part and wide lower part; the feed inlet of the feed cylinder valve is connected with the feed module through a hose;

5. The solid-liquid material combined dual spray 3D printer of claim 4, wherein: the liquid material printing unit also comprises a feeding module, wherein the feeding module and the wire feeding module are arranged on the upper end surface of the XY-surface moving slide block side by side, and the feeding module comprises a feeding mechanism and at least one three-way valve suite; the feeding mechanism comprises a feeding motor, a peristaltic cavity shell, more than two peristaltic rollers and at least one peristaltic hose, wherein a peristaltic hose feeding port and a peristaltic hose discharging port are respectively arranged at two ends of the peristaltic hose, the feeding motor is in driving connection with the peristaltic rollers, and the peristaltic rollers are arranged on the peristaltic hose at intervals;

6. The solid-liquid material combined dual spray 3D printer of claim 5, wherein: the two three-way valve assemblies are provided, the number of the pressure charging cylinders is two, and the two pressure charging cylinders are respectively communicated with the two three-way valve sleeve members; the two peristaltic rubber tubes are arranged in the peristaltic cavity shell side by side and are respectively communicated with the two three-way valve sleeve pieces; the mixing pipe assembly comprises a static mixing pipe and a mixing pipe tee fitting, a discharge port of the static mixing pipe is communicated with a feed inlet of the feed cylinder valve, two feed inlets of the mixing pipe tee fitting are respectively communicated with two tee valve assemblies, and a feed inlet of the static mixing pipe is communicated with a discharge port of the mixing pipe tee fitting.

7. The solid-liquid material combined dual spray 3D printer of claim 1, wherein: the solid material printing unit also comprises a wire tray filled with solid wires, and the wire tray is connected with the solid printing head module through a wire feeding module; the wire tray and the pressure charging barrel are respectively fixed on the outer side of the frame;

8. A printing method using the solid-liquid material combined type double-nozzle 3D printer according to any one of claims 1 to 7, characterized by comprising the steps of: