CN222959219U - Printing nozzle and printer - Google Patents

Abstract

The utility model belongs to the technical field of printers, and discloses a printing nozzle and a printer. The printing nozzle includes a frame, a heat sink, a nozzle assembly, a heating element and an air source assembly. The frame is provided with a feed hole, a clamping hole and a heat dissipation cavity which are connected in sequence; the heat sink is arranged in the heat dissipation cavity and clamped with the clamping hole, the heat sink is provided with a first channel, and a plurality of heat sinks are arranged at intervals on the outer wall of the heat sink along the length direction. The heat sink and the wire are cooled by the air source assembly and the heat sink. The cross-sectional area of the heat sink on the side away from the feed hole is larger than the cross-sectional area of the heat sink on the side close to the feed hole, so that the wire at one end of the heat sink close to the heating element can be quickly cooled down, and the heat accumulation can be reduced while facilitating the stable extrusion of the wire. Among the adjacent multiple heat sinks, each heat sink is provided with at least one air guide groove. Combining one of the air guide grooves on each heat sink can form an annular air guide channel, which further reduces the heat accumulation at the inlet end of the printing nozzle.

Description

Printing nozzle and printer

Technical Field

The utility model relates to the technical field of printers, in particular to a printing nozzle and a printer.

Background

3D printing is a rapid prototyping technology, based on digital model files, using bondable materials such as powdered metal or plastic, to build objects by means of layer-by-layer printing.

3D printing typically employs a 3D printer to perform a printing operation, and an existing 3D printer includes a wire feeding assembly and a printing nozzle, in which a wire is fed through the wire feeding assembly into the printing nozzle, and a melted wire is extruded through the printing nozzle. For processing of some composite materials, the printing spray head is required to be capable of printing at a high temperature of more than 300 ℃, and the heat accumulation at the inlet end of the printing spray head is easy to occur in the high-temperature printing process of the existing printing spray head, so that the wire at the inlet end is locally softened, the propelling force of the wire feeding assembly on the wire is insufficient, the melted wire cannot be stably extruded, and the requirement of stable printing cannot be met.

Disclosure of utility model

The utility model aims to provide a printing nozzle and a printer, which reduce heat accumulation at the inlet end of the printing nozzle, and the wire feeding assembly can stably extrude wires and can meet the requirement of stable printing.

To achieve the purpose, the utility model adopts the following technical scheme:

In one aspect, there is provided a print head comprising:

The rack is provided with a feeding hole, a clamping hole and a heat dissipation cavity which are sequentially communicated, and the side wall of the heat dissipation cavity is provided with an air outlet hole;

The heat radiation body is arranged in the heat radiation cavity and is clamped with the clamping hole, the heat radiation body is provided with a first channel, an inlet of the first channel is communicated with the feeding hole, a plurality of heat radiation fins are arranged on the outer wall of the heat radiation body at intervals along the length direction, the cross section area of the heat radiation fin far away from the feeding hole is larger than the cross section area of the heat radiation fin near the feeding hole, and each heat radiation fin is provided with at least one air guide groove in the adjacent plurality of heat radiation fins, so that one air guide groove on each heat radiation fin can be combined to form an annular air guide channel;

A nozzle assembly having an inlet in communication with the outlet of the first passageway, the outlet of the nozzle assembly capable of extruding a wire;

the heating piece is arranged on the spray head assembly and used for heating the wire;

the air source assembly is arranged on the frame, and an air outlet of the air source assembly is communicated with the heat dissipation cavity.

In some possible embodiments, the plurality of cooling fins are divided into two groups, the cooling fins close to one side of the feeding hole are divided into one group, the cooling fins far away from one side of the feeding hole are divided into another group, in the group of cooling fins far away from one side of the feeding hole, the plurality of cooling fins are distributed on the cooling body at equal intervals, the cross section area of each cooling fin is the same, and the projections of the plurality of air guide grooves forming the annular air guide channel on the cross section of the cooling body are distributed at equal intervals in the circumferential direction.

In some possible embodiments, in the projection, the interval angle between the central lines of two adjacent wind guide grooves is 45 degrees, 60 degrees or 90 degrees.

In some possible embodiments, the print head further comprises a temperature sensor for detecting the temperature of the head assembly and a temperature closed-loop control assembly in communication with the temperature sensor and in communication with the air supply assembly.

In some possible embodiments, the rack includes a rack body, a first connecting piece and a housing, the rack body is provided with the feed port and the clamping hole, the rack body, the first connecting piece and the housing enclose to form the heat dissipation cavity, the first connecting piece is detachably connected with the rack body, and the housing is detachably connected with the first connecting piece.

In some possible embodiments, the printing nozzle further includes an annular fixing member and a locking assembly, the heating member is sleeved outside the nozzle assembly, the annular fixing member is sleeved outside the heating member, and the locking assembly abuts the annular fixing member outside the heating member.

In some possible embodiments, the air source assembly includes an air guide assembly, an air outlet of which communicates with the heat dissipation cavity, and a fan disposed at an air inlet of the air guide assembly.

In some possible embodiments, the spray head assembly comprises a throat and a nozzle, the heat radiator is provided with a mounting hole, the throat penetrates through the rack and is fixed in the mounting hole, the throat is provided with a second channel, an inlet of the second channel is communicated with an outlet of the first channel, the nozzle is fixed at the outer end of the throat and is communicated with an outlet of the second channel, and the heating piece is arranged on the nozzle.

In some possible embodiments, the printing nozzle further includes a second connecting piece, the frame, the radiator, the nozzle assembly and the heating piece are all provided with at least one group, the air source assembly is provided with one group, the heat dissipation cavity of each group of the frame is all communicated with the air outlet of the air source assembly, and at least one frame is all fixed on the second connecting piece.

On the other hand, the printer comprises a machine base, a nozzle mounting seat, a wire feeding mechanism and the printing nozzle according to any one of the schemes, wherein the nozzle mounting seat is fixed on the machine base, the machine frame is arranged on the nozzle mounting seat, and the wire feeding mechanism is fixed on the machine base and used for moving wires to enter from a feeding hole of the machine base and extrude from an outlet of a nozzle assembly.

The utility model has the beneficial effects that:

The utility model provides a printing spray head which comprises a frame, a heat radiation body, a spray head component, a heating piece and a gas source component. Because the radiator of keeping away from feed port one side is nearer to the heating member, the temperature of the wire of this part is higher, and is great to the softening effect of wire, will keep away from the cross-sectional area of the fin of feed port one side and be greater than the cross-sectional area of the fin of being close to feed port one side, can realize the quick cooling to the wire that the radiator is close to heating member one end, when reducing the heat accumulation, can guarantee that the wire that is located the heat dissipation is solid, when sending the wire subassembly to remove the wire, the wire in the heat dissipation can act as the plunger and stably extrude the wire of the interior molten state of shower nozzle subassembly. Among the adjacent multiple radiating fins, each radiating fin is provided with at least one air guide groove, one of the air guide grooves on each radiating fin can be combined to form an annular air guide channel, gas can flow along the annular air guide channel to form high-speed rotary air flow, the heat exchange speed between the gas and the outer wall of the radiating body and between the gas and the radiating fin is increased, and the heat accumulation of the inlet end of the printing nozzle is further reduced.

Drawings

FIG. 1 is a schematic view of a first view angle structure of a print head according to the present utility model;

FIG. 2 is a schematic view of a second view angle structure of a print head according to the present utility model;

FIG. 3 is a schematic view of a part of the structure of a print head according to the present utility model;

FIG. 4 is a cross-sectional view of a print head provided by the present utility model;

Fig. 5 is a schematic diagram of the structure of the radiator and the heat sink according to the present utility model.

In the figure:

1. The device comprises a rack, a feeding hole, a clamping hole, a heat dissipation cavity, a 14, an air outlet hole, a 15, a rack body, a 16, a first connecting piece, a 161, a first connecting hole, a 162, an air inlet hole, a 17 and a shell, wherein the rack is provided with a first connecting piece;

2. the heat sink comprises a heat radiation body, a first channel, a mounting hole and a second channel;

3. 31, an air guide groove;

4. 41 parts of spray head component, 411 parts of throat pipe, 42 parts of second channel and nozzle;

5. a heating member;

6. An air source assembly; 61, fans, 62, air ducts, 63, an air guide cover, 64, a connecting plate, 641 and a third connecting hole;

7. the device comprises a temperature sensor, an annular fixing piece, 81, a locking hole and 9, a second connecting piece.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present utility model are shown in the drawings.

In the description of the present utility model, unless explicitly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may, for example, be fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

As shown in fig. 1 to 5, the utility model provides a printing nozzle, which improves the cooling efficiency in the printing process, can realize stable extrusion of high-temperature and high-performance composite materials such as polyphenylene sulfide (PPS) and polyether ether ketone (PEEK) under the high-temperature printing condition of more than 300 ℃, and expands the application range and the field of a 3D printing process. In addition, the printing nozzle has simple structure and light weight. The printing spray head comprises a frame 1, a heat radiation body 2, a spray head assembly 4, a heating piece 5 and an air source assembly 6, wherein the frame 1 is provided with a feed hole 11, a clamping hole 12 and a heat radiation cavity 13 which are sequentially communicated, the side wall of the heat radiation cavity 13 is provided with an air outlet hole 14, the heat radiation body 2 is arranged in the heat radiation cavity 13 and is clamped with the clamping hole 12, the heat radiation body 2 is provided with a first channel 21, the inlet of the first channel 21 is communicated with the feed hole 11, the outer wall of the heat radiation body 2 is provided with a plurality of cooling fins 3 at intervals along the length direction, the cross section area of the cooling fin 3 at one side far from the feed hole 11 is larger than the cross section area of the cooling fin 3 at one side close to the feed hole 11, at least one air guide groove 31 is arranged in each cooling fin 3 adjacent to the plurality of cooling fins 3, one air guide groove 31 on each cooling fin 3 can be combined to form an annular air guide channel, the inlet of the spray head assembly 4 is communicated with the outlet of the first channel 21, the outlet of the spray head assembly 4 can extrude wire, the heating piece 5 is arranged on the spray head assembly 4 and is used for heating wire, the air source assembly 6 is arranged on the frame 1, and the air outlet of the air source assembly 6 is communicated with the heat radiation cavity 13. During operation, wires sequentially pass through the feed hole 11 and the first channel 21 and enter the spray head assembly 4, the wires in the spray head assembly 4 are heated through the heating piece 5, then the melted wires are extruded from the outlet of the spray head assembly 4, and in the process, the heat dissipation is carried out on the heat dissipation body 2 and the wires through the combined action of the air source assembly 6 and the heat dissipation fins 3.

Because the radiator 2 far away from one side of the feed hole 11 is closer to the heating element 5, the temperature of the wire of the part is higher, the wire is easy to soften, the radiator 2 near one side of the feed hole 11 is farther from the heating element 5, the temperature of the wire of the part is relatively lower, the wire is difficult to soften, the cross-sectional area of the radiating fin 3 far away from one side of the feed hole 11 is larger than that of the radiating fin 3 near one side of the feed hole 11, the quick cooling of the wire near one end of the radiator 2 near the heating element 5 can be realized, the wire in the radiator 2 can be ensured to be solid while heat accumulation is reduced, the wire in the radiator 2 can serve as a plunger to stably extrude the wire in a molten state in the nozzle assembly 4 when the wire feeding assembly moves, and the requirement of stable printing can be met. In addition, in the adjacent plurality of cooling fins 3, each cooling fin 3 is provided with at least one air guide groove 31, one of the air guide grooves 31 on each cooling fin 3 can form an annular air guide channel in a combined mode, gas flowing into the cooling cavity 13 from the air outlet of the air source assembly 6 can flow along the annular air guide channel to form high-speed rotating air flow, the heat exchange speed between the gas and the outer wall of the cooling body 2 and between the gas and the cooling fin 3 is increased, and heat accumulation at the inlet end of the printing nozzle is further reduced. After that, the high-speed rotating air flow is discharged from the air outlet holes 14 on the side wall of the heat dissipation cavity 13, so that the stability of the air pressure in the heat dissipation cavity 13 is ensured.

Alternatively, in the present embodiment, the plurality of cooling fins 3 are divided into two groups, the cooling fins 3 on the side close to the feed hole 11 are grouped into one group, the cooling fins 3 on the side far from the feed hole 11 are grouped into another group, the plurality of cooling fins 3 are distributed on the heat radiation body 2 at equal intervals in the group of cooling fins 3 on the side far from the feed hole 11, the cross sectional area of each cooling fin 3 is the same, and the projections of the plurality of air guide grooves 31 forming the annular air guide channel on the cross section of the heat radiation body 2 are distributed at equal intervals in the circumferential direction. So set up, conveniently process fin 3 and wind-guiding groove 31, and annular wind-guiding passageway is the heliciform wind-guiding passageway of equidistant pitch, makes the heat dissipation comparatively even. In this embodiment, the heat dissipation body 2 has a cylindrical structure, and a plurality of heat dissipation fins 3 are distributed on the heat dissipation body 2 at equal intervals in a group of heat dissipation fins 3 near one side of the feed hole 11.

Optionally, in projection, the interval angle of the center lines of two adjacent air guide grooves 31 is 45 degrees, 60 degrees or 90 degrees, so that the processing is convenient. The smaller the spacing angle, the better the guiding effect on the air flow, and the lower the air outlet power requirement on the air source assembly 6. The setting position of the air guide groove 31 needs to be matched with the number of the radiating fins 3, so that the air flow can bypass the radiating body 2 for a circle, and the radiating tube can uniformly radiate heat for a circle. If the spacing angle is 90 degrees, the radiating fins 3 are arranged at least four, if the spacing angle is 60 degrees, the radiating fins 3 are arranged at least six, and if the spacing angle is 45 degrees, the radiating fins 3 are arranged at least eight.

Optionally, the printing nozzle further includes a temperature sensor 7 and a temperature closed-loop control component, the temperature sensor 7 is used for detecting the temperature of the nozzle component 4, and the temperature closed-loop control component is in communication connection with the temperature sensor 7 and in communication connection with the air source component 6. Alternatively, the temperature sensor 7 is adhered to the heating member 5, specifically, the temperature sensor 7 is adhered to the heating member 5 by a high-temperature adhesive, so that the fixation is more secure. During operation, the temperature sensor 7 collects real-time temperature of the spray head assembly 4 and feeds temperature data back to the temperature closed-loop control assembly, the temperature closed-loop control assembly adjusts power of the air source assembly 6 through the temperature data, if the temperature is lower than an expected value, power and rotating speed of the air source assembly 6 are regulated down, heat dissipation capacity is reduced, if the temperature is higher than the expected value, power of the air source assembly 6 is regulated up, heat dissipation capacity is increased, accuracy and stability of temperature of the spray head assembly 4 are further guaranteed, and closed-loop control of the temperature of the spray head assembly 4 is achieved.

The closed-loop temperature control assembly may also control the power of the heater 5 to preheat or heat the showerhead assembly 4 during printing. The preheating is a process of preheating the nozzle assembly 4 before the formally starting of the printing task, so that the problems of blockage of the nozzle assembly 4, insufficient dissolution of wires and the like caused by temperature fluctuation in the printing process are prevented, and the preheating is switched to heating after the printing conditions are met. The closed-loop control of the temperature of the spray head assembly 4 is suitable for regulating and controlling the preheating temperature and also suitable for regulating and controlling the heating temperature.

The control of the preheating temperature is controlled by a preheating program, and the control of the heating temperature is controlled by a heating program, wherein the heating temperature has a larger and stronger influence on the printing forming quality of the composite material, so that the priority of the heating program is higher than that of the preheating program, specifically, when the temperature exceeds a preheating temperature set value, the heating program is operated, the preheating program stops operating, when the heating program is suspended from operating, the preheating program is operated for preparing for the next heating of the spray head assembly 4, and the low-priority preheating program is scheduled to operate only when the high-priority heating program is not operated. In addition, the priority of the heating and preheating processes is higher than the priority of the power regulation of the gas source assembly 6.

Optionally, the rack 1 includes a rack body 15, a first connecting piece 16 and a housing 17, the rack body 15 is provided with a feeding hole 11 and a clamping hole 12, the rack body 15, the first connecting piece 16 and the housing 17 surround to form a heat dissipation cavity 13, the first connecting piece 16 is detachably connected with the rack body 15, and the housing 17 is detachably connected with the first connecting piece 16. So set up, conveniently carry out the dismouting to frame 1. In other embodiments, the first connector 16 is integrally provided with the housing body 15. Specifically, in order to make the connection between the frame body 15 and the first connection member 16 stronger, as shown in fig. 2, the first connection member 16 is provided with a plurality of first connection holes 161, a plurality of fasteners are provided corresponding to the plurality of first connection holes 161, and the fasteners pass through the first connection holes 161 and are screwed with the frame body 15. In addition, the housing 17 is clamped with the first connecting member 16, or the housing 17 is provided with external threads, the inner wall of the first connecting member 16 is provided with internal threads, the external threads are in threaded connection with the internal threads, or the housing 17 is provided with a plurality of second connecting holes, a plurality of fasteners are correspondingly arranged with the plurality of second connecting holes, and the fasteners penetrate through the second connecting holes and are in threaded connection with the first connecting member 16.

Optionally, as shown in fig. 3, the printing nozzle further includes an annular fixing member 8 and a locking assembly, the heating member 5 is sleeved outside the nozzle assembly 4, the annular fixing member 8 is sleeved outside the heating member 5, and the locking assembly abuts the annular fixing member 8 outside the heating member 5. By providing the annular fixing member 8 and the locking assembly, the heating member 5 is reinforced. In this embodiment, the two ends of the annular fixing member 8 are respectively provided with locking holes 81, and the locking assembly passes through the two locking holes 81 to tightly support the annular fixing member 8 outside the heating member 5. Specifically, the locking assembly comprises a bolt and a nut, wherein the bolt penetrates through two locking holes 81 and is in threaded connection with the nut, or the locking assembly comprises a clamping column and a buckle, and the clamping column penetrates through two locking holes 81 and is in buckling connection with the buckle.

Optionally, the air source assembly 6 includes an air guide assembly and a fan 61, an air outlet of the air guide assembly is communicated with the heat dissipation cavity 13, and the fan 61 is disposed at an air inlet of the air guide assembly. Air is supplied by the fan 61, and cost is saved. In this embodiment, as shown in fig. 1 and 4, the air guide assembly includes an air guide pipe 62 and an air guide cover 63 with a triangular inner cavity section, the first connecting piece 16 is provided with an air inlet 162, the air outlet of the air guide pipe 62 is communicated with the air inlet 162 of the first connecting piece 16, the air inlet of the air guide pipe 62 is communicated with the air outlet of the air guide cover 63, and the fan 61 is arranged at the air inlet of the air guide cover 63. The air outlet of the air duct 62 is communicated with the air inlet 162 of the first connecting piece 16, so that the air outlet of the air source assembly 6 is communicated with the heat dissipation cavity 13. The air guide cover 63 with the inner cavity having the triangular cross section is arranged, so that the air guide effect on the air flow is good. Optionally, as shown in fig. 3, the air guide assembly further includes a connection plate 64, a bolt and a nut, the connection plate 64 is fixed on the air guide tube 62, the connection plate 64 is provided with a plurality of third connection holes 641, the air guide cover 63 is provided with a plurality of fourth connection holes, and the bolt passes through the third connection holes 641 and the fourth connection holes and is in threaded connection with the nut. The connecting plate 64 and the wind scooper 63 are fastened through threads, so that the installation strength of the structure of the air source assembly 6 can be improved, and convenient installation can be realized.

Alternatively, as shown in fig. 4 and 5, the spray head assembly 4 includes a throat 41 and a nozzle 42, the heat sink 2 is provided with a mounting hole 22, the throat 41 passes through the chassis 1 and is fixed in the mounting hole 22, the throat 41 is provided with a second channel 411, an inlet of the second channel 411 is communicated with an outlet of the first channel 21, the nozzle 42 is fixed at an outer end of the throat 41 and is communicated with an outlet of the second channel 411, and the heating member 5 is provided at the nozzle 42. The throat 41 passes through the frame 1 and is fixed in the mounting hole 22, so that the throat 41 is convenient to mount and saves space. In this embodiment, the inner wall of the mounting hole 22 is provided with an internal thread, the outer wall of the throat 41 is provided with an external thread, and the internal thread is in threaded connection with the external thread, so that the mounting hole is convenient to detach and firm in connection. In operation, the wire passes through the feed hole 11, the first channel 21 and the second channel 411 in order and enters the nozzle 42, after which the melted wire is extruded from the outlet of the nozzle 42, and in this embodiment, the diameter of the wire extruded through the nozzle 42 is not less than 0.5 mm, so that the printing accuracy can be ensured. In addition, the printing nozzle further comprises a quick connector, and the wire enters the feeding hole 11 of the frame 1 through the quick connector.

Optionally, as shown in fig. 1 and fig. 2, the printing nozzle further includes a second connecting piece 9, at least one group of the frame 1, the radiator 2, the nozzle assembly 4 and the heating piece 5 is provided, the air source assembly 6 is provided with one group, the heat dissipation cavity 13 of each group of the frame 1 is communicated with the air outlet of the air source assembly 6, and at least one frame 1 is fixed on the second connecting piece 9. By the arrangement, one or more wires can be printed, and the printing range of the printing nozzle is expanded.

The utility model provides a printer which comprises a machine base, a nozzle mounting seat, a wire feeding mechanism and a printing nozzle, wherein the nozzle mounting seat is fixed on the machine base, a machine frame 1 is arranged on the nozzle mounting seat, and the wire feeding mechanism is fixed on the machine base and is used for moving wires to enable the wires to enter from a feed hole 11 of the machine base and extrude from an outlet of a nozzle assembly 4. In the printing process, the printer reduces heat accumulation at the inlet end of the printing nozzle, ensures stable extrusion of molten wires in the nozzle assembly 4, and meets the requirement of stable printing.

It is to be understood that the above examples of the present utility model are provided for clarity of illustration only and are not limiting of the embodiments of the present utility model. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the utility model. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are desired to be protected by the following claims.

Claims (10)

1. A print head, comprising:

The machine frame (1) is provided with a feeding hole (11), a clamping hole (12) and a heat dissipation cavity (13) which are sequentially communicated, and the side wall of the heat dissipation cavity (13) is provided with an air outlet hole (14);

The heat radiation body (2) is arranged in the heat radiation cavity (13) and is clamped with the clamping hole (12), the heat radiation body (2) is provided with a first channel (21), an inlet of the first channel (21) is communicated with the feeding hole (11), a plurality of cooling fins (3) are arranged on the outer wall of the heat radiation body (2) at intervals along the length direction, the cross section area of the cooling fin (3) at one side far away from the feeding hole (11) is larger than the cross section area of the cooling fin (3) at one side close to the feeding hole (11), and at least one air guide groove (31) is arranged in each cooling fin (3) in the adjacent cooling fins (3), so that one air guide groove (31) on each cooling fin (3) can form an annular air guide channel;

A nozzle assembly (4), an inlet of the nozzle assembly (4) being in communication with an outlet of the first channel (21), an outlet of the nozzle assembly (4) being capable of extruding a wire;

a heating element (5) arranged on the nozzle assembly (4) and used for heating the wire;

The air source assembly (6) is arranged on the frame (1), and an air outlet of the air source assembly (6) is communicated with the heat dissipation cavity (13).

2. The printing nozzle according to claim 1, wherein a plurality of cooling fins (3) are divided into two groups, the cooling fins (3) close to one side of the feeding hole (11) are one group, the cooling fins (3) far from one side of the feeding hole (11) are another group, the cooling fins (3) far from one side of the feeding hole (11) are distributed on the cooling body (2) at equal intervals, the cross sectional area of each cooling fin (3) is the same, and projections of a plurality of air guide grooves (31) forming the annular air guide channel on the cross section of the cooling body (2) are distributed at equal intervals in the circumferential direction.

3. A print head as claimed in claim 2, characterized in that in the projection the centre lines of adjacent two of the air guide grooves (31) are spaced apart by 45 degrees, 60 degrees or 90 degrees.

4. The printing head according to claim 1, further comprising a temperature sensor (7) and a temperature closed-loop control assembly, the temperature sensor (7) being adapted to detect the temperature of the head assembly (4), the temperature closed-loop control assembly being in communication with the temperature sensor (7) and in communication with the air supply assembly (6).

5. The printing nozzle according to claim 1, characterized in that the frame (1) comprises a frame body (15), a first connecting piece (16) and a housing (17), the frame body (15) is provided with the feeding hole (11) and the clamping hole (12), the frame body (15), the first connecting piece (16) and the housing (17) are surrounded to form the heat dissipation cavity (13), the first connecting piece (16) is detachably connected with the frame body (15), and the housing (17) is detachably connected with the first connecting piece (16).

6. The printing nozzle according to claim 1, further comprising an annular fixing member (8) and a locking assembly, wherein the heating member (5) is sleeved outside the nozzle assembly (4), the annular fixing member (8) is sleeved outside the heating member (5), and the locking assembly tightly abuts the annular fixing member (8) outside the heating member (5).

7. The printing nozzle according to any one of claims 1-6, wherein the air supply assembly (6) comprises an air guide assembly and a fan (61), an air outlet of the air guide assembly being in communication with the heat dissipation chamber (13), the fan (61) being arranged at an air inlet of the air guide assembly.

8. The printing nozzle according to any one of claims 1 to 6, wherein the nozzle assembly (4) comprises a throat (41) and a nozzle (42), the heat sink (2) is provided with a mounting hole (22), the throat (41) passes through the frame (1) and is fixed in the mounting hole (22), the throat (41) is provided with a second channel (411), an inlet of the second channel (411) is communicated with an outlet of the first channel (21), the nozzle (42) is fixed at an outer end of the throat (41) and is communicated with an outlet of the second channel (411), and the heating element (5) is arranged on the nozzle (42).

9. The printing nozzle according to any one of claims 1-6, characterized in that the printing nozzle further comprises a second connecting piece (9), wherein the frame (1), the heat sink (2), the nozzle assembly (4) and the heating piece (5) are all provided with at least one group, the air source assembly (6) is provided with one group, the heat dissipation cavity (13) of each group of the frame (1) is communicated with the air outlet of the air source assembly (6), and at least one frame (1) is fixed on the second connecting piece (9).

10. A printer comprising a housing, a nozzle mount, a wire feeder and a print nozzle as claimed in any one of claims 1 to 9, the nozzle mount being secured to the housing, the housing (1) being arranged on the nozzle mount, the wire feeder being secured to the housing for moving wire into the feed opening (11) of the housing and out of the outlet of the nozzle assembly (4).