Heating head for three-dimensional printing pen

The invention provides a heating head for a three-dimensional printing pen. The heating head includes a heating pipe, a heating member, a heat insulation pipe, a heat insulation sleeve, and a heat sink. The heating member is disposed on the heating pipe. The heat insulation pipe penetrates into the heating pipe. The heat insulation sleeve is sleeved on the heating pipe and opposite to the heating member. The heat insulation sleeve partly covers the heat insulation pipe, and the heat insulation pipe and the heat insulation sleeve are separated by the heating pipe. The heat sink and the heat insulation sleeve mutually lean against, wherein the heat insulation sleeve is located between the heating member and the heat sink, and the heat insulation pipe penetrates into the heat sink.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China patent application serial no. 201511027271.7, filed on Dec. 31, 2015. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of the specification.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a heating head and specifically relates to a heating head for a three-dimensional printing pen.

Description of Related Art

Along with the continuous development of technology recently, various methods using the additive manufacturing technology to build physical three-dimensional (3-D) models have been proposed, such as building a model layer by layer. Generally speaking, the additive manufacturing technology converts design data of three-dimensional models designed with, for example, computer-aided design softwares into a plurality of thin (pseudo-two-dimensional) cross-sectional layers that are continuously stacked. At the same time, many technical means capable of forming a plurality of thin cross-sectional layers have also been gradually proposed. For example, a printing unit of a three-dimensional printing apparatus may move along an XY plane above the printing platform according to spatial coordinate axes (namely, X-axis, Y-axis, and Z-axis) built from the design data of a three-dimensional model, such that the building material may form a proper shape of a cross-sectional layer, and then, the printing unit is driven to move along the Z-axis layer by layer, so that a plurality of cross-sectional layers are gradually stacked and solidified layer by layer to form the three-dimensional object.

However, the volume of the three-dimensional printing apparatus is comparatively large, so that the three-dimensional printing apparatus has low mobility and high cost. On the other hand, the three-dimensional printing apparatus is mostly used to manufacture large-sized three-dimensional objects, and the three-dimensional printing apparatus is hardly used to actualize specifically the detailed outline of the three-dimensional objects, to build other detailed features on the existing three-dimensional objects, or to repair the damage of the three-dimensional objects. Accordingly, a three-dimensional printing pen having a smaller volume, low cost, and high mobility, etc., emerges. Because the heat source used by the heating wire is disposed inside the three-dimensional printing pen, how to build a good heat-insulation mechanism is becoming more important, so as to prevent the hand gripping the three-dimensional printing pen of the user from being burned or being heated.

SUMMARY OF THE INVENTION

The invention provides a heating head of a three-dimensional printing pen that having a good heat insulation effect.

The invention proposes a heating head for a three-dimensional printing pen. The heating head includes a heating pipe, a heating member, a heat insulation pipe, a heat insulation sleeve, and a heat sink. The heating member is disposed on the heating pipe. The heat insulation pipe penetrates into the heating pipe. The heat insulation sleeve is sleeved on the heating pipe and opposite to the heating member. The heat insulation sleeve partly covers the heat insulation pipe, and the heat insulation pipe and the heat insulation sleeve are separated by the heating pipe. The heat sink and the heat insulation sleeve mutually lean against, wherein the heat insulation sleeve is located between the heating member and the heat sink, and the heat insulation pipe penetrates into the heat sink.

In one embodiment of the invention, the heating pipe has a feeding port and a discharging port opposite to the feeding port. The heat insulation sleeve is adjacent to the feeding port and leans against an outer wall surface of the heating pipe. The heat insulation pipe penetrates into the feeding port and leans against an inner wall surface of the heating pipe, and the heating member is adjacent to the discharging port.

In one embodiment of the invention, the heating head further includes a nozzle. The nozzle is spirally connected to the discharging port of the heating pipe.

In one embodiment of the invention, the heat sink includes a plate portion and a pipe portion connecting to the plate portion. The heat insulation sleeve and the plate portion lean against each other, and the heat insulation pipe penetrates into the pipe portion.

In one embodiment of the invention, the heating head further includes a protective cover. The protective cover covers a part of the heating pipe, the heating member, a part of the heat insulation sleeve, and a part of the heat sink. The protective cover and another part of the heat insulation sleeve lean against each other, and the protective cover and the heat sink are separated by the other part of the heat insulation sleeve.

In one embodiment of the invention, the heat sink has at least one first locking hole. The heat insulation sleeve has at least one second locking hole. The protective cover has at least one third locking hole. The first locking hole, the second locking hole, and the third locking hole are aligned with each other, and the second locking hole is located between the first locking hole and the third locking hole. The heating head further includes a first locking member. The first locking member passes through the first locking hole, the second locking hole, and the third locking hole, so as to fix the heat sink, the heat insulation sleeve, and the protective cover.

In one embodiment of the invention, the heating head further includes a heat dissipation cover. The heat dissipation cover is sleeved on the protective cover and covers a part of the heat sink and a part of the heat insulation sleeve. The heat dissipation cover has a plurality of heat dissipation slots. The heat dissipation slots expose a part of the heat sink and a part of the heat insulation sleeve.

In one embodiment of the invention, a part of the protective cover covered by the heat dissipation cover has at least one fourth locking hole. The heat dissipation cover has at least one fifth locking hole, and the fourth locking hole and the fifth locking hole are aligned with each other. The heating head further includes at least one second locking member. The second locking member passes through the fourth locking hole and the fifth locking hole, so as to fix the protective cover and the heat dissipation cover.

In one embodiment of the invention, the second locking member further passes through at least one sixth locking hole of a main body of the three-dimensional printing pen, so as to fix the protective cover and the heat dissipation cover to the main body.

In one embodiment of the invention, the thermal conductivity coefficient of the heat insulation pipe is from 0.2 to 0.3 W/m·K.

In one embodiment of the invention, the thermal final conductivity coefficient of the heat insulation sleeve is from 0.28 to 0.35 W/m·K.

Based on the above, the heat insulation pipe and the heat insulation sleeve are separated by the heating pipe in the heating head of the invention, wherein the heat sink and the heat insulation sleeve lean against each other, the heating member and the heat sink are separated by the heat insulation sleeve, and the heat insulation pipe penetrates into the heat sink. Therefore, the temperature around the heating pipe is able to be maintained at a high temperature and is not easy to be declined. In addition, the parts of the heat insulation pipe and the heat insulation sleeve that are farther away from the heating pipe has a lower temperature, therefore, the temperature around the heat sink is maintained at a relatively low temperature. The heat sink is relatively closer to the portion of the three-dimensional printing pen that the user grips, so as to prevent the hand gripping the three-dimensional printing pen of the user from being burned or being heated.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a schematic exploded view of a three-dimensional printing pen of an embodiment of the invention.FIG. 2is schematic view of the three-dimensional printing pen inFIG. 1after being assembled.FIG. 3is a schematic cross-sectional view of a heating head inFIG. 2. Referring toFIGS. 1-3, in the present embodiment, a three-dimensional printing pen10includes a main body20and a heating head30. The main body20is configured to have a control unit (not shown) and a driving unit (not shown). The control unit (not shown) is used to control the heating head30to be on or off. The driving unit (not shown) is used to drive the wire (not shown) to move-in or move-out the heating head30. The main body20includes a first end part21and a second end part22opposite to each other. The heating head30may be detachably assembled with the first end part21. The wire (not shown) may enter inside of the main body20from an opening23of the second end part22, and is driven by the driving unit (not shown) to move to the heating head30. The heating head30heats the wire (not shown) to raise the temperature of the wire to the melting point, the heating head30spurts the melted wire (not shown) out, and the user can hold the three-dimensional printing pen10by hand to draw three-dimensional patterns or three-dimensional objects. In general, the wire (not shown) may be made of acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), wherein the melting point of acrylonitrile butadiene styrene is about 210 degrees Celsius, and the melting point of polylactic acid is about 180 degrees Celsius.

The heating head30includes a heating pipe31, a heating member32, a heat insulation pipe33, a heat insulation sleeve34, and a heat sink35. The heating member32is disposed on the heating pipe31and electrically connected with the control unit (not shown) of the main body20. Therefore, the control unit (not shown) may be used to control the electric current to the heating member32to make the heating member32generate heat. As shown inFIG. 2andFIG. 3, the heating member32is, for example, disposed surrounding the outer peripheral surface of the heating pipe31and thermally coupled to the heating pipe31, so that the heat generated by the heating member32may be conducted to the heating pipe31. Herein, the material of the heating pipe31may be aluminum, or other metals or alloys with high thermal conductivity, or may be diamond-like carbon, nanometer carbon, or high molecular materials with high thermal conductivity.

The heat insulation pipe33penetrates into the heating pipe31and a distance is kept between the heat insulation pipe33and the heating member32disposed on the heating pipe31. The heat insulation sleeve34is sleeved on the heating pipe31. The heat insulation sleeve34and the heating member32are disposed opposite to each other, and a distance is kept between the heat insulation sleeve34and the heating member32. In the present embodiment, the heating pipe31has a feeding port311and a discharging port312opposite to the feeding port311, wherein the heat insulation sleeve34is adjacent to the feeding port311and leans against an outer wall surface31aof the heating pipe31, and the heating member32is adjacent to the discharging port312. One end of the heat insulation pipe33penetrates into the feeding port311and leans against an inner wall surface31bof the heating pipe31. As shown inFIG. 3, the heat insulation pipe33and the heat insulation sleeve34are respectively disposed inside and outside of the heating pipe31, and a part of the heat insulation pipe33that is exposed to outside of the heating pipe31is not in contact with a part of the heat insulation sleeve34that does not lean against the outer wall surface31aof the heating pipe31, and the heat insulation pipe33and the heat insulation sleeve34are separated by the heating pipe31. In the present embodiment, the part of the heat insulation sleeve34that does not lean against the outer wall surface31aof the heating pipe31surrounds the part of the heat insulation pipe33that is exposed to outside of the heating pipe31, that is to say, the heat insulation sleeve34partly covers the heat insulation pipe33. On the other hand, the heat sink35and the bottom341of the heat insulation sleeve34lean against each other, wherein the heat insulation sleeve34is located between the heating member32and the heat sink35, and the heat insulation pipe33penetrates into the heat sink35. In other words, two end parts of the heat insulation pipe33penetrate into the heating pipe31and the heat sink35respectively, and the heating pipe31and the heat sink35are separated by the heat insulation sleeve34. More specifically, the heat sink35includes a plate portion351and a pipe portion352connecting to the plate portion351. The bottom341of the heat insulation sleeve34and the plate portion351lean against each other, and one end of the heat insulation pipe33penetrates into the pipe portion352. As shown inFIG. 3, the pipe portion352is extended outwardly from two opposite sides the plate portion351, and a part of the pipe portion352is covered by the heat insulation sleeve34. The end of the heat insulation pipe33penetrates into a part of the pipe portion352that is covered by the heat insulation sleeve34and is extended to another part of the pipe portion352that is not covered by the heat insulation sleeve34.

In the present embodiment, the heating head30further includes a nozzle36. The nozzle36is spirally connected to the discharging port312of the heating pipe31. Considering the feeding path of the wire (not shown), firstly, the wire (not shown) may enter inside of the main body20from an opening23of the second end part22, and is driven by the driving unit (not shown) to move into the pipe portion352of the heat sink35. Subsequently, the wire (not shown) moves to the heat insulation pipe33penetrating into the pipe portion352, and moves through the heat insulation pipe33into the heating pipe31. After that, the heating member32generates heat and the heat is conducted to the heating pipe31, so as to maintain the temperature of a block A of the heating pipe31corresponding to the heating member32at about 210 degrees Celsius, and to maintain the temperature of a block B between the block A and the feeding port311at about 170 degrees Celsius. On the other hand, the temperature of the feeding port311of the heating pipe31is maintained at about 160 degrees Celsius. Therefore, when moving into the heat insulation pipe33penetrating into the feeding port311and the block B of the heating pipe31, the wire (not shown) begins to soften. After moving into the block A of the heating pipe31, the softened wire (not shown) begins to melt. At this time, the melted wire (not shown) may spurt through the discharging port312of the heating pipe31and the nozzle36.

In other words, in order to melt the wire (not shown) successfully, the temperature around the heating pipe31needs being maintained from 160 to 210 degrees Celsius. In the present embodiment, the material of the heat insulation pipe33is polytetra fluoroethylene having a thermal conductivity coefficient from 0.2 to 0.3 W/m·K. The material of the heat insulation sleeve34may be nylon PA66-GF30 having a thermal conductivity coefficient from 0.28 to 0.35 W/m·K. Under the circumstance that a material having a lower thermal conductivity coefficient is used to form the heat insulation pipe33and the heat insulation sleeve34, the heat conduction velocity from the heating pipe31to the heat insulation pipe33and the heat insulation sleeve34is slow. On the other hand, the heating member32and the heat sink35are separated by the heat insulation sleeve34, and the heat insulation pipe33and the heat insulation sleeve34are separated by the heating pipe31, therefore, the temperature around the heating pipe31is maintained from 160 to 210 degrees Celsius and is not easy to be declined. In addition, the parts of the heat insulation pipe33and the heat insulation sleeve34that are farther away from the heating pipe31has a lower temperature, therefore, the temperature around the heat sink35is maintained at about 60 degrees Celsius. The heat sink35is relatively closer to the portion of the main body20that the user grips, therefore, the temperature of the portion of the main body20that the user grips may be maintained under 60 degrees Celsius, so as to prevent the hand gripping the main body20of the user from being burned or being heated.

Referring toFIGS. 1-3, in the present embodiment, the heating head30further includes a protective cover37and a heat dissipation cover38. The protective cover37covers a part of the heating pipe31, the heating member32, a part of the heat insulation sleeve34, and a part of the heat sink35, and the nozzle36passes through the opening371of the protective cover37. On the other hand, the plate portion351of the heat sink35and the bottom341of the heat insulation sleeve34lean against each other, the protective cover37and the bottom341of the heat insulation sleeve34lean against each other, and the protective cover37and the heat sink35are separated by the bottom341of the heat insulation sleeve34. The heat dissipation cover38is sleeved on the protective cover37and covers a part of the heat sink35and a part of the heat insulation sleeve34. The heat dissipation cover38has a plurality of heat dissipation slots381, and the heat dissipation slots381expose a part of the heat sink35and a part of the heat insulation sleeve34. Therefore, the heat conducted to the bottom341of the heat insulation sleeve34, the heat conducted from the bottom341of the heat insulation sleeve34to the heat sink35, and the heat conducted from the heat insulation pipe33to the heat sink35can be discharged to the outside through the heat dissipation slots381, so that the temperature around the heat sink35is maintained at about 60 degrees Celsius.

More specifically, the heat sink35has at least one first locking hole353(schematically illustrated as two first locking holes), the two first locking holes353are located at the plate portion351of the heat sink35. The heat insulation sleeve34has at least one second locking hole342(schematically illustrated as two second locking holes), the two second locking holes342are located at the bottom341of the heat insulation sleeve34. The protective cover37has at least one third locking hole372(schematically illustrated as two third locking holes), wherein each of the first locking holes353, the corresponding second locking hole342, and the corresponding third locking hole372are aligned with each other, and each of the second locking holes342is located between the corresponding first locking hole353and the corresponding third locking hole372. In the present embodiment, the heating head30further includes at least one first locking member39(schematically illustrated as two first locking members), and each of the first locking members39respectively passes through the first locking hole353, the second locking hole342, and the third locking hole372that are aligned with each other, so as to fix the heat sink35, the heat insulation sleeve34, and the protective cover37. On the other hand, a part of the protective cover37covered by the heat dissipation cover38has at least one fourth locking hole373(schematically illustrated as two fourth locking holes). The heat dissipation cover38has at least one fifth locking hole382, and each of the fourth locking holes373and the corresponding fifth locking hole382are aligned with each other. The heating head30further includes at least one second locking member39a(schematically illustrated as two second locking members), and each of the second locking members39arespectively passes through the fourth locking hole373and the fifth locking hole382that are aligned with each other, so as to fix the protective cover37and the heat dissipation cover38. More specifically, the main body20has at least one sixth locking hole24(schematically illustrated as two sixth locking holes), the two sixth locking holes24are located adjacent to the first end part21. Each of the sixth locking holes24, the corresponding fourth locking hole373, and the corresponding fifth locking hole382are aligned with each other, and each of the sixth locking holes24is located between the corresponding fifth locking hole382and the corresponding fourth locking hole373. Each of the second locking members39a, for example, passes through the corresponding fifth locking hole382and sequentially passes through the corresponding sixth locking hole24and the corresponding fourth locking hole373, so as to fix the protective cover37and the heat dissipation cover38to the main body20. According to the above assembly method, the heating head30is able to be firmly disposed on the main body20, so as to improve the reliability in operation. In another way, the heating head30may be disassembled and it is convenient for the user to repair or to replace components.

In summary, the heat insulation pipe and the heat insulation sleeve are separated by the heating pipe in the heating head of the invention, wherein the heat sink and the heat insulation sleeve lean against each other, the heating member and the heat sink are separated by the heat insulation sleeve, and the heat insulation pipe penetrates into the heat sink. Because the heat insulation pipe and the heat insulation sleeve are formed by materials having low thermal conductivity coefficient, the heat conduction velocity from the heating pipe to the heat insulation pipe and the heat insulation sleeve is slow, and therefore, the temperature around the heating pipe is able to be maintained at a high temperature and is not easy to be declined. In addition, the parts of the heat insulation pipe and the heat insulation sleeve that are farther away from the heating pipe has a lower temperature, therefore, the temperature around the heat sink is maintained at a relatively low temperature. On the other hand, the heat dissipation slots may expose a part of the heat sink and a part of the heat insulation sleeve. Therefore, the heat conducted to the heat insulation sleeve, the heat conducted from the heat insulation sleeve to the heat sink, and the heat conducted from the heat insulation pipe to the heat sink, and all the heat from the heat sink can be discharged to the outside through the heat dissipation slots, so that the temperature around the heat sink is maintained at a relatively low temperature. In other words, the heating head of the invention may have good heat dissipation and heat insulation effects. The heat sink is relatively closer to the portion of the three-dimensional printing pen that the user grips, so as to prevent the hand gripping the three-dimensional printing pen of the user from being burned or being heated.

Although the present invention and the advantages thereof have been described in detail, it should be understood that various changes, substitutions, and alternations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. That is, the discussion included in this invention is intended to serve as a basic description. It should be understood that the specific discussion may not explicitly describe all embodiments possible; many alternatives are implicit. The generic nature of the invention may not fully explained and may not explicitly show that how each feature or element can actually be representative of a broader function or of a great variety of alternative or equivalent elements. Again, these are implicitly included in this disclosure. Neither the description nor the terminology is intended to limit the scope of the claims.