WO2016173061A1

WO2016173061A1 - Antidrip spray nozzle for 3d printer

Info

Publication number: WO2016173061A1
Application number: PCT/CN2015/080185
Authority: WO
Inventors: 朱曦
Original assignee: 金葆青
Priority date: 2015-04-30
Filing date: 2015-05-29
Publication date: 2016-11-03
Also published as: CN204585860U

Abstract

Disclosed is an antidrip spray nozzle for a 3D printer, so as to solve the defect of an existing spray nozzle easy to drip. A connection block is disposed between a heating block and a heat dissipation block, and a thin neck portion is arranged on the connection block; and by using the neck portion of the connection block as a boundary, the part under the boundary is a hot end of the spray nozzle, and the part above the boundary is a cold end of the spray nozzle. A printing material on the cold end keeps in a normal state and does not start to melt. When a printing material entering the hot end is heated to a required temperature, the printing material is normally melted. The volume of the melted printing material is greatly decreased compared with that before the improvement, the weight of the melted printing material is also greatly decreased, and at the same time the frictional force on the extended thin portion of the extended spray nozzle front end is increased, thereby ensuring that the drip phenomenon is not to occur. Or, a transition portion is arranged between a thick portion and a thin portion of a central hole of the spray nozzle, and a balanced point can be found more easily due to the design of the transition portion, thereby ensuring that the drip phenomenon is not to occur because of sufficient frictional force, and a motor is not prevented from pushing a printing material to go forwards because of no excessively great frictional force.

Description

Anti-drip nozzle for 3D printer

Technical field

The utility model relates to the technical field of 3D printers, in particular to an anti-drip nozzle of a 3D printer.

Background technique

3D printing technology, also known as Rapid Prototyping Manufacturing (RP technology), can be divided into three-dimensional lithography (SLA), laminated solid molding (LOM), fused deposition molding (FDM), depending on the molding method. Selective laser sintering (SLS) and the like. The biggest difference between fused deposition (FDM) rapid prototyping systems and SLA, LOM, SLS and other systems is that fused deposition (FDM) does not use a laser system, so it can minimize the cost and is the most widely used 3D printing. technology.

Existing fused deposition modeling (FDM) 3D printers generally have the problem of nozzle dripping, especially in the case of multiple nozzles, which is a very serious problem, affecting the smoothness of the surface of the object and reducing the print quality. As shown in FIG. 1, the nozzles are generally composed of a nozzle 1, a heating block 2, a heat sink block 3, and a heating rod 4. The nozzle 1 has an external thread, the heating block 2 has an internal thread, and the heat sink 3 has an internal thread. The heating block 2 is first screwed onto the nozzle 1, and the heat sink 3 is screwed onto the nozzle 1. The heating rod 4 is inserted into a circular hole in the heating block for heating.

However, the heating block 2 in the existing nozzle is relatively large, the heat dissipation block 3 has a low heat dissipation efficiency, and the high temperature region of the nozzle 1 is too large, so that the printing material in the nozzle 1 melts too much. The melted printed material will naturally flow downward under the influence of gravity. The length of the small portion of the front end of the nozzle 1 is too short, and there is not enough friction against the gravity of the printing material, causing the nozzle to drip. Because the fused deposition molding (FDM) process generally uses low-melting filament materials, such as PLA or ABS plastic filaments, the direct result of such dripping is the occurrence of drawing between several printed objects that are not in contact. At the same time, the other caused by dripping A possible phenomenon is that the outer surface of the printed object causes unevenness and affects the appearance of the object.

Therefore, it is necessary to provide a new 3D printer anti-drip nozzle to solve the above problems.

Utility model content

The purpose of the utility model is to provide an anti-drip nozzle of a 3D printer, change the structure of the nozzle, adjust the size of each component of the nozzle, increase the friction of the printing material inside the nozzle, reduce the weight of the printing material in the melted state, and make the friction The force is greater than the gravity of the printed material to avoid dripping of the nozzle.

The technical solution for achieving the above object is: a drip-proof nozzle of a 3D printer, comprising a nozzle, the upper end of the nozzle center hole is a thick portion, the lower end is a thin portion, and the thin portion extends downward to have an extended detail, and the connecting block is located above the nozzle The heating block is respectively fixedly fixed with the lower portion of the nozzle and the connecting block, the heating block is provided with a circular hole, and the heating rod is disposed in the circular hole, and the heat dissipating block is located above the heating block and cooperates with the upper part of the connecting block Fixed, a neck is provided between the upper portion and the lower portion of the connecting block.

In the above technical solution, the nozzle and the connecting block are provided with external threads, and the heating block is provided with internal threads that are fixedly coupled with the external threads of the nozzle and the connecting block.

In the above technical solution, the heat dissipating block is provided with an internal thread and is fixedly coupled with the external thread of the connecting block.

In the above technical solution, the nozzle is made of copper having good heat conduction effect.

In the above technical solution, the heating block is made of aluminum having good heat conduction effect.

In the above technical solution, the heat dissipation block is made of aluminum with good heat conduction effect.

In the above technical solution, the heat dissipation block is provided with a plurality of toothed fins to increase the heat dissipation area.

In the above technical solution, a heat dissipating fan is fixed on the heat dissipating block to improve the heat dissipating speed.

In the above technical solution, the connecting block is made of stainless steel with poor thermal conductivity.

According to the technical solution of the present invention, a connecting block is arranged between the heating block and the heat dissipating block, and a neck is arranged on the connecting block, so that the neck of the connecting block is demarcated, and the lower end is the hot end of the nozzle, and the upper surface is the nozzle. Cold end. The printed material on the cold end remained in a normal state and did not begin to melt. Entering the heat The printed material at the end is heated to the required temperature and melts normally. The volume of the melted printing material is much smaller than before the improvement, and the weight is much lighter. And the extended extension of the front end of the nozzle increases the friction, which ensures that the dripping phenomenon does not occur.

Another technical solution for achieving the above object is: an anti-drip nozzle of a 3D printer, comprising a nozzle, the upper end of the nozzle center hole is a thick portion, the lower end is a thin portion, and the thin portion extends downward to have an extended detail, and the thick portion is A transition portion is disposed between the thin portions, the transition portion is larger than the thin portion and smaller than the thick portion, and the connecting block is located above the nozzle, and the heating block is respectively fixed and fixed with the lower portion of the nozzle and the connecting block, and the heating block is provided with a circular hole The heating rod is disposed in the circular hole, and the heat dissipating block is located above the heating block and is fixedly fixed with the upper portion of the connecting block, and a neck portion is disposed between the upper portion and the lower portion of the connecting block.

According to the technical solution of the present invention, a connecting block is arranged between the heating block and the heat dissipating block, and a neck is arranged on the connecting block, so that the neck of the connecting block is demarcated, and the lower end is the hot end of the nozzle, and the upper surface is the nozzle. Cold end. The printed material on the cold end remained in a normal state and did not begin to melt. The printed material entering the hot end is heated to the desired temperature and melts normally. The volume of the melted printing material is much smaller than before the improvement, and the weight is much lighter. And adding a transition between the detail and the thick part of the nozzle center hole, the balance point can be found more easily, ensuring that there is enough friction to not cause dripping, and there is not much resistance to hinder the motor from pushing the print. The material is moving forward.

DRAWINGS

1 is a schematic structural view of a printer nozzle in the prior art;

2 is a schematic structural view of an anti-drip nozzle of a 3D printer according to a first embodiment of the present invention;

Figure 3 is a schematic view showing the structure of the nozzle of Figure 2;

4 is a schematic view of a parallel plate experiment in the first embodiment;

FIG. 5 is a schematic view showing the nozzle structure of the anti-drip nozzle of the 3D printer in the second optimized embodiment of the present invention.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that these descriptions It is intended to be illustrative, and not to limit the scope of the invention. In addition, descriptions of well-known structures and techniques are omitted in the following description in order to avoid unnecessarily obscuring the inventive concept.

2 is a schematic structural view of an anti-drip nozzle of a 3D printer according to a first embodiment of the present invention; FIG. 3 is a schematic view showing the structure of the nozzle of FIG.

As shown in FIG. 2 and FIG. 3, an anti-drip nozzle of a 3D printer includes a nozzle 1. The upper end of the center hole of the nozzle 1 is a thick portion 11 and a lower end is a thin portion 12, and the thin portion 12 extends downward to be extended. For the detail 13, the aperture 1 of the nozzle 1 extension portion 13 is between 0.2 mm and 0.5 mm, and preferably 0.4 mm.

The connecting block 2 is located above the nozzle 1 , and the heating block 3 is respectively fixedly fixed with the lower part of the nozzle 1 and the connecting block 2 . In the embodiment, the nozzle 1 and the connecting block 2 are provided with external threads. The heating block 3 is provided with internal threads that are fitted and fixed to the external threads of the nozzle 1 and the connecting block 2.

The heating block 3 is provided with a circular hole, and the heating rod 31 is disposed in the circular hole for heating the printing material in the nozzle 1. In the embodiment, the nozzle has a good heat conduction effect. The copper is made to ensure that the heat of the heating rod 31 can be quickly transferred to the printing material, thereby facilitating rapid heating of the printing material in the nozzle 1. Moreover, the heating block 3 is made of aluminum with good heat conduction effect, which ensures the heat can be quickly transmitted to the nozzle while reducing the cost.

The heat dissipating block 4 is located above the heating block 3 and is fixedly fixed with the upper part of the connecting block 2. In the embodiment, the heat dissipating block 4 is provided with internal threads and is fixedly fixed with the external threads of the connecting block 2. The heat dissipating block 4 is disposed above the heating block 3 to dissipate heat, and the heat dissipating block 4 is also made of aluminum having a good heat conducting effect, and at the same time, the heat dissipating block 4 is formed with a plurality of toothed fins. It is possible to increase the heat dissipation area to ensure that the heat on the heat sink can be quickly dissipated. At the same time, a cooling fan is fixed on the heat sink block, which greatly increases the speed of heat dissipation.

A neck portion 21 is disposed between the upper portion and the lower portion of the connecting block 2, and the connecting block 2 is thermally conductive. Made of very poor stainless steel. This increases the strength of the material, ensures that the neck 21 does not break, and reduces the transfer of heat to the top, ensuring that the printed material inside the upper portion of the connecting block 2 does not melt due to overheating. The neck 21 of the connecting block 2 is demarcated, the lower end is the hot end of the nozzle, and the upper side is the cold end of the nozzle. The printed material on the cold end remained in a normal state and did not begin to melt. The printed material entering the hot end is heated to the desired temperature and melts normally. The volume of the melted printing material is much smaller than before the improvement, and the weight is much lighter. At the same time, because the extended tip 13 of the extended nozzle front end increases the friction, it ensures that the dripping phenomenon does not occur.

The extended detail 13 increases the frictional force, wherein the increased frictional force here is mainly derived from two aspects: the capillary action caused by the surface tension and the resistance generated by the viscosity of the liquid.

Among them, surface tension is a physical effect, which makes the surface of the liquid always try to obtain the smallest, smooth area, as if it is a layer of elastic film. The reason is that the surface of the liquid always tries to reach the state of the lowest energy. The tension at the interface between materials of all two different physical states in a broad sense is called surface tension. The surface tension is an internal force, and surface tension exists even in a balanced state.

Capillary phenomenon (also known as capillary action) refers to the phenomenon that the liquid rises inside the thin tubular object due to the difference in cohesion and adhesion and overcomes gravity. Capillary action is the attraction of a liquid surface to a solid surface.

The liquid rise height in the capillary phenomenon is:

In the formula: γ is the surface tension; θ is the contact angle; ρ is the liquid density; g is the gravitational acceleration;

r is the radius of the thin tube.

When θ>90°, it means that the meniscus is convex, and h<0, indicating that the liquid drops in the capillary.

The surface tension of the printing material is 30 to 40 mN/m. The density is about the same as water, at 1g/cm^3. The gravitational acceleration g is 9.8 m/s^2. The radius of the thin tube is 0.4 mm. The contact angle is experimentally determined according to different materials, ranging from 30 degrees to 60 degrees. Assuming a contact angle of 45 degrees, the height is calculated to be 12.6 mm according to the above parameters.

When a liquid or gas flows, the property of internal friction between its molecules is called the viscosity of the liquid. The size of the viscosity is expressed by the viscosity and is used to characterize the resistance factor related to the properties of the liquid. For example, two plates with an area of 1 m ² are immersed in a liquid, and the distance between the two plates is 1 m. If a tangential force of 1 N is applied to a certain plate so that the relative velocity between the two plates is 1 m/s, then The viscosity of this liquid was 1 Pa·s.

Fig. 4 is a view showing a parallel plate experiment in the first embodiment.

As can be seen from Fig. 4, in the vicinity of the non-moving plate, the speed of liquid movement rapidly decreases with the decrease of the distance, which means that the resistance caused by the viscosity rises rapidly. Since the front end of the nozzle has a hole diameter of 0.4 mm, the resistance caused by the viscosity will be large.

The technical solution of the first embodiment increases the friction by extending the small portion of the front end of the nozzle, thereby ensuring that the dripping phenomenon does not occur, but at the same time, the resistance when the printed material is extruded is increased, and the squeeze motor needs to be sufficient. The power to push the printed material forward. If the small portion of the front end of the nozzle is too long, the resistance may be too large, and the squeeze motor does not have enough force to push the printing material forward. Therefore, it is necessary to optimize the length of the small part of the front end of the nozzle, which has sufficient friction to ensure that no dripping phenomenon occurs, and there is not much resistance which does not hinder the motor from pushing the printing material forward, so that a more optimized solution is needed to ensure the nozzle It is also easy to use on the basis of no dripping.

FIG. 5 is a schematic view showing the structure of a nozzle in an anti-drip nozzle of a medium 3D printer according to a second preferred embodiment of the present invention.

The same components in FIG. 5 as those in FIG. 2 are denoted by the same reference numerals, and the existing components which do not relate to the improvement of the present invention will not be described, and the composition which is improved with respect to the above-described first embodiment will be mainly described. component.

As shown in FIG. 5, a drip-proof nozzle of a 3D printer includes a nozzle 1 having an upper end of a central portion of the nozzle 1 as a thick portion 11 and a lower end as a thin portion 12, and the thin portion 12 extends downwardly with an extended detail portion 13 And a transition portion 14 is disposed between the thick portion 11 and the thin portion 12, the transition portion 14 is larger than the thin portion 12 and smaller than the thick portion 11, and the design of the transition portion 14 can find a balance point more easily. To ensure that there is enough friction to not cause dripping, and there is not much resistance that will prevent the motor from pushing the printing material forward. Thereby, the defects in the above-described first embodiment are better solved.

In addition, the heat dissipating block 4, the heating block 3, and the connecting block 2 disposed between the head structures are the same as those in the first embodiment, that is, the structure in FIG. 2, and details are not described herein again.

The utility model aims to protect an anti-drip nozzle of a 3D printer by providing a connecting block 2 between the heating block 3 and the heat dissipating block 4, and providing a thin neck 21 on the connecting block 2, The neck 21 of the connecting block 2 is a boundary, the lower end of which is the hot end of the nozzle, and the upper side is the cold end of the head. The printed material on the cold end remained in a normal state and did not begin to melt. The printed material entering the hot end is heated to the desired temperature and melts normally. The volume of the melted printing material is much smaller than before the improvement, and the weight is much lighter. At the same time, the extended tip 13 of the front end of the nozzle increases the friction, which ensures that the dripping phenomenon does not occur. Or a transition portion 14 is provided between the thick portion 11 of the nozzle center hole and the detail portion 12. The design of the transition portion 14 makes it easier to find a balance point to ensure that there is sufficient friction. The rubbing force does not cause dripping, and there is not much resistance that does not hinder the motor from pushing the printing material forward.

The above-described embodiments of the present invention are intended to be illustrative only and not to limit the invention. Therefore, any modifications, equivalents, improvements, etc., which are made without departing from the spirit and scope of the invention, are intended to be included within the scope of the invention. Rather, the scope of the appended claims is intended to cover all such modifications and

Claims

An anti-drip nozzle of a 3D printer, comprising: a nozzle, wherein an upper end of the nozzle center hole is a thick portion, a lower end is a thin portion, and the thin portion extends downward to have an extended detail portion, and the connecting block is located above the nozzle, and the heating block respectively Cooperating with the nozzle and the lower portion of the connecting block, the heating block is provided with a circular hole, the heating rod is disposed in the circular hole, and the heat dissipating block is located above the heating block and is fixedly fixed with the upper portion of the connecting block, A neck is provided between the upper portion and the lower portion of the connecting block.
The anti-drip nozzle of the 3D printer according to claim 1, wherein the nozzle and the connecting block are provided with external threads, and the heating block is provided with internal threads that are fitted and fixed with the external threads of the nozzle and the connecting block.
The anti-drip nozzle of the 3D printer according to claim 2, wherein the heat dissipating block is provided with an internal thread and is fixedly coupled to the external thread of the connecting block.
The drip-proof nozzle of the 3D printer according to claim 1, wherein the nozzle is made of copper having a good heat conduction effect.
The anti-drip nozzle of the 3D printer according to claim 1, wherein the heating block is made of aluminum having a good heat conduction effect.
The anti-drip nozzle of the 3D printer according to claim 1, wherein the heat dissipating block is made of aluminum having good heat conduction effect.
The anti-drip nozzle of the 3D printer according to claim 6, wherein the heat dissipating block is provided with a plurality of toothed fins to increase a heat dissipating area.
The anti-drip nozzle of the 3D printer according to claim 7, wherein a heat dissipating fan is fixed on the heat dissipating block to increase the heat dissipation speed.
The anti-drip nozzle of the 3D printer according to claim 1, wherein the connecting block is made of stainless steel having poor thermal conductivity.
An anti-drip nozzle of a 3D printer, comprising: a nozzle, an upper end of the nozzle center hole is a thick portion, a lower end is a thin portion, the thin portion extends downward to have an extended detail portion, and a transition between the thick portion and the detail portion is provided a transition portion larger than the detail portion and smaller than the thick portion, the connection block Located above the nozzle, the heating block is respectively fixedly coupled with the lower portion of the nozzle and the connecting block, the heating block is provided with a circular hole, the heating rod is disposed in the circular hole, and the heat dissipating block is located above the heating block and connected thereto The upper portion of the block is fitted and fixed, and a neck portion is provided between the upper portion and the lower portion of the connecting block.