Nozzle with multiple spraying holes for cooperative spraying, preparation method and application of nozzle to spraying additive equipment

Abstract

The invention discloses a nozzle with multiple spraying holes cooperatively spraying, a preparation method and application of the nozzle to spraying additive equipment. The nozzle comprises a nozzle body and the spraying holes formed in the nozzle body, the lower portion of the nozzle body is mainly composed of a plurality of layers of metal foils, and the spraying holes are composed of through holes basically and coaxially formed in all the metal foils; the preparation method comprises the steps that operation is carried out in a vacuum environment by means of a microscope, a plurality of layers of metal foils are stacked layer by layer in a mold according to the designed thickness, and all through holes in the same vertical position of the stacked metal foils are basically and coaxially formed; and the metal foil on the top layer is pressed through a pressing plate, then molten metal melt is poured around the metal foil, fine trimming and thread machining are conducted after cooling, and the nozzle is obtained. The nozzle of the binder injection system is low in machining cost and machining difficulty, the machining precision is easy to control, and the binder injection requirement can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of binder jetting, and in particular relates to a nozzle for coordinated jetting of multiple jet holes, a preparation method and an application thereof in a jetting additive device. Background Art

[0002] Binder jetting additive technology is an emerging technology that produces parts / components by combining binder jetting, powder laying and sintering processes. It has the advantages of high efficiency, low cost and suitability for mass production.

[0003] Binder jetting additive manufacturing mainly consists of a powder laying system, a binder jetting system, a motion control system and other parts. The nozzle of the binder jetting system is a very critical component in the entire equipment.

[0004] At present, the nozzles of the binder injection system mainly use nozzles with multiple nozzle holes for coordinated injection, such as the nozzle developed by Eskay Company with 1080 nozzle holes; the printing method and injection unit of the injection binder and catalyst disclosed in document CN112658208B use an integrated injection unit with dozens or even hundreds of nozzle holes; document CN1982067B discloses an inkjet head with a laminate structure, which contains several forming holes. However, the nozzle holes in the existing nozzles have problems such as high processing cost, high processing difficulty, and difficult to control processing accuracy. Summary of the invention

[0005] The purpose of the present invention is to provide a nozzle for coordinated injection of multiple nozzle holes, a preparation method and its application in injection additive equipment. The provided nozzle has the advantages of low processing cost, low processing difficulty and easy control of processing accuracy.

[0006] The present invention adopts the following technical solution.

[0007] A nozzle with multiple nozzle holes for coordinated injection comprises a nozzle body and nozzle holes arranged on the nozzle body. The lower part of the nozzle body is mainly composed of several layers of metal foils, and the nozzle holes are composed of through holes arranged substantially coaxially on all the metal foils.

[0008] As a preferred solution, the metal foil is copper foil or stainless steel foil.

[0009] As a preferred solution, the wall thickness of the metal foil does not exceed 0.5 mm.

[0010] As a preferred solution, each layer of metal foil is provided with a plurality of through holes arranged in an array, and the distance between adjacent through holes is no greater than 2 mm.

[0011] Furthermore, the metal foil has a length difference, so that the end of the metal foil forms a stepped structure, and all the edges of the metal foil are welded together. Adopting such a solution can ensure that the strength and rigidity of the nozzle meet the requirements, and the role of the stepped structure formed at the end of the metal foil includes: quickly guiding the metal melt to effectively weld with the end of the metal foil while taking into account the position accuracy of the through hole, and facilitating the shaping of the nozzle.

[0012] As a preferred solution, the surface roughness of the metal foil is no greater than 2 μm.

[0013] As a preferred solution, the through holes are distributed in a rectangular manner as a whole, so that the cross section of the ejected fluid is rectangular.

[0014] As a preferred solution, threads are provided above all edges of the metal foil as mounting parts of the nozzles.

[0015] As a preferred solution, all metal foils are copper foils with a wall thickness not exceeding 10 μm.

[0016] Furthermore, the method for preparing the nozzle comprises the following steps: Step 1, using a microscope to operate in a vacuum environment, first stacking several layers of metal foils in a mold according to the designed thickness, and all through holes at the same vertical position on the stacked metal foils are basically coaxially arranged; through holes are pre-processed on the metal foils; Step 2: Use a pressing plate to press the top metal foil, then pour molten metal around the metal foil, and after cooling, fine-tune and process the threads to obtain a nozzle.

[0017] Furthermore, the nozzle is installed on a jet additive device to spray metal powder binder droplets.

[0018] Beneficial effects: The nozzle of the binder injection system provided by the present invention has low processing cost, low processing difficulty, and easy control of processing accuracy, and can be processed by many copper foil processing plants; the nozzle provided by the present invention has a strength that is basically equivalent to that of a conventional nozzle, can meet the binder injection requirements, and the nozzle hole accuracy of the binder discharge section is high, which can meet the nozzle hole accuracy requirements of ten to twenty microns. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional schematic diagram of the nozzle in Example 1; Figure 2 A schematic diagram of the metal foils of the adjacent layers of the nozzle in Example 1; Figure 3 This is a schematic diagram of the stacked metal foils in Example 1; Figure 4 This is a schematic cross-sectional view of the nozzle in Example 1. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the present invention, the specific size of the working surface of the nozzle is adjusted by those skilled in the art according to actual needs. Example 1

[0021] Combination Figures 1 to 4 As shown, a nozzle for coordinated spraying with multiple nozzle holes is installed on a spray additive device for spraying metal powder binder droplets. The nozzle includes a nozzle body 1 and a nozzle hole 2 arranged on the nozzle body 1. The lower part of the nozzle body 1 is mainly composed of several layers of metal foil 4. The nozzle hole 2 is composed of through holes 3 arranged basically coaxially on all the metal foils. The upper part of the nozzle body 1 has threads and flow channels 6, and the middle part of the nozzle body 1 has a hexagonal structure and a fluid distribution chamber 5. In this embodiment, the metal foil 4 is made of copper foil with a wall thickness of 6μm, and the surface roughness of the metal foil 4 is not greater than 2μm. In this embodiment, a plurality of through holes 3 arranged in an array are provided on each layer of metal foil 4, and the spacing between adjacent through holes 3 is 1mm. The metal foil 4 of adjacent layers has a length difference (such as Figure 2 As shown, the Nth layer of metal foil 4 and the N+1th layer of metal foil 4 have a length difference, but the through holes 3 at the corresponding positions on the two layers of metal foil can be coaxial after being stacked), so that the end of the metal foil 4 forms a stepped structure 8, all the edges of the metal foil 4 are welded together, and threads are provided above the edges of all the metal foils 4 as the mounting part of the nozzle. Among them, the through holes 3 are distributed in a rectangular manner as a whole, so that the cross-section of the ejected fluid is rectangular as a whole.

[0022] In this embodiment, the metal foil 4 (copper foil) can be a customized microporous copper foil produced by Guangdong Jiayuan Technology Co., Ltd., or a commercially available copper foil can be purchased and etched to form holes to obtain a copper foil with through holes 3. The base edge size of all copper foils is the same. When processing the nozzle in the present invention, the operation is performed under a vacuum environment with the help of a microscope. First, several layers of copper foil are stacked layer by layer in a mold according to the designed thickness. All through holes 3 at the same vertical position on the stacked copper foil are basically coaxially arranged (except for error factors, they should be considered coaxial). The state at this time is as follows: Figure 3 As shown, the top copper foil is then pressed by a pressing plate, and then the molten copper is poured around the copper foil. After cooling, the copper foil is finely trimmed and the threads are processed to obtain the following: Figure 1 and Figure 4The nozzle shown. In this solution, the metal foil 4 (copper foil) and the parts other than the thread are all cast by melt. Since the extremely thin metal foil 4 (copper foil) is stacked together in a vacuum environment, the copper foils of adjacent layers can be completely attached to each other. In this state, the edges of the copper foil ( Figure 3 and Figure 4 The light-colored area (shown by the lines in the medium area) can be metallurgically combined with the melt after pouring the molten copper (the area with the through hole 3 on the copper foil will not be remelted), thereby fixing the multi-layer extremely thin microporous copper foil into shape.

[0023] The solution of the present invention greatly reduces the processing difficulty and processing cost of the nozzle (compared with the processing cost of hundreds or even thousands of yuan / piece for the existing 25μm aperture nozzles with basically the same specifications and performance, the processing cost of the nozzle in the present invention can be reduced to tens of yuan / piece), and it is easy to control the processing accuracy (during the processing, the accuracy of the through hole on the metal foil is mainly controlled. In this case, the difficulty of controlling the accuracy is much smaller than when directly forming a hole on the traditional nozzle body); although the present invention uses an extremely thin metal foil as a key component of the nozzle, it has a strength that is basically equivalent to that of a conventional nozzle (because the flexibility / flexibility disadvantage of the copper foil is overcome after the edges of multiple layers of tightly overlapping metal foils are fused and formed), can meet the requirements of binder injection, and the nozzle accuracy of the binder discharge section is high, which can meet the nozzle accuracy requirements of ten to twenty microns. Example 2

[0024] A nozzle for coordinated injection of multiple nozzle holes, referring to Example 1, the main difference between it and Example 1 is that the metal foil is made of stainless steel foil, and its wall thickness does not exceed 0.5 mm.

[0025] Although only one specification of copper foil is listed in Example 1, in the actual processing, the user can select copper foils of other thicknesses to process the through holes 3 according to the needs, wherein copper foils with a thickness of 3.5-20 μm are preferably used to process the through holes 3 .

Claims

1. A nozzle for coordinated injection of multiple nozzle holes, comprising a nozzle body (1) and nozzle holes (2) arranged on the nozzle body (1), characterized in that: The lower part of the nozzle body (1) is mainly composed of several layers of metal foil (4), and the spray hole (2) is composed of through holes (3) arranged substantially coaxially on all the metal foils.

2. The nozzle according to claim 1, characterized in that: The metal foil (4) is copper foil or stainless steel foil.

3. The nozzle according to claim 2, characterized in that: The wall thickness of the metal foil (4) does not exceed 0.5 mm.

4. The nozzle according to any one of claims 1 to 3, characterized in that: Each layer of metal foil (4) is provided with a plurality of through holes (3) arranged in an array, and the distance between adjacent through holes (3) is no greater than 2 mm.

5. The nozzle according to claim 4, characterized in that: The metal foils (4) have different lengths, so that the ends of the metal foils (4) form a stepped structure (8), and all the edges of the metal foils (4) are welded together.

6. The nozzle according to claim 5, characterized in that: The surface roughness of the metal foil (4) is no greater than 2 μm.

7. The nozzle according to claim 6, characterized in that: The through holes (3) are distributed in a rectangular manner as a whole, so that the cross-section of the ejected fluid is rectangular.

8. The nozzle according to claim 7, characterized in that: A thread is provided above the edge of the metal foil (4) as a mounting portion for the nozzle.

9. The method for preparing a nozzle according to any one of claims 1 to 8, characterized in that the steps include: Step 1, using a microscope to operate in a vacuum environment, first stacking a plurality of layers of metal foil (4) layer by layer in a mold according to a designed thickness, wherein all through holes (3) at the same vertical position on the stacked metal foil (4) are arranged substantially coaxially; the through holes (3) are pre-processed on the metal foil (4); Step 2, using a pressing plate to press the top metal foil (4), then pouring molten metal around the metal foil (4), and after cooling, fine trimming and thread processing to obtain a nozzle.

10. The use of the nozzle according to any one of claims 1 to 9 in a jetting additive device, characterized in that: The nozzle is installed on a jetting additive device to spray metal powder binder droplets.

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