Spray head for spraying and melting thermoplastic powder and spraying and melting device

Abstract

The utility model discloses a spray head and a spray melting device for thermoplastic powder spray melting, and the spray head comprises a pipe body which is hollow inside to form a heating cavity and a spray melting cavity which are communicated with each other; an air inlet is formed in one end of the heating cavity, so that an airflow channel from the heating cavity to the spraying and melting cavity is formed in the pipe body; the connected ends of the heating cavity and the spraying and melting cavity are shrunk inwards; a heating wire for heating airflow is arranged in the heat flow cavity; a feeding hole for thermoplastic powder to enter is formed in the side wall of the spraying and melting cavity; a drainage pipe is inserted into the feeding opening, and at least part of the drainage pipe protrudes out of the inner side wall of the spraying and melting cavity so as to guide the thermoplastic powder to enter the airflow channel from the position close to the middle of the spraying and melting cavity; according to the utility model, the spraying starting point of the thermoplastic powder is started from the inner middle part of the spraying and melting cavity, so that the thermoplastic powder is prevented from being quickly heated by hot air when entering the spraying and melting cavity initially, and is prevented from being adhered in the spraying process along the side wall of the spraying and melting cavity, the spraying efficiency is reduced, and the spraying uniformity is influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of material processing devices, in particular to a nozzle for thermoplastic powder melt spraying and a melt spraying device. Background Art

[0002] Thermoplastic powder refers to a coating with thermosetting resin as the main film-forming substance. When this coating is cured, the film-forming substance in the coating becomes a hard, insoluble and infusible polymer network structure through cross-linking and other reactions. The main varieties include amino alkyd coatings, thermosetting acrylic coatings, epoxy resin materials, polyester coatings and polyurethane coatings.

[0003] In the prior art, when a workpiece is sprayed with a spray gun dedicated to powder spraying, the thermoplastic powder enters one side of the pipe from the feed port on the spray gun, is melted at high temperature, and is sprayed onto the workpiece surface with the hot air flow. However, since the powder enters one side of the spray gun pipe during feeding, the powder first flows along the wall of the pipe with the hot air flow. However, due to the temperature change in the pipe, the thermoplastic powder is easily adhered to the side wall of the pipe, thereby affecting the spraying effect.

[0004] Therefore, it is necessary to provide a nozzle and a spraying device for thermoplastic powder spraying to solve the problem in the prior art that the thermoplastic powder is quickly heated by hot air when it first enters the spraying chamber, and forms adhesion during the spraying process along the side wall of the spraying chamber, thereby reducing the spraying efficiency and affecting the spraying uniformity. Utility Model Content

[0005] The utility model aims to provide a nozzle and a spraying device for thermoplastic powder spraying to solve the technical problems raised in the background technology.

[0006] In order to solve the above technical problems, the utility model specifically provides the following technical solutions:

[0007] In the first aspect of the utility model, a nozzle for thermoplastic powder melt spraying is provided, comprising: a tube body, the interior of which is hollow to form a heating chamber and a melt spraying chamber that are interconnected; an air inlet is provided at one end of the heating chamber to form an air flow channel from the heating chamber to the melt spraying chamber inside the tube body; the connecting ends of the heating chamber and the melt spraying chamber contract inwardly to form an air flow channel that contracts first and then expands inside the tube body; a heating wire for heating the air flow is provided in the heating chamber; a feed port for thermoplastic powder to enter is provided on the side wall of the melt spraying chamber; wherein a drainage tube is inserted inside the feed port, and the drainage tube at least partially protrudes from the inner wall of the melt spraying chamber to guide the thermoplastic powder to enter the air flow channel from a position close to the middle of the melt spraying chamber.

[0008] Furthermore, a baffle for blocking the airflow is provided at the end of the spray melting chamber near the feed port; wherein the baffle extends to the middle of the spray melting chamber along the blanking direction; the baffle extends from the central axis of the drainage tube to both sides along its width direction to form a flow blocking surface to hinder the airflow in the airflow channel from flowing through the discharge end of the drainage tube.

[0009] Furthermore, a baffle for blocking the airflow is provided at the end of the spray melting chamber near the feed port; wherein the baffle extends to the middle of the spray melting chamber along the blanking direction; the baffle extends to one side from the central axis of the drainage tube along its width direction to form a semi-blocking surface to hinder part of the airflow in the airflow channel from flowing through the discharge end of the drainage tube.

[0010] Furthermore, the baffle includes an arc-shaped curved plate; wherein, both sides of the baffle are bent along the airflow direction to form an arc-shaped curved plate; an insulation layer is provided on the inner curved surface of the arc-shaped curved plate to reduce heat absorption of the inner curved surface of the arc-shaped curved plate in the hot air flow.

[0011] Furthermore, the end of the baffle is arranged to be inclined toward the flow direction of the airflow.

[0012] In a second aspect of the present invention, a thermoplastic powder melt-spraying device is provided, which is applied with the thermoplastic powder melt-spraying nozzle provided in the first aspect, and the device comprises:

[0013] a powder container containing thermoplastic powder capable of being transported by the air flow;

[0014] A spray gun, one end of which is connected to the air inlet of the tube body, and a negative pressure element is provided inside the spray gun to form an air flow into the air flow channel;

[0015] The pipeline is used to connect the powder container and the drainage tube on the pipe body. The pipeline is provided with a pumping element for conveying the thermoplastic powder to the drainage tube.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The utility model can introduce the hot air in the heating chamber into the spray melting chamber through the arrangement of the pipe body, so as to melt the thermoplastic powder in the spray melting chamber, and then spray it onto the surface of the workpiece to be processed in time, and one side of the nozzle extends the drainage pipe to the inside of the spray melting chamber, so that the spraying starting point of the thermoplastic powder is from the inner middle part of the spray melting chamber, so as to avoid the thermoplastic powder being quickly heated by the hot air when it first enters the spray melting chamber, and forming adhesion in the process of spraying along the side wall of the spray melting chamber, thereby reducing the spraying efficiency and affecting the spraying uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0019] Figure 1 A schematic diagram of the structure of a thermoplastic powder spray melting device provided by the utility model;

[0020] Figure 2 A cross-sectional view of a nozzle for thermoplastic powder spraying provided by the utility model;

[0021] Figure 3 A cross-sectional view of a nozzle for thermoplastic powder spraying in another embodiment of the utility model;

[0022] Figure 4 for Figure 3 Schematic diagram of the position of the middle baffle in the tube body;

[0023] Figure 5 This is a schematic diagram of the position of the arc-shaped bent plate in the tube body in another embodiment provided by the utility model.

[0024] Figure 6 A cross-sectional view of a nozzle for thermoplastic powder spraying in another embodiment of the utility model;

[0025] Figure 7 This is a schematic structural diagram of an arc-shaped bent plate in another embodiment provided by the utility model.

[0026] The numbers in the figure represent the following:

[0027] 1. Tube body; 11. Heating chamber; 111. Air inlet; 12. Spray melting chamber; 121. Feeding port; 122. Drainage tube; 13. Heating wire; 2. Air flow channel; 3. Baffle; 31. Arc-shaped bent plate; 32. Insulation layer; 4. Powder container; 5. Spray gun; 6. Pipeline. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] like Figure 1-2As shown, the utility model provides a nozzle for thermoplastic powder melting and a thermoplastic powder melting device, the nozzle comprising:

[0030] The tube body 1 is hollow inside to form a heating chamber 11 and a spraying chamber 12 that are interconnected; an air inlet 111 is provided at one end of the heating chamber 11 to form an air flow channel 2 from the heating chamber 11 to the spraying chamber 12 inside the tube body 1; the connecting ends of the heating chamber 11 and the spraying chamber 12 are contracted inwardly to form an air flow channel 2 that contracts first and then expands inside the tube body 1; a heating wire 13 for heating the air flow is provided in the heating chamber 11; a feed port 121 for thermoplastic powder to enter is provided on the side wall of the spraying chamber 12;

[0031] A drainage tube 122 is inserted inside the feed port 121 , and the drainage tube 122 at least partially protrudes from the inner wall of the spray melting chamber 12 to guide the thermoplastic powder to enter the air flow channel 2 from a position close to the middle of the spray melting chamber 12 .

[0032] The utility model aims to introduce the hot air in the heating chamber 11 into the spray melting chamber 12 through the setting of the tube body 1, so as to melt the thermoplastic powder in the spray melting chamber 12, and then spray it onto the surface of the workpiece to be processed in time. In addition, one side of the nozzle provided by the utility model extends the drainage tube 122 into the inside of the spray melting chamber 12, so that the spraying starting point of the thermoplastic powder is from the inner middle part of the spray melting chamber 12, so as to avoid the thermoplastic powder being quickly heated by the hot air when it first enters the spray melting chamber 12, and forming adhesion during the process of spraying along the side wall of the spray melting chamber 12, thereby reducing the spraying efficiency and affecting the spraying uniformity.

[0033] In order to further delay the melting time of the powder entering from the feed port 121 in the hot air flow, as Figure 3 As shown, in the preferred embodiment provided by the utility model based on the above embodiment, a baffle 3 for blocking airflow is provided at the end of the spray melting chamber 12 close to the feed port 121;

[0034] Among them, the baffle 3 extends to the middle of the spray melting chamber 12 along the blanking direction; the baffle 3 extends from the central axis of the drainage tube 122 to both sides along its width direction to form a blocking surface to hinder the airflow in the airflow channel 2 from flowing through the discharge end of the drainage tube 122.

[0035] In this embodiment, a baffle 3 is provided upstream of the feed port 121 to obstruct the hot air flow, so that the powder can be exposed to the hot air after entering the spray-melting chamber 12 for a period of time, thereby delaying the melting time of the powder and preventing it from flowing along the side wall of the spray-melting chamber 12 with the hot air flow when it first enters the spray-melting chamber 12, causing adhesion during the flow process, thereby improving the efficiency of powder spraying and also facilitating the improvement of the powder spraying effect.

[0036] In the above embodiment, the powders flow out from the end of the baffle 3 together and are exposed to the hot air flow. During this process, a large amount of powders are heated and melted by the hot air. Due to the temperature change in the tube body 1, the powder particles are easily bonded together, thereby affecting the spraying effect.

[0037] In order to solve the above problems, Figure 4 As shown, in the preferred embodiment provided by the utility model based on the above embodiment, a baffle 3 for blocking airflow is provided at the end of the spray melting chamber 12 close to the feed port 121;

[0038] Among them, the baffle 3 extends to the middle of the spray melting chamber 12 along the blanking direction; the baffle 3 extends to one side from the central axis of the drainage tube 122 along its width direction to form a semi-blocking surface to hinder part of the airflow in the airflow channel 2 from flowing through the discharge end of the drainage tube 122.

[0039] In this embodiment, the baffle 3 partially shields the falling powder, so that the powder entering the spray melting chamber 12 can be heated and melted in at least two streams, which can reduce the problem of sintering when the powder particles are heated together.

[0040] In order to prevent the powder from melting and adhering to the baffle 3 under the heat conduction effect, Figure 5 , 7 As shown, the baffle 3 includes an arc-shaped bent plate 31;

[0041] The two sides of the baffle 3 are bent along the airflow direction to form an arc-shaped curved plate 31; a heat insulation layer 32 is provided on the inner curved surface of the arc-shaped curved plate 31 to reduce the heat absorption of the inner curved surface of the arc-shaped curved plate 31 in the hot airflow.

[0042] In this embodiment, the arrangement of the arc-shaped bent plate 31 can not only guide the oncoming hot air flow to prevent the air flow from hitting the baffle 3 and causing excessive air flow resistance, but also the arrangement of the heat insulation layer 32 can ensure that the heat absorbed by the side of the arc-shaped bent plate 31 in contact with the powder is not sufficient to melt the powder, thereby reducing the occurrence of powder sticking to the arc-shaped bent plate 31.

[0043] More specifically, in order to further reduce the probability of powder bonding on the baffle 3, as Figure 6 As shown, in the preferred embodiment provided by the utility model based on the above embodiment, the end of the baffle 3 is inclined toward the flow direction of the airflow.

[0044] In this embodiment, by means of the inclined baffle plate 3, most of the powder does not contact the baffle plate 3 when falling into the spray melting chamber 12, thereby preventing the heat absorbed by the baffle plate 3 from melting the powder and causing adhesion.

[0045] The utility model provides a thermoplastic powder spray melting device based on any of the above embodiments, comprising:

[0046] a powder container 4, wherein the powder container 4 contains thermoplastic powder that can be transported with the air flow;

[0047] The spray gun 5 has one end connected to the air inlet 111 of the tube body 1, and a negative pressure element is provided inside the spray gun 5 to form an air flow into the air flow channel 2;

[0048] The pipeline 6 is used to connect the powder container 4 and the drainage tube 122 on the tube body 1 . The pipeline 6 is provided with a pumping element for conveying the thermoplastic powder to the drainage tube 122 .

[0049] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A nozzle for thermoplastic powder spraying, characterized in that: include: The tube body (1) is hollow inside and forms a heating chamber (11) and a spraying chamber (12) which are interconnected; An air inlet (111) is provided at one end of the heating chamber (11) to form an air flow channel (2) from the heating chamber (11) to the spraying chamber (12) inside the tube body (1); The connecting ends of the heating chamber (11) and the spray melting chamber (12) are contracted inwardly to form an air flow channel (2) inside the tube body (1) that contracts first and then expands; A heating wire (13) for heating the airflow is provided in the heating chamber (11); A feed port (121) for thermoplastic powder to enter is provided on the side wall of the spray melting chamber (12); A drainage tube (122) is inserted into the feed port (121), and the drainage tube (122) at least partially protrudes from the inner wall of the spray-melting chamber (12) to guide the thermoplastic powder to enter the airflow channel (2) from a position close to the middle of the spray-melting chamber (12).

2. The nozzle for thermoplastic powder melting according to claim 1, characterized in that: A baffle (3) for blocking airflow is provided at the end of the spray melting chamber (12) close to the feed port (121); Wherein, the baffle (3) extends to the middle of the spray melting chamber (12) along the material falling direction; The baffle (3) extends from the central axis of the guide tube (122) to both sides along its width direction to form a flow blocking surface to prevent the airflow in the airflow channel (2) from flowing through the discharge end of the guide tube (122).

3. The nozzle for thermoplastic powder melting according to claim 1, characterized in that: A baffle (3) for blocking airflow is provided at the end of the spray melting chamber (12) close to the feed port (121); Wherein, the baffle (3) extends to the middle of the spray melting chamber (12) along the material falling direction; The baffle (3) extends from the central axis of the guide tube (122) to one side along its width direction to form a semi-blocking surface to prevent part of the airflow in the airflow channel (2) from flowing through the discharge end of the guide tube (122).

4. The nozzle for thermoplastic powder melt spraying according to claim 2 or 3, characterized in that: The baffle (3) comprises an arc-shaped bent plate (31); Wherein, the two sides of the baffle (3) are bent along the airflow direction to form the arc-shaped bent plate (31); A heat insulation layer (32) is provided on the inner curved surface of the arc-shaped curved plate (31) to reduce heat absorption by the inner curved surface of the arc-shaped curved plate (31) in the hot air flow.

5. The nozzle for thermoplastic powder melting according to claim 4, characterized in that: The end of the baffle (3) is arranged to be inclined toward the flow direction of the airflow.

6. A thermoplastic powder spraying device using the thermoplastic powder spraying nozzle according to claim 5, characterized in that: include: a powder container (4), wherein the powder container (4) contains thermoplastic powder that can be transported along with the air flow; A spray gun (5), one end of which is connected to the air inlet (111) of the tube body (1), and a negative pressure element is provided inside the spray gun (5) for forming an air flow to enter the air flow channel (2); A pipeline (6) is used to connect the powder container (4) and the drainage pipe (122) on the pipe body (1); the pipeline (6) is provided with a pumping element for conveying thermoplastic powder to the drainage pipe (122).

Images