Anti-blocking liquid injection spray gun

Abstract

The utility model provides a kind of anti-blocking liquid injection spray gun, it is related to spray gun field, including spray pipe, and the one end of spray pipe is equipped with spout;Valve needle, valve needle can be moved in the spray pipe along its axis, there is the passage for liquid flow in the inner wall of valve needle and spray pipe;Wherein, valve needle end has valve needle extension, when valve needle extension moves with valve needle, close the spout or form liquid flow channel with the spout.The utility model, the conical frustum portion of valve needle extension is completely embedded or covered on spout, forms reliable physical seal, this not only can prevent liquid drip, more importantly, the contact of liquid and air at spout is isolated, to effectively prevent the blockage caused by liquid solidification.

Description

Technical Field

[0001] This utility model relates to the field of spray guns, and in particular to an anti-clogging liquid injection spray gun. Background Technology

[0002] In existing spray gun structures (such as...) Figure 1 and Figure 2 As shown in the diagram, when the nozzle is closed, the valve needle retracts into the nozzle to form an annular groove. This design creates a stagnation space with volume between the valve needle retraction end and the nozzle inner wall. Under high temperature and high pressure conditions, the molten medium seeps into this stagnation space through the nozzle gap under fluid pressure. Due to heat conduction, the medium solidifies or pyrolyzes and carbonizes within the stagnation space. The continuous accumulation of solid residues reduces the nozzle flow cross-sectional area until it is completely blocked, leading to two types of technical defects: firstly, complete nozzle blockage causes functional failure, preventing the medium from being ejected; secondly, in the partially blocked state, the medium flow channel exhibits unsteady changes, causing abnormal pulsations in injection pressure and uncontrollable fluctuations in output flow, severely affecting process stability. Utility Model Content

[0003] The purpose of this invention is to provide an anti-clogging liquid injection gun to solve the above-mentioned technical problems.

[0004] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: A clog-resistant liquid injection gun includes a nozzle with a nozzle at one end; a valve needle that can move along its axis inside the nozzle, and the valve needle and the inner wall of the nozzle have a channel for liquid flow. The valve needle has a valve needle extension at its end. When the valve needle moves, the valve needle extension either closes the nozzle or forms a liquid flow channel with the nozzle.

[0005] Preferably, the valve needle extension has a frustum-shaped structure, with the narrow end of the frustum-shaped structure connected to the main body of the valve needle and the wide end facing outward; when the valve needle extension closes the nozzle, it is inverted and sealed onto the nozzle.

[0006] Preferably, it also includes an elastic element for applying a biasing force to the valve needle to tend to close the nozzle.

[0007] Preferably, it further includes a receiving pipe connected to the nozzle, the receiving pipe being used to receive liquid, the pressure generated by the liquid entering the receiving pipe acting on the valve needle to overcome the biasing force of the elastic element, causing the valve needle to move to the open position.

[0008] Preferably, it also includes a spacer at the end of the nozzle away from the nozzle, and a valve needle extends outward from the nozzle and the spacer into the receiving tube; A septum, which is fitted over the outward-extending part of the valve needle; A nut, which is screwed onto the outwardly protruding part of the valve needle against the spacer, is used to adjust the axial position of the spacer relative to the spacer sleeve; The elastic element is a spring, which is located in the spacer. One end of the spring enters a pre-set slot at the nozzle port, and the other end abuts against the spacer.

[0009] Preferably, adjusting the nut can change the initial distance between the spacer and the spacer sleeve.

[0010] Preferably, the spacer sleeve is provided with at least one through hole for liquid to pass through, so that liquid entering the receiving pipe can flow into the channel.

[0011] Preferably, the end of the nozzle away from the nozzle is connected to a receiving pipe, and the interior of the receiving pipe forms a accommodating space for receiving external liquid supply lines and buffering liquid pressure.

[0012] Preferably, the valve needle has two centering posts with a flat structure. The centering posts ensure that the valve needle axis always coincides with the nozzle axis, and the liquid can pass through the centering posts.

[0013] The beneficial effects of this utility model are: In this invention, the truncated cone portion of the valve needle extension is completely embedded in or covers the nozzle, forming a reliable physical seal. This not only prevents liquid leakage, but more importantly, it isolates the liquid at the nozzle from contact with air, thereby effectively preventing blockage caused by liquid solidification. Attached Figure Description

[0014] Figure 1 This is a structural diagram of an existing spray gun in its closed state; Figure 2 for Figure 1 The diagram shows the structure of the spray gun in the open state; Figure 3 This is a structural diagram of an anti-clogging liquid injection gun in its closed state. Figure 4 for Figure 3 The diagram shows the structure of the spray gun in the open state; Figure 5 for Figure 3 Enlarged view of point A in the middle; Figure 6 for Figure 4 Enlarged view at point B in the middle; Reference numerals: 1. Nozzle; 2. Receiving pipe; 3. Sealing gasket; 4. Valve needle; 5. Spacer; 6. Through hole; 7. Spring; 8. Spacer plate; 9. Nut; 10. Valve needle extension; 11. Nozzle; 12. Centering column. Detailed Implementation

[0015] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0017] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0018] Example 1 This embodiment presents an anti-clogging liquid injection gun; please refer to [link / reference]. Figures 3-6 The anti-clogging liquid injection gun includes a nozzle 1, which is a hollow tubular structure with a nozzle 11 at its front end for liquid injection. The rear end of the nozzle 1 is fixedly connected to a receiving pipe 2 via a threaded connection (a sealing gasket 3 is used at the connection to enhance the sealing effect). The interior of the receiving pipe 2 forms a receiving space for connecting to an external liquid supply line (not shown) and also serves to buffer the liquid pressure. A valve needle 4 is a slender rod coaxially disposed inside the nozzle 1. The outer diameter of the valve needle 4 is smaller than the inner diameter of the nozzle 1, thus forming an annular channel for liquid to flow from the rear of the gun to the nozzle 11 at the front. Further, the valve needle 4 contains two centering posts 12. The outer diameter of the centering posts 12 is the same as the inner diameter of the nozzle 1, and they are then milled flat to allow liquid to pass through. The centering posts 12 ensure that the axis of the valve needle 4 always coincides with the axis of the nozzle 1. The key innovation of this invention lies in the front end of the valve needle 4, which is integrally formed or firmly connected to a special valve needle extension 10. In this preferred embodiment, the valve needle extension 10 is designed as a frustum-shaped structure. The narrow end of the frustum smoothly transitions and connects to the body of the valve needle 4, while its wide end faces outwards towards the nozzle 11. This design allows the frustum-shaped side of the valve needle extension 10 to fit tightly with the inner edge or end face of the nozzle 11 when the valve needle 4 moves forward to the closed position, forming an inverted, highly effective sealing cap structure.

[0019] Please continue reading. Figures 3-6The nozzle 1 has a stepped groove at the end away from the nozzle 11. Additionally, a spacer 5, a spring 7, a spacer plate 8, and an adjusting nut 9 are provided. Further, the spacer 5 is an annular or tubular gasket fixed to the rear end of the nozzle 1, or integrally formed with the nozzle 1. At least one (usually multiple, to ensure smooth fluid flow) through hole 6 is formed in the wall of the spacer 5. The tail of the valve needle 4 passes through the rear end of the nozzle 1, the central hole of the spacer 5, and extends outward into the interior of the receiving tube 2. A disc-shaped spacer plate 8 is fitted onto this extended portion of the valve needle 4. The spring 7 is housed within the spacer 5 (the spring 7 fits the valve needle 4), with one end of the spring 7 abutting against a specially provided groove at the rear end of the nozzle 1, and the other end abutting against the side of the spacer plate 8 facing the spacer 5. The spring 7 constantly applies an outward pushing force to the partition 8. This force is transmitted to the valve needle 4 through the partition 8, thus creating a biasing force that causes the valve needle 4 to move forward and close the nozzle 11. The end of the protruding portion of the valve needle 4 is machined with external threads, and two nuts 9 are screwed onto these external threads and tightly abut against the outside of the partition 8. In this embodiment, when there is no external liquid pressure, the spring 7 is in its preset compressed state. At this time, the truncated cone portion of the valve needle extension 10 is completely embedded in or covers the nozzle 11, forming a reliable physical seal. This not only prevents liquid leakage, but more importantly, it isolates the liquid at the nozzle 11 from contact with air, thereby effectively preventing blockage caused by liquid solidification. Conversely, when the external liquid supply system starts working, liquid with a certain pressure enters the receiving pipe 2, and the liquid fills the receiving pipe 2's accommodating space and enters the channel between the valve needle 4 and the nozzle 1 through the through hole 6 on the partition 5. At this time, the liquid pressure acts on all effective pressure-bearing surfaces of the valve needle 4 and the partition 8 facing the direction of liquid flow, generating a powerful hydraulic thrust pointing backwards towards the nozzle. When this hydraulic thrust exceeds the preset bias force of the spring 7, the valve needle 4 will move against the elastic force of the spring 7. The backward movement of the valve needle 4 causes its front valve needle extension 10 to disengage from the nozzle 11, thereby forming an annular liquid flow channel between them. The liquid then flows through this channel and is ejected at high speed from the nozzle 11.

[0020] The flow rate regulation function in this embodiment is achieved by adjusting the maximum opening stroke of the valve needle 4. The operator can change its axial position on the threaded rod of the valve needle 4 by rotating the nut 9. When the nut 9 is tightened clockwise, the partition 8 is pushed closer to the spacer 5, which reduces the initial distance between the partition 8 and the rear end face of the spacer 5. Therefore, the maximum backward stroke that the valve needle 4 can move under liquid pressure is correspondingly reduced. A smaller stroke means a smaller cross-sectional area of ​​the liquid flow channel formed between the valve needle extension 10 and the nozzle 11, resulting in a smaller liquid flow rate. Conversely, when the nut 9 is loosened counterclockwise, the initial distance between the partition 8 and the spacer 5 increases, the maximum backward stroke of the valve needle 4 also increases, the cross-sectional area of ​​the liquid flow channel increases, thereby increasing the liquid flow rate. In this way, the user can conveniently, intuitively and repeatably set the required injection flow rate according to process requirements.

[0021] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0022] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A clog-resistant liquid injection gun, characterized in that: Includes a nozzle, with a nozzle at one end; The valve needle can move along its axis inside the nozzle, and there is a channel between the valve needle and the inner wall of the nozzle for liquid flow. The valve needle has a valve needle extension at its end. When the valve needle moves, the valve needle extension either closes the nozzle or forms a liquid flow channel with the nozzle.

2. The anti-clogging liquid injection gun according to claim 1, characterized in that: The valve needle extension has a truncated cone structure. The narrow end of the truncated cone structure is connected to the main body of the valve needle, and the wide end faces outward. When the valve needle extension closes the nozzle, it is inverted and sealed on the nozzle.

3. A clog-resistant liquid injection gun according to claim 1 or 2, characterized in that: It also includes an elastic element for applying a biasing force to the valve needle to tend to close the nozzle.

4. The anti-clogging liquid injection gun according to claim 3, characterized in that: It also includes a receiving pipe that communicates with the nozzle. The receiving pipe is used to receive liquid. The pressure generated by the liquid entering the receiving pipe acts on the valve needle, overcoming the biasing force of the elastic element, and causing the valve needle to move to the open position.

5. The anti-clogging liquid injection gun according to claim 4, characterized in that: It also includes a spacer sleeve, which is located at the end of the nozzle away from the nozzle, and a valve needle extends outward from the nozzle and the spacer sleeve into the receiving tube. A septum, which is fitted over the outward-extending part of the valve needle; A nut, which is screwed onto the outwardly protruding part of the valve needle against the spacer, is used to adjust the axial position of the spacer relative to the spacer sleeve; The elastic element is a spring, which is located in the spacer. One end of the spring enters a pre-set slot at the nozzle port, and the other end abuts against the spacer.

6. The anti-clogging liquid injection gun according to claim 5, characterized in that: The initial distance between the spacer and the spacer sleeve is changed by adjusting the nut.

7. A clog-resistant liquid injection gun according to claim 6, characterized in that: The spacer is provided with at least one through hole for liquid to pass through, so that the liquid entering the receiving pipe can flow into the channel.

8. A clog-resistant liquid injection gun according to claim 6, characterized in that: The end of the nozzle away from the nozzle is connected to the receiving pipe, and the interior of the receiving pipe forms a accommodating space for receiving external liquid supply lines and buffering liquid pressure.

9. A clog-resistant liquid injection gun according to claim 1, characterized in that: The valve needle has two centering posts, which are flat structures. The centering posts ensure that the valve needle axis always coincides with the nozzle axis.

10. A clog-resistant liquid injection gun according to claim 9, characterized in that: Liquid can pass through the centering column.

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