A glue spraying device

Abstract

The application discloses a glue spraying device and belongs to the technical field of spraying equipment. The glue spraying device comprises a gun body, a spraying head and a protective cap. The gun body is provided with a gas flow channel and a glue liquid flow channel. The spraying head is connected with the gun body. The spraying head is provided with a main spraying hole and a plurality of auxiliary spraying holes which are arranged around the main spraying hole in a circumferential direction. The main spraying hole is in communication with the gas flow channel and the glue liquid flow channel. The auxiliary spraying holes are in communication with the gas flow channel. The protective cap is sleeved on the outer periphery of the spraying head and is connected with the gun body. The protective cap is provided with a through flow guide cavity. The flow guide cavity is oppositely arranged with the spraying head. The inner diameter of the flow guide cavity gradually expands along the jet direction of the spraying head. A plurality of flow guide holes are arranged around the spraying head on the peripheral wall of the flow guide cavity. At the cross section of the protective cap corresponding to the flow guide hole, the line between the flow guide hole and the center of the cross section and the axis of the flow guide hole jointly define a flow guide angle. The glue spraying device is favorable for reducing flying objects generated during glue spraying and improving the effective adhesion rate of the glue spraying.

Description

Technical Field

[0001] This invention relates to the field of spraying equipment technology, and in particular to a glue spraying device. Background Technology

[0002] In related technologies, when glue guns spray glue, there is generally a lot of glue flying off, meaning that a large amount of glue is scattered into non-target areas, causing pollution and hindering factory assembly line operations. In addition, there is a defect of low effective adhesion rate of the glue. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a glue spraying device that helps to reduce flying debris generated during glue spraying and improves the effective adhesion rate of the glue.

[0004] According to an embodiment of the present invention, a glue spraying device includes: a gun body having a gas flow channel and a glue flow channel; a nozzle connected to the gun body, the nozzle having a main spray hole and a plurality of auxiliary spray holes arranged circumferentially around the main spray hole, the main spray hole communicating with the gas flow channel and the glue flow channel, and the auxiliary spray holes communicating with the gas flow channel; a protective cap sleeved on the outer periphery of the nozzle and connected to the gun body, the protective cap having a through-flow guiding cavity, the guiding cavity being disposed opposite to the nozzle, the inner diameter of the guiding cavity gradually increasing along the jet direction of the nozzle, the protective cap having a plurality of guiding holes arranged around the nozzle on the peripheral wall of the guiding cavity; at the cross-section of the protective cap corresponding to the guiding hole, the line connecting the guiding hole and the center of the cross-section and the axis of the guiding hole together define the guiding angle.

[0005] According to embodiments of the present invention, the adhesive spraying device has at least the following beneficial effects: the gun body has a gas flow channel and an adhesive flow channel, the nozzle is connected to the gun body, the nozzle has a main spray hole communicating with the gas flow channel and the adhesive flow channel, and a secondary spray hole communicating with the gas flow channel, and multiple secondary spray holes are arranged around the main spray hole. The mounting device also includes a protective cap, the protective cap has a guide cavity that is arranged opposite to and penetrates the nozzle, the inner diameter of the guide cavity gradually expands along the spraying direction of the nozzle, that is, the inner diameter of the guide cavity is gradually expanding. The protective cap can constrain and guide the adhesive sprayed by the nozzle through the arrangement of the guide cavity, which can make the spraying of the adhesive more concentrated, which is beneficial to improving the effective adhesion rate of the sprayed adhesive and maintaining a certain degree of scattering. The main spray hole mixes the adhesive with the gas. After being combined, the air is sprayed out, forming the main atomized airflow. Multiple secondary nozzles are arranged around the main nozzle. After the secondary nozzles spray airflow, they can form a protective airflow around the main atomized airflow, thereby reducing the contact between the main atomized airflow and the inner wall of the protective cap, reducing the residue of the adhesive at the protective cap. The protective airflow can suppress the flying objects generated by the main atomized airflow and reduce the interference of external airflow on the main atomized airflow, improving the stability of the main atomized airflow. The protective cap has multiple guide holes arranged around the nozzle on the peripheral wall of the guide cavity, and the guide holes have a certain guide angle, which makes the main atomized airflow generate a composite motion of tangential and axial directions, which is conducive to improving the atomization effect of the adhesive and further reducing the particle size of the atomized particles, thereby improving the effect of adhesive spraying.

[0006] According to some embodiments of the present invention, the inner wall surface of the flow guiding cavity is provided with a hydrophobic coating and a hydrophilic coating, the hydrophobic coating and the hydrophilic coating are arranged sequentially along the jet direction of the nozzle, and the flow guiding hole is located in the coverage area of ​​the hydrophilic coating.

[0007] According to some embodiments of the present invention, multiple guide holes are located at the same cross-section of the protective cap, and the multiple guide holes are arranged at circumferential intervals.

[0008] According to some embodiments of the present invention, a plurality of flow guide holes are distributed along a spiral on the inner wall surface of the flow guide cavity.

[0009] According to some embodiments of the present invention, the arrangement of the plurality of guide holes conforms to the following formula:

[0010] r = a + bθ

[0011] Where r is the radial distance from the center of the guide hole to the axis of the guide cavity, θ is the polar angle of the line connecting the center of the guide hole and the axis of the guide cavity, a is the initial radius of the helix, and b is the expansion coefficient of the helix.

[0012] According to some embodiments of the present invention, the axial length of the helix is ​​L, and the ratio of L to the axial length of the guide cavity ranges from 0.55 to 0.7; L satisfies the following formula:

[0013]

[0014] Where, θ max θ is the maximum unfolding angle of the helix, and θ0 is the minimum unfolding angle of the helix.

[0015] According to some embodiments of the present invention, the gun body is provided with a mixing chamber, one end of which is connected to a gas flow channel and a glue flow channel, and the other end is connected to a main spray hole. The mixing chamber has an inner constriction section, the inner diameter of which gradually decreases in the direction of approaching the nozzle.

[0016] According to some embodiments of the present invention, the inner wall surface of the concave section is provided with a plurality of guide blocks arranged circumferentially at intervals. The guide blocks extend spirally around the axis of the mixing chamber to guide the fluid to swirl. The guiding swirl direction of the guide blocks is the same as the guiding swirl direction of the guide holes.

[0017] According to some embodiments of the present invention, the gun body further includes a housing, a drive block, and a linear drive component. The nozzle and the protective cap are both connected to the housing. The housing is provided with a gas flow channel and a glue flow channel. The drive block is disposed inside the housing and communicates with the gas flow channel and the glue flow channel. The drive block and the nozzle together define a mixing chamber. The linear drive component is connected to the housing and the drive block to drive the drive block to move closer to or away from the nozzle.

[0018] According to some embodiments of the present invention, the protective cap is provided with a groove at the end away from the guide hole, the outer periphery of the nozzle is provided with a limiting ring, a gasket and a sealing ring are provided in the groove, one end of the gasket abuts against the end face of the groove, the other end of the gasket abuts against the limiting ring, and the sealing ring is used to close the end of the limiting ring away from the guide hole.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0021] Figure 1 This is a schematic diagram of the structure of the glue spraying device according to an embodiment of the present invention, showing the separation of the nozzle and the protective cap;

[0022] Figure 2 This is a schematic diagram of the combined structure of the nozzle and protective cap of the glue spraying device according to an embodiment of the present invention;

[0023] Figure 3 for Figure 2 The front view of the glue spraying device shown in the figure;

[0024] Figure 4 for Figure 3 A cross-sectional view of the glue spraying device shown in the figure;

[0025] Figure 5 for Figure 3 The protective cap of the glue spraying device is shown in a cross-sectional view at the corresponding guide hole;

[0026] Figure 6 This is a partial structural diagram of the nozzle and protective cap of the glue spraying device according to an embodiment of the present invention, combined with the gun body.

[0027] Icon labels:

[0028] 100. Nozzle; 110. Main nozzle; 120. Secondary nozzle; 130. Limiting ring;

[0029] 200, Protective cap; 210, Flow guide cavity; 220, Flow guide hole; 230, Slot; 240, Rotating part; 250, Internal thread;

[0030] 300. Gun body; 310. Gas flow channel; 320. Glue flow channel; 330. Threaded rod; 340. Drive block; 350. Mixing chamber; 360. Retracting section; 370. Annular chamber. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0033] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0034] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0035] Reference Figures 1 to 6As shown, an embodiment of the adhesive spraying device of the present invention includes: a gun body 300, a spray head 100, and a protective cap 200.

[0036] Reference Figure 1 , Figure 2 and Figure 6 As shown, the gun body 300 can be held by the user or connected to the frame. The gun body 300 has a gas flow channel 310 and an adhesive flow channel 320. The adhesive spraying device can be used with an external air pump and adhesive pump. The air pump can be connected to the gas flow channel 310 to supply high-pressure gas into the gas flow channel 310. The adhesive pump is connected to the adhesive flow channel 320 to supply the adhesive to be sprayed into the adhesive flow channel 320.

[0037] Reference Figure 1 , Figure 2 and Figure 6 As shown, the nozzle 100 is fixedly connected to the gun body 300. The nozzle 100 can be used to assist in the atomization of the adhesive. Specifically, the rear end of the nozzle 100 is connected to the front end of the gun body 300. The middle part of the front end of the nozzle 100 is provided with a main spray hole 110. The main spray hole 110 is connected to the gas flow channel 310 and the adhesive flow channel 320 to achieve the mixing of gas and adhesive. Under the shearing action of high-pressure airflow, the adhesive is atomized to form the main atomizing airflow. The nozzle 100 also has multiple secondary nozzles 120 arranged circumferentially around the main nozzle 110 at its front end. These secondary nozzles 120 are connected to the gas flow channel 310 to form a protective airflow surrounding the main atomizing airflow. The protective airflow from the multiple secondary nozzles 120 collectively forms an air curtain around the main atomizing airflow, thereby reducing the contact between the main atomizing airflow and the inner wall of the protective cap 200, reducing the residue of colloid at the protective cap 200. The protective airflow suppresses flying debris generated by the main atomizing airflow and reduces interference from external airflow, improving the stability of the main atomizing airflow. The diameter of the main nozzle 110 is larger than the diameter of the secondary nozzles 120.

[0038] Reference Figure 3 , Figure 4 and Figure 5 As shown, the adhesive spraying device also includes a protective cap 200, which is sleeved on the outside of the nozzle 100 and fixedly connected to the front end of the gun body 300. The protective cap 200 has a through-flow guiding cavity 210, which is arranged opposite to the nozzle 100. The inner diameter of the guiding cavity 210 gradually expands along the jet direction of the nozzle 100, that is, the inner diameter of the guiding cavity 210 is gradually expanding. The protective cap 200 can constrain and guide the adhesive sprayed by the nozzle 100 through the arrangement of the guiding cavity 210, which can make the spraying of the adhesive more concentrated, which is beneficial to improving the effective adhesion rate of the sprayed adhesive and maintaining a certain degree of scattering.

[0039] Reference Figure 3 , Figure 4and Figure 5 As shown, the protective cap 200 has multiple guide holes 220 arranged around the nozzle 100 on the peripheral wall of the guide cavity 210. At the cross-section of the protective cap 200 corresponding to the guide hole 220, the line connecting the guide hole 220 and the center of the cross-section and the axis of the guide hole 220 together define the guide angle. Through the setting of the guide hole 220, the main atomizing airflow and the protective airflow generate a composite motion of tangential and axial directions. The protective cap 200 can guide the airflow to generate swirling flow through the setting of the guide hole 220. For atomized particles with larger particle size, they are guided and thrown towards the inner wall of the protective cap 200 to form a liquid film and achieve secondary atomization. Atomized particles with smaller particle size mainly move along the axial direction, which improves the uniformity of particle size distribution by about 40%.

[0040] Reference Figure 3 , Figure 4 and Figure 5 As shown, the inventors conducted multiple experiments. The experimental data showed that by setting the guide hole 220 on the protective cap 200, the atomized particle size was reduced from the original 58μm to 32μm, and the particle size distribution span (SPAN) value was reduced to 0.81, which improved the atomization effect of the colloid and further reduced the particle size of the atomized particles, thereby improving the effect of spraying adhesive.

[0041] Reference Figure 1 , Figure 3 and Figure 4 As shown, it can be understood that the inner wall surface of the flow guiding cavity 210 is provided with a hydrophobic coating and a hydrophilic coating, and the hydrophobic coating and the hydrophilic coating are arranged sequentially along the jet direction of the nozzle 100, and the flow guiding hole 220 is located in the coverage area of ​​the hydrophilic coating.

[0042] Reference Figure 1 , Figure 3 and Figure 4 As shown, the adhesive spraying device employs a coating design on the inner wall of the guide cavity 210 to achieve an alternating distribution of hydrophobic and hydrophobic coatings. The protective cap 200 uses a superhydrophobic coating (contact angle > 150°) in the coverage area near the nozzle 100, which helps reduce adhesive residue on the wall. The protective cap 200 uses a moderately hydrophilic coating (contact angle 60° to 90°) in the coverage area of ​​the guide cavity 210 away from the nozzle 100, thereby guiding the atomized particles to form a thin liquid film and undergo secondary atomization. This effectively reduces material loss and decreases the particle size of the atomized particles, thus improving the uniformity of the adhesive spraying.

[0043] Reference Figure 1 , Figure 3 and Figure 4 As shown, the inventors conducted multiple experiments, and the experimental data showed that, compared with traditional spraying equipment, after the adhesive spraying device worked continuously for 8 hours, the amount of adhesive residue decreased from the original 3.2g to 0.08g, the cleaning cycle was extended by five times, and the maintenance frequency was greatly reduced.

[0044] It should be noted that the hydrophobic coating can be a nano-silica / fluorosilane composite material, carbon nanotube (CNT) or graphene-based coating, etc. The hydrophilic coating can be polyvinylpyrrolidone, polyethylene glycol or plasma-treated polymer, etc., which will not be elaborated here.

[0045] Reference Figure 3 , Figure 4 and Figure 6 As shown, it is understandable that, considering that the protective cap 200 bears a greater force in the area near the nozzle 100 than in the area away from the nozzle 100, the thickness of the protective cap 200 gradually decreases along the expansion direction of the guide cavity 210. That is, the protective cap 200 is thicker at the rear end of the guide cavity 210 and thinner at the front end of the guide cavity 210. This enhances the overall stability of the protective cap 200 and reduces the manufacturing cost of the adhesive spraying device.

[0046] Reference Figure 3 , Figure 4 and Figure 5 As shown, it can be understood that multiple guide holes 220 are located at the same cross-section of the protective cap 200, and the multiple guide holes 220 are arranged at equal intervals. All guide holes 220 are located on the circumference of the same cross-section of the protective cap 200, and the angle (guide angle) between their central axis and the line connecting the center of the guide hole 220 and the center of the circle forms the direction of the synthesis of tangential and axial velocity components. The tangential component can be used to induce airflow to generate swirling flow, enhance centrifugal classification, and allow larger particles to contact the wall of the protective cap 200 to achieve secondary atomization. The axial component can maintain the propulsion of the main atomizing airflow.

[0047] Reference Figure 3 , Figure 4 and Figure 5 As shown, the adhesive spraying device, through the circumferential arrangement of multiple guide holes on the protective cap 200, can generate a self-cleaning effect of the flow field. By guiding the airflow in the guide cavity 210 to generate swirling flow, the circumferential shear force generated by the swirling flow can not only achieve the shearing of atomized particles, but also be used to peel off the adhesive residue on the inner wall of the protective cap 200, thereby further reducing the amount of adhesive residue, extending the cleaning cycle, and reducing the maintenance frequency.

[0048] It should be understood that, in some other embodiments, a plurality of flow guide holes 220 are distributed along a spiral on the inner wall surface of the flow guide cavity 210.

[0049] Specifically, the arrangement of the multiple guide holes 220 conforms to Archimedes' spiral formula:

[0050] r = a + bθ

[0051] Where r is the radial distance from the center of the guide hole 220 to the axis of the guide cavity 210, θ is the polar angle of the line connecting the center of the guide hole 220 and the axis of the guide cavity 210, a is the initial radius of the helix, and b is the expansion coefficient of the helix.

[0052] That is, the adhesive spraying device plans multiple guide holes 220 according to the Archimedes spiral formula so as to generate uniform swirling flow in the guide cavity 210, reduce turbulence, and help to reduce the fluctuation range of the spraying width, resulting in a smaller uniformity of the film thickness formed by spraying.

[0053] This adhesive spraying device can be specifically designed to adjust the spiral expansion coefficient according to the viscosity of the adhesive. For example, for high-viscosity adhesives (>1000 mPa·s): the value of b is increased to enhance centrifugal force and prevent droplet aggregation; for low-viscosity adhesives (<10 mPa·s): the value of b is decreased to suppress excessive fragmentation and prevent the dispersion of nano-sized droplets. Specifically, the value of b ranges from 0.05 to 0.2r. a can be the radius of the guide cavity 210 at a certain cross-section.

[0054] Furthermore, the axial length of the flow guiding cavity 210 of the adhesive spraying device is S, and L is the axial length of the spiral. The ratio of L to S ranges from 0.55 to 0.7. L is also the axial length of the flow guiding cavity 210 in the hydrophilic coating. That is, the adhesive spraying device increases the weight of the hydrophilic coating to extend the coverage area of ​​the hydrophilic coating to match the requirements of fluid spread.

[0055] Specifically, L satisfies the following formula:

[0056]

[0057] Where, θ max θ0 is the maximum unfolding angle of the helix, which can be 360°, and θ0 is the minimum unfolding angle of the helix, which can be 0°.

[0058] This adhesive spraying device can use the aforementioned formula to define the axial length of the spiral, i.e., the axial length of the guide cavity 210 within the hydrophilic coating. This combines the geometric characteristics of the synchronous motion of the Archimedean spiral with the physical requirements of fluid diffusion, thereby achieving a match between the gradually expanding shape of the guide cavity 210 and the spiral parameters. This helps reduce energy loss and is particularly suitable for applications that balance flow field uniformity and structural compactness. Specifically, the guide holes 220 are provided with 10 holes.

[0059] Reference Figure 1 , Figure 2 and Figure 6As shown, it can be understood that in this embodiment, the gun body 300 is provided with a mixing chamber 350. One end of the mixing chamber 350 is connected to the gas flow channel 310 and the adhesive flow channel 320, and the other end is connected to the main spray hole 110. The mixing chamber 350 has an inner diameter section 360, and the inner diameter of the inner diameter section 360 gradually narrows in the direction of approaching the nozzle 100.

[0060] Reference Figure 1 , Figure 2 and Figure 6 As shown, the adhesive spraying device can achieve gas and adhesive mixing in advance through the setting of the mixing chamber 350, so as to improve the mixing uniformity. Furthermore, the change of the inner diameter of the concave section 360 is beneficial to increasing the jet speed of the main atomizing airflow, which is beneficial to improving the effective adhesion rate of the sprayed adhesive.

[0061] Reference Figure 1 , Figure 2 and Figure 6 As shown, it should be understood that in some other embodiments, the inner wall surface of the recessed section 360 is provided with a plurality of guide blocks arranged circumferentially at intervals. The guide blocks extend spirally around the axis of the mixing chamber 350 to guide the fluid to swirl. The guiding swirl direction of the guide blocks is the same as the guiding swirl direction of the guide hole 220.

[0062] Reference Figure 1 , Figure 2 and Figure 6 As shown, the spraying device, through the setting of the guide block, can make the main atomized airflow sprayed out have a certain swirling flow, and the guiding swirling direction of the guide block is consistent with the guiding swirling direction of the guide hole 220. The two can play a superimposed role. The swirling flow causes the atomized particles to be broken down a second time through the centrifugal force, so as to improve the uniformity of the atomization of the colloid, which is conducive to further reducing the particle size of the atomized particles and reducing the particle size distribution span value.

[0063] Reference Figure 1 , Figure 2 and Figure 6 As shown, it can be understood that in this embodiment, the gun body 300 also includes a housing, a drive block 340, and a linear drive component. The nozzle 100 and the protective cap 200 are both connected to the housing. The housing is provided with a gas flow channel 310 and an adhesive flow channel 320. The drive block 340 is disposed inside the housing and communicates with the gas flow channel 310 and the adhesive flow channel 320. The drive block 340 and the nozzle 100 together define a mixing chamber 350. The linear drive component is connected to the housing and the drive block 340 to drive the drive block 340 to move closer to or away from the nozzle 100.

[0064] Reference Figure 1 , Figure 2 and Figure 6As shown, specifically, the linear drive component includes a threaded rod 330. The rear end of the housing is provided with a threaded hole. The threaded rod 330 is threadedly connected to the threaded hole and rotatably connected to the drive block 340. The drive block 340 can restrict the rotation of the drive block 340 by the mutual limiting of its wall surface and the inner wall surface of the housing, thereby restricting the movement of the drive block 340 to linear sliding relative to the housing.

[0065] Reference Figure 1 , Figure 2 and Figure 6 As shown, the user can rotate the threaded rod 330 in the forward direction and adjust the engagement position of the threaded rod 330 with the threaded hole, thereby driving the drive block 340 to slide forward in a straight line relative to the housing, so that the drive block 340 is closer to the nozzle 100, thereby reducing the space of the mixing chamber 350, thereby increasing the impact flow velocity and enhancing the shear force, which is suitable for scenarios requiring fine atomization.

[0066] Reference Figure 1 , Figure 2 and Figure 6 As shown, the user can rotate the threaded rod 330 in the opposite direction and adjust the engagement position of the threaded rod 330 with the threaded hole, thereby driving the drive block 340 to slide backward in a straight line relative to the housing, so that the drive block 340 is further away from the nozzle 100, thereby increasing the space of the mixing chamber 350, which can prolong the residence time of the fluid in the chamber and make the adhesive and gas more fully mixed. By adjusting the size of the mixing chamber 350, the atomization requirements of adhesives with different viscosities can be matched.

[0067] Reference Figure 1 , Figure 2 and Figure 6 As shown, specifically, the rear end of the drive block 340 is provided with a first through hole communicating with the gas flow channel 310, so that the high-pressure gas flow can enter the mixing chamber 350 from the adhesive flow channel 320. The rear end of the drive block 340 is provided with a second through hole communicating with the adhesive flow channel 320, so that the adhesive can enter the mixing chamber 350 from the adhesive flow channel 320.

[0068] Reference Figure 1 , Figure 2 and Figure 6 As shown, it is understandable that in order to ensure that the mixing chamber 350 maintains good sealing during the linear sliding of the drive block 340 along the housing, thereby reducing adhesive leakage, the nozzle 100 has a rearwardly open positioning groove at the main spray hole 110. The front end shape of the drive block 340 is adapted to the shape of the positioning groove, and the recessed section 360 is located at the front end of the drive block 340. Through the fit between the outer peripheral surface of the drive block 340 and the inner peripheral surface of the positioning groove, it is ensured that the gap between the drive block 340 and the nozzle 100 will not increase during the linear sliding of the drive block 340.

[0069] Reference Figure 1 , Figure 2 and Figure 6 As shown, specifically, the rear end of the positioning groove is cylindrical, and the front end of the drive block 340 is also cylindrical, so that the drive block 340 fits into the rear end of the positioning groove. A sealing strip can be provided on the inner edge of the rear end of the positioning groove. The sealing strip abuts against the outer circumferential surface of the drive block 340 to reduce the risk of adhesive leakage.

[0070] Reference Figure 1 , Figure 2 and Figure 6 As shown, it can be understood that the outer peripheral surface of the front end of the drive block 340 and the inner wall surface of the nozzle 100 together define the annular chamber 370. The annular chamber 370 is arranged around the main nozzle 110 and communicates with multiple auxiliary nozzles 120. The housing is provided with a bypass branch. One end of the bypass branch is connected to the gas flow channel 310, and the other end of the bypass branch is connected to the annular chamber 370. The opening of the bypass branch adjacent to the gas flow channel 310 exceeds the sliding stroke of the drive block 340, thereby avoiding the problem of the drive block 340 sliding and causing the bypass branch to close.

[0071] Reference Figure 1 , Figure 2 and Figure 6 As shown, the gas can pass through the bypass branch and enter the annular chamber 370, and then be ejected from the secondary nozzle 120, thereby forming a protective airflow around the main atomizing airflow to suppress flying objects generated by the main atomizing airflow and reduce interference caused by the external environment, so as to improve the stability of the spray adhesive.

[0072] Reference Figure 1 , Figure 2 and Figure 6 As shown, it can be understood that the protective cap 200 has a slot 230 at the end away from the guide hole 220, and the protective cap 200 has an internal thread 250 at the end of the slot 230 away from the guide hole 220. Correspondingly, the front end of the gun body 300 has an external thread.

[0073] Reference Figure 1 , Figure 2 and Figure 6 As shown, after the nozzle 100 is fixed to the front end of the gun body 300, the user can put the protective cap 200 on the outside of the nozzle 100 and fix the protective cap 200 to the gun body 300 through the cooperation of the internal thread 250 and the external thread. The slot 230 is provided with a gasket and a sealing ring. One end of the gasket abuts against the end face of the slot 230, and the other end of the gasket abuts against the limiting ring 130. The sealing ring is used to close the end of the limiting ring 130 away from the guide hole 220, so that the gasket and the sealing ring are located on both sides of the limiting ring 130 respectively. The gasket can play a buffering and sealing role, and the sealing ring is used to seal the rear end of the nozzle 100.

[0074] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that the outer peripheral surface of the rear end of the protective cap 200 is provided with a rotating part 240. The outer surface of the rotating part 240 is provided with multiple grooves arranged circumferentially at intervals. The multiple grooves are arranged in a circular and equally spaced manner, that is, the outer peripheral surface of the rear end of the protective cap 200 is provided with a textured surface. The rotating part 240 is provided corresponding to the internal thread 250 on the inner side of the protective cap 200, so as to increase the coefficient of friction between the rotating part 240 of the protective cap 200 and the human hand, so that the user can rotate the protective cap 200 by rotating the rotating part 240 to realize the assembly or disassembly of the protective cap 200 and the gun body 300.

[0075] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A glue spraying device, characterized in that, The application relates to a spraying gun, comprising: a gun body (300) provided with a gas flow channel (310) and a glue flow channel (320); a spraying head (100) connected with the gun body (300), wherein the spraying head (100) is provided with a main spraying hole (110) and a plurality of auxiliary spraying holes (120) arranged around the main spraying hole (110), the main spraying hole (110) is communicated with the gas flow channel (310) and the glue flow channel (320), and the auxiliary spraying holes (120) are communicated with the gas flow channel (310); a protective cap (200) sleeved on the outer periphery of the spraying head (100) and connected with the gun body (300), wherein the protective cap (200) is provided with a flow guide cavity (210) penetrating through the protective cap (200), the flow guide cavity (210) is arranged opposite to the spraying head (100), the inner diameter of the flow guide cavity (210) gradually increases along the jet direction of the spraying head (100), the protective cap (200) is provided with a plurality of flow guide holes (220) arranged around the spraying head (100) on the peripheral wall of the flow guide cavity (210), and the line connecting the flow guide hole (220) with the center of the section and the axis of the flow guide hole (220) jointly define a flow guide angle at the section corresponding to the flow guide hole (220) of the protective cap (200); the inner wall surface of the flow guide cavity (210) is provided with a hydrophobic coating and a hydrophilic coating, the hydrophobic coating and the hydrophilic coating are arranged in sequence along the jet direction of the spraying head (100), and the flow guide hole (220) is arranged in the covered area of the hydrophilic coating; the gun body (300) is provided with a mixing cavity (350), one end of the mixing cavity (350) is communicated with the gas flow channel (310) and the glue flow channel (320), the other end of the mixing cavity (350) is communicated with the main spraying hole (110), and the mixing cavity (350) is provided with an inner contraction section (360), the inner diameter of the inner contraction section (360) gradually decreases towards the direction close to the spraying head (100); the inner wall surface of the inner contraction section (360) is provided with a plurality of flow guide blocks arranged in a circumferential interval, the flow guide blocks extend spirally around the axis of the mixing cavity (350) and are used for guiding the rotational flow of fluid, and the rotational flow direction of the flow guide blocks is the same as that of the flow guide hole (220).

2. The glue spraying apparatus according to claim 1, wherein: A plurality of flow guide holes (220) are arranged on the same cross section of the protective cap (200), and the plurality of flow guide holes (220) are arranged in a circumferential interval.

3. The glue spraying apparatus of claim 1, wherein: A plurality of flow guide holes (220) are arranged in a spiral line on the inner wall surface of the flow guide cavity (210).

4. The glue spraying apparatus of claim 3, wherein: The arrangement of the plurality of flow guide holes (220) meets the following formula: wherein r is the radial distance of the center of the flow guide hole (220) to the axis of the flow guide cavity (210), is the polar angle of the line connecting the center of the flow guide hole (220) and the axis of the flow guide cavity (210), a is the initial radius of the spiral, and b is the expansion coefficient of the spiral.

5. The glue application apparatus of claim 4, wherein: the axial length of the spiral line is L, the ratio of L to the axial length of the flow guide cavity (210) ranges from 0.55 to 0.7, and L meets the following formula: ； wherein is the maximum unwinding angle of the helix, is the minimum unwinding angle of the helix.

6. The glue spraying apparatus of claim 1, wherein: The gun body (300) further comprises a shell, a driving block (340) and a linear driving member, the spray head (100) and the protective cap (200) are connected with the shell, the shell is provided with the gas flow channel (310) and the glue flow channel (320), the driving block (340) is arranged in the shell, the driving block (340) is communicated with the gas flow channel (310) and the glue flow channel (320), the driving block (340) and the spray head (100) jointly define the mixing cavity (350), and the linear driving member is connected with the shell and the driving block (340) to drive the driving block (340) to move close to or away from the spray head (100).

7. The glue spraying apparatus of claim 1, wherein: The protective cap (200) is provided with a clamping groove (230) at one end away from the flow guide hole (220), the outer periphery of the spray head (100) is arranged in a limiting ring (130), a gasket and a sealing ring are arranged in the clamping groove (230), one end of the gasket abuts against the end face of the clamping groove (230), the other end of the gasket abuts against the limiting ring (130), and the sealing ring is used for closing one end of the limiting ring (130) away from the flow guide hole (220).

Images