Hot melt adhesive spiral spray gun

Abstract

The utility model relates to the technical field of spiral spray guns, and particularly discloses a hot melt adhesive spiral spray gun which comprises a gun body, an air flow heating cavity, an air inlet, an air guide hole, a cavity sealing piece and an electrical bar are arranged at the bottom of the gun body, the electrical bar is used for heating air flow entering the air flow heating cavity, and the air flow heating cavity is composed of a plurality of bent channels; the glue spraying valve is connected and mounted on the gun body through a screw, a through hole is formed in the center of the glue spraying valve, and a coaxial two-stage threaded seat, a nozzle, a biconical valve core and a gas guide sleeve are sequentially arranged at the bottom of the glue spraying valve; by means of the conical matching structure of the air guide sleeve and the nozzle and the design of the air guide groove, a stable spiral airflow field is formed, spiral rubber threads with the width as low as 3 mm can be sprayed in combination with control over flowing of rubber liquid through the double-conical valve element, the rubber threads are evenly and continuously distributed, and the spraying effect is good. And the narrow bonding requirements of paper bag sealing, bonding of a wet locking cover and a packaging box and the like are met.

Description

Technical Field

[0001] This utility model belongs to the field of spiral spray gun technology, specifically relating to a hot melt adhesive spiral spray gun. Background Technology

[0002] Hot melt adhesive spraying technology is widely used in paper products, packaging, and sanitary materials. Its core principle is to heat the hot melt adhesive to a molten state and then spray it onto the substrate surface for rapid bonding. Traditional spraying equipment mostly uses linear spraying, but spiral spraying, due to its advantages such as uniform adhesive filament distribution and large bonding area, is gradually becoming the industry mainstream.

[0003] However, in practical applications, existing spiral spray guns suffer from inconsistent spiral air guide hole settings, which affect the spraying effect of spiral hot melt adhesive. When spraying spiral hot melt adhesive with a width of less than 5mm, the stability is not ideal. The requirements for the stability of spiral air pressure, hot melt adhesive pressure, and hot melt adhesive viscosity are extremely high, which can easily interrupt the spiral spraying and reduce the bonding strength of the object. Utility Model Content

[0004] The purpose of this invention is to provide a hot melt adhesive spiral spray gun to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A hot melt adhesive spiral spray gun, comprising:

[0007] The gun body has an airflow heating chamber, an air inlet, an air guide hole, a chamber seal, and an electric heating rod at its bottom. The electric heating rod is used to heat the airflow entering the airflow heating chamber, which is a channel composed of multiple bends.

[0008] The glue spray valve is installed on the gun body by screw connection. It has a through hole in the center. The bottom of the glue spray valve is provided with a coaxial two-stage threaded seat, a nozzle, a double conical valve core and an air guide sleeve in sequence.

[0009] The coaxial two-stage threaded seat has a glue channel hole at the top that extends to the bottom. The lower part of the rectangular surface of the coaxial two-stage threaded seat has a small-stage external thread and a large-stage external thread, and one side has an air inlet hole that communicates with the air guide hole. The end face of the large-stage external thread has several vent holes that communicate with the air inlet hole and are used to direct the heated airflow into the air guide sleeve.

[0010] The nozzle is fixed to a coaxial two-stage threaded seat by a small-stage external thread. The nozzle has a conical spray hole at its center and a conical surface on its outer periphery. The taper of the conical spray hole is between 20° and 24°. Several air guide grooves are provided on the conical surface.

[0011] The air guide sleeve is fixed to the coaxial two-stage threaded seat by a large external thread. The air guide sleeve has a conical through hole that matches the outer conical surface of the nozzle and forms a spiral air guide groove with the air guide groove.

[0012] Preferably, the lower part of the rectangular surface of the coaxial two-stage threaded seat is provided with two-stage external threads, wherein the smaller-stage external thread matches the internal thread of the nozzle, and the larger-stage external thread matches the internal thread of the air guide sleeve.

[0013] Preferably, the port of the conical through hole of the air guide sleeve is engaged with the outer conical surface of the nozzle, and the engagement of the two forms a continuous spiral air guide channel in the air guide groove.

[0014] Preferably, the air guide hole of the airflow heating chamber is coaxially connected to the air inlet hole of the coaxial two-stage threaded seat.

[0015] Preferably, the air guide groove of the nozzle is an inclined groove, the number of the air guide grooves is 4-8, the groove depth is 0.5-1.2mm, and they are evenly distributed on the outer conical surface. The central axis of the air guide groove makes an angle of 35°-45° with the central axis of the nozzle cone, and the central axis of the air guide groove makes an angle of 80°-88° with the tangent of the bottom surface of the cone. The starting point coincides with the tangent point.

[0016] Preferably, the heating rod extends along the axial direction of the airflow heating chamber.

[0017] Preferably, the gun body has a glue outlet on one side and a glue inlet on the other side, the glue outlet and the glue inlet are connected, and a filter screen is provided at the connection point.

[0018] Preferably, the double-cone valve core is disposed within the through hole of the glue spray valve, including a small conical end and a large conical end, the large conical end cooperating with the end face of the conical glue spray hole, and the angle range of the small conical end being 30°.

[0019] -40°, the angle range of the large conical end is 70°-80°, and the small conical end is used to push the remaining glue to accelerate the spraying when the glue is closed.

[0020] Preferably, the cavity seal is located at the bottom of the airflow heating cavity.

[0021] Preferably, the valve body of the glue spraying valve is provided with a glue inlet hole, which is located in the middle of the valve body and communicates with the glue outlet hole of the gun body, and the outlet end extends through to the glue channel hole of the coaxial two-stage threaded seat.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] (1) Through the conical matching structure of the air guide sleeve and the nozzle, and the design of the air guide groove, a stable spiral airflow field is formed. Combined with the control of the flow of adhesive by the double conical valve core, spiral adhesive filaments with a width as low as 3mm can be sprayed. The adhesive filaments are evenly and continuously distributed, meeting the bonding needs of application scenarios such as sealing paper bags, bonding moisture-locking caps and packaging boxes, and widths greater than 3mm.

[0024] (2) The large conical end of the double conical valve core fits tightly with the conical spray nozzle end face, quickly blocking the flow of adhesive; the small conical end pushes the remaining adhesive in the hole at the same time to remove the remaining adhesive, avoiding the pollution and waste caused by the negative pressure of the spiral airflow field on the nozzle orifice of the traditional spray gun.

[0025] (3) The airflow heating chamber adopts a multi-bend design, combined with the axial extension layout of the heating rod, to improve the heat exchange efficiency. Attached Figure Description

[0026] Figure 1 This is one of the perspective views of this utility model;

[0027] Figure 2 This is an exploded view of the present invention;

[0028] Figure 3 This is a cross-sectional view of the internal structure of this utility model;

[0029] Figure 4 This is an exploded view of the adhesive spraying valve, coaxial two-stage threaded seat, nozzle, and air guide sleeve of this utility model.

[0030] Figure 5 This is a cross-sectional view of the coaxial two-stage threaded seat, nozzle, and air guide sleeve of this utility model;

[0031] Figure 6 This is a second perspective view of the present utility model;

[0032] In the diagram: 1. Gun body; 101. Airflow heating chamber; 102. Air inlet; 103. Air guide port; 104. Chamber seal; 105. Heating rod; 106. Glue outlet; 107. Glue inlet; 108. Filter screen;

[0033] 2. Glue spray valve; 201. Glue inlet hole;

[0034] 3. Coaxial two-stage threaded seat; 301. Glue passage hole; 302. Small-stage external thread; 303. Large-stage external thread; 304. Air inlet hole; 305. Vent hole;

[0035] 4. Nozzle; 401. Conical spray nozzle; 402. Conical surface; 403. Air guide groove;

[0036] 5. Double conical valve core; 501. Small conical end; 502. Large conical end;

[0037] 6. Air guide sleeve; 601. Conical through hole. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] Example 1:

[0040] Please see Figures 1-6 As shown, a hot melt adhesive spiral spray gun includes:

[0041] The gun body 1 has an airflow heating chamber 101, an air inlet 102, an air guide hole 103, a chamber seal 104, and an electric heating rod 105 at its bottom. The electric heating rod 105 is used to heat the airflow entering the airflow heating chamber 101. The airflow heating chamber 101 is a channel composed of multiple bends.

[0042] The glue spraying valve 2 is installed on the gun body 1 by screw connection. It has a through hole in the center. The bottom of the glue spraying valve 2 is provided with a coaxial two-stage threaded seat 3, a nozzle 4, a double conical valve core 5 and an air guide sleeve 6 in sequence.

[0043] The coaxial two-stage threaded seat 3 has a glue channel hole 301 at the top that extends to the bottom. The lower part of the rectangular surface of the coaxial two-stage threaded seat 3 has a small-stage external thread 302 and a large-stage external thread 303. One side has an air inlet hole 304 that communicates with the air guide hole 103. The end face of the large-stage external thread 303 has several vent holes 305 that communicate with the air inlet hole 304 and are used to direct the heated airflow into the air guide sleeve 6.

[0044] The nozzle 4 is fixed to the coaxial two-stage threaded seat 3 by the small-stage external thread 302. The nozzle 4 has a conical spray hole 401 at its center and a conical surface 402 on its outer periphery. The conical spray hole 401 has a taper range of 20°-24°, which can reduce the flow rate of the adhesive and achieve finer adhesive filament stretching in conjunction with the spiral airflow. At the same time, it reduces turbulence and ensures the continuity and uniformity of the adhesive filament. Several air guide grooves 403 are provided on the conical surface 402.

[0045] The air guide sleeve 6 is fixed to the coaxial two-stage threaded seat 3 by the large-stage external thread 303. The air guide sleeve 6 has a conical through hole 601, which cooperates with the outer conical surface 402 of the nozzle 4 and forms a spiral air guide groove with the air guide groove 403.

[0046] In one embodiment of this utility model, the lower part of the rectangular surface of the coaxial two-stage threaded seat 3 is provided with two-stage external threads, wherein the smaller external thread 302 matches the internal thread of the nozzle 4, and the larger external thread 303 matches the internal thread of the air guide sleeve 6.

[0047] In one embodiment of this utility model, the port of the conical through hole 601 of the air guide sleeve 6 is engaged with the outer peripheral conical surface 402 of the nozzle 4, and the two are engaged to form a continuous spiral air guide channel in the air guide groove 403.

[0048] In one embodiment of this utility model, the air guide hole 103 of the airflow heating chamber 101 is coaxially connected with the air inlet hole 304 of the coaxial two-stage threaded seat 3.

[0049] In one embodiment of this invention, the air guide groove 403 of the nozzle 4 is an inclined groove. There are 4-8 air guide grooves 403, with a groove depth of 0.5-1.2 mm, evenly distributed on the outer conical surface 402. The angle between the central axis of the air guide groove 403 and the conical central axis of the nozzle 4 is 35°-45°. This angle directly affects the rotational intensity of the airflow. This angle range can balance the centrifugal force and axial velocity of the spiral airflow, preventing excessively rapid airflow diffusion. Furthermore, the angle between the central axis of the air guide groove 403 and the tangent to the bottom surface of the cone is 80°-88°, with the starting point coinciding with the tangent point. This near-vertical tangent angle enhances the tangential force between the airflow and the outer layer of the adhesive, forming a tightly wrapped spiral adhesive filament while reducing energy loss.

[0050] In one embodiment of the present invention, the heating rod 105 extends along the axial direction of the airflow heating chamber 101.

[0051] In one embodiment of this utility model, a glue outlet 106 is provided on one side of the gun body 1, and a glue inlet 107 is provided on the other side. The glue outlet 106 and the glue inlet 107 are connected, and a filter screen 108 is provided at the connection point.

[0052] In one embodiment of this utility model, the double-conical valve core 5 is disposed in the through hole of the glue spray valve 2, including a small conical end 501 and a large conical end 502. The large conical end 502 is engaged with the end face of the conical glue spray hole 401. The angle range of the small conical end 501 is 30°-40°. This angle design can quickly push out the residual glue when closed, reduce residue, and avoid glue overflow pollution. This angle range can ensure sufficient pushing force without increasing the friction between the valve core and the spray hole due to the angle being too small. The angle range of the large conical end 502 is 70°-80°. This angle can ensure a large contact area with the conical glue spray hole, improve sealing, and block the flow of glue more thoroughly. The small conical end 501 is used to push out the residual glue to accelerate spraying when the glue is closed.

[0053] In one embodiment of the present invention, the cavity seal 104 is disposed at the bottom of the airflow heating cavity 101.

[0054] In one embodiment of the present invention, the valve body of the glue spraying valve 2 is provided with a glue inlet hole 201. The glue inlet hole 201 is located in the middle of the valve body and communicates with the glue outlet hole 106 of the gun body 1. The outlet end passes through to the glue channel hole 301 of the coaxial two-stage threaded seat 3.

[0055] As can be seen from the above, during use, the power is first turned on and the heating rod 105 is started to preheat the airflow heating chamber 101 at the bottom of the gun body 1. External gas enters the heating chamber through the air inlet 102 and is heated to the set temperature through the curved channel.

[0056] Hot melt adhesive enters the gun body 1 through the glue inlet 107, and after impurities are filtered by the filter screen 108, it flows into the glue outlet 106. The hot melt adhesive enters the glue channel hole 301 of the coaxial two-stage threaded seat 3 through the glue inlet hole 201 of the glue valve 2, and is finally delivered to the tapered glue outlet 401 of the nozzle 4.

[0057] The heated airflow enters the air inlet 304 of the coaxial two-stage threaded seat 3 through the airflow heating chamber 101 via the air guide hole 103, and then flows into the air guide sleeve 6 through the vent hole 305 on the end face of the large-stage external thread 303. The conical through hole 601 of the air guide sleeve 6 is tightly fitted with the conical surface 402 on the outer periphery of the nozzle 4. The air guide groove 403 and the inner wall of the air guide sleeve 6 form a spiral air guide groove hole, which forces the airflow to be ejected in a spiral form.

[0058] Hot melt adhesive is sprayed out from the conical spray hole 401 of nozzle 4, while a spiral airflow surrounds the adhesive liquid. The rotation of the airflow causes the hot melt adhesive to form a spiral adhesive thread, which is evenly sprayed onto the target surface. The width of the spiral adhesive thread can be controlled by adjusting the air pressure or the parameters of the air guide groove 403, such as groove depth and angle.

[0059] When the glue is closed, the large conical end 502 of the double conical valve core 5 is in contact with the end face of the conical glue spraying hole 401, blocking the flow of glue. The small conical end 501 pushes the remaining glue in the hole to accelerate the spraying out, avoiding the residual glue from overflowing and contaminating the workpiece due to the negative pressure generated by the spiral airflow at the nozzle.

[0060] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hot melt adhesive spiral spray gun, characterized in that, include: The gun body (1) has an airflow heating chamber (101), an air inlet (102), an air guide hole (103), a chamber seal (104), and an electric heating rod (105) at its bottom. The electric heating rod (105) is used to heat the airflow entering the airflow heating chamber (101). The airflow heating chamber (101) is composed of multiple curved channels. The glue spray valve (2) is installed on the gun body (1) by screw connection. It has a through hole in the center. The bottom of the glue spray valve (2) is provided with a coaxial two-stage threaded seat (3), a nozzle (4), a double conical valve core (5) and an air guide sleeve (6) in sequence. The coaxial two-stage threaded seat (3) has a glue channel hole (301) at the top and extends to the bottom. The lower part of the rectangular surface of the coaxial two-stage threaded seat (3) is provided with a small-stage external thread (302) and a large-stage external thread (303). One side is provided with an air inlet (304) that communicates with the air guide hole (103). The end face of the large-stage external thread (303) is provided with several ventilation holes (305). The ventilation holes (305) communicate with the air inlet (304) and are used to direct the heated airflow into the air guide sleeve (6). The nozzle (4) is fixed to the coaxial two-stage thread seat (3) by a small external thread (302). The nozzle (4) has a conical spray hole (401) at its center and a conical surface (402) on its outer periphery. The conical spray hole (401) has a taper range of 20°-24° and a number of air guide grooves (403) on the conical surface (402). The air guide sleeve (6) is fixed to the coaxial two-stage thread seat (3) by a large external thread (303). The air guide sleeve (6) is provided with a conical through hole (601), which cooperates with the outer conical surface (402) of the nozzle (4) and forms a spiral air guide groove with the air guide groove (403).

2. The hot melt adhesive spiral spray gun according to claim 1, characterized in that: The small-stage external thread (302) matches the internal thread of the nozzle (4), and the large-stage external thread (303) matches the internal thread of the air guide sleeve (6).

3. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The port of the conical through hole (601) of the air guide sleeve (6) is engaged with the outer conical surface (402) of the nozzle (4), and the two are engaged to form a continuous spiral air guide channel in the air guide groove (403).

4. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The air guide hole (103) of the airflow heating chamber (101) is coaxially connected with the air inlet hole (304) of the coaxial two-stage threaded seat (3).

5. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The air guide groove (403) of the nozzle (4) is an inclined groove. The number of air guide grooves (403) is 4-8, the groove depth is 0.5-1.2mm, and they are evenly distributed on the outer conical surface (402). The central axis of the air guide groove (403) and the conical central axis of the nozzle (4) are at an angle of 35°-45°, and the central axis of the air guide groove (403) and the tangent of the bottom surface of the cone are at an angle of 80°-88°, with the starting point coinciding with the tangent point.

6. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The heating rod (105) extends along the axial direction of the airflow heating chamber (101).

7. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The gun body (1) has a glue outlet (106) on one side and a glue inlet (107) on the other side. The glue outlet (106) and the glue inlet (107) are connected, and a filter screen (108) is provided at the connection.

8. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The double-cone valve core (5) is located in the through hole of the glue spraying valve (2), including a small conical end (501) and a large conical end (502). The large conical end (502) is engaged with the end face of the conical glue spraying hole (401). The angle range of the small conical end (501) is 30°-40°, and the angle range of the large conical end (502) is 70°-80°. The small conical end (501) is used to push the remaining glue to accelerate the spraying when the glue is closed.

9. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The cavity seal (104) is located at the bottom of the airflow heating cavity (101).

10. A hot melt adhesive spiral spray gun according to claim 1, characterized in that: The glue spray valve (2) has a glue inlet hole (201) on its valve body. The glue inlet hole (201) is located in the middle of the valve body and communicates with the glue outlet hole (106) of the gun body (1). The outlet end passes through the glue channel hole (301) of the coaxial two-stage threaded seat (3).

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