WO2014205937A1 - Nozzle of spray gun, and spray gun thereof - Google Patents

Abstract

A nozzle (10) comprises a cylindrical connecting portion (11), a conical transition portion (12), and a cylindrical spray head (13). An upper bottom surface of the cylindrical connecting portion (11) and a lower bottom surface of the conical transition portion (12) are coplanar. The nozzle (10) is integrally molded by using tungsten steel. A spray gun comprises the nozzle (10), a nozzle supporting frame (20) in communication with a spray gun feed tank, and a spray needle (30) disposed in the nozzle supporting frame (20) and used for closing or opening the nozzle (10). The cylindrical connecting portion (11) of the nozzle (10) is connected to the nozzle supporting frame (20) in an interference-fitted manner. In the nozzle (10) of the spray gun, tungsten steel is used to replace conventional stainless steel, and accordingly, the nozzle (10) has better abrasion resistance and longer service life.

Description

 Gun nozzle and its spray gun

View

 The present invention relates to a spray gun nozzle and spray gun, and more particularly to a spray gun for spraying paint and/or paint. Scene

 Spray guns are often used in painting or other spray processes. The paint or paint spray gun works by pulling the spray gun hand assembly off the nozzle and creating a pressure differential between the pressure in the tank and the air pressure in front of the nozzle to eject the material from the tank.

 During the operation of the gun, the needle often collides with the nozzle to open the nozzle or close the nozzle. At the same time, the material in the tank is usually chemical, which easily corrodes the nozzle and causes the nozzle to wear. After the nozzle is worn, the needle does not effectively close the nozzle, so that the gun does not work properly, and the nozzle needs to be replaced frequently.

 The prior art, such as the Chinese patent "Abrasion Resistant Nozzle for Spray Guns" of the publication No. CN202006142U, discloses that the nozzle and the spray gun are separately designed and then pressed or welded together. However, this patent only gives a very rough idea of the split design of the nozzle and the spray gun. After the nozzle and the spray gun are separately designed, how to solve the problem of fixed connection between the nozzle and the spray gun, how to solve the concentric circle problem caused by the split design of the nozzle and the spray gun, and how to solve the problem of sealing the needle and the nozzle become a split nozzle The problems that must be solved with the industrialization and large-scale production of spray guns.

Summary of the invention

The object of the present invention is to solve the above problems in the prior art, and to provide a spray gun nozzle which has a long service life, a good sealing effect and is suitable for industrial applications. m 3⁄4

 The object of the present invention can be achieved by the following technical solutions: a spray gun nozzle comprising a cylindrical connecting portion, a conical transition portion and a cylindrical nozzle portion; the nozzle is integrally formed of tungsten steel and has a Rockwell hardness HRC greater than 70 The inner surface roughness Ra of the cylindrical nozzle portion is less than or equal to 0.4, the outer surface roughness Ra of the cylindrical connecting portion is less than or equal to 0.8, and the concentricity of the cylindrical nozzle portion and the cylindrical connecting portion is within 0.02 mm.

 In the above spray gun nozzle, the composition of the tungsten steel includes tungsten carbide, titanium carbide, cobalt, nickel, and a trace component, and the mass of the tungsten carbide and the titanium carbide is not less than 80% of the total mass, and the mass of the cobalt and the nickel is not Less than 15% of the total mass.

 In the above spray gun nozzle, in the tungsten steel, the mass percentage of tungsten carbide is 80-82%, the mass percentage of titanium carbide is 4 to 6%, the mass percentage of cobalt is 8-10%, and the mass percentage of nickel is 5 to 8%.

 In the above spray gun nozzle, the trace components include molybdenum, silicon and sulfur.

 The invention also provides a spray gun comprising the above nozzle, a nozzle support frame communicating with the spray gun tank, and a spray needle disposed inside the nozzle support frame for closing or opening the nozzle; the nozzle support frame is made of stainless steel material, The cylindrical connecting portion of the nozzle is connected with the nozzle support by an interference fit, and the interference is less than or equal to 0.03 mm; the concentricity of the cylindrical head portion, the cylindrical connecting portion and the nozzle holder is within 0.02 mm.

 In the above spray gun, a hand-held assembly is also included for controlling the advance or retreat motion of the needle.

 In the above-described spray gun, a plurality of through holes circumferentially distributed around the central axis of the nozzle are formed on the front end surface of the nozzle support frame, and the through holes spray gas when the nozzle sprays the raw material to atomize the raw material.

 In the above lance, the axis of each of the through holes is at an angle of less than 45 degrees with respect to the central axis of the nozzle.

By adopting the invention, the following beneficial effects are obtained: m 3⁄4

 1. The nozzle is made of tungsten steel material, and the inner surface is smooth and polished, so that the nozzle has good wear resistance, long service life and is very suitable for spraying spray guns, paints and other chemicals. And the needle can be well sealed to the nozzle.

 2. The nozzle is made of tungsten steel, and the nozzle support is made of stainless steel. The hardness of the tungsten steel is greater than the hardness of the stainless steel so that the cylindrical connection of the nozzle can be directly matched with the nozzle support without the need to provide other sealing fittings. At the same time, only the nozzle part of the entire spray gun is made of tungsten steel, which also saves costs.

 3. Although the nozzle is closely matched with the nozzle support body, it is possible to replace only the smaller volume nozzle when the nozzle is worn for a long time or inadvertently colliding without any replacement, thereby reducing the cost.

 4. The parameters are used to define the surface roughness of the nozzle, the concentricity and the interference of the spray gun, etc., so that the nozzle is suitable for industrial production, and the sealing performance of the nozzle and the needle is better, and the connection performance between the nozzle and the spray gun is better, the spray gun The atomization effect of the sprayed material is more

turn off

 Figure 1 is a perspective view of a nozzle of the present invention;

 Figure 2 is a perspective view of the nozzle of Figure 1 in close fitting connection with the nozzle support;

 Figure 3 is a cross-sectional view of the spray gun of the present invention when the nozzle is closed;

 Figure 4 is a cross-sectional view showing the spray gun of the present invention with the nozzle open. ^

 The technical examples of the present invention are further described below with reference to the specific embodiments of the present invention, but the present invention is not limited to the embodiments.

Referring to FIG. 1, in a preferred embodiment of the present invention, the nozzle 10 includes a cylindrical connecting portion 11, a conical transition portion 12, and a cylindrical head portion 13. m 3⁄4

 The nozzle is integrally formed of tungsten steel material, the nozzle has a Rockwell hardness HRC of more than 70, the inner surface roughness Ra is less than or equal to 0.4, the outer surface roughness Ra of the cylindrical connecting portion is less than or equal to 0.8, and the cylindrical nozzle portion and the cylindrical connecting portion The concentricity is within 0.02 mm.

 The Rockwell hardness value of the nozzle is limited, so that the tungsten steel material of the nozzle is different from the general tungsten steel material.

 The tungsten steel material may be selected from tungsten steel materials which are more common to those skilled in the art, such as tungsten steel materials of the grades YG3X, YG6A, YK15. Preferably, in this embodiment, the composition of the tungsten steel material comprises tungsten carbide, titanium carbide, cobalt, nickel and trace components, the mass of the tungsten carbide and the titanium carbide is not less than 80% of the total mass, the quality of the cobalt and the nickel and not Less than 15% of the total mass. Tungsten carbide and titanium carbide are used as refractory metal compounds, and cobalt and nickel are used as bonding metal components. Preferably, the mass percentage of tungsten carbide is 80 to 82%, the mass percentage of titanium carbide is 4 to 6%, the mass percentage of cobalt is 8 to 10%, the mass percentage of nickel is 5 to 8%, and the mass of the trace component is Less than 1% of the total mass, even 0. Among them, the trace components mainly involve one, two or three of molybdenum, silicon and sulfur.

 Tungsten carbide as a main component ensures high hardness and wear resistance of tungsten steel as a whole, and the addition of a small amount of titanium carbide can improve the brittleness of the material. A small amount of trace components can change the mechanical properties of the tungsten steel.

 In one embodiment, the mass percentages of the tungsten steel components are: tungsten carbide 80%, titanium carbide 4%, cobalt 8%, nickel 7%, and molybdenum 1%. The tungsten steel HRC is 75.

 In another embodiment, the mass percentages of the tungsten steel components are: tungsten carbide 81%, titanium carbide 5%, cobalt 9%, and nickel 5%. The tungsten steel HRC is 73.

 In another embodiment, the mass percentages of the tungsten steel components are: tungsten carbide 82%, titanium carbide 5%, cobalt 8%, and nickel 5%. The tungsten steel HRC is 83.

In another embodiment, the mass percentage of each component of the tungsten steel is: tungsten carbide 80%, titanium carbide 6%, cobalt 8%, nickel 5%, molybdenum 0.8%, silicon 0.18%, sulfur 0.02%. m 3⁄4

The tungsten steel HRC is 85.

 Limiting the roughness of the inner surface of the cylindrical nozzle portion of the nozzle makes the needle and nozzle seal better. If the roughness of the inner surface of the cylindrical nozzle is not up to standard, there will be a gap between the nozzle and the needle, resulting in leakage of material or The atomization is uneven when the raw material is ejected.

 The outer surface roughness value defining the cylindrical connecting portion is such that the fixing effect of the cylindrical connecting portion and the nozzle supporting portion are in an interference fit.

 The concentricity of the cylindrical nozzle portion and the cylindrical connecting portion is defined so that when the material is ejected from the nozzle, no deflection occurs, and the atomization effect of the material is more uniform.

 Please refer to Figure 2, Figure 3, and Figure 4. Fig. 2 is a perspective view showing the nozzle 10 of Fig. 1 in close fitting relationship with the nozzle supporting body 20. Fig. 3 and Fig. 4 are respectively sectional views showing the nozzle of the present invention when the nozzle is closed and the nozzle is opened. The spray gun of the present invention comprises a nozzle 10, a nozzle support frame 20 in communication with a spray gun tank (not shown), and a spray needle 30 disposed within the nozzle support frame 20 for closing or opening the nozzle.

 The working principle of the spray gun of the present invention is as follows: The initial state of the spray gun is the state shown in Fig. 3, the spray needle 30 seals the nozzle 10, and when the hand held assembly of the spray gun (not shown) is pulled, the spray needle 30 moves backward so that The nozzle 10 is opened, at which time a small vacuum area is formed in front of the nozzle 10, the gas tank has a gas pressure, and the gas pressure difference between the tank and the vacuum area causes the raw material stored in the tank to be sprayed out through the nozzle. After spraying, the hand held assembly is released and the needle 30 seals the nozzle 10 again.

 As can be seen from the above description, the nozzle 10 of the spray gun of the present invention is often in contact with high speed chemicals while also requiring frequent collisions with the needle 30. The above problems are effectively solved by using the above-mentioned nozzle made of tungsten steel material, and the nozzle life can be as long as three years or more.

In addition, the performance requirements of other parts of the spray gun are not exactly the same as those of the nozzle 10. The nozzle 10 mainly emphasizes its wear resistance, while the nozzle holder 20 mainly emphasizes its toughness and cost. The tough nozzle support 20 can be well matched with other parts of the spray gun. For example, the nozzle support frame 20 made of stainless steel has a better toughness and a nozzle made of tungsten steel because of its hardness. High, making the nozzle pass the circle m 3⁄4

The cylindrical joint 11 can be directly fitted to the nozzle support 20 without the need to provide other sealing fittings.

 In the present invention, the nozzle cylindrical connecting portion 11 is connected to the nozzle supporting body 20 by an interference fit, and the interference is less than or equal to 0.03 mm. Since the material of the nozzle is different from the material of the nozzle support, the setting of the interference amount when the cylindrical connection of the nozzle and the nozzle support are connected by the press fit is particularly important. The determination of the interference needs to specifically consider the brittleness, toughness and hardness of the two materials. If the interference is too small, the connection between the nozzle and the nozzle support is poor. If the interference is too large, the nozzle will be crushed. The reason is that the nozzle made of tungsten steel has good wear resistance but is less brittle.

 At the same time, the concentricity of the cylindrical nozzle part, the cylindrical connecting part and the nozzle support frame is controlled within 0.02 mm, so that after the nozzle is mounted to the nozzle support frame, the material is not deflected when being sprayed out from the nozzle, so that the material is not atomized. Evenly.

 Referring again to Fig. 2, the front end surface of the nozzle holder 20 of the present invention is provided with a plurality of through holes 21 circumferentially distributed around the central axis of the nozzle. The through hole 21 injects gas when the nozzle sprays the raw material to atomize the raw material. The spray gun of the present invention is provided with an atomizing through hole around the nozzle, so that the atomization effect of the nozzle itself is not required, and the processing performance of the nozzle is required to be lowered.

 Preferably, the axis of each of the through holes 21 is at an angle of less than 45 degrees with respect to the central axis of the nozzle 10, for example, an angle of 10 to 15 degrees. With this setting, the atomization effect of the spray gun is better.

 The specific embodiments described herein are merely illustrative of the spirit of the invention. A person skilled in the art can make various modifications or additions to the specific embodiments described, or in a similar manner, without departing from the spirit of the invention or as defined by the appended claims. The scope.

Claims

Claim  A spray gun nozzle, characterized by: a cylindrical connecting portion, a conical transition portion and a cylindrical nozzle portion; the nozzle is integrally formed of tungsten steel and has a Rockwell hardness The HRC is greater than 70, the inner surface roughness Ra of the cylindrical head portion is less than or equal to 0.4, the outer surface roughness Ra of the cylindrical joint portion is less than or equal to 0.8, and the concentricity of the cylindrical head portion and the cylindrical connecting portion is within 0.02 mm.  2. The spray gun nozzle according to claim 1, wherein: the composition of the tungsten steel comprises tungsten carbide, titanium carbide, cobalt, nickel and a trace component, and the mass of the tungsten carbide and the titanium carbide is not less than 80% of the total mass. %, the mass of cobalt and nickel is not less than 15% of the total mass.  The spray gun nozzle according to claim 2, wherein in the tungsten steel, the mass percentage of tungsten carbide is 80 to 82%, the mass percentage of titanium carbide is 4 to 6%, and the mass percentage of cobalt is 8 ~10%, the mass percentage of nickel is 5~8%.  4. The spray gun nozzle of claim 2 wherein: said minor component comprises molybdenum, silicon and sulfur.  A spray gun, comprising: the nozzle according to any one of claims 1 to 4, a nozzle support frame communicating with the spray gun canister, and a spray needle disposed inside the nozzle support frame for closing or opening the nozzle; The nozzle support frame is made of stainless steel material, and the cylindrical connecting portion of the nozzle is connected with the nozzle support frame by an interference fit, and the interference is less than or equal to 0.03 mm; the cylindrical nozzle portion, the cylindrical connecting portion and the nozzle support The concentricity of the frame is within 0.02 mm.  6. The spray gun of claim 5 further comprising a hand held assembly for controlling said needle advancement or retraction action.  The spray gun according to claim 5, wherein: the front end surface of the nozzle support frame is provided with a plurality of through holes circumferentially distributed around the central axis of the nozzle, and the through holes are sprayed with raw materials at the nozzles. The gas is injected to atomize the raw material.  8. The spray gun of claim 7 wherein: the axis of each of said through holes is at an angle of less than 45 degrees from said central axis of said nozzle.