JP2008023465A - Spray gun - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a high grade silver mirror surface on a uneven surface to be coated. <P>SOLUTION: A spray gun 1 for forming the silver mirror surface on the surface to be coated by blowing a first liquid (a) and a second liquid (b) at the same time is provided with: a nozzle port group JG comprising two first coating nozzle ports Ja communicating with a first coating flow passage P1 through which the first liquid (a) flows and opened and closed by a needle valve 26a, two second coating nozzle port Jb communicating with a second coating flow passage P2 through which the second liquid (b) flows and opened and closed by a needle valve 26b; and an annular air nozzle port K surrounding the nozzle port group JG. The first coating nozzle ports Ja and the second coating nozzle ports Jb are alternately and evenly spaced on a circumference L concentric to the air nozzle port K. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spray gun that simultaneously sprays a first liquid, which is a metal salt-containing solution, and a second liquid, which is a reducing agent-containing solution, and forms a silver mirror surface on the surface to be coated by the silver mirror reaction.

  As this type of spray gun, the one described in Patent Document 1 is known. The spray gun disclosed in Patent Document 1 includes a first discharge unit that discharges the first liquid in a mist form and a second discharge unit that discharges the second liquid in a mist form in parallel on the front surface of the gun body. ing. Each of the first and second discharge units includes an annular air nozzle port around the paint nozzle port, and the first liquid mist body and the second liquid mist body are connected to each other from each discharge section. It sprays in the direction which crosses.

  Therefore, the first liquid and the second liquid can be uniformly mixed on the surface to be coated by positioning the surface to be coated at the crossing position of the mist-like body, and high quality with excellent glossiness. A silver mirror surface can be formed.

JP 2003-38988 A

  However, in many cases, the surface to be coated is formed with a complex uneven surface. At this time, for example, in the concave portion or the convex portion, the first liquid and the second liquid are not uniformly mixed because they are out of the intersecting position, and there is a problem that the quality of the silver mirror surface is partially impaired.

  Therefore, the present invention provides two paint nozzle ports for the first liquid and two paint nozzle ports for the second liquid on the inner side of one annular air nozzle port, and a circumference concentric with the air nozzle port. It can be discharged as one atomized body in which the atomized particles of the first liquid and the atomized particles of the second liquid are uniformly dispersed on the basis that they are alternately arranged at equal intervals on the line, An object of the present invention is to provide a spray gun capable of forming a high-quality silver mirror surface even when the surface to be coated is a complex uneven surface.

In order to achieve the above object, the invention of claim 1 of the present application is that a first liquid that is a metal salt-containing solution and a second liquid that is a reducing agent-containing solution are sprayed at the same time, A first spray nozzle port which is connected to a first paint flow path through which the first liquid passes and which is opened and closed by a first needle valve, and a second gun through which the second liquid passes. A nozzle port group comprising two second paint nozzle ports that communicate with the two paint flow paths and are respectively opened and closed by a second needle valve;
And an air nozzle port that forms an annular shape surrounding the nozzle port group and that atomizes and sprays the first and second liquids from the first paint nozzle port and the second paint nozzle port by discharging air. And
The first paint nozzle port and the second paint nozzle port are alternately arranged at equal intervals on a circumferential line concentric with the air nozzle port.

  The invention according to claim 2 is characterized in that the diameter of the circumferential line is 4.0 to 8.0 mm.

  In the invention of claim 3, the first needle valve and the second needle valve have axes parallel to each other, and a rear end portion of each needle valve is moved forward and backward by a trigger. It is connected to the base shaft.

  The invention of claim 4 is characterized in that spring means for biasing each needle valve forward is interposed between the rear end portion of each needle valve and the base shaft.

  As described above, in the present invention, two first paint nozzle ports for the first liquid and two second paint nozzle ports for the second liquid are provided inside one annular air nozzle port. ing. Therefore, the first liquid and the second liquid from each paint nozzle port can be atomized by the discharge air from the air nozzle port. At this time, since the first and second paint nozzle ports are alternately arranged at equal intervals on a circumferential line concentric with the air nozzle port, the atomized particles of the first liquid and the second liquid The atomized particles are sprayed as a single mist that is uniformly dispersed.

  In the atomized body, the silver mirror reaction does not occur because each atomized particle maintains an independent non-contact state. However, when the atomized object hits the surface to be coated, each atomized particle is liquefied and the first particle is liquefied. The 1st liquid and the 2nd liquid mix and generate a silver mirror reaction. At this time, since the atomized particles of the first liquid and the second liquid are uniformly dispersed, even when the surface to be coated is a complicated uneven surface, the distance between the spray gun and the surface to be coated (that is, spraying) Even when the (distance) changes, uniform mixing of the first liquid and the second liquid is ensured, and a high-quality silver mirror surface can be formed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of the spray gun of the present invention, and FIG. 2 is a front view of the front end thereof.

  1 and 2, the spray gun 1 of the present embodiment simultaneously sprays a first liquid a that is a metal salt-containing solution and a second liquid b that is a reducing agent-containing solution, and the surface of the surface to be coated by the silver mirror reaction. In this example, a spray gun for forming a silver mirror film is illustrated as a so-called hand gun for manual operation.

  Here, as the metal salt-containing solution which is the first liquid a, an ammoniacal silver nitrate solution obtained by adding ammonia and an aqueous sodium hydroxide solution to an aqueous silver nitrate solution is generally known. Further, as the reducing agent-containing solution which is the second liquid b, an aqueous solution containing a reducing agent such as sodium gluconate, glucitol, glucose, tartaric acid, formaldehyde and a strong alkali component such as sodium hydroxide or potassium hydroxide is generally known. ing.

  In this example, the spray gun 1 has a pistol shape in which a head portion 3 is provided at the front end of the gun body 2. The front surface 3S of the head portion 3 has two first paint nozzle ports Ja and Ja for discharging the first liquid a and two second paint nozzle ports Jb and Jb for discharging the second liquid b. And an annular air nozzle port K surrounding the nozzle port group JG is formed.

  The first paint nozzle ports Ja and Ja are electrically connected to the first paint flow path P1 extending from the first liquid intake port A1 connected to the first liquid supply source Q1, and the second paint nozzle ports Jb. , Jb is electrically connected to the second paint flow path P2 extending from the second intake A2 connected to the second liquid supply source Q2. The air nozzle port K is electrically connected to an air flow path P3 extending from an air intake A3 connected to an air supply source Q3.

  In addition, on-off valves V1 to V3 are interposed in the flow paths P1 to P3. In this example, the pulling operation to the trigger 4 causes the on-off valves V1 to V3 to operate in conjunction with each other, and the flow paths P1 to P3 Can be released.

  Next, the spray gun 1 will be described in detail. As shown in FIG. 1, the gun body 2 has a pistol shape in which a barrel portion 6 is arranged on the upper end of a handle 5, and the upper end of the trigger 4 is formed on the barrel portion 6. It is pivotally attached.

  In this example, the air flow path P3 includes an inflow hole 8 extending from the air intake A3 provided at the lower end of the handle 5 to the valve housing hole 7 formed through the handle 5 in the front-rear direction. There is a throttle valve 9 capable of adjusting the air flow rate. The valve housing hole 7 is a hole portion for housing the on-off valve V3, and is divided into front and rear air chambers 7F and 7R via a valve seat 10. The inflow hole 8 is conducted to the rear air chamber 7R and the rear end thereof is closed by the end fitting 13. The air flow path P3 includes a guide hole 14 extending from the previous air chamber 7F through the body portion 6 to the head portion 3.

  In the present example, the on-off valve V3 includes the valve seat 10 and a base shaft 11 that is a valve shaft that opens and closes the valve seat 10. The base shaft 11 is axially sealed by a receiving portion 12 at the front end of the valve housing hole 7 and is slidable forward and backward, and is urged forward by a spring means 15 accommodated between the end fitting 13. The

  Next, as shown in FIG. 2 and FIG. 3 which is a sectional view taken along the line AA in FIG. 2 and FIG. 4 which is a sectional view taken along the line BB in FIG. A nozzle port group JG composed of two first paint nozzle ports Ja opened and closed by 26a and two second paint nozzle ports Jb opened and closed by the second needle valve 26b, and an air flow path P3. An air nozzle port K having an annular shape surrounding the nozzle port group JG is opened at the front surface 3S of the head portion 3. At this time, the first paint nozzle port Ja and the second paint nozzle port Jb are equidistant from each other on a circumferential line L concentric with the annular air nozzle port K in the circumferential direction. Alternatingly arranged.

  Accordingly, the first liquid a and the second liquid b from the paint nozzle ports Ja and Jb are atomized equally and simultaneously by the discharge air from the air nozzle port K, and the first liquid a and the second liquid b The atomized particles are sprayed from the spray gun 1 as one atomized body in which the atomized particles are uniformly dispersed. In this atomized body, since each atomized particle is separated from each other, no silver mirror reaction occurs. However, when it hits the surface to be coated, the atomized particles are liquefied on the surface to be coated, and the first and second liquids are mixed to generate a silver mirror reaction. Thus, since the atomized particles of the first liquid and the second liquid are uniformly dispersed and sprayed, even when the surface to be coated is a complicated uneven surface, the distance between the spray gun and the surface to be coated ( Even when the spraying distance is changed, uniform mixing of the first liquid and the second liquid is ensured, and a high-quality silver mirror surface can be formed.

  At this time, the diameter of the circumferential line L is preferably in the range of 4.0 to 8.0 mm. When the diameter is 4.0 mm or less, it is difficult to form the head portion 3 such that the paint nozzle ports Ja and Jb are too close to each other and the needle valves 26a and 26b cannot be arranged. In addition, when the first liquid a and the second liquid b are atomized from the paint nozzle ports Ja and Jb, there is a risk that the silver mirror reaction may occur due to contact first. On the other hand, when the diameter exceeds 8.0 mm, atomization is difficult and the dispersion of atomized particles tends to be non-uniform. From such a viewpoint, it is more preferable that the lower limit value of the diameter of the circumferential line L is 5.0 mm or more and the upper limit value is 6.5 mm or more. Even when the paint nozzle ports Ja and Jb are not arranged alternately at equal intervals and when they are not arranged on the same circumferential line L, the dispersion of atomized particles becomes non-uniform.

  In this example, a cross-shaped concave groove 27 is formed on the front surface 3S of the head portion 3 from the center of the circumferential line L to the annular air nozzle port K through the paint nozzle ports Ja and Jb. This is an example. The concave groove 27 can facilitate atomization of the first liquid a and the second liquid b from the paint nozzle ports Ja and Jb when a part of the discharge air from the air nozzle port K passes through. . Therefore, the groove width of the concave groove 27 is preferably in the range of 1.0 to 2.0 mm, and the groove depth is preferably in the range of 0.5 to 3.0 mm.

  Next, as shown in FIGS. 2 and 3, the first paint flow path P1 is formed between the nozzle holes 28a and 28a which are parallel to each other and extend backward from the first paint nozzle openings Ja, and between the nozzle holes 28a and 28a. For example, two joint holes 29a and a side hole 30a extending from the first liquid inlet A1 to one of the nozzle holes 28a, and each nozzle hole 28a has the first needle The valve 26a is arranged concentrically.

  Similarly, in the second paint flow path P2, as shown in FIGS. 2 and 4, the nozzle holes 28b and 28b extending in parallel to the rear from the second paint nozzle port Jb and the nozzle holes 28b and 28b are connected to each other. For example, two joint holes 29b and a side hole 30b extending from the second liquid inlet A2 to one of the nozzle holes 28b, and each nozzle hole 28b has a second needle Valves 26b are arranged concentrically.

  Here, at the front end portions of the nozzle holes 28a, 28b, valve seat portions 31 are disposed to close the paint flow paths P1, P2 by contacting the front end portions of the needle valves 26a, 26b. As described above, in this example, the valve seat portion 31 and the first needle valve 26a provide the on-off valve V1 of the first paint flow path P1, and the valve seat portion 31 and the second needle valve 26b provide the first The on-off valve V2 of the second paint flow path P2 is formed, and the valve seat portion 31 is provided in the vicinity of the paint nozzle ports Ja and Jb, respectively. Therefore, it is possible to prevent the liquids a and b from remaining between the valve seat portion 31 and the paint nozzle ports Ja and Jb after the spraying, and the paint nozzle ports Ja and Jb from being clogged. . The “near” means a range in which the distance from the paint nozzle ports Ja and Jb is 3 mm or less. In particular, in this example, when the on-off valves V1 and V2 are closed, the tips of the needle valves 26a and 26b are formed so as to protrude forward or flush with the paint nozzle ports Ja and Jb. Thereby, the residual amount of each liquid a and b is further reduced.

  The needle valves 26a and 26b have their axes parallel to each other, and the rear end E of each needle valve 26a and 26b is connected to the base shaft 11 moved back and forth by the trigger 4 via a connecting fitting 33. Connected. The connection fitting 33 includes four sliding holes 32 that slidably hold the piston-like rear end E of the needle valves 26a and 26b back and forth. Each sliding hole 32 accommodates a spring means 34 that biases the rear end E forward. Accordingly, in normal times, the needle valves 26a and 26b can be in pressure contact with the valve seat portion 31 independently by the spring means 34, and the paint nozzle ports Ja and Jb can be reliably closed. The rear end E of the needle valves 26a and 26b is engaged with the front end 32E of the sliding hole 32 by the rearward movement of the base shaft 11 by the trigger 4, and retracts integrally with each other. The nozzle openings Ja and Jb can be opened.

  Next, the head unit 3 will be described in more detail. The head unit 3 includes, for example, a block-shaped head main body 35, a paint nozzle fitting 36, a paint nozzle fitting presser 37, and an air that are sequentially arranged on the front end side. And a cap 38.

  As shown in FIG. 5, the head body 35 includes a block-shaped base body 35A that is fixed to the front end of the body portion 6 of the gun body 2 with a bolt or the like, and a cylindrical mounting tube portion on the front surface thereof. 35B protrudes forward. An outer threaded portion 35Ba for screwing the nozzle bracket presser 37 is formed on the outer periphery of the mounting cylinder portion 35B, and a rear end portion of the paint nozzle bracket 36 is accommodated on the front surface of the mounting cylinder portion 35B. An accommodation recess 35Bb is provided.

  The head body 35 forms part of the air flow path P3 through the four holes 39 constituting the rear ends of the nozzle holes 28a and 28b and the guide hole 14 of the gun body 2. One hole 40 is formed. Each of the holes 39 and 40 penetrates back and forth between the bottom surface of the housing recess 35Bb and the back surface of the base body 35A. The rear end of the hole 39 is closed by a sealing fitting 42 having a seal ring for axially sealing the needle valves 26a and 26b. The head main body 35 is further formed with the first liquid inlet A1, the second liquid inlet A2, the joint holes 29a and 29b, and the side holes 30a and 30b, respectively.

  The paint nozzle fitting 36 has a flange portion 36B provided around the rear end of a stepped cylindrical body portion 36A having the paint nozzle ports Ja and Jb opened on the front surface. The flange portion 36B is mounted concentrically in the housing recess 35Bb via a positioning pin (not shown). In this example, the flange portion 36 </ b> B is mounted via a disk-shaped packing 43. The packing 43 is made of a material having good sealing properties such as rubber. In this example, the cylindrical body portion 36A is divided into a small diameter portion 36f on the front end side and a large diameter portion 36r on the rear end side through a tapered stepped portion. The paint nozzle fitting 36 is formed with four holes 44 extending rearward from the paint nozzle openings Ja and Jb and constituting the front end side of the nozzle holes 28a and 28b.

  The paint nozzle fitting presser 37 is formed at the front end of a cylindrical portion 37A having an inner threaded portion 37Ai screwed to the mounting cylinder portion 35B of the head main body 35 on the inner peripheral surface. A front wall portion 37B having a holding hole 37Bh for inserting and holding 36A is provided. Therefore, the coating material nozzle fitting presser 37 can hold the flange portion 36B between the front wall portion 37B and the bottom surface of the housing recess 35Bb, and attach the coating material nozzle fitting 36 concentrically with the housing recess 35Bb. A plurality of air insertion holes 37Ba are formed in the front wall portion 37B. The compressed air flows in from the hole portion 40 and passes through the gap between the inner periphery of the housing recess 35Bb and the outer periphery of the flange portion 36B. To the front. The outer peripheral surface of the cylindrical portion 37A is provided with an external screw portion 37Ao for screwing the air cap 38.

  Further, as shown in FIG. 3, the air cap 38 includes a cap body 45 that forms the air nozzle port K, and a nut ring 46 that attaches the cap body 45 to the paint nozzle fitting presser 37.

  The cap body 45 has a cap shape in which the front end of the cylindrical body 45A is closed by the front wall 45B, and the center of the front wall 45B surrounds the periphery of the small diameter portion 36f of the paint nozzle fitting 36. A port 47 that forms the annular air nozzle port K is formed between the small-diameter portion 36f. The front surface of the front wall 45B is flush with the front surface of the paint nozzle fitting 36. The rear end of the cylindrical body 45A is in contact with the paint nozzle fitting retainer 37. Therefore, the air flow path P3 is formed by the space between the cap body 45, the paint nozzle fitting 36 and the paint nozzle fitting retainer 37. The air reservoir H is formed between the air insertion hole 37Ba and the air nozzle port K.

  In this example, as shown in FIGS. 1 and 2, the front wall 45B includes a pair of corners 45Ba projecting forward at symmetrical positions on both outer sides in the radial direction across the air nozzle port K. A pattern air port 45Bb communicating with the air reservoir H is formed inward at the tip of the corner 45Ba. This pattern air port 45Bb can be eliminated as required. Further, in this example, the cap body 45 is configured such that the rear end of the cylindrical body 45 </ b> A is narrow between the front end of the nut ring 46 that is screwed to the paint nozzle bracket presser 37 and the paint nozzle bracket presser 37. It is fixed by being held.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

It is sectional drawing which shows one Example of the spray gun of this invention. It is a front view of the front end. It is the sectional view on the AA line of FIG. FIG. 3 is a sectional view taken along line B-B in FIG. 2. It is a perspective view which decomposes | disassembles and shows the principal part of a head part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spray gun 4 Trigger 11 Base shaft 26a 1st needle valve 26b 2nd needle valve 34 Spring means a 1st liquid b 2nd liquid E Needle valve rear end Ja 1st paint nozzle port Jb 2nd paint nozzle port JG Nozzle group K Air nozzle port L Circumferential line P1 First paint flow path P2 Second paint flow path

Claims (4)

A spray gun that simultaneously sprays a first liquid that is a metal salt-containing solution and a second liquid that is a reducing agent-containing solution, and forms a silver mirror surface on the surface to be coated by the silver mirror reaction,
Two first paint nozzle openings that communicate with the first paint flow path through which the first liquid passes and are opened and closed by the first needle valve, respectively, and a second paint flow path through which the second liquid passes and A nozzle port group comprising two second paint nozzle ports each opened and closed by two needle valves;
And an air nozzle port that forms an annular shape surrounding the nozzle port group and that atomizes and sprays the first and second liquids from the first paint nozzle port and the second paint nozzle port by discharging air. And
The spray gun, wherein the first paint nozzle port and the second paint nozzle port are alternately arranged at equal intervals on a circumferential line concentric with the air nozzle port.   The spray gun according to claim 1, wherein a diameter of the circumferential line is 4.0 to 8.0 mm.   The first needle valve and the second needle valve have axial axes parallel to each other, and a rear end portion of each needle valve is connected to a single base shaft that moves back and forth by a trigger. The spray gun according to claim 1 or 2.   4. The spray gun according to claim 3, wherein a spring means for biasing each needle valve forward is interposed between a rear end portion of each needle valve and the base shaft.

Images