Nozzle device in a spray gun

Abstract

The simplified structure ensures reliable spraying at all times, while also preventing problems such as liquid leakage when not in use. [Solution] The nozzle device 2 comprises a substantially horizontally elongated cylindrical nozzle body 6 with an opening at the front (tip), an inlet 7 formed at the lower part of the nozzle body 6 through which the spray liquid (LQ) in the pouch (PU) flows in, a pressure inlet 8 formed at the rear part of the nozzle body 6 through which high-pressure air enters, a substantially horizontally elongated pipe-shaped nozzle 9 housed within the nozzle body 6, a male screw portion 11 formed on the outer circumference of the front part of the nozzle body 6, a nozzle handle 13 having a female screw portion 12 on its inner circumference that screws into the male screw portion 11 and moves back and forth integrally with the nozzle 9, and a sealing means described later that seals the space between the outer surface of the nozzle 9 and the inner surface of the nozzle body 6.

Description

Technical Field

[0001] The present invention relates to a nozzle device in a spray gun used for injecting a liquid.

Background Art

[0002] Conventionally, as a spray gun for injecting a liquid, for example, there is a spray gun provided with a piston pump, wherein the piston pump has a suction port for sucking the liquid on the side surface, and a discharge port for the liquid is formed at the tip portion (front side portion), a cylinder, a piston that reciprocates in the cylinder, and a ring-shaped gasket provided between the suction port and the discharge port in the cylinder. The tip portion of the piston has a housing recess for housing the gasket, and the gasket is made movable along the reciprocating direction of the piston in the housing recess.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of the above-described spray gun, it is necessary to equip a cylinder, a piston that reciprocates in the cylinder, and a gasket housed in the tip portion of the piston behind the nozzle provided at the tip portion of the spray gun. As a result of the reciprocating movement of the piston being repeated with the use of the spray gun, the problem of wear and deterioration of the gasket could not be avoided. An object of the present invention is to provide a nozzle device in a spray gun that can always achieve reliable injection with a simplified structure.

Means for Solving the Problems

[0005] The present invention as described in claim 1 is a nozzle device for a spray gun comprising: a substantially horizontally elongated cylindrical nozzle body with an open front; an inlet formed at the lower part of the nozzle body through which a spray liquid flows in; a pressure inlet formed at the rear part of the nozzle body through which high-pressure air for spraying enters; a substantially horizontally elongated pipe-shaped nozzle housed within the nozzle body; a male screw portion formed on the outer circumference of the front part of the nozzle body; a nozzle handle having a female screw portion on its inner circumference that screws into the male screw portion, and which moves back and forth integrally with the nozzle; and a sealing means for sealing the space between the outer surface of the nozzle and the inner surface of the nozzle body. By rotating the nozzle handle backward, the sealing by the sealing means prevents the spray liquid from entering the inlet; and by rotating the nozzle handle forward, the sealing by the sealing means is released, allowing the spray liquid to enter the inlet and the spray liquid to be sprayed from the front end of the nozzle together with the high-pressure air for spraying entering through the pressure inlet.

[0006] The present invention as described in claim 2 is characterized in that, with respect to the nozzle device described in claim 1, the sealing means is a front O-ring mounted on the front outer circumference of the nozzle and a rear O-ring mounted on the rear outer circumference of the nozzle.

[0007] The present invention as described in claim 3 is a nozzle device as described in claim 1 or claim 2, wherein the discharge port of a spray gun is connected to the pressure inlet side of the nozzle body, and the inlet of a pouch is connected to the inlet of the nozzle body. [Effects of the Invention]

[0008] According to the present invention, reliable spraying by a spray gun can be achieved without complicating the structure, and liquid leakage and other issues can be reliably prevented when spraying is not being performed.

[0009] More specifically, when the nozzle knob is turned toward the nozzle body to tightly seal the nozzle inside the nozzle body, the sealing structure provided by the sealing means ensures that the sprayed fluid is securely sealed. Conversely, when the nozzle knob is turned in the opposite direction to the nozzle body to release the tight seal of the nozzle inside the nozzle body, the sprayed fluid is discharged. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view of a spray gun equipped with a nozzle device according to an embodiment of the present invention, showing the state in which a pouch is attached. [Figure 2] This is a cross-sectional view of the main part shown in Figure 1. [Figure 3] This is a cross-sectional view of the nozzle device of the same embodiment, where (a) shows the state in which the nozzle knob is closed and the liquid inside the pouch is not sprayed, and (b) shows the state in which the nozzle knob is turned and the liquid inside the pouch is sprayed. [Figure 4] This is a side cross-sectional view showing the relationship between the nozzle knob, the nozzle, and the O-ring, where (a) shows the state before the O-ring is attached to the nozzle, and (b) shows the relationship between the nozzle with the O-ring attached and the nozzle knob. [Figure 5] This is a cross-sectional view showing the relationship between the nozzle knob to which the nozzle is assembled and the nozzle body, where (a) shows the state before the nozzle knob is attached to the nozzle body, and (b) shows the state after the nozzle knob is attached to the nozzle body. [Modes for carrying out the invention]

[0011] Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[0012] In the present invention and this embodiment, front and rear, and up and down are based on Figure 1, with front referring to the left direction in Figure 1, i.e., the direction of spraying from the tip of the spray gun, and rear referring to the right direction in Figure 1, i.e., the direction opposite to the spraying from the tip of the spray gun. Furthermore, up refers to the upper direction in Figure 1, and down refers to the lower direction in Figure 1.

[0013] As shown in Figures 1 and 2, the nozzle device of the spray gun according to this embodiment first comprises a spray gun 1, a nozzle device 2 integrally assembled to the tip of the spray gun 1, and a pouch (PU) containing spray liquid (LQ) attached to the lower side of the nozzle device 2.

[0014] The spray gun 1 has a general high-pressure air injection structure similar to commercially available models, and includes a grip 3 for holding by hand, a high-pressure air connection 4 protruding from the lower part of the grip 3, and a trigger 5 hanging down in front of the grip 3 of the spray gun 1. A hose (not shown) of a compressor (not shown) is connected to the high-pressure air connection 4 to supply high-pressure air into the spray gun 1.

[0015] As shown in Figure 3, the nozzle device 2 comprises a roughly elongated cylindrical nozzle body 6 with an open front (tip) end, an inlet 7 formed at the bottom of the nozzle body 6 through which the spray liquid (LQ) in the pouch (PU) flows in, a pressure inlet 8 formed at the rear of the nozzle body 6 through which high-pressure air enters, a roughly elongated pipe-shaped nozzle 9 housed within the nozzle body 6, a male threaded portion 11 formed on the outer circumference of the front part of the nozzle body 6, a nozzle handle 13 having a female threaded portion 12 on its inner circumference that screws into the male threaded portion 11 and moves back and forth integrally with the nozzle 9, and the outer circumference of the nozzle 9 The nozzle is equipped with a sealing means, described later, that seals the space between the surface and the inner circumferential surface of the nozzle body 6. By rotating the nozzle handle 13 backward, the sealing by the sealing means prevents the spray liquid (LQ) from entering the inlet 7 (Figure 3a). By rotating the nozzle handle 13 forward, the sealing by the sealing means is released, allowing the spray liquid (LQ) to enter the inlet 7 and to be sprayed from the front (tip) of the nozzle 9 together with the high-pressure air entering from the pressure inlet 8 (Figure 3b).

[0016] As described above, the nozzle 9 is generally in the shape of a substantially horizontally long pipe, and a flange 16 is provided around the front-end side portion of its outer peripheral surface. The protrusion 16a on the outer periphery of the flange 16 fits into the inner periphery of the nozzle gripper 13 outside thereof, and the nozzle 9 is structured to be coupled with the nozzle gripper 13 and move integrally with the nozzle gripper 13. Further, a front-side annular groove 17 is formed in the portion of the outer peripheral surface of the nozzle 9 near the flange 16, and a front-side O-ring 14 is mounted in the front-side annular groove 17. Also, a rear-side annular groove 18, which will be described later, is formed in the portion of the outer peripheral surface of the nozzle 9 near the rear end, and a rear-side O-ring 15 is mounted in the rear-side annular groove 18.

[0017] The nozzle gripper 13 has a substantially inverted U-shaped cross section and has a through hole 13a into which the front end 9b of the nozzle 9 is inserted on the front side, and is shaped to be open at the rear side.

[0018] In the present embodiment, the sealing means includes the front-side O-ring 14 mounted on the outer periphery of the front-side portion of the nozzle 9 and the rear-side O-ring 15 mounted on the outer periphery of the rear-side portion of the nozzle 9, and the outer peripheral surface of the nozzle 9 has a front-side annular groove 17 for mounting the front-side O-ring 14 and a rear-side annular groove 18 for mounting the rear-side O-ring 15.

[0019] In the drawing, reference numeral 21 denotes a protrusion formed on the outer peripheral surface of the nozzle body 6, which is contacted by the rear edge 13b portion of the nozzle gripper 13. Also, reference numeral 22 denotes a C-ring related to the attachment and detachment of the adapter 23 to which the spray gun 1 is connected and the nozzle body 6. Furthermore, in the present embodiment, an O-ring receiving portion 6c with which the rear-side O-ring 15 contacts is formed on the rear-side portion of the inner peripheral surface 6b of the nozzle body 6.

[0020] Next, as shown in FIGS. 4 and 5, an example of the assembly procedure of the nozzle device 2 described above will be explained. First, the front O-ring 14 is fitted into the front annular groove 17 on the outer peripheral surface of the nozzle 9, and the rear O-ring 15 is fitted into the rear annular groove 18 on the outer peripheral surface of the nozzle 9 (FIG. 4a). Then, the nozzle 9 with the front O-ring 14 and the rear O-ring 15 attached is inserted into the nozzle gripper 13 (FIG. 4b). Next, by fitting the nozzle gripper 13 to the nozzle body 6 (FIG. 5a), the assembly of the nozzle device 2 is completed (FIG. 5b).

[0021] Next, as shown in FIG. 3, the specific operation procedure of the nozzle device 2 according to the present embodiment will be explained. FIG. 3a shows a state where the nozzle gripper 13 is turned backward and the rear end 13b of the nozzle gripper 13 abuts against the protrusion 21 on the outer peripheral surface of the nozzle body 6. In this case, the rear end 9c of the nozzle 9 abuts against the inner rear wall 6d of the nozzle body 6 and this part is closed, and at the same time, the rear O-ring 15 on the outer periphery of the nozzle 9 abuts against the O-ring receiving portion 6c formed at a portion near the rear end of the inner peripheral surface of the nozzle body 6, thereby preventing the spraying liquid (LQ) in the pouch (PU) from entering the nozzle 9. At this time, the sealing state by the front O-ring 14 is maintained.

[0022] FIG. 3b shows a state where the nozzle gripper 13 is turned forward and the rear end 13b of the nozzle gripper 13 is separated from the protrusion 21 on the outer peripheral surface of the nozzle body 6. In this case, the rear end 9c of the nozzle 9 is separated from and abuts against the inner rear wall 6d of the nozzle body 6 and this part is released, and at the same time, the rear O-ring 15 on the outer periphery of the nozzle 9 is separated from the O-ring receiving portion 6c of the nozzle body 6, so that the spraying liquid (LQ) in the pouch (PU) can enter the nozzle 9. In this state, by pulling the trigger 5 of the spray gun 1, high-pressure fluid enters the nozzle 9 in the nozzle body 6, so that the inside of the nozzle 9 becomes a negative pressure state. Along with this, the spraying liquid (LQ) in the pouch (PU) is jetted together with the high-pressure fluid.

Industrial Applicability

[0023] According to the present invention, a simplified structure allows for easy liquid ejection, while reliably preventing liquid leakage when not in use. Therefore, it is expected to have a wide range of applications in the field of nozzle devices for spray guns. [Explanation of symbols]

[0024] 1 spray gun 2 Nozzle device 5. Spray gun trigger 6. Nozzle body 7 Inlet 8 Pressure Inlet 9 nozzles 11 Male threaded section 12 Female thread section 13. Nozzle knob 14 Front O-ring 15 Rear O-ring 16 flange 17 Anterior annular groove 18 Rear annular groove

Claims

1. A nozzle device for a spray gun comprising: a substantially elongated cylindrical nozzle body with an open front; an inlet formed at the lower part of the nozzle body through which a spray liquid flows in; a pressure inlet formed at the rear part of the nozzle body through which high-pressure air for spraying enters; a substantially elongated pipe-shaped nozzle housed within the nozzle body; a male threaded portion formed on the outer circumference of the front part of the nozzle body; a nozzle handle having a female threaded portion on its inner circumference that screws into the male threaded portion, and which moves back and forth integrally with the nozzle; and a sealing means for sealing the space between the outer surface of the nozzle and the inner surface of the nozzle body, wherein rotating the nozzle handle backward blocks the entry of the spray liquid from the inlet due to sealing by the sealing means, and rotating the nozzle handle forward releases the sealing by the sealing means, allowing the spray liquid to enter from the inlet and the spray liquid to be sprayed from the front end of the nozzle together with the high-pressure air for spraying entering from the pressure inlet.

2. The nozzle device for a spray gun according to claim 1, wherein the sealing means is a front O-ring mounted on the front outer circumference of the nozzle and a rear O-ring mounted on the rear outer circumference of the nozzle.

3. A nozzle device for a spray gun according to claim 1 or claim 2, wherein the discharge port of a spray gun is connected to the pressure inlet side of the nozzle body, and the inlet of a pouch is connected to the inlet of the nozzle body.

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