JP2006116402A - Nozzle tip unit air-less gun - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of parts, to realize cost reduction and to contribute to miniaturization and light weight of a gun constitution in a two-stage atomization system air-less gun. <P>SOLUTION: A nozzle tip unit 6 attached to a nozzle head of the air-less gun has a nozzle holder 7 inserted to an attachment hole of a holder support member; and a lever 8. A mounting hole 7b communicating with a coating material introduction hole of the holder support member is formed on the nozzle holder 7 so as to be penetrated in a direction perpendicular to an axial direction. A nozzle tip 9 and a gasket 10 are inserted into the mounting hole 7b and are pressed and fixed by a pressing screw 11. A shaft hole 11c having a small diameter is formed on a central part of a rotation operation groove 11b of the pressing screw 11 and a shaft hole 11d having a large diameter is formed on a downstream side in a coating injection direction so as to communicate with the shaft hole 11c having the small diameter. An atomization flow passage is formed by the shaft hole 11c having the small diameter and the shaft hole 11d having the large diameter. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an airless gun of a type in which paint itself is pressurized and sprayed, and a nozzle tip unit used in the airless gun.

The airless gun is characterized in that the paint itself is pressurized and sprayed by a pressurizing means such as a pump, so that the atomized paint particles are less scattered than the air spray method and the coating efficiency to the object is good. is there.
In general, the airless gun, depending on the viscosity of the paint used, and applying a pressure of about ^{100kg / cm 2 ~140kg / cm 2} . At such a high pressure, the jetting speed is high, so there are many rebounds and scattering from the object to be coated (surface to be coated), resulting in a deterioration of the working environment and a decrease in use efficiency of the paint (injection medium).
In the case of the high-pressure system, a high-pressure pressure hose or pump must be used, and there is also a problem that equipment costs (and thus running costs) are high.
When the pressure is simply lowered, it is unavoidable that a so-called tail in which the upper and lower lines are darkened when the paint is moved from the left to the right, for example, by flat spraying.

In order to cope with such a problem, a so-called double tip structure in which a tip having another orifice function is integrally or individually provided in front of a nozzle tip having an orifice function for atomizing paint (upstream side in the paint injection direction). Things have been proposed.
Generally, the nozzle tip is integrated into a nozzle tip unit that is detachably attached to a nozzle head attached to the tip of the gun body.
In the nozzle tip unit, a nozzle tip and a sealing material (gasket) are mounted in a mounting hole formed in a shaft-shaped nozzle holder, and a screw screw is screwed into the mounting hole from the upstream side in the paint spraying direction to attach the nozzle tip. It has a structure for pressing and fixing. The push screw is formed with a flow path through which the paint passes.
When the nozzle tip is worn out or when it is desired to change the spray pattern, the so-called cartridge system is used in which the entire nozzle tip unit is replaced without replacing only the nozzle tip as a micro component.
In the double tip system, for example, another tip having an orifice function is arranged between the seal material and the push screw.

  In the double tip (double orifice) system, the paint is atomized stepwise, so the degree of atomization in the final injection state is high, and the paint surface that does not produce tails without applying high pressure as described above. Obtainable.

JP 2001-162197 A

As described above, in the double tip method, the atomization degree of the paint can be increased so that a low pressure can be realized. However, there are two or two tips having an orifice function and a structure in which a push screw is further provided. Therefore, there are problems that the number of parts is large and the shaft diameter of the nozzle holder becomes large.
For this reason, the manufacturing cost and assembly cost increased due to the large number of parts, and the size and weight reduction of the nozzle holder were hindered by the large diameter of the nozzle holder.

  The present invention provides a nozzle tip unit that can reduce the number of parts and realize cost reduction in the double tip system, can contribute to a compact and lightweight gun configuration, and an airless gun including the nozzle tip unit. Objective.

According to the first aspect of the present invention, a nozzle tip is formed by inserting a nozzle tip into an attachment hole formed in the nozzle holder, and screwing a set screw into the attachment hole from the upstream side in the paint injection direction to fix the nozzle tip. In the unit
In the nozzle tip unit, the push screw has an atomizing flow path for atomizing the paint.

  According to a second aspect of the present invention, in the nozzle tip unit according to the first aspect, the atomizing flow path has a small-diameter shaft hole and a large-diameter shaft hole communicating with the small-diameter shaft hole downstream in the paint injection direction. It is a nozzle tip unit characterized by comprising.

  A third aspect of the invention is an airless gun including the nozzle tip unit according to the first or second aspect.

According to the present invention, the push screw itself that has been used only as a fixing member for the nozzle tip is provided with a function of atomizing the paint, in other words, the existing pressing member necessary as the fixing member for the nozzle tip. Since the screw is used to carry out one of the two-stage atomization, there is no need to separately provide a tip for atomization, and the number of parts can be reduced. Thereby, reduction of manufacturing cost and assembly cost can be aimed at.
By reducing the number of parts, a double orifice function can be obtained without increasing the diameter (shaft diameter) of the nozzle holder 7.
It can also contribute to making the gun configuration compact and lightweight in the double tip system.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a nozzle head 2 is detachably attached to a gun body 1 (not shown).
The nozzle head 2 includes a nozzle guard (also referred to as a “tip guard”) 4 integrally provided with a connection screw 3 that is screwed to the tip of the gun body 1, and a paint spraying direction (arrow F direction) inside the connection screw 3. A holder support member (also referred to as “spray tip”) 5 that is mounted from the upstream side, has a coating introduction hole inside, and has a mounting hole 5a that penetrates in the direction perpendicular to the same direction at the tip of the coating material injection direction, and the holder The nozzle chip unit 6 is detachably mounted by being inserted into the mounting hole 5a of the support member 5.
In FIG. 1, the paint valve of the gun body 1 and the trigger lever for opening and closing the gun body 1 are omitted because well-known configurations can be adopted.

As shown in FIG. 2, the nozzle tip unit 6 is fixed so as to enclose a metal-made shaft-like nozzle holder 7 inserted into the mounting hole 5 a of the holder support member 5 and a head 7 a of the nozzle holder 7. It has a T-shaped lever 8 made of plastic.
One end side of the horizontal portion of the lever 8 is formed in a triangular shape, and this direction corresponds to a normal position (injection position) of a nozzle chip 11 described later. When the lever 8 is rotated by 90 °, the paint introduction hole of the holder support member 5 is closed and the injection is locked. When the lever 8 is rotated 180 °, the direction of the nozzle tip 11 is reversed, and so-called discarding blow is possible.
A stopper surface 8 a that restricts the amount of insertion of the nozzle holder 7 into the mounting hole 5 a is formed at the lower end of the lever 8. Although not shown, a restricting surface for restricting rotation of 180 ° or more in the same direction is formed in the vicinity of the stopper surface 8 a of the lever 8 relative to the holder support member 5.
A synthetic resin material having a paint flow path is provided on the paint introduction hole side of the mounting hole 5a of the holder support member 5, so that the nozzle holder 7 can be inserted in an airtight state.

The nozzle holder 7 is formed with an attachment hole 7b that communicates with the paint introduction hole of the holder support member 5 so as to penetrate in a direction orthogonal to the axial direction.
A nozzle chip 9 for finally injecting paint and determining an injection pattern and a circular ring-shaped gasket 10 as a sealing material are sequentially inserted into the attachment hole 7b in the paint injection direction F. 7b is pressed and fixed by a set screw 11 that is screwed into a female screw 7c formed on the inner surface of the upstream end of the paint injection direction.
The nozzle chip 9 has a shaft hole 9a that communicates with the shaft hole 10a of the synthetic resin gasket 10, a conical hole 9b that gradually decreases in diameter toward the paint spraying direction, and a spray port 9c. When being compressed by the conical hole 9b and sprayed to the outside from the small-diameter injection port 9c, the paint is atomized by the orifice action.

As shown in FIGS. 3 to 5, the push screw 11 is formed in a cylindrical shape as a whole, and a male screw 11 a is formed on the outer surface thereof so as to be screwed into the female screw 7 c of the mounting hole 7 b.
A rotary operation groove 11b for inserting and turning a screwdriver or the like is formed at the upstream end portion of the push screw 11 in the paint spraying direction over the entire radial direction. A small-diameter shaft hole 11c is formed in the central portion of the rotation operation groove 11b, and a large-diameter shaft hole 11d is formed on the downstream side in the paint injection direction in communication with the small-diameter shaft hole 11c. An atomizing flow path is formed by the small diameter shaft hole 11c and the large diameter shaft hole 11d.

The paint supplied from the gun body 1 passes through the paint introduction hole of the holder support member 5 and enters the rotation operation groove 11b of the push screw 11, and then reaches the large diameter shaft hole 11d through the small diameter shaft hole 11c. When it exits from the small diameter shaft hole 11c to the large diameter shaft hole 11d, it is atomized by the orifice action.
The atomized paint enters the nozzle tip 9 through the shaft hole 10 a of the gasket 10, and is atomized again as described above when leaving the nozzle tip 9.
As described above, the push screw 11 itself that has been used only as a fixing member for the nozzle tip 9 is provided with a function of atomizing the paint, so that a double orifice (two-stage atomization) function can be obtained. There is no need to provide additional components, and the number of components can be reduced. Thereby, reduction of manufacturing cost and assembly cost can be aimed at.
By reducing the number of parts, a double orifice function can be obtained without increasing the diameter (shaft diameter) of the nozzle holder 7.
This can contribute to a compact and lightweight gun configuration in the double chip system.

In the present embodiment, the atomizing flow path in the push screw 11 is configured by the small-diameter shaft hole 11c and the large-diameter shaft hole 11d. However, the present invention is not limited to this. The design may be changed.
For example, the small-diameter shaft hole 11c may be simply a circular hole, and the large-diameter shaft hole 11d may be a conical hole whose diameter gradually increases in the paint injection direction.
Further, the gasket 10 is not always necessary, and is not necessary when the airtightness is maintained in terms of shape or material on the contact surface between the nozzle tip 9 and the push screw 11.
In the above-described embodiment, the nozzle tip unit 6 is detachably attached to the nozzle head 2 attached to the gun body 1. However, the nozzle tip unit 6 is also mounted on the type directly attached to the gun body 1. can do.

It is a principal part perspective view of the airless gun in one Embodiment of this invention. It is a longitudinal cross-sectional view of a nozzle tip unit. It is a perspective view of a push screw. It is the figure which looked at a set screw from the paint injection direction upstream. It is a side view of a set screw.

Explanation of symbols

6 Nozzle tip unit 7 Nozzle holder 7a Mounting hole 9 Nozzle tip 11 Press screw 11c Small diameter shaft hole 11d Large diameter shaft hole

Claims (3)

In the nozzle tip unit formed by inserting the nozzle tip into the mounting hole formed in the nozzle holder, and screwing the set screw into the mounting hole from the upstream side in the paint spraying direction to fix the nozzle tip,
The nozzle tip unit, wherein the set screw has an atomizing flow path for atomizing paint. In the nozzle tip unit according to claim 1,
The nozzle tip unit, wherein the atomizing flow path includes a small-diameter shaft hole and a large-diameter shaft hole communicating with the small-diameter shaft hole on the downstream side in the paint injection direction. An airless gun comprising the nozzle tip unit according to claim 1.

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