JPH0528438U - Airless painting equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] The nozzle tip is provided with a paint spray hole that sprays a flat paint spray that spreads in a fan shape in a plane including the axis, and the paint spray hole is connected to a high-pressure paint supply path. In the airless coating device, the shape and size of the paint jet pattern can be adjusted with a simple structure. A pair of air ejection holes 15 opening forward inward are provided on both sides of a paint ejection hole 14 along a spreading direction of a paint jet at a front portion of an outer cover 12 which extends forward while covering a nozzle tip 6. The ejection direction of the air ejection hole 15 is substantially tangential to the arcuate front end portion 17a of the film-shaped fan-shaped portion 17 generated at the base of the paint ejection flow from the paint ejection hole 14.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an airless coating device having a nozzle tip provided with a paint spray hole for spraying a flat paint spray spreading in a fan shape in a plane including an axis, and the paint spray hole being connected to a high-pressure paint supply passage. In particular, it relates to an airless coating device capable of adjusting the shape and size of a paint jet pattern.

[0002]

[Prior Art]

 Conventionally, an airless coating device capable of adjusting the size and shape of a paint jet pattern has already been known, for example, from Japanese Utility Model Publication No. 63-4524.

[0003]

[Problems to be solved by the device]

 In the above-mentioned conventional one, a nozzle tip having a paint ejection hole connected to the paint supply passage is surrounded by an air ejection port to form a flat fumarole, and a flat fan-shaped paint jet is ejected from the flat fumarole. The shape and dimensions of the paint jet pattern are adjusted by ejecting air from a pair of auxiliary air ejection holes that open inwardly in the rear of the flat air outlet.

However, in this conventional technique, it is necessary to supply air in two systems, which complicates the structure of the coating gun and makes it difficult to adjust the air supply balance between the two systems.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an airless coating device capable of adjusting the shape and size of a paint jet pattern with a simple configuration.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, according to the present invention, a pair of frontward and inward openings are provided on both sides of a paint ejection hole along a spreading direction of a paint jet, in a front portion of an outer cover that covers a nozzle tip and extends forward. Air jet holes are provided, and the jetting directions of these air jet holes are set substantially tangentially to the arcuate front end of the film-shaped fan-shaped portion generated at the base of the paint jet from the paint jet holes. .

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1, a nozzle chip is attached to a front end of a gun body 4 formed in a cylindrical shape having a paint supply passage 3 connected to a high-pressure paint supply source (not shown) coaxially with a cap nut 5. 6 is fixed. That is, a small-diameter bottomed cylindrical connecting portion 4a is coaxially projected at the front end of the gun body 4, and a male screw 7 is engraved on the outer surface of the connecting portion 4a. The nozzle tip 6 has a disk-shaped base 6a having an outer diameter that is substantially the same as the outer diameter of the connecting portion 4a, and a bottomed cylinder that is coaxially projecting forward from the base 6a. And the projecting portion 6b are coaxially connected to each other via the stepped portion 6c, and the cap nut 5 that engages with the stepped portion 6c is screwed into the male screw 7 to be tightened, so that the nozzle tip 6 is fixed to the gun body 4. Will be fixed to the front end of.

At the front end of the gun body 4, that is, in the connecting portion 4a, a small-diameter communication passage 8 that is concentrically connected to the paint supply passage 3 through a step is provided, and in the nozzle tip 6, the communication passage 8 is provided. A continuous passage 9 is provided. Moreover, the gun body 4 is provided with a hemispherical valve body portion 10a at the front end which can be seated on the opening edge of the communication passage 8 on the side of the paint supply passage 3 and shut off between the paint supply passage 3 and the communication passage 8, that is, the passage 9. The valve shaft 10 is inserted so as to be movable in the axial direction, and the amount of coating material supplied to the nozzle tip 6 is adjusted by operating the valve shaft 10 in the axial direction.

The gun body 4 and the cap nut 5 are screwed into an outer cover 12 formed in a cylindrical shape having an internal thread 11 on the inner surface, and the inner surface of the outer cover 12 near the front end is covered by the cap nut 5. A stopper 13 for abutting and restricting the axial position of the cap nut 5, that is, the nozzle tip 6 with respect to the outer cover 12 is integrally provided so as to project radially inward. Thus, the front end portion of the outer cover 12 covers the nozzle chip 6 and extends forward.

Referring also to FIG. 2, a paint spray hole 14 communicating with the passage 9 is provided at the center of the front end surface of the protrusion 6 b of the nozzle tip 6, and the paint spray hole 14 has its axis lined up. It is formed in a lip shape so as to eject a flat paint jet that spreads in a fan shape in one plane including the plane (the plane parallel to the paper surface of FIG. 1).

Further, on the inner surface of the front portion of the outer cover 11 that extends forward and covers the nozzle tip 6, a pair of air ejection holes 15 and 15 that open inwardly on both sides of the paint ejection hole 14 along the spreading direction of the paint jet flow. Are provided, and the air ejection holes 15 and 15 are connected to the air supply passages 16 and 16 formed in the outer cover 12 so as to be connected to the same pressurized air supply source (not shown).

By the way, at the base of the paint jet ejected from the paint ejecting hole 14, a film-shaped fan-shaped portion 17 that remains in a liquid state and has a fan shape is generated, and the ejection directions of the both air ejecting holes 15 and 15 are In a plane including the axes of the air ejection holes 15 and 15 and the paint ejection hole 14, the arcuate front end 17a of the film-shaped fan-shaped portion 17 is set substantially tangentially.

Next, the operation of this embodiment will be described. A high-pressure paint of, for example, about 100 kg / cm ² is supplied from the paint supply passage 3 to the paint ejection hole 14, whereby the paint ejection hole 14 is flattened. A fan-shaped paint jet is ejected. Further, relatively low pressure air of, for example, 1 kg / cm ² or less is ejected from the pair of air ejection holes 15 and 15, and the air jets from both air ejection holes 15 and 15 are located at the base of the fan-shaped paint jet. It collides with the arcuate front end portion 17a of the membrane fan-shaped portion 17 in a substantially tangential direction. Thus, the shape and size of the paint jet pattern are adjusted by adjusting the air jet pressure from both air jet holes 15, 15.

[0015] Here, the coating material delivery pressure of 100 kg / cm ^2, when changing the air injection pressure between 0~1.0kg / cm ^2, and 300 mm the distance L from the nozzle tip 6 forward The change in the width W of the paint jet pattern at the above position is shown in FIG. 3, and it can be seen that the width W becomes smaller as the air jet pressure is increased.

Moreover, regarding the coating efficiency, a maximum coating efficiency of about 75% can be obtained when the air ejection pressure is 0.5 kg / cm ² or more. On the other hand, in the case of airless coating without air ejection from the air ejection holes 15 and 15, only a coating efficiency of about 60% can be obtained as shown by the chain line in FIG. In this case, only a maximum coating efficiency of about 40% can be obtained.

In this way, the shape and size of the paint jet pattern can be adjusted with a simple structure in which the pair of air jet holes 15, 15 are provided in the front portion of the outer cover 12 that covers the nozzle tip 6. There is no need to pay attention to the supply balance because only one system is required.

[0018]

[Effect of the device]

 As described above, according to the present invention, the front portion of the outer cover that extends forward while covering the nozzle tip has a pair of air ejection holes that open inwardly on both sides of the paint ejection hole along the spreading direction of the paint jet. A simple structure is provided in which the jet direction of these air jet holes is set almost tangential to the arcuate front end of the film-shaped fan-shaped portion generated at the base of the paint jet from the paint jet hole. The shape and dimensions of the jet pattern can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment.

FIG. 2 is a front view taken along the line 2-2 of FIG.

FIG. 3 is a graph showing changes in pattern width and coating efficiency due to air ejection pressure.

[Explanation of symbols]

 3 Paint Supply Channel 6 Nozzle Tip 12 Outer Cover 14 Paint Jet Hole 15 Air Jet Hole 17 Membrane Fan 17a Arc Front End

Claims (1)

[Scope of utility model registration request] 1. A paint comprising a nozzle tip (6) provided with a paint spray hole (14) for spraying a flat paint spray spreading in a fan shape in a plane including an axis, the paint spray hole (14) having a high pressure. In the airless coating device connected to the supply passage (3), at the front part of the outer cover (12) that extends forward while covering the nozzle tip (6), on both sides of the paint ejection hole (14) along the spreading direction of the paint jet. A pair of air ejection holes (15) opening inward in the forward direction is provided, and the ejection direction of these air ejection holes (15) occurs at the base of the paint jet from the paint ejection hole (14) (a film-shaped fan portion ( 17) An airless coating device, which is set substantially tangential to the arcuate front end (17a).