JPS5830606Y2 - Marking device for flaw detection - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a marking device that indicates a defective location on the surface of a material to be detected where a defect has been detected by a magnetic flaw detection device or a quasi-nondestructive flaw detection device.

Generally, marking devices used for this type of purpose use a method in which a marking liquid, such as paint, is sprayed with a spray gun.

Normally, these spray guns have a compressed air outlet installed close to the paint outlet, and blow out compressed air at high speed to induce negative pressure at the paint outlet. It sucks up the paint inside and sprays it out.

The mixture of paint and air takes place outside of each outlet, so in order to keep the density and size of the marking pattern constant, the condition of the paint blowing nozzle, the concentration of the paint, the air pressure, etc. It is necessary to maintain and manage the equipment under reasonable conditions at all times.

However, when used continuously for a long time, the condition inside the nozzle may change,
For example, the marking display may be interrupted due to paint clogging, or the paint film may become thicker than necessary due to increased air pressure, causing variations in the density and size of the marking pattern, etc. There was instability as a result.

The purpose of this invention is to realize a marking device for flaw detection that eliminates these instabilities.In particular, the air and paint are mixed in the space inside the device, and the mixture is then transferred to the paint outlet. The present invention attempts to provide a device that prevents clogging of paint within the nozzle lumen by improving the guide path for guiding the paint into a streamlined spindle shape.

Hereinafter, embodiments of this invention will be explained with reference to the drawings, while comparing them with examples of conventional devices.

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the device of this invention, Fig. 2 is a plan view of the above-mentioned embodiment, Fig. 3 is a diagram illustrating the configuration of the same embodiment of the device, and Fig. 4 is a diagram of the conventional device. It is a longitudinal cross-sectional view of an injection part.

1 and 2, 1 is a solenoid part, 2 is a paint introduction part, 3 is a nozzle, 3' is a paint outlet, 3'' is a mixture guiding path 4 is an air introduction pipe, 4 is an air flow path, and 5 1 is a paint hose connection port, 6 is a piston, 7 is a connecting portion, and 7' is a valve head contact surface, with a part of the connecting portion being processed into a flat surface as shown in the figure.

8 is a compression spring, 9 is a solenoid, 10 is an O-ring, 11
is a joint.

Further, the black arrow indicates the inflow direction of paint, and the white arrow indicates the inflow direction of compressed air.

Next, in FIG. 3, A is a marking device, Pl is a compressed air source for pressurizing paint, T is a paint tank, P2 is a compressed air source for spraying, C is a joint, and ■ is a pressure reducing valve for adjusting air pressure.

In addition, in FIG. 4, the same numbers are applied to the same operating parts as in FIGS. 1 and 2, but 6' is the valve head, which is disk-shaped and is provided on the piston 6 and is in contact with the lower end plane of the nozzle 3. It looks like this.

12 is an air jet hole, 13 is a paint outlet hole, 14 is a valve head gasket, and 15 is a nozzle gasket.

The paint in the paint tank T is supplied via the paint hose to the paint hose connection D5 by the air pressure applied in the tank, and is further filled around the piston 6.

When the solenoid 9 is not working, the screw I/N 6 is urged upward in the figure by the compression spring 8, and the valve head 6' is pressed against the contact surface of the connecting portion 7. .

The paint outlet [13' of the nozzle 3 is therefore closed and the paint is blocked.

When a current flows through the solenoid 9 and is excited by the signal related to the flaw detection signal (the power supply and wiring are not shown)
, the piston 6 is pulled downward against the compression spring 3, a gap is created between the valve head 6' and the contact surface 7', and a gap is created between the paint introduction part 2 and the connecting part 7 around the piston 6. The filled paint at a constant pressure overflows upward through the gap and flows out around the conical protrusion of the valve head 6'.

On the other hand, since compressed air is supplied to the air introduction pipe 4 via the joint 11, the air is supplied from the air flow path 4' to the outer circumferential surface of the central cylinder of the nozzle 3 and the inner circumferential surface of the hole in the connecting part 7. High-pressure air is blown toward the entire circumference of the base of the conical protrusion of the valve head 6 through the annular introduction path formed between the valve head 6, and the paint flowing into this area is strongly blown into the air. The paint mixes.

Note that a funnel-shaped guide hole 3'' is formed at the lower end of the paint outlet 3' of the nozzle 3, and the shape corresponds to the conical projection of the valve head, so the mixture of air and paint flows through the conical projection of the valve head. Due to the surface and the funnel-shaped guide hole 3'', the paint receives very little resistance, becomes a fluid, is pushed out toward the paint outlet 3', and is emitted from the outlet 3' into the atmosphere in the form of a spray.

In the conventional general spray gun system, as shown in FIG.
2, the paint is suctioned and injected using the negative pressure created when air is ejected, and the air and paint are mixed immediately after the air is irradiated into the atmosphere. The sprayed liquid may be ejected in the form of particles, resulting in uneven marking pattern density, or when continuous use is interrupted, paint residue may stick to the paint outlet hole 13 and clog it. This caused inconveniences such as.

In the device of this invention, the paint and air are always mixed inside the device before irradiation, and the mixed fluid is pushed out through a guide path with a rectifying effect and radiated to the outside, so it is possible to create a marking pattern. It is extremely effective in making the concentration uniform.

In addition, in this design, the airflow is always maintained in the streamlined flow path inside the nozzle, and only the flow of paint is opened and closed, so all paint flowing into the inner cavity of the nozzle 3 is blown away by the high-speed airflow. The injection hole is kept clean at all times without being atomized and emitted, collecting in the corners and solidifying.

Therefore, there is no fear that paint will remain inside the nozzle and solidify and clog the holes.

Next, the marking pattern emitted from the paint outlet 3' by this device is displayed in a circular shape on the stationary surface of the material to be tested, but it is displayed in an oval shape on the surface of the material to be tested that is being fed at a certain speed. be exposed.

In this device, as shown in FIG. 3, by adjusting the air pressure from the compressed air source P2 for spraying using a pressure reducing valve V, the diameter of the circle of the marking pattern emitted from the paint blower 113' can be changed. Therefore, it is possible to freely adjust the size of the oval marking pattern on the surface of the moving target material.

As detailed above, this invention provides a marking liquid injection device that can always provide a circular or oval marking pattern of uniform density, prevents nozzle clogging, and is easy to manage and maintain during continuous use. It is something that

[Brief explanation of the drawings] Figure 1 is a longitudinal sectional view of an embodiment of this invention, and Figure 2 is the same.
A top view of the embodiment, FIG. 3 is a configuration diagram of the embodiment device. FIG. 4 is a longitudinal cross-sectional view of the injection section of a conventional example of the device. 1: Solenoid part, 2: Paint introduction part, 3: Nozzle, 3'
, paint outlet, 3″: funnel-shaped guide hole, 4: air introduction pipe, 4′: air flow path, 5: paint hose connection port, 6: piston 6/ , 6tt , valve head, 7: connection part, 7 ': Valve head contact surface, 8: Compression spring, 9 [Solenoid, 10: O-ring, 11: Joint, 12: Air jet hole, 13: Paint outflow hole,
14: Valve head gasket, 15: Nozzle gasket.

Claims (1)

[Scope of utility model registration request] a compressed air inlet in the inner cavity of the nozzle body from which paint is to be ejected;
In a paint injection device that has a paint inlet with a solenoid-controlled on-off valve, a valve head with a conical protrusion is provided at the tip of the piston that serves as the valve body, and the inlet for compressed air for spraying is connected to the valve head. A marking device for flaw detection, which is opened at a position covering the entire periphery of the base of a conical protrusion, and a portion of the inner cavity of the paint outlet corresponding to the conical protrusion serves as a corresponding funnel-shaped introduction part.