JPH0798291B2 - Manufacturing method of fan-shaped spray nozzle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a fan-shaped spray nozzle used for airless spray coating and the like.

[Prior art]

As a fan-shaped spray nozzle that prevents the generation of tails, a rip-shaped nozzle formed by a concave hole having a dome-shaped concave surface and a cylindrical flow path and a V-shaped groove intersecting with the concave hole is provided.
In particular, a nozzle in which a stepped annular corner portion is formed at the boundary between the dome-shaped concave surface and the tubular flow channel is widely used.

However, in actual production, since the raw material made of superhard material such as cemented carbide or ceramic obtained by sintering after powder molding is the one in which the annular corner is omitted, A V-shaped groove is first engraved from the outside of the raw material to open the rip-shaped injection port, and then a processing tool is inserted from the rear into the dome-shaped concave hole to mechanically grind or discharge the corners. Grinding is performed so that the corners are formed so as not to leave fillets and the step is not large, so that not only a good result can be obtained, but also the intersection with the V-shaped groove can be obtained. Since it is necessary to strictly define the dimensions, there is a great difficulty in the grinding process, which requires highly accurate processing machinery and skilled workers.

[Problems to be solved by the invention]

Although it is possible to form the corners at the powder molding stage, the nozzle hole diameter is small, and the diameter of the dome-shaped concave surface is usually about 0.3 to 1.0 mm. Since it is extremely small, about 1/100 to 5/100 mm, there are many problems in the production of molding dies with precise steps.

Also, the small diameter of the dome-shaped concave hole molding die means
Since the powder is molded under high pressure, there is a defect that the mold itself is easily damaged, and a structure that is not easily damaged is desired.

Therefore, an object of the present invention is to provide a method for manufacturing a tail-prevention fan-shaped spray nozzle that uses a molding die that can be easily manufactured, and that can form a step easily. To do.

[Means for solving problems]

In order to achieve the above object, the present invention provides a core having a cylindrical die surface, a shoulder stepped die surface at its tip, a dome-shaped die surface on the stepped die surface, and a step adjusting die surface. A super-hard material is powder-molded and sintered using the required outer mold, and a V-shaped groove is formed on the whole surface of this sintered material from the outside in a direction that matches the minor axis direction of the shoulder step. It is characterized in that the depth of the groove is substantially equal to or slightly deeper than the base end of the dome-shaped concave surface.

〔Example〕

Hereinafter, embodiments of the method of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, as a mold for molding the nozzle main body 1, a dome-shaped mold surface 2 at the tip and a substantially small oval with a short diameter that is substantially the same as or slightly larger than the diameter of the dome-shaped mold surface 2. A lower mold 7 in which a core 5 having a shoulder-shaped step-shaped mold surface 3 and a cylindrical mold surface 4 having the shoulder-shaped step-shaped mold surface 3 as an end is projected on a base 6 in an upright state. An outer mold 9 having a cylindrical surface 8 adapted to mold the outer periphery of the nozzle main body 1 and a cylindrical surface of the outer mold 9 that can slide, and molding of the tip of the material A of the nozzle main body 1. Upper mold 11 with concave section 10 to accommodate
Using, and while the lower die 7 and the outer die 9 are connected to each other, the upper die 11 is placed under the condition that the outer die 9 is filled with the powder of the super hard material such as cemented carbide or ceramic. After the material A is strongly advanced from above to press-mold the material A, the material A is taken out and sintered at an appropriate temperature, whereby the dome-shaped concave surface 12 and the concave surface 12 are formed as shown in FIG. There is a substantially oval shoulder-shaped step portion 13 in contact with the base end, and a cylindrical flow path 14 in the rear open state having the shoulder-shaped step portion 13 as the front end portion, and the base end diameter of the dome-shaped concave surface 12 is almost the same. A material A for the nozzle main body 1 having a shoulder-shaped step portion 13 having the same or a slightly larger minor diameter was manufactured, and a V-shaped groove 15 was formed on the material A from the outside of the top thereof.
As shown in FIG. 4, the depth of the valley of the groove reaching the base end of the dome-shaped concave surface 11 or a little deeper than that is obtained by grinding in the direction coinciding with the short diameter of the shoulder step portion 13. Set up,
The lip-shaped nozzle 16 is opened.
It is possible to easily obtain a nozzle that prevents the generation of tails.

Since it is important to prevent the tail from occurring, it is important to make the dimensions of the dome-shaped concave surface 12 and the short-diameter portion of the shoulder-shaped cut portion 13 the same, or to select an appropriate dimensional difference. It is only necessary to form a step adjusting mold surface 4'on the cylindrical mold surface 4 in Fig. 4 to change the degree of machining of the step adjusting mold surface 4 ', and as shown in FIG. The minor diameter of the shaped mold surface 3 may be the same as the diameter of the dome shaped mold surface 2,
Further, the stepped mold surface 3 may not be a flat surface, but may be a conical surface in order to form a shoulder shape as shown in FIG.

〔The invention's effect〕

As described above, the method of the present invention has the following effects.

(A) Since a core having a shoulder step mold surface and a cylindrical mold surface having this as an end is actuated to mold, the core is made thick and the molding mold is broken during molding. It can be used for a long period of time without doing this, and since this shoulder-shaped stepped surface can form a shoulder-shaped stepped portion in the nozzle upstream of the nozzle, this allows turbulent flow and small vortex flow in the upstream just before the nozzle. Can be used to improve atomization and prevent tail generation.

(B) Since it is possible to form the stepped portion or the corner portion near the both ends of the lip-shaped injection port for the purpose of preventing the tail generation by grinding during the powder molding without grinding, it is possible to form a large amount of a uniform product. It is suitable for production and can be manufactured with high precision.

(C) The grinding process for the nozzle is an internal process,
The processing of the molding die is processing on the outer surface, and accordingly, the processing is remarkably simple and the dimensional adjustment is easy.

[Brief description of drawings]

In the drawings, FIG. 1 is a vertical sectional front view showing a state at the time of powder molding, FIG. 2 is a perspective view showing only a core, FIG. 3 is a vertical sectional front view showing a raw material after powder molding, and FIG. 4 is completed. FIG. 5 is a vertical sectional front view of the nozzle, and FIG. 5 and FIG. 6 are perspective views respectively showing only the main part of the core in another embodiment. 1 …… Nozzle main 2 …… Dome shape surface 3 …… Shoulder step surface 4 …… Cylinder surface 4 ′ …… Step adjustment surface 5 …… Core 12 …… Dome concave surface 13… … Shoulder-shaped step 14 …… Cylindrical flow path 15 …… V-shaped groove 16 …… Rip-shaped injection port A …… Material

Claims (1)

[Claims] 1. A dome-shaped mold surface, a shoulder stepped mold surface having a short diameter that is substantially the same as or slightly larger than the diameter of the dome-shaped mold surface, and a tubular shape whose end is the shoulder stepped mold surface. Using a molding die having a core having a mold surface, a nozzle-based material is powder-molded with an ultra-hard material and then sintered, thereby forming a dome-shaped concave surface, a shoulder-shaped step portion, and a tubular flow path. After manufacturing a material mainly consisting of a nozzle, a V-shaped groove is engraved on this material so as to intersect with the dome-shaped concave surface in the direction corresponding to the minor diameter direction of the shoulder step, Opened a spout and said V
A method for manufacturing a fan-shaped spray nozzle, characterized in that the troughs are formed so that the valleys thereof coincide with the base end of the dome-shaped concave surface or are slightly deeper than that.