JPH0798168B2 - Fan-shaped spray nozzle and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a nozzle for ejecting a spray in a fan shape in the absence of air and a method for manufacturing the nozzle.

[Conventional technology]

As a nozzle for ejecting the spray in a fan shape in the airless manner, generally, a lip-shaped orifice type formed by intersecting a dome-shaped concave surface in the rear open state and a V-shaped groove in the front open state. Nozzles with jets are used.

Since a fan-shaped spray nozzle having such a lip-shaped orifice-type injection port tends to have tails at both ends of the spray when spraying high-viscosity paint, various measures have been taken to prevent the tail generation. However, as an example, there is a technique described in JP-A-63-178867.

The technique described in the above publication, upstream to the dome-shaped concave surface,
The dome-shaped concave surface has a flow passage area sufficiently larger than the cross-sectional area of the rear end portion thereof, and the front end is provided with a hollow oval or oval cylindrical flow passage, and the connecting portion between the dome-shaped concave surface and the cylindrical flow passage is In addition to smoothly connecting to the dome-shaped concave surface at the short diameter part of the front end of the tubular flow path, a shoulder-shaped step is formed at the long diameter part, and a V-shaped groove intersecting the dome-shaped concave surface is formed in the cylindrical flow path. It is provided in such a way that it matches the short-diameter part of the groove and the valley of the groove is close to the step and does not intersect with the step. Keep it small, generate turbulence and small vortexes by the shoulder-shaped step portion that is close to the injection port, and generate the effect of preventing tail generation, especially in the vicinity of both ends of the injection port as the source of tail generation Both sides of the straight flow deflected by the flow and shoulder steps Preventing tail generated by the collision disrupting the deflecting flow of Luo 衝触, in which effects of the like can be obtained.

[Problems to be Solved by the Invention]

In the above-mentioned conventional technique, the effect of preventing the generation of tails is relatively good, but not only it is necessary to form the tip portions of the shoulder crescent-shaped step portions in an opposing state in which they approach each other, but Although it is necessary to engrave the V-shaped groove so that the valley of the V-shaped groove is located in the narrow portion in the middle, this kind of nozzle is made of a remarkably hard material such as cemented carbide or ceramic, and The dimensions are so small that the diameter of the dome-shaped concave surface is about 0.2 mm to 1.0 mm, so high-precision processing technology is required. Therefore, it will be manufactured by high-precision processing equipment and skilled workers, making it unsuitable for mass production. Not only that, but it also has the drawback of making the product expensive.

Further, it is usual to manufacture the orifice type fan type spray nozzle from a sintered material of cemented carbide or ceramic,
When the sintered body is obtained by forming a powdered raw material into a molded product and sintering it at a high temperature, the center axis of the dome-shaped concave surface and the cylindrical flow path does not match the center axis of the nozzle main body. Since the outer shape of the nozzle main body is also uneven because it is distorted, even when chucking the outer shape of the nozzle main body when grinding the V-shaped groove with a grinding wheel, it becomes a reference dome shape. Since the position of the concave surface differs for each individual, it is extremely difficult to align the tip edge of the grinding wheel with the center of the dome-shaped concave surface.

Further, it is most desirable that the pointed portion of the crescent-shaped step portion is formed by a combination of a corner portion having no fillet and a sharp ridge portion, and if they are rounded, the effect of preventing tail generation is reduced. Therefore, for the molding core for forming the stepped portion, it is necessary to form a corner without a fillet when molding the ridge, but since the shape is delicate and the size is fine. , It is extremely difficult to make molding cores.

Therefore, an object of the present invention is to improve the invention described in JP-A-63-178867, to provide a tailless nozzle having a structure that improves the effect of preventing tail generation and is easy to manufacture. Is to provide an easy way to make a tailless nozzle.

[Means for Solving the Problems]

According to the present invention, in order to achieve the above object, crescent-shaped shoulder step portions are formed on both sides of the concave surface on the upstream side of the deformed dome-shaped concave surface in which the substantially semicircular inclined flat surface portions are formed to face each other. Under the condition, a cylindrical channel having an elongated cross-section is continuously provided, and further, a connecting portion between the end of the inclined flat surface portion of the deformed dome and the front end of the cylindrical flow passage or a portion near this connecting portion is linear in the left-right direction. Are provided symmetrically in parallel with each other, and V-shaped grooves intersecting from the front are formed in the concave surface to a depth such that the valleys thereof coincide with the corners. .

In addition, as a manufacturing method, from a super-hard material having a truncated cone portion having a flat top or a low cone and a dome-shaped protrusion at the center of the top, a substantially semicircular inclined plane portion is opposed to the dome portion. Molding with a core and other necessary molding die members that are machined obliquely so that they are formed, and the truncated cone part is machined into a planar shape in an obtuse angle relationship with the inclined flat surface portion. A nozzle is used to mold a material mainly composed of a nozzle with an ultra-hard material, and thereafter, sintering and engraving of a V-shaped groove are performed.

[Action]

According to the nozzle having the above configuration, the concave hole formed of the deformed dome-shaped concave surface and the cylindrical flow path that is continuously provided upstream and has a large flow area is formed, and the injection port is formed at the front end of the concave hole. The pressurized liquid supplied is supplied to the nozzle without pressure loss, and in the vicinity of both ends of the lip-shaped nozzle, the turbulent flow due to the collision between the straight flow from the upstream and the deflected flow generated by the shoulder step and the corners Tail generation is effectively prevented by the synergistic action of the tail generation prevention effect, and the corners are necessarily lengthened appropriately due to the formation of the inclined plane. Even if it shifts to, there is no adverse effect on the formation of the injection port and the prevention of tail generation.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

The embodiment shown in FIGS. 1 to 3 is a deformed dome-shaped concave surface in which a substantially semi-circular inclined flat surface portion 2, 2 is formed to face a nozzle main body 1 made of a super hard material such as cemented carbide or ceramic. 3 and a cylindrical flow path 5 having an elongated front end portion in which substantially crescent-shaped shoulder step portions 4 and 4 are formed on both sides of the rear end arc portion of the concave surface 3 under the condition of rearward opening. In addition to being connected in a common axis relation with each other, obtuse corners 6 and 6 having no fillet are parallel to the connecting portion with the cylindrical flow path 5 at the linear end of the inclined flat surface portion 2 in the concave surface 3. When forming the corner portions 6, 6, the flat portions 7, 7 are formed in the upstream portion corresponding to the inclined flat portion 2 in the inner surface of the tubular flow path 5 so as to form the flat portions. 7
And the inclined flat surface portion 2 may be brought into contact with each other at an angle such that the inside thereof becomes an obtuse angle. Further, the groove 8 having a V-shaped cross section is opened at the front end of the nozzle body 1 in a state where the valley is opened forward. In the vicinity of the center of the linear corner portions 6, 6, the lip-shaped injection port 9 is opened by engraving at a depth that slightly intersects.

The modified dome-shaped concave surface 3, shoulder-shaped step portion 4, tubular flow path 5, 5 corner portion
6. In order to form the flat surface portion 7 and the like, the nozzle main body is formed by the molding die 10 including the molding core 10 as shown in FIG. 4 and other necessary mold members such as outer mold and upper and lower molds. It is obtained by molding the material of No. 1 and then sintering it.
As shown in the figure, for a super-hard core material with a truncated cone part and a dome-shaped protrusion in the center of the top, the semi-circular inclined flat surface part is diagonally formed so as to face the dome part. As shown in FIG. 4, by performing the grinding, the frustoconical surface is ground flatly in an obtuse angle relationship with the inclined flat surface portion, and the grinding degree of both is appropriately selected. Deformed dome-shaped mold surface adapted to molding of deformed dome-shaped concave surface 3
11, shoulder step portion 4, 4, step portion mold surface 12, 12 adapted for molding, cylindrical mold surface 13 adapted for molding of the tubular flow path 5, ridge angle adapted for molding of corner portions 6, 6. The die surfaces 14, 14 and the flat die surfaces 15, 15 adapted to the molding of the flat surface portions 7, 7 are formed.

Regarding the core 10, as shown in FIG. 6 or 7,
Depending on the degree of grinding of the ground surface, the ridge angle mold surface 14 is slightly displaced to the cylindrical mold surface 13 side or the deformed dome-shaped mold surface 11 side,
Accordingly, the corner portions 6, 6 may be formed in the front and rear of the shoulder step portion 4, both of which are effective in preventing tail generation.

Regarding the depth of engraving of the V-shaped groove 8, it is best to slightly intersect the corner portion 6, for example, 1/10 of the diameter of the concave surface 3.
A depth of 0 to 1/10 is good, but even if it is deeper than that or even if it is shallow enough not to intersect the corner portion 6, the tail generation preventing effect can be obtained, and if it is shallow, the diameter of the concave surface 3 The limit is about 1/100 of this.

Regarding the cross-sectional shape of the V-shaped groove 8, for example, as shown in FIG. 8 or 9, the valley portion may have a rounded shape or a bottom with a width, and the corner portion 6 has an appropriate length. It is convenient because of the relationship.

Further, the shoulder-shaped step portion 4 is not limited to a plane shape orthogonal to the axis, but may be inclined in a shoulder shape, and the top of the truncated cone portion as a material of the molding core 10 may be formed into a low conical surface. .

〔effect〕

As described above, according to the present invention, the following effects can be obtained.

(A) It is possible to form a cylindrical flow path reaching the injection port with a flow cross-sectional area that is significantly larger than the rear end portion of the deformed dome-shaped concave surface, and to supply pressure liquid to the injection port without causing pressure loss. As a result, the atomization efficiency is reduced, and the atomization efficiency is not reduced, and the generation of the tail is suppressed because the atomization pressure is high.

(B) By forming the shoulder-shaped step portion at a position extremely close to the nozzle, the supply liquid causes a turbulent flow and a vortex near the nozzle, effectively preventing the tail from being generated.

(C) Since a gradually decreasing step portion is formed on both sides slightly away from the valley of the V-shaped groove, and an obtuse angle corner portion is formed so as to coincide with or significantly approach the valley of the V-shaped groove, a lip shape is thereby formed. At the valleys at both ends as the tail generating part in the nozzle, not only the relatively small deflected flow with disturbance caused by the corners collides from both sides, but at the same time it collides with the forward flow from the upstream to prevent the generation of the tail. , The diverging deflected flow accompanied by disturbance is collided from the tip of the stepped part in the facing state, which is a little farther than the corner part, and collides with the forward flow from the upstream side. It is possible to effectively prevent the generation of a tail by generating a disturbance due to a collision flow having an active and appropriate spread inside the part, and in particular, due to the collision flow of the deflection flow from the tip of the step and the corner portion. Collision flow The large and small double disrupting effects it is possible to synergistically improve the tail prevention effect.

(D) Since the tail generation preventing effect is remarkable as in the above (a), (b), and (c), the allowable range of the depth of the V-shaped groove is wide, which is advantageous in manufacturing.

(E) The deformed dome-shaped concave surface is adopted, and it is engraved so that the valley of the V-shaped groove is located near the center of the rear end edge of the substantially flat semi-circular inclined plane portion having a moderate width. There may be a misalignment of the character-shaped groove in the left-right direction, and the groove engraving work is easy.

(F) Since the collision flows generated by the shoulder-shaped step portions need to be generated at positions slightly apart from each other and also to have a spread, the deformation dome-shaped mold surface 11 and the stepped mold surface 12 are connected to each other. Even if the corners have roundness, there is no problem, and therefore the core can be easily manufactured.

[Brief description of drawings]

In the drawings, FIG. 1 and FIG. 2 are respectively a vertical sectional side view and a front view showing a fan-shaped spray nozzle in one embodiment, FIG. 3 is a cross-sectional plan view, and FIG. 4 is a main part showing a molding core. FIG. 5 is a perspective view, FIG. 5 is a side view of an intermediate material of the molding core, and FIGS. 6 and 7 are respectively oblique views showing only the essential parts of the molding core in another embodiment. 8
FIG. 9 and FIG. 9 are schematic views each showing the cross-sectional shape of the V-shaped groove in another embodiment. 1 ... Nozzle main body 2 ... Inclined flat surface 3 ... Concave surface 4 ... Shoulder step 5 ... Cylindrical flow path 6 ... Corner 7 ... Flat 8 ... Groove 9 ... Jet 10 ... … Core 11 …… Deformed dome-shaped surface 12 …… Stepped surface 13 …… Cylinder surface 14 …… Ridge surface 15 …… Flat surface

Claims (2)

[Claims] 1. A deformed dome-shaped concave surface (3) in which a substantially semi-circular inclined flat surface portion (2), (2) is formed to face a nozzle main body (1), and a rear end of this concave surface (3). The crucible fan-shaped step portions (4), (4) are formed on both sides of the circular arc portion, and the cylindrical flow path (5) having an elongated front end portion is opened rearward in a common axial relationship. In addition to the continuous installation, the concave surface (3) has an obtuse angle with no fillet near the connecting portion with the tubular flow path (5) at an approaching front and rear position including the straight edge of the inclined flat surface portion (2). The corners (6), (6) are formed symmetrically, and a groove (8) having a V-shaped cross section is formed at the front end of the nozzle body (1) in a front open state, and the valley thereof has the above-mentioned corners (6). ，
A fan-shaped spray nozzle in which a lip-shaped injection port (9) is opened by engraving at a depth such that it slightly crosses near the center of (6) to slightly cross it. 2. A semi-hard material having a truncated cone portion having a flat or low-cone top and a dome-shaped protrusion at the center of the top, and a substantially semi-circular inclined plane portion is formed in the dome portion so as to face each other. As it is cut diagonally,
The truncated conical portion is flatly machined in an obtuse angle relationship with the inclined flat surface portion, whereby a modified dome-shaped die surface (11) and a shoulder-shaped step portion adapted for molding of the modified dome-shaped concave surface (3). (4),
Step mold surfaces (12), (12) suitable for molding of (4), cylindrical mold surface (13) suitable for molding of tubular flow path (5), corner portions (6), (6) Rectangle type surface (14), (1
4), using a molding die having a core (10) having flat mold surfaces (15), (15) adapted to mold flat parts (7), (7) A method for manufacturing a fan-shaped spray nozzle, which comprises molding a raw material with an ultra-hard material, sintering the raw material, and then engraving a V-shaped groove (8) on the front end of the nozzle main body (1).