EP1042073B1 - Spray nozzle with directly mounted plate - Google Patents

Abstract

A spray nozzle includes a central swirl chamber (9), receiving the fluid tangentially through lateral fluid inlet channels (14) from a peripheral front cavity (8), and projecting the fluid in outlet through a coaxial outlet passage (12). The coaxial outlet passage (12), the central swirl chamber (9) and the fluid inlet channels (14) are made up of ribs and recesses in a front plate (15) engaged between a nozzle (1) hollow body and a rear core (5) which is itself formed by a core rear body (5a) and a rear plate (5b) with rear axial recess (17). Thus one can economically produce fluid inlet channels (14) and a central swirl chamber (9) with coaxial outlet passage (12) and rear axial recess (17) with very accurate dimensions, thereby ensuring satisfactory reproducibility of the features of the fluid spray jet at the outlet.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to spray nozzles of liquid, capable of being used in the most more diverse such as for example spray pumps, vaporizers, nozzles for combustion burners, internal combustion engine injectors.

The invention applies more particularly to the nozzles of spray into which the liquid to be sprayed is fed in a central channel swirling through channels side of fluid intake tangentially injecting the liquid which then leaves the central vortex chamber by a coaxial output passage.

Central chamber spray nozzles swirling generally ensures good spraying of the liquid.

These nozzles are usually made of metal, by traditional machining processes, and most often involve a nozzle hollow body, with a peripheral external wall of axis longitudinal, and with a radial anterior outer wall provided an axial outlet hole for the flow of the outlet flow from fluid. The central swirl chamber is limited by a peripheral wall of revolution of longitudinal axis, by a wall anterior to coaxial outlet passage, and through a wall later. The anterior wall with coaxial outlet passage is formed by said radial anterior outer wall, perpendicular to the longitudinal axis. At least one lateral intake channel of fluid is provided in the peripheral wall, open in the chamber swirl center, and shaped for flow flow fluid inlet and to tangentially inject the fluid into the central swirl chamber.

In their applications, the spray nozzles produce an output stream in the form of liquid sprayed in fine droplets, the flow being generally conical along the axis longitudinal, and the droplets distributed in the cone of randomly.

In an industrial production of spray nozzles by metal machining, there is a great dispersion of main parameters of the output stream, namely the size of the droplets, the value of the exit angle, and the spectrum of distribution of droplets in the cone.

The dispersions of the characteristics of the output stream cause considerable difficulties when using the spray nozzles. In particular, this leads to a random increase in carbon monoxide content and of hydrocarbons in the exhaust gases, to a decrease in the combustion efficiency, and fouling of the exchange walls thermal surrounding the combustion zone.

The dispersions of the output flow parameters of the liquid are due to a dispersion of the dimensions of the channels of fluid intake, and especially of the central chamber of swirling. It is not economically possible to reduce these dimensional dispersions with the methods of traditional manufacturing machining of metal parts constituting known spray nozzles, as this would require great machining precision which is not economically feasible, especially in the case of reduced size spray.

To facilitate manufacture, it has already been proposed in the document CH-421 009 A, to produce the peripheral walls and anterior to the swirl chamber, the coaxial passage of outlet and side channels for fluid intake as posterior grooves and recesses in an anterior plate reported in a hollow body of the nozzle and held in abutment against an anterior outer wall by a posterior nucleus.

The anterior plate and the posterior nucleus are all two held laterally independently of each other by the wall nozzle body device.

This added front plate structure does not allow however not to achieve economically and reproducibly in series of spray nozzles with a rear recess coaxial extending backward into the posterior nucleus the swirl chamber.

Such a coaxial posterior recess may have a advantage in particular for stabilizing the projection cone at the outlet nozzle.

STATEMENT OF THE INVENTION

The problem proposed by the present invention is to design a new chamber spray nozzle structure swirl center which can be manufactured in such a way economical and precise by implementing techniques of great precision, so that the fluid intake channels and the central swirl chamber are dimensioned so precise and repetitive, and so as to precisely center a posterior swirl chamber recess.

The invention aims in particular to produce such nozzles of small dimensions, in which the channels fluid inlet and central swirl chamber are reduced in size, so that the dimensional accuracy necessary lead to absolute details of the order of just a few microns.

Another problem proposed by the invention, in some embodiments, is to avoid the risks of degradation of the spray nozzle in the event of cold solidification of the fluid contained in the spray nozzle.

• un corps creux de buse avec une paroi externe périphérique d'axe longitudinal et avec une paroi externe antérieure radiale munie d'un trou axial de sortie,
• une chambre centrale de tourbillonnement limitée par une paroi périphérique de révolution d'axe longitudinal, par une paroi antérieure à passage coaxial de sortie plus petit que le trou axial de sortie, et par une paroi postérieure,
• au moins un canal latéral d'admission de fluide dans la paroi périphérique, ouvert dans la chambre centrale de tourbillonnement et conformé pour injecter tangentiellement le fluide dans la chambre centrale de tourbillonnement,
• une plaquette antérieure rapportée dans le corps creux de buse et en appui contre la paroi externe antérieure radiale, comportant des rainures et évidements postérieurs formant les parois périphérique et antérieure au moins de la chambre centrale de tourbillonnement, le passage coaxial de sortie, et ledit au moins un canal latéral d'admission de fluide,
• un noyau postérieur adapté dans le corps creux de buse, avec des canaux périphériques d'amenée de fluide, et avec une face antérieure repoussant ladite au moins une plaquette antérieure rapportée vers ladite paroi externe antérieure radiale du corps creux de buse,

   et dans laquelle :

• le noyau postérieur comprend un corps postérieur de noyau, retenu dans le corps creux de buse par des moyens de fixation, et une plaquette postérieure maintenue par le corps postérieur de noyau en appui axial contre la plaquette antérieure pour former la paroi postérieure de chambre centrale de tourbillonnement et pour limiter vers l'arrière ledit au moins un canal d'admission de fluide,
• les plaquettes antérieure et postérieure sont munies de moyens de centrage relatif assurant le centrage relatif des plaquettes l'une par rapport à l'autre autour de l'axe longitudinal,
• la plaquette postérieure comprend, selon l'axe longitudinal, un creux postérieur à section transversale plus faible que la chambre centrale de tourbillonnement,
• l'une au moins des plaquettes antérieure et postérieure est montée avec un jeu radial dans le corps creux de buse.

To achieve these and other objects, the invention provides a spray nozzle having:

• a hollow nozzle body with a peripheral external wall of longitudinal axis and with a radial front external wall provided with an axial outlet hole,
• a central swirl chamber limited by a peripheral wall of revolution with a longitudinal axis, by a front wall with a coaxial outlet passage smaller than the axial outlet hole, and by a rear wall,
• at least one lateral channel for admitting fluid into the peripheral wall, open in the central swirl chamber and shaped to tangentially inject the fluid into the central swirl chamber,
• an anterior plate attached to the hollow body of the nozzle and bearing against the radial anterior external wall, comprising posterior grooves and recesses forming the peripheral and anterior walls at least of the central swirl chamber, the coaxial outlet passage, and said at minus a lateral fluid intake channel,
• a posterior core adapted in the hollow nozzle body, with peripheral fluid supply channels, and with an anterior face pushing said at least one anterior plate attached towards said radial anterior external wall of the nozzle hollow body,

and in which:

• the posterior nucleus comprises a posterior nucleus body, retained in the hollow nozzle body by fixing means, and a posterior plate held by the posterior nucleus body in axial support against the anterior plate to form the posterior wall of the central chamber of to swirl and to limit said rear at least one fluid intake channel,
• the front and rear plates are provided with relative centering means ensuring the relative centering of the plates relative to each other around the longitudinal axis,
• the rear plate comprises, along the longitudinal axis, a posterior recess with a smaller cross section than the central swirl chamber,
• at least one of the front and rear plates is mounted with a radial clearance in the hollow body of the nozzle.

According to one possibility, the relative centering means of the plates are made on their front support faces respectively.

Preferably, the relative centering means of the platelets include a posterior peripheral rib of the front plate into which the periphery of the posterior plate.

SUMMARY DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue de côté globale en coupe longitudinale d'une buse de pulvérisation selon un mode de réalisation particulier de l'invention ;
• la figure 2 est une vue à plus grande échelle de la zone antérieure de la figure 1 ;
• la figure 3 est une vue d'arrière de la face postérieure d'une plaquette antérieure selon le mode de réalisation de la figure 2 ;
• la figure 4 est une vue en perspective de la face postérieure de plaquette antérieure de la figure 3 ;
• la figure 5 est une vue de côté partielle en coupe longitudinale à grande échelle d'une buse de pulvérisation selon un second mode de réalisation de l'invention ;
• la figure 6 est une vue de côté partielle en coupe longitudinale à grande échelle d'une buse de pulvérisation selon un troisième mode de réalisation de l'invention ;
• la figure 7 est une vue d'arrière de la face postérieure d'une plaquette antérieure selon le mode de réalisation de la figure 6 ; et
• la figure 8 est une vue en perspective de la face postérieure de la plaquette antérieure de la figure 7.

Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, given in relation to the attached figures, among which:

• Figure 1 is an overall side view in longitudinal section of a spray nozzle according to a particular embodiment of the invention;
• Figure 2 is an enlarged view of the front area of Figure 1;
• Figure 3 is a rear view of the rear face of a front plate according to the embodiment of Figure 2;
• Figure 4 is a perspective view of the rear face of the front plate of Figure 3;
• Figure 5 is a partial side view in longitudinal section on a large scale of a spray nozzle according to a second embodiment of the invention;
• Figure 6 is a partial side view in longitudinal section on a large scale of a spray nozzle according to a third embodiment of the invention;
• Figure 7 is a rear view of the rear face of a front plate according to the embodiment of Figure 6; and
• FIG. 8 is a perspective view of the rear face of the front plate of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In all the embodiments illustrated on the figures, a spray nozzle according to the present invention comprises a hollow body for nozzle 1, for example a hollow body cylindrical, limited by a peripheral external wall 2 of axis longitudinal I-I and of revolution, and closed by an external wall radial anterior 3 provided with an axial outlet hole 4.

A posterior core 5 is fitted in the hollow body of nozzle 1, with peripheral channels 6 and 7 for supplying fluid up to one or more peripheral anterior cavities 8, 8a and 8b. There is provision for access between the posterior nucleus 5 and the radial anterior outer wall 3, either by providing a reported radial anterior outer wall 3, either by providing a posterior nucleus 5 reported. In the embodiments illustrated in the figures, the posterior nucleus 5 is reported in the hollow body of nozzle 1, while the radial front wall 3 is in one piece with the peripheral external wall 2.

The spray nozzle according to the invention comprises in in addition to a central swirl chamber 9, limited by a peripheral wall 10 of revolution with longitudinal axis I-I, by a front wall 11 with coaxial outlet passage 12 for driving the fluid outlet flow, and through a rear wall 13. The central swirl chamber 9 is connected to the one or more peripheral anterior cavities 8, 8a and 8b by at least one channel side of fluid inlet 14, open in the central chamber swirl 9, and shaped to drive the input flow of fluid and to tangentially inject the fluid into the central swirl chamber 9, for example according to a direction substantially perpendicular to the longitudinal axis I-I.

In the embodiment illustrated in FIG. 2, the axial outlet hole 4 of the radial anterior outer wall 3 is oversized, i.e. the coaxial outlet passage 12 of the spray nozzle is smaller than the axial outlet hole 4. The peripheral walls 10 and anterior 11 of the chamber swirl center 9, the coaxial outlet passage 12 and said at least one lateral fluid intake channel 14 are formed by grooves and recesses made with precision in an anterior plate 15 added in the hollow body of the nozzle 1.

The added front plate 15 is pressed against the posterior face of the radial anterior outer wall 3 of the nozzle hollow body 1, and is pierced with an axial hole constituting the coaxial outlet passage 12. The front plate 15 is provided posterior grooves forming said at least one lateral channel fluid inlet 14, and is provided with a posterior recess axial constituting the central swirl chamber 9.

In the embodiment illustrated in Figures 3 and 4, the front plate 15 is shaped to achieve a plurality of lateral intake channels, for example provided with three posterior grooves 14, 14a and 14b constituting three channels intake side regularly distributed around the periphery of the central swirl chamber 9, and constituting the three peripheral anterior cavities 8, 8a and 8b.

The posterior nucleus 5 limits, by its anterior face 16, said at least one lateral fluid intake channel 14 and said central swirl chamber 9. The front face 16 of the posterior core 5 includes an axial posterior hollow 17, facing of the coaxial outlet passage 12, extending backwards the central swirl chamber 9 having a section transverse weaker than the swirl chamber 9.

In the embodiment shown in Figure 2, the centering of the front plate 15 in the hollow nozzle body 1 is provided by the periphery of the front plate 15 which engages with little or no play in the cylindrical bore limited by the peripheral external wall 2 of the hollow body of nozzle 1.

Alternatively, the front plate 15 may include, on its front side, a coaxial circular rib forming a lip surrounding the coaxial outlet passage 12, said rib being engaged substantially without play in the axial outlet hole 4 of the radial anterior outer wall 3 of the hollow nozzle body 1 to ensure its centering.

The front plate 15 is pressed between the wall external anterior radial 3 and the posterior nucleus 5, which is itself held in the hollow body of nozzle 1 by fixing means, for example by screwing into a threaded section 100 of the hollow body 1 shown in Figure 1.

According to the invention, as best seen in FIG. 2, the posterior nucleus 5 comprises a posterior nucleus body Sa, retained in the hollow body of nozzle 1 by the fixing means previously mentioned, and a posterior plate 5b maintained by the posterior core body 5a bearing against the plate anterior 15. Thus, the posterior plate 5b forms the wall posterior 13 of central swirl chamber 9 and limit backwards said at least one lateral intake channel of fluid 14.

Also, the rear plate 5b comprises, according to the longitudinal axis, an axial hole constituting said hollow posterior 17 with smaller cross section than the chamber swirl center 9, extending said central chamber backward swirl 9.

The anterior plates 15 and posterior 5b are provided relative centering means for ensuring their relative centering one in relation to the other. Such relative centering means may consist of male - female engagement means formed in respective positions on the two pads. In the extent that the wafers can be produced by means precise manufacturing, it is important that the centering means are also provided on the pads themselves.

At least one of the anterior and posterior plates 15 5b is mounted with a radial clearance in the hollow body of the nozzle, by example the peripheral radial clearance 24 around the wafer posterior 5b. In this way, the relative centering of the plates 15 and 5b is assured with certainty and with great precision. It follows that the posterior recess 17 is perfectly coaxial with the swirl chamber and with the passage coaxial output 12.

In the mode of. realization of figures 2 to 4, the means relative centering plates 15 and 5b include a rib posterior device 20 of the anterior plate 15 in which engages at least partially the periphery 21 of the posterior plate 5b.

The two plates 15 and 5b are pressed axially both between the radial anterior outer wall 3 and the posterior nucleus body Sa.

The front plate 15 is centered in the hollow body nozzle 1 by its periphery engaging with little or no play in the cylindrical bore limited by the peripheral external wall 2. Alternatively, centering could be provided by the periphery of the rear plate 5b engaged in the wall external peripheral 2.

One can also conceive a variant in which the fluid supply channels are provided by grooves provided not on the front plate 15, but on the plate posterior 5b, or on the two plates 15 and 5b.

In the embodiment illustrated in FIG. 5, we substantially regains the structure of the first embodiment illustrated in figure 2. The difference lies in the means of relative centering of plates 15 and 5b. In this case, the means of relative centering are carried out on the front support faces respective plates 15 and 5b, for example protuberances 22 provided on the front front face of the plate posterior 5b and coming to engage in corresponding recesses 23 of the anterior plate 15, or vice versa. The brochure anterior 15 is then devoid of peripheral rib in which fits the periphery of the rear plate 5b.

The embodiments of FIGS. 2 to 5 constitute a single-stage fluid supply system, i.e. the channels fluid intake sides direct fluid from the peripheral anterior cavity 8 to the swirl 9.

In the embodiment illustrated in FIGS. 6 to 8, three fluid inlet channels 14, 14a and 14b are provided connecting the central swirl chamber 9 to a first common intermediate coaxial annular chamber 18, itself connected to a second intermediate coaxial annular chamber common 25 by three intermediate channels 19, 19a and 19b injecting tangentially the fluid in the first annular chamber common coaxial 18 so as to rotate the fluid in the direction opposite of its rotation in the central vortex chamber 9. The second common intermediate coaxial annular chamber 25 is itself connected to peripheral anterior cavities 8, 8a and 8b and to the peripheral channels 6 and 7 for supplying fluid by three intermediate channels 26, 26a and 26b injecting tangentially the fluid in the second annular chamber coaxial joint 25 so as to rotate it in the direction of its rotation in the central vortex chamber 9.

According to another embodiment, one can provide a elastic element engaged between the rear plate 5b and the posterior core body 5a, to allow expansion reversible under stress of said at least one lateral channel fluid intake 14 and said central chamber of swirl 9.

We can naturally provide a number of channels admission different from 1 or 3 or more, and a number of stages different from 1 or 3.

The coaxial outlet passage 12 can advantageously be a section of cone whose half-angle at the top is between 0 ° and 3 °, and converges towards the exit.

Thanks to the special nozzle structure according to the invention, with plates 15 and 5b attached between a body nozzle hollow 1 and a posterior core body 5a, one can separate the production of external parts (hollow body of nozzle 1 and posterior core body 5a) ensuring the mechanical strength of the nozzle, and interior parts (front plate 15 and posterior plate 5b) defining the dimensions of the channels fluid intake such as channel 14, from the central chamber swirl 9, coaxial outlet passage 12 and hollow posterior axial 17. It is then possible to produce the plate anterior 15 and the posterior plate 5b of a material different from that constituting the external parts 1 and 5, and according to different manufacturing methods, allowing great precision in the realization of the central chamber of swirl 9, coaxial outlet passage 12, and channels fluid intake such as channel 14.

We can thus economically realize channels fluid intake such as channel 14, and a central chamber swirl 9 with coaxial outlet 12 and hollow posterior axial 17 whose dimensions are very precise, ensuring satisfactory reproducibility of the characteristics of the spray of fluid at outlet.

It is particularly advantageous and economical to use a plate such as the front plate 15 generally planar, so the fluid intake channels such as channel 14 are parallel to the posterior face of front plate 15.

The present invention is not limited to the modes of which have been explicitly described, but it includes the various variants and generalizations contained in the field of the claims below.

Claims (6)

1. Spray nozzle having:

   a hollow nozzle body (1) with a peripheral external wall (2) having a longitudinal axis (I-I) and a radial anterior external wall (3) incorporating an axial outlet hole (4),

   a central swirl chamber (9) delimited by a peripheral wall (10) with a shape of revolution about the longitudinal axis (I-I), an anterior wall (11) incorporating a coaxial outlet passage (12) smaller than the axial outlet hole (4), and a posterior wall (13),

   at least one lateral fluid inlet passage (14) in the peripheral wall (10), opening into the central swirl chamber (9) and shaped to inject the fluid tangentially into the central swirl chamber (9),

   an anterior plate (15) fastened into the hollow nozzle body (1) and bearing against the radial anterior external wall (3), incorporating posterior openings and grooves forming the peripheral (10) and anterior (11) walls at least of the central swirl chamber (9), the coaxial outlet passage (12), and said at least one lateral fluid inlet passage (14),

   a posterior core (5) fitted into the hollow nozzle body (1), with peripheral fluid feed passages (6, 7), and with an anterior face (16) pushing away said at least one attached anterior plate (15) towards said radial anterior external wall (3) of the hollow nozzle body (1),

      characterized in that :

   the posterior core (5) comprises a posterior core body (5a), retained in the hollow nozzle body (1) by fixing means, and a posterior plate (5b) held in position by the posterior core body (5a) and bearing axially against the anterior plate (15) to form the posterior wall (13) of the central swirl chamber (9) and to delimit said at least one fluid inlet passage (14) towards the rear,

   the anterior (15) and posterior (5b) plates are provided with relative centering means for centering the plates (15, 5b) relative to each other about the longitudinal axis (I-I),

   the posterior plate (5b) comprises, about the longitudinal axis (I-I), a posterior recess (17) with a smaller cross section than the central swirl chamber (9),

   at least one of the anterior (15) and posterior (5b) plates is mounted with radial clearance in the hollow nozzle body.
2. Spray nozzle according to claim 1, characterized in that the relative centering means for the plates (15, 5b) are on their respective front bearing faces.
3. Spray nozzle according to claim 1, characterized in that the relative centering means for the plates (15, 5b) comprise a posterior peripheral rib (20) on the anterior plate (15) in which the periphery (21) of the posterior plate (5b) engages.
4. Spray nozzle according to any one of claims 1 to 3, characterized in that a spring member is engaged between the posterior plate (5b) and the posterior core body (5a), to allow reversible expansion under load of said at least one lateral fluid inlet passage (14) and said central swirl chamber (9).
5. Spray nozzle according to any one of claims 1 to 4, characterized in that it comprises a plurality of lateral inlet passages (14, 14a, 14b) regularly distributed at the periphery of the central swirl chamber (9).
6. Spray nozzle according to claim 5, characterized in that the lateral inlet passages (14, 14a, 14b) connect the central swirl chamber (9) to a first common intermediate coaxial annular chamber (18) itself connected to a second common intermediate coaxial annular chamber (25) by a plurality of intermediate passages (19, 19a, 19b) injecting the fluid tangentially into the first common coaxial annular chamber (18) so that the fluid rotates in the direction opposite to that in which it rotates in the central swirl chamber (9), the second common intermediate coaxial annular chamber (25) being itself connected to peripheral anterior cavities (8, 8a and 8b) and to the peripheral fluid feed passages (6, 7) by a plurality of intermediate passages (26, 26a and 26b) injecting the fluid tangentially into the second common coaxial annular chamber (25) so that it rotates in the same direction as that in which it rotates in the central swirl chamber (9).

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