ES2480996T3 - Blasting nozzle - Google Patents

Abstract

Blasting nozzle (100) for emitting a blasting medium in a stream of pressurized air, containing at least: - a housing (10) of the blasting nozzle, which must be connected with a supply line (60) of the blasting means and with an air supply conduit (40), which flows into at least one air supply channel (11). - a blasting nozzle (20) with a hole (21) of the nozzle, which is provided with an inlet opening (24) at the end located in the housing (10) of the nozzle; - a feeding element (30) of the blasting means which is to be connected to the supply line of the blasting means, whose longitudinal axis is aligned with the longitudinal axis of the blasting nozzle (20), and which ends with a tip ( 31) of the supply nozzle of the blasting means in front of the inlet opening (24) of the blasting nozzle (20), - a cage element (50) with at least one air passage opening (51), which surrounds the feeding element (30) of the blasting means, and which is housed in a housing housing hole (10) into which the air supply channel (11) flows, presenting a front washer (54 ) funnel of the cage element (50) a funnel cone-shaped opening, within which a cone-shaped tip of the feed nozzle (31; 31 ') of the feed element (30) extends ) of the blasting means, an inner annular groove (52) being configured, with conical surface shape, between the inner diameter of the funnel front washer (54) and the outer diameter of the supply element (30) of the blasting means, characterized in that - the feeding element (30) of the blasting means it comprises a metallic or ceramic outer sleeve (35; 35 ') with a tip (35.1; 35.1') shaped like a cone section at least in some area, and an inner sleeve (36; 36 ') inserted in the former removable, with a tip (36.1; 36.1' ), whose tips (35.1, 36.1; 35.1 ', 36.1') have the same cone angle, and configure the tip (31; 31 ') of the nozzle of the blasting means, - the front edge of the area of the tip (35.1; 35.1 '), in the shape of a cone section, of the outer bushing (35; 35'), extends, seen in the direction of blasting, up to the front of the funnel washer (54), being opposed to the front washer (54) funnel only the tip (35.1; 35.1 '), in the form of a cone section, of the outer bushing (35; 35'), freely supporting the tip (36.1; 36.1 ') of the inner bushing ( 36; 36 ') in the opening (24) of the blasting nozzle (20).

Description

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DESCRIPTION

Blasting nozzle

The invention relates to a blasting nozzle for emitting a blasting medium in a stream of pressurized air, containing at least:

-a casing of the blasting nozzle, which has to be connected with a supply line of the blasting medium and with an air supply conduit, which flows into at least one air supply channel.

-a blasting nozzle with a nozzle hole, which is provided with an inlet opening at the end located in the nozzle housing;

-a supply element of the blasting means to be connected to the supply line of the blasting means, whose longitudinal axis is aligned with the longitudinal axis of the blasting nozzle, and which ends with a tip of the medium feeding nozzle blasting in front of the inlet opening of the blasting nozzle, a cage element with at least one air passage opening, which surrounds the feeding element of the blasting means, and which is housed in a housing of The housing, into which the air supply channel ends, a funnel cone-shaped opening having a funnel cone-shaped opening, inside which a cone-shaped tip of the feeding nozzle extends of the feeding element of the blasting means, an inner annular groove being formed, in the shape of a conical enveloping surface, between the inside diameter of the arand the front funnel and the outer diameter of the feeding element of the blasting medium.

The blasting nozzles serve to feed the blasting medium, mix it with pressurized air, and then expel the mixture with great speed through the nozzle opening, in order to treat the surface of a piece.

In a blasting nozzle published in DE 201 06 816 U1, the feeding of the blasting means takes place through a supply element of the blasting means, which is aligned with the opening of the nozzle. The feeding element of the blasting medium flows into a mixing chamber in the housing. Pressurized air is blown into the mixing chamber laterally, drags the blasting medium into the funnel-shaped inlet opening of the blasting nozzle, and again leaves the blasting nozzle through the nozzle opening. The area of the mixing chamber is very prone to wear, since swirling particles, normally abrasive, wear both the funnel-shaped inlet opening of the blasting nozzle and also the inclined tip of the feeding element of the medium of blasting

With an increase in wear, the width of the groove and the shape thereof between the tip of the cone and the mouth of the funnel are modified, through which the proportions of the flow of the blasting nozzle are modified in the case of increase of the operating time. A readjustment of the slit requires time, and also cannot be checked by measuring instruments, since it cannot be observed inside the chamber. When disassembling the nozzle from the blasting means, the nozzle element with the funnel hole and the supply element of the blasting means with the conical tip must be removed separately. However, it is not possible to adjust and check exactly the position of one another with respect to the other outside the housing. The nozzle adjustment of the blasting medium by the operator can therefore be performed only empirically.

A blasting nozzle of the exposed genus is published in DE 20 2008 016 923 U1. Through that in this blasting nozzle the feeding element of the blasting means is inserted in a cage element, which is housed in a housing hole in which the air supply channel also flows, and through that at least one air passage opening is located in the envelope of the cage element, a geometrically defined inner annular groove is formed between the inner diameter of a funnel annular washer in the cage element and the diameter outside of the supply element of the blasting medium, which determines the configuration of the air flow, and thereby determines a constant mixture of air and blasting medium.

The oriented air flow is originated previously in the envelope of the supply element of the blasting medium, and not first in the area of its mouth. The air flow can therefore be set in a stabilized manner, and then travel along the outer perimeter of the supply element of the blasting means, before it enters the inner chamber inside the blasting nozzle, provided with a protection against wear, where mixing takes place with the blasting medium. Irregularities in the annular groove, whether caused by local wear in certain angular positions, or through a modified width of the air gap as a whole, and motivated by wear, lead either to the fall of the pneumatic supply of the blasting medium, because the air flow is not strong enough to drag an amount of blasting medium and accelerate it, or to too strong wear in the area between the tip of the blasting media feed nozzle and the inlet mouth of the mouthpiece itself

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blasting, because too much blasting medium is aspirated. On the contrary, the remedy consists only in the change of worn parts, that is, especially the feeding element of the blasting medium, in whose tip and inner hole the strongest wear occurrences during operation are shown, since the amount of blasting medium introduced into the supply element of the blasting medium expands, immediately after passing the front edge of the tip of the nozzle of the blasting medium, into the chamber formed by the inlet funnel of the nozzle , and crashes into it especially against the thin area of the tip edge. Since, however, only the feeding elements of the tempered metal or ceramic blasting medium have a sufficient useful life, the frequent change of the supply element of the blasting medium is very expensive. However, if the change is delayed for economic reasons, the other parts adjacent to the mixing chamber, between the tip of the nozzle of the blasting medium and the inlet funnel of the nozzle, also wear massively until destruction of the housing.

With this, the objective of the invention is to enable economical operation of the blasting nozzle.

This objective is achieved by means of a blasting nozzle with the characteristics of claim 1.

The outer bushing therefore does not in any way come into contact with the blasting medium, while the inner bushing is not completely destroyed. Through which the tapered tip of the outer sleeve reaches further forward, seen in the direction of the flow, on the annular funnel washer of the cage element, those parts that define the annular groove, decisive for the air flow, They are protected from wear and are preset to each other in a geometrically accurate position.

The inner bushing is inserted into the outer bushing, and extends forward in its length beyond the outer bushing. Through this, the cone-shaped tip of the inner bushing and the cone-shaped tip of the outer bushing can configure a joint tip of the feeding element of the blasting means, which also has a cone shape. Partial tips of the bushings have an identical cone angle of 15 ‘at 50 °, so that a homogeneous conical surface is formed at the tip of the supply element of the blasting medium.

"The cone shape" designates, in the sense of this invention, both concave and convex geometries, which are presented respectively in the form of a reference surface. However, curved wrap surfaces with spherical shape are also contained here, that is, sphere sections in the strict geometric sense.

In the blasting nozzle according to the invention, wear predominantly appears in the front edge of the tip of the inner sleeve, where the blasting medium comes out from the inner hole of the supply element of the blasting means, and to one side in the mixing chamber in the area of the inlet opening of the blasting nozzle, as well as in the inner hole itself.

If the inner sleeve is worn, it can be replaced simply according to the invention. For this, the inner sleeve can be configured very economically of synthetic material. It has been especially shown that wear, in the case of strongly abrasive blasting means such as corundum, can be reduced through the use of elastic materials such as rubber, especially also with polyurethane molding resins with a hardness of approximately 40 at 90 Shore-A, since these absorb the energy of the particles of blasting material that impact, and through it the abrasion of the surface of the material is decreased.

The change can take place simply by means of the fact that the inner bushing of the supply element of the blasting means is removed backwards after the withdrawal of the feed conduit from the blasting means. Preferably, the inner bushing has at that end a flange that not only simplifies the extraction from the outer bushing, but also offers other advantages:

In the use of soft elastic materials, the flange can perform the function of a joint washer. In any case, the flange covers the rear front side of the outer bushing, and protects it from the colliding blasting means, especially when there is a diameter jump in the transition from the supply line of the blasting medium to the feeding element of the medium of blasting.

It is also possible to configure the inner sleeve so that, in the case of wear, it can continue to be pushed forward. The cone shape can be cut again by the user himself in the case of inner bushings of synthetic material.

In very thin inner cylindrical bushings it is not even necessary to eventually provide them with a conical shape at their end. It is enough that the inner sleeve protrudes somewhat from the front edge of the outer sleeve to protect it.

It is also possible to provide at the front end a flange shaped like a cone section, which rests in front of the front side of the outer sleeve and protects it very well from wear.

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It is only important in all configurations of the inner and outer bushing that the outer bushing has at least one area in the shape of a cone section, which extends axially to the front of the ring funnel washer. With this, the annular groove is always defined exactly, regardless of the state of wear, in the following axial end section, of the area of the tip. Although it is advantageous for the flow that there is a general, conical, and transition-free conical surface around the tip. However, the posterior part in the annular groove is decisive, while the deviations of later do not have as much weight.

Depending on the type of blasting medium, and according to the other economic considerations of the company, inner hard metal bushings, especially boron carbide, can also be used in the same blasting nozzle sleeve according to the invention. Although its manufacturing costs are in a percentage of 100 to 1000 more expensive, the higher price of the material can be amortized nonetheless because, through the use of high strength materials, longer durations are reached, and with this results in shorter preparation and assembly times, precisely when the blasting nozzle according to the invention is stationary installed in places of difficult access to an installation, or when replacement is only possible under certain protective measures for personnel , etc.

The user is therefore free in the assembly of the blasting nozzle, and does not need to place different blasting nozzles for different purposes of use and places of use, but can provide them with the usable type of inner cap that is more Economical for your goals.

The thin annular groove configures the decisive obstacle of the flow, through which the amount of air for the operation of the blasting nozzle and the circulation speed can be adjusted. The annular groove can be constructively predetermined in a simple manner, and can be verified in maintenance, since the supply element of the blasting medium can be mounted outside the housing in the cage element. The two pieces therefore adopt in the verification the same relative position with each other as in the state of assembly, conditioned by fixed axial stops.

This is advantageous when the front ring funnel washer can be inserted into the cage element. The ring funnel washer can be manufactured as a single piece considerably easier and more accurately than in a single-piece cage element. In case of wear, the funnel ring washer can be replaced easily, without the need for manual adjustment or vacuum control that exists in operation.

Annular funnel washers with different axial dimensions may be provided, in order to adjust the annular groove through the choice of an annular funnel washer.

It is preferably provided to manufacture a funnel ring unitary washer, and place at least one spacer ring between it and the cage element, so as to move the surface of the cone forward or backward in the axial direction, and thereby make the annular groove narrower or wider.

Preferably, the cage element, the supply element of the blasting means and the blasting nozzle can be introduced from the same side of the holes, and in that order. In this, the support of the cage element and the feeding element of the blasting medium takes place on a support step on the rear side of the housing, which surrounds a hole through which parts of the medium feeding element protrude. of blasting. Thus, the inside of the housing can be drilled and drilled easily. Due to the solid support step, no cover, flange or similar is needed to be placed on the back side of the housing to support the construction groups located inside.

The supply element of the blasting means should have a flange that sits on a fixed support on the blasting nozzle housing. With this, the axial position of the supply element of the blasting medium within the housing is fixed, and also the relative position with respect to the cage element.

The invention will be described in more detail below by means of examples of execution of a blasting nozzle according to the invention, and with reference to the drawing.

The figures show in detail:

Fig. 1

a cut of a mounted blasting nozzle;

Fig 2

a detail of the blasting nozzle of figure 1;

Fig. 3

blasting nozzle parts in exploded representation, and

Fig. 4

pieces of another embodiment of a feeding element of the blasting medium.

Figure 1 shows a blasting nozzle 100, which is essentially composed of a housing 10, a blasting nozzle 20, a supply element of the blasting means 30 and a cage element 50.

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In the housing 10, in the rear zone, that is to say, in the area opposed to the blasting nozzle 20, a flange 18 is fixed as a fixed seat on which the feeding element of the blasting means 30 rests. From behind it it has screwed, in a thread 32 of the supply element of the blasting means 30, an adaptation element 62 of a supply conduit 60 of the blasting means, with a union nut 61.

The part of the feeding element of the blasting means 30 that is inside the housing 10 is housed in a cage element 50. This has at its front end an annular funnel washer 54, through which a forward tip 31 of the feeding nozzle of the blasting means of the feeding element 30 of the blasting medium up into a mixing chamber that is configured within a conical inlet opening 24 of the blasting nozzle 20, since there they are mixed there the air flow introduced into the housing 10 through an air supply conduit 40 and the blasting means.

The hole 21 of the nozzle ends at a mouth 22. The blasting nozzle 20 is screwed in the front in the housing 10. The sealing with respect to the cage element 50 takes place by means of an annular gasket.

The feeding element of the blasting means 30 is formed by an outer bushing 35 and an inner bushing 36 inserted inside. Both together form a cone-shaped tip 31 of the nozzle of the blasting means at the left end of Figure 1. Approximately in the middle of the length a flange 33 is formed in the outer bushing, in order to be able to fix exactly the position of the feeding element 30 of the blasting means in the housing 10.

The cage element 50 has annular washers on one side, of which at least one is removable, and has on its perimeter the shape of a funnel shaped like a cone section, whose cone angle coincides with the cone angle of the tip 31 of the nozzle for feeding the blasting medium, as shown in particular in figure 2 in enlarged representation. Through this, an exact annular groove is formed between the tip 31 of the feed nozzle of the blasting means and the funnel annular washer 54, the annular groove also having the same groove width along the whole of its axial length , and with it neither narrows nor widens. The other advantage is that the blasting material itself does not protrude until the cage element 50, even in the case of complete wear.

The vertical line of dashes and dots in Figure 2 marks the plane of the front edge of the cone-shaped tip 35.1 on the outer sleeve 35. It is clearly visible that it ends, in the direction of flow, in front of the front face of the funnel ring washer 54.

In the housing a housing hole is provided to accommodate the cage element 50. The air supply channel 11 also flows into the area of the housing opening.

Figure 3 shows the fundamental parts of the blasting nozzle 100, in exploded view, in the position of one in relation to the other before assembly. The inner bushing has a flange 36.2 at the rear, in order to fix the axial position with respect to the outer bushing 36 after insertion.

The funnel ring washer 54 is inserted into the cage element 50, and can therefore be replaced in case of wear, but also to vary the position and width through funnel ring washers configured differently.

Figure 4 shows in a section a tip 31 ’of the feeding nozzle of the alternately configured blasting means. A cone-shaped tip 35.1 'of an outer bushing 35' extends on the other hand outwardly extending beyond the annular groove 52, configured with the funnel annular washer 54. Different from the embodiment described above, it is that the zone 36.1 'of the cone-shaped tip of an inner bushing 36' is configured in a flange 36.2 ', which covers a front side 35.2' of the outer bushing 35 ', and protects it from wear.

The function of the blasting nozzle 100 is described again, with reference to Figure 1:

To the adaptation element 60 a supply line 40 for blasting means is connected, through which a blasting means, for example corundum, can be aspirated. Down in the housing 10 the air supply line 40 is connected to a source of pressurized air. As soon as the air flow is released, pressurized air flows through the air supply channel 11, and from there to the outer annular groove 55, then through the air passage openings 51 of the cage element 50 , through the inner annular channel 53 to the annular groove 52 between the funnel annular washer 54, located in front of the cage element 50, and the funnel shaped tip 31, of the nozzle of the blasting means of the feeding element 30 of the blasting medium. In addition, the funnel-shaped tip 31 of the nozzle of the blasting means is positioned opposite to the funnel opening 24 of the blasting nozzle 20, so that there is formed a channel chamfering of air, through which the air flow is conducted to the hole 21 of the nozzle.

The overpressure in the area of the inlet opening 24 leads to a lower pressure in the feed element 30 of the blasting medium, and thereby an aspiration of the blasting element is reached

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through the supply line of the blasting medium. The blasting medium is then stirred inside the mixing chamber, configured in the funnel opening 24 inside the blasting nozzle 100, and reaches the mouth 22 through the hole 21 of the nozzle.

Claims (7)

E12161926 07-11-2014 1. Blasting nozzle (100) for emitting a blasting medium in a stream of pressurized air, containing at least: -a housing (10) of the blasting nozzle, which has to be connected with a duct (60) for supplying the blasting medium and with an air supply duct (40), which flows into at least one channel of 5 air supply (11). - a blasting nozzle (20) with a hole (21) of the nozzle, which is provided with an inlet opening (24) at the end located in the housing (10) of the nozzle; -a feeding element (30) of the blasting means that is to be connected to the feeding conduit of the blasting means, whose longitudinal axis is aligned with the longitudinal axis of the blasting nozzle (20), and 10 which ends with a tip (31) of the nozzle of the blasting medium in front of the opening (24) nozzle inlet (20) blasting, -a cage element (50) with at least one air passage opening (51), which surrounds the feeding element (30) of the blasting means, and which is housed in a hole (10) for housing the housing in which the air supply channel (11) ends, presenting a funnel front washer (54) of the 15 cage element (50) a funnel cone-shaped opening, within which a cone-shaped tip of the feeding nozzle (31; 31 ') of the feeding element (30) of the middle extends of blasting, an inner annular groove (52) having a conical wrapping surface being formed between the inner diameter of the funnel front washer (54) and the outer diameter of the feeding element (30) of the blasting means, 20 characterized by -the feeding element (30) of the blasting means comprises a metallic or ceramic outer bushing (35; 35 ') with a tip (35.1; 35.1') shaped like a cone section at least in some area, and an inner bushing (36; 36 ') inserted in the former removable, with a tip (36.1; 36.1'), whose tips (35.1, 36.1; 35.1 ', 36.1') have the same cone angle, and configure the tip (31 ; 31 ') of the nozzle of 25 blasting media feed, -the front edge of the tip area (35.1; 35.1 '), in the shape of a cone section, of the outer sleeve (35; 35'), is extended, seen in the direction of blasting, to the front of the front washer (54) funnel, only the tip (35.1; 35.1 '), in the form of a cone section, of the outer bushing (35; 35') being opposed to the funnel front washer (54), freely supporting the tip (36.1 ; 36.1 ') of the inner sleeve 30 (36; 36 ’) in the opening (24) of the jet nozzle (20). 2. Blasting nozzle (100) according to claim 1, characterized in that a flange (36.2 ') shaped as a cone section, which covers the front side (35.2) is configured at the front end of the inner sleeve (36') ') of the outer sleeve (35'). 3. Blasting nozzle (100) according to claim 1 or 2, characterized in that the angle of the cone is between 15 and 50 °.

Four.

Blasting nozzle (100) according to one of claims 1 to 3, characterized in that the inner sleeve (36; 36 ’) is made of hard metal, especially boron carbide.

5.

Blasting nozzle (100) according to one of claims 1 to 3, characterized in that the inner sleeve (36; 36 ') is made of a polyurethane molding resin elastomeric material, with a hardness of 40 ... 90 Shore A .

6. Blasting nozzle (100) according to one of claims 1 to 5, characterized in that the inner sleeve (36; 36 ') extends through the entire length of the outer sleeve (35; 35'), and has at least one of the ends an enlarged diameter by a flange (36.2, 36.2 ').

7. Blasting nozzle (100) according to one of claims 1 to 5, characterized in that the funnel front washer (54) can be inserted into the cage element (50).

8. Blasting nozzle (100) according to claim 6, characterized in that at least one spacer ring is placed between the front funnel washer (54) and the cage element (50).

9. Blasting nozzle (100) according to one of the preceding claims, characterized in that the cage element (50), the feeding element (30) of the blasting means, and the blasting nozzle (20) can be introduced into the housing hole (10) from the same side. 10. Blasting nozzle (100) according to one of the preceding claims, characterized in that the element 7 E12161926 07-11-2014 Supply (30) of the blasting means has a flange (33) that sits on a fixed support (18) of the housing (10) of the blasting nozzle. 8