CH711659B1 - Waterjet cutting head by high pressure. - Google Patents

Abstract

The invention relates to a cutting head (1) with a high-pressure jet of water comprising a water inlet under pressure (11), a nozzle (12) for forming the water jet opening into a chamber of water mixture (13) provided with an inlet (15) for an abrasive, and a focusing gun (14) mounted at the outlet of the mixing chamber (13). According to the invention, the mixing chamber (13) comprises a lower portion (160) provided with a cavity (104) defining a volume in which the water / abrasive mixture is made, and an upper portion (101) mounted on the lower part, comprising protection means (102) of the water jet opening into the lower part of the mixing chamber (13) and below the duct (15) for the abrasive.

Description

CH 711 659 B1

Description

FIELD OF THE INVENTION The invention relates to systems for cutting by high pressure water jet. The invention relates more particularly to abrasive-charged water jet cutting heads.

BACKGROUND OF THE INVENTION In known manner, the cutting heads by water jet loaded with abrasive comprise an inlet for pressurized water connected to the inlet of a cutting head which generally comprises a collimation tube intended to conduct the pressurized water to a water jet forming nozzle which is housed at the outlet of this collimation tube and which opens into a mixing chamber where abrasive powder is introduced by aspiration. The abrasive-laden jet of water leaving the mixing chamber then passes through the cylindrical channel of a focusing gun. The downstream end of the collimation tube, the jet forming nozzle, and the upstream end of the focusing gun are carried by a body formed by the mixing chamber.

A drawback of such a solution is that the abrasive comes into direct contact with the water jet in the mixing chamber, which disturbs the water jet as it leaves the nozzle.

Summary of the invention The aim of the invention is in particular to overcome the various drawbacks of these known techniques.

More specifically, an objective of the invention is to provide a water jet cutting head loaded with abrasive in which the water jet is not disturbed by the abrasive.

The invention also aims, at least in one particular embodiment, to produce a more compact cutting head while providing a homogeneous distribution of the abrasive in the mixing chamber.

These objectives, as well as others which will appear more clearly hereinafter, are achieved according to the invention using a cutting head by high pressure water jet comprising a pressurized water inlet. , a nozzle for forming the water jet opening into a mixing chamber provided with a conduit for the entry of an abrasive, and a focusing gun mounted at the outlet of the mixing chamber.

According to the invention, the mixing chamber comprises a first part, called the lower part, comprising a cavity defining a volume in which the water / abrasive mixture is made, and a second part, called the upper part, mounted on the part lower, comprising means for protecting the water jet opening into the lower part of the mixing chamber.

Thus, the object of the present invention, by various functional and structural aspects described above, makes it possible to obtain a cutting head of reduced length.

[0010] In accordance with other advantageous variants of the invention:

- the means of protection of the water jet open below the lateral entry for the abrasive;

- the entry for the abrasive is formed in the lower part of the mixing chamber;

- the entry for the abrasive is formed in the upper part of the mixing chamber;

- The upper part of the mixing chamber includes a housing for receiving the nozzle;

- The protection means have a conical shape;

- The protection means comprise a channel over all or part of their height to guide the flow of water towards the lower part of the mixing chamber;

- The protection means and the upper part of the mixing chamber form a one-piece element.

Summary description of the drawings [0011] Other particularities and advantages will emerge clearly from the description which is given below, for information and in no way limitative, with reference to the attached drawings, in which:

fig. 1 is a schematic sectional view of a cutting head according to the prior art;

fig. 2 is a schematic sectional view of a cutting head according to the invention according to a first embodiment;

fig. 3 is a schematic sectional view of a cutting head according to the invention according to a second embodiment.

Detailed description of the preferred embodiments A cutting head by abrasive water jet according to the prior art is illustrated in FIG. 1.

CH 711 659 B1 As can be seen, the abrasive water jet cutting head comprises a body 10 carrying a pressurized water inlet formed by a collimation tube 11 which has an internal channel 16, and a focusing gun 14 which is mounted on the body 10 and which has an internal channel 17 whose inlet 18 has a conical shape. The body 10 has a side inlet 15 configured to convey an abrasive material. A nozzle 12 for forming a water jet is housed in the body 10 at the outlet of the collimation tube 11, and opens into a mixing chamber 13 which is formed or attached to the body 10 and which communicates with the inlet 18 of the internal channel 17 of the focusing gun 14 and with the lateral inlet 15.

In operation, pressurized water, symbolized by the flow line L, flows in the internal channel 16 of the collimation tube 11 until it meets the nozzle 12. The water comes out of the nozzle 12 in the form of a very high pressure jet, the passage of which at high speed through the mixing chamber 13 causes the abrasive to be suctioned by the Venturi effect at the inlet 15. The water loaded with abrasive passes then in the inlet 18 of the internal channel 17 of the focusing gun 14, where the jet is channeled until being projected by the outlet 19 of the focusing gun 14.

The abrasive water jet cutting head according to the invention visible in lafig. 2 comprises a pressurized water inlet formed by the collimating tube 11, a nozzle 12 for forming the water jet opening into a mixing chamber 13 provided with an inlet 15 for supplying it with abrasive, and a barrel focusing tube 14 mounted at the outlet of the mixing chamber 13, the focusing gun 14 comprising an internal cylindrical channel 17.

According to one embodiment of the invention, illustrated in fig. 2, the mixing chamber 13 comprises a first part, called the lower part 100, which may include the inlet 15 for the abrasive and a cavity defining a volume in which the water / abrasive mixture is made. The mixing chamber 13 also comprises a second part, called the upper part 101, mounted on the lower part 100, and which comprises means 102 for protecting the water jet which open into the lower part 100 of the mixing chamber 13.

The upper part 101 can be removably mounted on the lower part 100. One can, for example, imagine that the upper part 101 is screwed onto the lower part 100 so as to form a single element. The assembly of the upper 101 and lower 100 parts of the mixing chamber 13 forms an internal cavity 104 in which the water / abrasive mixture is carried out.

According to another embodiment, illustrated in FIG. 3, the upper part 101 may include an inlet 15 for the abrasive, the inlet opening at the level of the protection means 102 of the water jet.

The lower 100 and upper 101 parts of the mixing chamber 13 can be made of a hard material such as diamond, ceramics, sapphire or tungsten carbide.

According to a particular aspect of the invention, the protection means 102 of the water jet open below the inlet 15 for the abrasive, so that the abrasive does not strike the water jet in the mixing chamber 13.

Advantageously, the upper part 101 of the mixing chamber 13 comprises a housing for receiving the nozzle 12, such an arrangement making it possible to make the cutting head more compact. The nozzle 12 can also be subsequently mounted on the mixing chamber 13.

As illustrated in FIG. 2, the protection means 102 have a conical shape so as not to obstruct the lateral entry 15 of the lower part 100.

The protection means 102 include a bore 103 over all or part of their height to guide and protect the flow of water to the lower part 100 of the mixing chamber 13, the bore 103 opening into the lower part 100 of the mixing chamber 13.

According to the illustrated embodiment, the protection means 102 and the upper part 101 form a one-piece element so as to facilitate machining.

Thanks to these various aspects of the invention, there is a more compact cutting head and allowing better mixing of the abrasive with water. In fact, when the abrasive is sucked up, it strikes the protection means 102 of the water jet, which has the effect of having a more homogeneous dispersion of the abrasive in the mixing chamber 13.

Of course, the present invention is not limited to the illustrated example but is capable of various variants and modifications which will appear to those skilled in the art within the scope of the claims.

Nomenclature [0027]

I. Cutting head,

10. Body,

II. Collimation tube,

12. Nozzle,

CH 711 659 B1

13. Mixing chamber,

14. Focusing gun,

15. Entrance,

16. Internal channel of the collimation tube,

17. Internal channel of the focusing gun,

18. Entrance of the focusing gun,

19. Exit from the focusing gun,

100. Lower part of the mixing chamber,

101. Upper part of the mixing chamber,

102. Means of protection of the water jet,

Claims (5)

103. Boring of means of protection, 104. Internal cavity of the mixing chamber, L. Water flow line. claims 1. High-pressure water jet cutting head (1) comprising a pressurized water inlet (11), a nozzle (12) for forming the water jet opening into a mixing chamber (13) provided a conduit (15) for the entry of an abrasive, and a focusing gun (14) mounted at the outlet of the mixing chamber (13), characterized in that the mixing chamber (13) comprises a first part, called the lower part (100), comprising a cavity (104) defining a volume in which the water / abrasive mixture is made, and a second part, called the upper part (101), mounted on the lower part (100), comprising means of protection (102) of the water jet opening into the lower part (100) of the mixing chamber (13) and below the duct (15) for the abrasive. 2. Cutting head (1) according to claim 1, wherein the conduit (15) for the abrasive is formed in the lower part (100) of the mixing chamber (13). 3. Cutting head (1) according to claim 1, wherein the conduit (15) for the abrasive is formed in the upper part (101) of the mixing chamber (13). 4. Cutting head (1) according to one of claims 1 to 3, wherein the upper part (101) of the mixing chamber (13) comprises a housing for receiving the nozzle (12). 5. Cutting head (1) according to one of claims 1 to 4, in which the protection means (102) have a conical shape.