Fluid distribution nozzle and machining installation incorporating such a nozzle

Abstract

The invention relates to a fluid distribution nozzle (1) comprising a nozzle body (14), a fluid circuit (15) passing through said nozzle body (14) and extending from at least one inlet orifice (5) configured to be supplied with fluid to at least one outlet orifice (6), a bearing surface (14c) of said nozzle body (14) intended to be arranged opposite at least a part of the machining tool (4) and / or a tool holder (2) intended to carry said machining tool (4), a rear surface (14a) and a front surface (14b) of said nozzle body (14) arranged on either side of the bearing surface (14c), said at least one outlet orifice (6) being provided on the front surface (14b) of the nozzle (1). According to the invention, the inlet orifice (5) is provided on the rear surface (14a) of the nozzle (1). Figure for the abstract: [Fig.1]

Description

Title of the invention: Fluid distribution nozzle and machining installation comprising such a nozzle

[0001] The present invention relates to a fluid distribution nozzle suitable for use in a machining installation and process for distributing said fluid to at least a portion of a machining area and / or at least a portion of the machining tool. The invention also relates to a nozzle and tool holder assembly and a machining installation comprising said nozzle or tool holder assembly. The nozzle according to the invention distributes said fluid to cool the machining area and / or the machining tool. In addition to its cooling effect, the fluid can also lubricate the machining area and / or the machining tool.

[0002] The invention can be implemented in various machining processes such as drilling, cutting, turning, milling, and boring. Machining is understood to be a process of removing material from raw parts to give them the desired dimensions and shape. It applies in particular to the machining of one or more metal parts. The nozzle according to the invention is particularly suitable for dispensing cryogenic liquid or supercritical fluid.

[0003] A cryogenic liquid is defined as a fluid cooled to a temperature below its boiling point at the pressure considered. In particular, a cryogenic fluid is cooled to a temperature low enough to be in a liquid state at atmospheric pressure, specifically below -50°C, particularly below -170°C, or even below -200°C. A nozzle according to the invention can, in particular, be used for the distribution of liquid nitrogen or liquid carbon dioxide.

[0004] A supercritical fluid is defined as a fluid whose temperature is raised above its critical temperature and whose pressure is greater than its critical pressure. A supercritical fluid exhibits behavior and properties intermediate between the gaseous and fluid states; it is dense and compressible.

[0005] Machining devices generally comprise a machining tool, also called a cutting tool, used to remove material and thus shape the workpiece, and a tool holder to which the tool can be attached. Material removal is accompanied by the formation of chips. Furthermore, during the interaction between the cutting tool and the workpiece material, heating, friction, and / or rubbing occur in the machined area and / or on the machining tool, necessitating the use of a cooling and / or lubrication system for the machining area.

[0006] Managing heat and chip removal is of paramount importance. The high temperatures generated by friction during cutting are the main cause of damage to tools and can limit cutting speed, or even lead to defects in finished products.

[0007] In this context, it is common practice to distribute a cooling and / or lubricating fluid, also called cutting fluid, to the machining area in order to reduce heat generation between the tool and the workpiece, lubricate the interaction zone between the tool and the workpiece, decrease friction between the chips generated during machining and the tool, and remove the formed chips. This increases tool life and improves machining quality and precision. Oil-based lubricants or oil-based and aqueous emulsions are commonly used as cutting fluids.

[0008] However, conventional coolants and / or lubricants may prove insufficiently effective or unsuitable depending on the intended application. For example, in machining operations requiring significant cooling, such as machining hard materials like stainless steel at high speeds, the heat generated is too great to be effectively absorbed by conventional fluids. Oils are also unsuitable due to the surface and / or environmental contamination they generate. Dry machining, on the other hand, is only a viable alternative for processes requiring a low level of cooling.

[0009] More recently, machining assistance solutions using cryogenic liquids, such as liquid nitrogen or liquid carbon dioxide, or supercritical fluids, have emerged. Such processes are described in particular in WO-A-2014 / 170583 and WO-A-2020 / 212187 filed by the Applicant. In addition to improved cooling and lubrication of the machining area, these fluids also reduce contamination of surfaces and generated chips, thereby facilitating chip recycling and improving tool life.

[0010] Effective implementation of a cryogenic fluid requires maximizing the amount of fluid projected in liquid form onto the tool and the machining area. Indeed, if the fluid jet contains gas, its cooling capacity is reduced. To achieve maximum performance, a key element is the design of the fluid distribution nozzle. Fluid distribution nozzles with one or two internal fluid distribution circuits are known from WO-A-2007 / 145649 and WO-A-2017 / 003342, in which the cryogenic fluid is supplied via the tool holders. The tool holder is equipped with a fluid delivery channel that communicates fluidly with the nozzle's fluid circuit when the nozzle is mounted on the tool holder. The drawback of this type of configuration is that the nozzle is dependent on the tool holder, which necessitates installation The existing system requires a change to the tool holder(s) to accommodate cryogenic machining assistance. Furthermore, the fluid delivery configuration from the tool holder necessitates a significant change of direction between the inlet port and the fluid circuit, on the order of 90°. This results in increased pressure losses and a greater risk of cryogenic fluid vaporization (a phenomenon known as "flash"), which reduces the amount of fluid delivered in liquid form to the tool and degrades cooling and lubrication performance.

[0011] Furthermore, WO-A-2011 / 161670 is known to designate a nozzle comprising a fluid circuit independent of the tool holder, supplied through an orifice arranged on the top of the nozzle. However, in this configuration, the fluid also undergoes a significant change of direction between its supply direction and its ejection direction from the nozzle, which generates substantial pressure losses in the fluid. In addition, a machining center generally includes a workpiece rotation system and a turret that supports several tools and moves to position the tool at the desired location relative to the rotating workpiece. The turret has an axis of rotation parallel to that of the workpiece. By design, most machining centers use a cutting fluid delivery system with an axis parallel to the axis of rotation of the workpiece and / or the tool.It is indeed in this configuration that the fluid supply system best follows the machine's movements. The cryogenic fluid supply lines are rigid and relatively bulky. Supplying fluid from the top of the nozzle, that is, along an axis perpendicular to the machine's axis of rotation, requires a redesign of the machine to allow it to function.

[0012] It should be noted that current systems for assisting machining operations with cryogenic fluid generally do not use nozzles fed independently of the tool holder. One of the reasons users prefer feeding through the tool holder is that the overall supply of cutting fluid is carried out by a turret supporting several tool holders. Thus, with a general turret supply, it is possible to feed different tool holders with different tools, and therefore to use a multitude of tools without intervening on the machine during machining. While this is relevant in oil- or emulsion-assisted machining, it becomes limited for cryogenic assistance because the delivery of the cryogenic fluid through the turret and then through the tool holder can lead to significant heat losses, promoting the fluid's phase change from liquid to gas.It should also be noted that current systems do not include thermal insulation within the nozzle and / or between the nozzle and the tool holder, which further increases the phenomenon of cryogenic fluid vaporization through heat transfer to the walls and consequently reduces the efficiency of the cryogenic assistance. For a... With cryogenic fluids, heat loss through the tool holder can lead to an increase in temperature and a transition to a two-phase fluid, resulting in a decrease in the workpiece's cooling capacity and therefore premature wear of the machining tools. For supercritical fluids, heat loss through the tool holder can cause their temperature to drop below the critical temperature, resulting in a transition to a liquid state and a loss of the fluid's specific supercritical properties.

[0013] The present invention aims in particular to solve all or part of the problems mentioned above, by proposing a fluid distribution nozzle allowing the distribution of a fluid, in particular a cryogenic liquid or a supercritical fluid, under the best possible conditions at the level of the tool and / or the machining area and whose implementation offers more flexibility than in the prior art.

[0014] To this end, the invention relates to a fluid distribution nozzle, in particular for cryogenic fluid, comprising - a nozzle body, - a fluid circuit passing through said nozzle body and extending from at least one inlet orifice configured to be supplied with fluid to at least one outlet orifice configured to distribute said fluid to at least part of a machining area and / or a machining tool, - a bearing surface for said nozzle body intended to be arranged opposite at least part of the machining tool and / or a tool holder intended to support said machining tool, - a rear surface and a front surface of said nozzle body arranged on either side of the support surface, said at least one outlet orifice being provided on the front surface of the nozzle, - characterized in that said at least one inlet orifice is provided on the rear surface of the nozzle.

[0015] Depending on the case, the exchanger according to the invention may include one or more of the features stated below.

[0016] Said inlet orifice is positioned at a first distance from the support surface and said at least one outlet orifice is positioned at a second distance from the support surface, the first distance and the second distance being measured orthogonally to the support surface and the first distance being greater than the second distance.

[0017] The first distance is greater than the second distance by a multiplier factor of at least 1.5, preferably of at most 40, preferably still between 5 and 25.

[0018] The fluid circuit comprises, successively from the inlet port to the outlet port, a rear portion and a front portion, said fluid circuit comprising in in addition to an intermediate portion connected to the rear portion on one side and to the front portion on the other, the intermediate portion having walls defining, in a cutting plane orthogonal to the support surface, an internal profile formed of two curves each presenting a point of inflection.

[0019] Each curve of the internal profile has opposite concavities on either side of the inflection points, said concavities having radii of curvature between 5 and 40 mm, preferably between 10 and 20 mm.

[0020] The rear surface of the nozzle body extends globally orthogonally to the bearing surface of said nozzle body.

[0021] The nozzle includes, on the rear surface of the nozzle body, an assembly part fluidly connected to the inlet orifice on one side and configured to be mechanically and fluidly connected to a fluid supply pipe on the other side, the assembly part having an external dimension, measured orthogonally to the bearing surface, of at least 10 mm, preferably between 15 and 25 mm.

[0022] The nozzle body includes a fixing orifice passing through said nozzle body in a direction substantially orthogonal to the support surface, the fluid circuit including a bypass portion arranged between the front portion and the intermediate portion and spaced from said fixing orifice, the walls of the bypass portion define, in a cutting plane parallel to the support surface, two concave curved portions, with radii of curvature preferably between 1 and 20 mm, in particular between 5 and 15 mm.

[0023] At least a part of the fluid circuit is divided, upstream of the rear portion, into two internal channels each opening onto a respective outlet orifice and each having a bypass portion arranged on either side of the fixing orifice.

[0024] The fluid circuit has a decrease in its fluid passage cross-section towards the outlet orifice, the inlet orifice having a first fluid passage cross-section and the outlet orifice having a second fluid passage cross-section, the second fluid passage cross-section being smaller than the first fluid passage cross-section by a multiplier factor of at least 15, preferably at most 70, preferably still between 20 and 30.

[0025] The fluid circuit comprises, successively from the inlet port to the outlet port, a rear portion opening onto the inlet port and oriented along a rear axis and a front portion opening onto the outlet port and oriented along a front axis, the rear axis extending parallel to the support surface.

[0026] The front axis forms with the rear axis, in a cutting plane orthogonal to the support surface and passing through the front axis, a first non-zero angle between these axes of up to 45°, preferably between 1 and 10°, and / or the front axis forms with the axis rear, in a cutting plane parallel to the support surface and passing through the front axis, a second angle less than or equal to 180°, preferably between 90 and 153°.

[0027] The support surface includes a surface texture in the form of reliefs or a porous structure formed on at least a part of said support surface.

[0028] The nozzle body has, in a direction orthogonal to the support surface, a progressive decrease in its height towards the outlet orifice.

[0029] Furthermore, the invention relates to an assembly consisting of a fluid distribution nozzle according to the invention and a tool holder, in which said fluid distribution nozzle is secured to said tool holder with the bearing surface of the nozzle body arranged opposite at least a part of the tool holder, said tool holder being devoid of any means of fluid circulation.

[0030] Furthermore, the invention relates to a cryogenic machining installation comprising at least one cutting tool, a tool holder carrying the cutting tool, a fluid distribution nozzle attached to said tool holder with the bearing surface of the nozzle body arranged opposite at least a part of the tool holder, a cryogenic fluid source, at least one thermally insulated cryogenic fluid supply line fluidically connecting said cryogenic fluid source to at least one inlet orifice of said nozzle, said line preferably having an outside dimension of at least 25 mm, the nozzle being configured according to the invention or the nozzle and the tool holder forming an assembly according to the invention.

[0031] The invention will now be better understood from the following description, given by way of non-limiting example and with reference to the attached figures, among which:

[0032] [Fig.1] represents a three-dimensional view of a nozzle according to an embodiment of the invention arranged on a tool holder and equipped with a fluid supply channel.

[0033] [Fig.2], [Fig.3], [Fig.4], [Fig.5], [Fig.6] represent different views of a nozzle according to embodiments of the invention.

[0034] With reference to [Fig.1], [Fig.2] and [Fig.3], a fluid distribution nozzle 1 according to an embodiment of the invention comprises a nozzle body 14 and a fluid circuit 15 passing through said nozzle body 14. The circuit 15 extends from at least one inlet orifice 5 to at least one outlet orifice 6. The fluid is distributed through the outlet orifice 6 at the level of the machining tool and / or the machining area, in particular the area of ​​the workpiece where material removal and chip generation take place.

[0035] During operation, the inlet port 5 is supplied with fluid, preferably from a fluid supply line 18 connected to a fluid source or reservoir (not shown). The reservoir is advantageously a thermally insulated cryogenic tank. Its enclosure may comprise two perimeter walls spheres separated by a space filled with insulating material, such as perlite, and drawn under vacuum to thermally insulate the contents of the tank.

[0036] Preferably, the fluid comprises liquid nitrogen, liquid carbon dioxide, and / or supercritical carbon dioxide. It should be noted that the fluid may be composed of a single component, but the use of a mixture of several distinct components is also possible. The cryogenic liquid is then a fluid cooled to a temperature below the lowest boiling point of these components. In particular, the fluid may be composed of liquid nitrogen at a temperature of -196 °C or lower. The fluid may also be composed of supercritical carbon dioxide at a temperature of 31 °C or higher.

[0037] The pipe 18 is advantageously a pipe equipped with thermal insulation, in particular a double-insulated pipe. Preferably, the pipe 18 comprises an inner tube suitable for channeling the cryogenic fluid from a cryogenic fluid source to the inlet port 5 and an outer tube arranged around the inner tube, with fluidic insulation means for the volume formed between the inner and outer tubes from the external environment. A vacuum can thus be established and / or thermally insulating material arranged in the volume delimited between the inner and outer tubes. Preferably, the pipe 18 has an outside dimension of at least 25 mm, more preferably at least 28 mm, and in particular at least 50 mm. In particular, the pipe is generally cylindrical in shape and the outside dimension corresponds to the outside diameter of the pipe.

[0038] The nozzle body 14 includes a bearing surface 14c arranged, when the nozzle is mounted on the tool holder 2 supporting the tool 4, opposite at least a part of the machining tool 4 and / or the tool holder 2. Preferably, at least a part of the bearing surface 14c extends globally in a plane, said plane being in particular parallel to at least a part of an upper surface of the tool holder 2 and / or the tool 4 opposite which the bearing surface 14c is arranged. In particular, the bearing surface 14c includes, when the nozzle is assembled to the tool holder 2, at least one part in contact with the machining tool 4 and / or the tool holder 2. The nozzle body 14 further includes a rear surface 14a and a front surface 14b arranged opposite each other, on either side of the bearing surface 14c.Note that the nozzle body 14 may also include a top surface 14d opposite the support surface 14c and side walls connecting the top surface 14d and the support surface 14c. Preferably, the rear surface 14a and / or the front surface 14b extend globally orthogonally to the support surface 14c.

[0039] The outlet orifice 6 is provided on the front surface 14b of the nozzle 1. In the illustrated case, the nozzle 1 comprises two outlet orifices 6 opening at the level of the Front surface 14b. According to the invention, the inlet 5 is provided on the rear surface 14a of the nozzle 1. Thus, it is possible to supply the nozzle 1 with fluid without passing through the tool holder 2. Unlike prior art devices in which the nozzle's fluid circuit is fluidly connected to a fluid delivery channel within the tool holder 2, the fluid circuit of the nozzle according to the invention is independent of the tool holder. This improves the flexibility of the machining setup, as the same nozzle can be more easily adapted to different tool holders, or conversely, different nozzles can be adapted to the same tool holder. A nozzle according to the invention can therefore be adapted to an existing machining setup.This also avoids the need for a mechanical and fluidic connection between the tool holder and the nozzle, as this type of connection promotes pressure losses and potential vaporization of a cryogenic fluid. This reduces heat loss to the fluid, thus maximizing the amount of fluid projected in liquid or supercritical form onto the area to be cooled. Furthermore, positioning the inlet orifice 5 on the rear surface of the nozzle minimizes changes in direction experienced by the fluid as it flows through the fluid circuit. This reduces pressure losses to the fluid and consequently the associated vaporization and two-phase transition phenomena.

[0040] Furthermore, the positioning of the inlet orifice 5 on the rear surface of the nozzle allows fluid to be supplied to the machine along an axis parallel to the machine's axis of rotation. The nozzle according to the invention can therefore be implemented without requiring any modification to the machine's configuration. The fluid supply system does not impede the machine's movements. The integration of a cryogenic fluid supply line with an existing machine is greatly facilitated.

[0041] With reference to [Fig. 5], the inlet orifice 5 can advantageously be positioned at a first distance hl from the bearing surface 14c and the outlet orifice 6 is positioned at a second distance h2 from the bearing surface 14c, with the first distance hl greater than the second distance h2. The first distance hl and the second distance h2 are measured orthogonally to the bearing surface 14c. The height of an orifice is understood to be the position of the center of said orifice along the direction of height measurement, that is to say, the distance separating the center from the bearing surface 14c measured in this direction orthogonal to the surface 14c.Thus, the inlet port 5 is offset from the support surface 14a, allowing the connection of a relatively bulky pipe, such as thermally insulated pipes with an external diameter ranging from 28 to 60 mm, without the pipe obstructing the movement of the tool holder or coming into contact with any machine component. The outlet port. 6 is positioned closer to the support surface 14c in order to distribute the cryogenic fluid under the best possible conditions and to efficiently cool the machining area.

[0042] Preferably, the first distance hl is greater than the second distance h2 by a factor of at least 1.5, preferably at most 40, and preferably between 5 and 25. Such factors make it possible to limit the curvature of the internal circuit and to reduce the pressure losses experienced by the fluid. The first distance hl may, in particular, be between 7 and 20 mm, especially between 9 and 13 mm, and the second distance h2 may, in particular, be between 0.2 and 18 mm, especially between 0.5 and 2 mm.

[0043] [Fig.2] and [Fig.3] schematically illustrate an advantageous embodiment in which the circuit Fluid circuit 15 comprises, successively from the inlet port 5 to the outlet port 6, a rear portion 15a opening onto the inlet port 5 and a front portion 15b opening onto the outlet port 6, said fluid circuit 15 further comprising an intermediate portion 15c connected to the rear portion 15a on the one hand and to the front portion 15b on the other. The intermediate portion 15c of the circuit 15 comprises internal walls defining, in a cross-sectional plane orthogonal to the support surface 14c, an internal profile formed by two curves Cl, C2, each having an inflection point PI, P2. Preferably, the two curves Cl, C2 are tangent to each other and successively concave and convex, the intermediate portion 15c connecting tangentially to the rear portion 15a on the one hand and to the front portion 15b on the other.

[0044] [Fig.3] represents an embodiment of the rear portion 15a of the fluid circuit 15 The rear portion 15b is oriented along a rear axis A, and the front portion 15b is oriented along a front axis A'. The rear axis A extends parallel to the bearing surface 14c and orthogonally to the rear surface 14a. The front axis A' and the rear axis A lie in the same plane. The internal profile is determined in a cutting plane orthogonal to the bearing surface 14c and passing through a tangent T to one of the curves at its point of inflection. The cutting plane is orthogonal to the bearing surface 14c and orthogonal to the rear surface 14a.

[0045] Note that other orientations of the front axis A' and the rear axis A are possible, in particular a first non-zero angle B between these axes of up to 45°, preferably between 1 and 10°, in a cutting plane orthogonal to the support surface 14c and passing through the front axis A, and / or a second angle C less than or equal to 180° between these axes, preferably between 90 and 153°, in a cutting plane parallel to the support surface 14c and passing through the front axis A. Such configurations are illustrated in [Fig. 6]. Such angles make it possible to limit the changes in direction experienced by the fluid within the nozzle.

[0046] In particular, each Cl, C2 curve of the internal profile may exhibit concavities opposite each other on either side of the inflection points PI, P2, said concavities having radii of curvature between 5 and 40 mm, preferably between 10 and 20 mm. Such values ​​limit the changes in direction experienced by the fluid within the nozzle while facilitating the integration of the pipe 8 with the machine configuration.

[0047] Preferably, the nozzle 1 comprises on its rear surface 14a an assembly portion 7 fluidly connected to the inlet orifice 5 on one side and configured to be mechanically and fluidly connected to a fluid supply line 18 on the other. The assembly portion 7 has an external dimension, measured orthogonally to the bearing surface 14a, of at least 10 mm, preferably between 15 and 25 mm. The assembly portion 7 is preferably a tubular part comprising a threaded outer surface or a tapped inner surface, cooperating with a complementary thread or tapped hole in the line 18. Preferably, the assembly portion is formed as a single unit with the nozzle body 14.

[0048] The nozzle 1 may include means for fixing the nozzle body 14 to the tool holder 2. In particular, the nozzle body 14 may include a through-hole 3 extending in a direction substantially orthogonal to the bearing surface 14c. The hole 3 is configured to receive a fixing means, such as a screw, for securing the nozzle 1 to the tool holder 2. In this configuration, the fluid circuit 15 includes a bypass portion 15d arranged between the front portion 15b and the intermediate portion 15c and spaced from said fixing hole 3. The walls of the bypass portion 15d define, in a cutting plane parallel to the bearing surface 14c, two concave curved portions, with radii of curvature preferably between 1 and 20 mm, in particular between 5 and 15 mm.

[0049] Preferably, at least a portion of the fluid circuit is divided, upstream of the rear portion 15a, into at least two internal channels each opening onto a respective outlet orifice 6 and each having a bypass portion 15c arranged on either side of the fixing orifice 3. This allows the fluid distribution to be balanced in the width of the nozzle.

[0050] Preferably, the fluid circuit 15 has a decrease in its fluid passage cross-section towards the outlet orifice 6, the inlet orifice 5 having a first fluid passage cross-section and the outlet orifice 6 having a second fluid passage cross-section, the second cross-section being smaller than the first cross-section by a factor of at least 15, preferably at most 70, preferably still between 20 and 30. This makes it possible to increase the ejection velocity of the fluid at the outlet of the nozzle.

[0051] Note that by "fluid passage section" we mean a transverse surface of a circuit through which the fluid can flow. For example, on [Fig. 2] and [Fig.3], the cross-section of the rear portion 15a is determined in a plane orthogonal to the rear axis A and to the support surface 14c.

[0052] The outlet orifice 6 and / or the inlet orifice 5 may have a circular cross-section. The diameter of the outlet orifice 6 may range from 0.1 to 4 mm. The ratio between the diameter of the inlet orifice 5 and the outlet orifice 6 may be between 1 and 100, preferably between 2 and 15. The inlet orifice 5 has a diameter that may be between 4 and 24 mm. The ratio between the diameter of the inlet orifice and the inlet of each of the channels after division is ideally between 1 and 20, preferably between 2 and 4.

[0053] Preferably, the nozzle body 14 has, in a direction orthogonal to the support surface 14c, a gradual decrease in its height towards the outlet orifice 6. This reduces the overall size of the nozzle and allows easier access to certain areas of the workpiece. Typically, the ratio between the maximum and minimum heights of the nozzle body can be between 1 and 5.

[0054] The dimensions of the nozzle body and the fluid circuit can be adapted according to the area of ​​the workpiece to be machined.

[0055] In the illustrated embodiments, the fluid circuit 15 may consist of a rear portion 15a with a circular cross-section, dividing at a junction with the intermediate portion 15c into two internal channels, each with a circular cross-section and diameters that gradually decrease from the junction towards the front portion 15b. The rear portion 15a may also have a gradual decrease in cross-section towards the front portion 15b. At the point of division of the rear portion, the walls of the internal channels form a concave profile, preferably with a radius of curvature between 0.05 and 10 mm. This configuration helps to limit the risk of creating low-pressure zones. These low-pressure zones are to be avoided because they promote fluid expansion and the formation of gases, thus reducing the desired thermal efficiency.

[0056] Advantageously, at least a portion of the bearing surface 14c of the nozzle body 14 has a surface texture 19 in the form of raised areas or a porous structure. This reduces the heat transfer that can occur from the fluid to the tool holder via the nozzle. Due to the presence of raised areas or porosity, the bearing surface 14c of the nozzle body 14 has a portion of its surface devoid of material. Preferably, the surface texture is shaped so that the ratio between the surface devoid of material and the surface containing material is as low as possible, preferably between 5 and 50%, and even more preferably between 10 and 20%. Preferably, the bearing surface has a first border 20 arranged around the periphery of the untextured, i.e., solid, bearing surface 14c, and optionally a second border 21 arranged around the mounting orifice 3. devoid of texture.

[0057] It should be noted that the surface texture 19 can be in the form of reliefs, or patterns, imprinted or created in or on the material constituting the nozzle body. Preferably, these reliefs define, in cross-section, cavities open on the bearing surface. For example, micro-reliefs of various sizes or morphologies, such as discreet or continuous grooves, striations, protrusions, etc., can be formed or deposited on the surface.

Claims

Demands

1. Fluid dispensing nozzle (1), in particular for cryogenic fluid, comprising: - a nozzle body (14), - a fluid circuit (15) passing through said nozzle body (14) and extending from at least one inlet orifice (5) configured to be supplied with fluid to at least one outlet orifice (6) configured to distribute said fluid to at least part of a machining area and / or a machining tool (4), - a bearing surface (14c) of said nozzle body (14) intended to be arranged opposite at least a part of the machining tool (4) and / or a tool holder (2) intended to carry said machining tool (4), - a rear surface (14a) and a front surface (14b) of said nozzle body (14) arranged on either side of the support surface (14c), said at least one outlet orifice (6) being provided on the front surface (14b) of the nozzle (1), characterized in that said at least one inlet orifice (5) is provided on the rear surface (14a) of the nozzle (1), the fluid circuit (15) comprising, successively from the inlet orifice (5) to the outlet orifice (6), a rear portion (15a) and a front portion (15b), said fluid circuit (15) further comprising an intermediate portion (15c) connected to the rear portion (15a) on the one hand and to the front portion (15b) on the other hand, the intermediate portion (15c) having walls defining, in a cutting plane orthogonal to the support surface (14c), an internal profile formed of two curves (C1, C2) each having an inflection point (P1, P2), each curve (C1, C2) of the internal profile having opposite concavities on either side of the inflection points (P1, P2), said concavities having radii of curvature between 5 and 40 mm.

2. Nozzle according to claim 1, characterized in that said inlet orifice (5) is positioned at a first distance (hl) from the support surface (14c) and said at least one outlet orifice (6) is positioned at a second distance (h2) from the support surface (14c), the first distance (hl) and the second distance (h2) being measured orthogonally to the support surface (14c) and the first distance (hl) being greater than the second distance (h2).

3. Nozzle according to one of claims 1 or 2, characterized in that the first distance (hl) is greater than the second distance (h2) by a multiplier factor of at least 1.5, preferably of at most 40, preferably still between 5 and 25.

4. Nozzle according to any one of the preceding claims, characterized in that said concavities have radii of curvature between 10 and 20 mm.

5. Nozzle according to any one of the preceding claims, characterized in that the rear surface (14a) of the nozzle body (14) extends globally orthogonally to the bearing surface (14c) of said nozzle body (14).

6. Nozzle according to any one of the preceding claims, characterized in that it comprises, on the rear surface (14a) of the nozzle body (14), an assembly part (7) fluidically connected to the inlet orifice (5) on the one hand and configured to be mechanically and fluidly connected to a fluid supply pipe (18) on the other hand, the assembly part (7) having an external dimension, measured orthogonally to the bearing surface (14a), of at least 10 mm, preferably between 15 and 25 mm.

7. Nozzle according to any one of the preceding claims, characterized in that the nozzle body (14) comprises a fixing orifice (3) passing through said nozzle body (14) in a direction substantially orthogonal to the support surface (14c), the fluid circuit (15) comprising a bypass portion (15d) arranged between the front portion (15b) and the intermediate portion (15c) and spaced from said fixing orifice (3), the walls of the bypass portion (15d) defining, in a cutting plane parallel to the support surface (14c), two concave curved portions, with radii of curvature preferably between 1 and 20 mm, in particular between 5 and 15 mm.

8. Nozzle according to claim 7, characterized in that at least a part of the fluid circuit is divided, upstream of the rear portion (15a), into two internal channels each opening onto a respective outlet orifice (6) and each having a bypass portion (15c) arranged on either side of the fixing orifice (3).

9. Nozzle according to any one of the preceding claims, characterized in that the fluid circuit (15) has a reduction in its passage cross-section of fluid towards the outlet port (6), the inlet port (5) having a first fluid passage section and the outlet port (6) having a second fluid passage section, the second fluid passage section being smaller than the first fluid passage section by a multiplier factor of at least 15, preferably at most 70, preferably still between 20 and 30.

10. Nozzle according to any one of the preceding claims, characterized in that the fluid circuit (15) comprises, successively from the inlet orifice (5) to the outlet orifice (6), a rear portion (15a) opening onto the inlet orifice (5) and oriented along a rear axis (A) and a front portion (15b) opening onto the outlet orifice (6) and oriented along a front axis (A'), the rear axis (A) extending parallel to the support surface (14c).

11. Nozzle according to claim 10, characterized in that the front axis (A') forms with the rear axis (A), in a cutting plane orthogonal to the support surface (14c) and passing through the front axis (A), a first non-zero angle (B) between these axes of up to 45°, preferably between 1 and 10°, and / or the front axis (A') forms with the rear axis (A), in a cutting plane parallel to the support surface (14c) and passing through the front axis (A), a second angle (C) less than or equal to 180°, preferably between 90 and 153°.

12. Nozzle according to any one of the preceding claims, characterized in that the bearing surface (14c) comprises a surface texture in the form of reliefs or a porous structure formed on at least a part of said bearing surface (14c).

13. Nozzle according to any one of the preceding claims, characterized in that the nozzle body (14) has, in a direction orthogonal to the bearing surface (14c), a progressive decrease in its height towards the outlet orifice (6).

14. Assembly consisting of a fluid distribution nozzle (1) and a tool holder (2), wherein said fluid distribution nozzle (1) is secured to said tool holder (2) with the bearing surface (14c) of the nozzle body (14) arranged opposite at least a part of the tool holder (2), the nozzle being as defined by any one of claims 1 to 13, said tool holder (2) being devoid of any means of fluid circulation.

15. Cryogenic machining installation comprising at least one cutting tool (4), a tool holder (2) carrying the cutting tool (4), a fluid distribution nozzle (1) attached to said tool holder (2) with the surface support (14c) of the nozzle body (14) arranged opposite at least a part of the tool holder (2), a cryogenic fluid source, at least one thermally insulated cryogenic fluid supply line (18) fluidically connecting said cryogenic fluid source to at least one inlet orifice (5) of said nozzle (1), said line (18) preferably having an outside dimension of at least 25 mm, the nozzle being as defined by any one of claims 1 to 14 or the nozzle (1) and the tool holder (2) forming an assembly as defined by claim 15.

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