The present invention relates to a vane handling framework and a method of using this framework.

It is known a vane handling frame comprising a plurality of individual housings for each vane. Such a framework provides support vanes for simultaneous movement in a heat treatment furnace.

The framework is generally made of a metallic material and covered with a thin layer of yttria stabilized zirconia deposited by a plasma spraying technique. Adding this type of coating is required to avoid contact between a blade and the metallic material of the frame that could lead to the formation of a eutectic on the blades resulting in a reduction of the metallurgical qualities of the blades at points of contact .

However, it was observed that after undergoing several heat treatments, the yttria-stabilized zirconia is detached from the frame and can be deposited on the blades, leading to their disposal for lack of mechanical compliance.

The invention particularly aims to provide a simple, efficient and economical problems of the prior art described above.

To this end, it proposes a blade handling frame comprising a bottom wall having a plurality of intersecting longitudinal and transverse partitions forming a grid defining a plurality of housings each adapted to receive a blade, characterized in that it comprises support rods and maintaining the blades at a distance from the bottom wall and said longitudinal and transverse bulkheads, these rods passing through the longitudinal and transverse bulkheads, extending into the housing and being formed at least externally in a thermally insulating material.

According to the invention, the blades are supported by rods having at least one external surface made of a thermally insulating material, which makes it possible to avoid contact between the blades and the bottom wall as well as with longitudinal and transverse bulkheads . With this framework, it is possible to remove the coating of yttria stabilized zirconia, which prevents deposits of this material on the blades and the subsequent pollution of the blades. The blades compliance is thus greatly increased.

Preferably, the thermally insulating material is a ceramic material such as alumina 5X25.

Advantageously, the rods extend substantially parallel to the longitudinal or transverse partitions.

According to another characteristic of the invention, each housing is penetrated by three rods groups, each formed by at least two substantially parallel rods to one another, the rods of a first group being arranged so as to support and maintain the blades at a distance from the bottom wall, the rods of a second group being arranged to hold off the blades of the longitudinal bulkheads, the rods of a third group are arranged so as to maintain at a distance the vanes transverse bulkheads.

The rods of the first group providing a support of the blades along a vertical axis while the rods of the second and third groups provide lateral retention of the blades in the two spatial directions perpendicular to each other and the above vertical direction.

According to yet another feature of the invention, each rod is formed of a rigid metal wire around which are engaged ceramic material tubes.

The use of a wire with insulating material tubes ensures good mechanical strength and good deformability of this set in a heat treatment furnace of the blades.

In a practical embodiment of the invention, the bottom wall comprises orifices and is in contact with a first grid of first longitudinal and transverse bulkheads and connected by arm perpendicular to the bottom wall to a second grid of second partitions longitudinal and transverse.

The invention further relates to a heat treatment method of a blade, comprising:

a) providing a frame of the type described above,

b) inserting the blades in at least some of the frame housing so that they come into contact with the support rods and holding

c) inserting the frame carrying the blades in a heat treatment furnace of the blades.

The invention will be better understood and other details, advantages and features of the invention appear on reading the following description given by way of example, with reference to the accompanying drawings in which:

- Figure 1 is a schematic side perspective of a frame according to the invention;

- Figure 2 is a schematic perspective view of the top of the frame of Figure 3;

- Figure 3 is an enlarged view of the area bounded My dotted in Figure 4;

- Figure 4 is an enlarged view of the area bounded Mb dotted in Figure 4;

- Figure 5 is an enlarged view of a side of the frame according to the invention;

- Figure 6 is a schematic view of a part of the housing according to the invention, a blade being arranged in the housing;

- Figure 7 is a schematic representation of a rod according to the invention.

firstly refers to Figure 1 which shows a frame 10 or vane handling plate according to the invention. In the following description, the vertical direction is represented by the Z axis and the two other spatial directions are represented by X and Y axes perpendicular to each other and to the axis Z (the Y axis is shown along the right edge of the frame 10 of Figure 1). The frame shown in Figures has a rectangular shape in an XY plane. The frame 10 comprises a bottom wall 12 which has orifices 14 of air circulation and which is in direct contact with a first grid 16 formed of a plurality of first longitudinal partitions 16a (extending along the X axis and perpendicular to the bottom wall 12 and first transverse walls 16b extending in the Y axis and perpendicular to the bottom wall 12 (figures 2, 3 and 4). the first longitudinal bulkheads 16a and 16b are planar and cross-s 'intersect. the first grid 16 is connected by means of arms 18 extending along the Z axis, to a second gate 20 formed of second longitudinal planar walls 20a and transverse 20b. As shown in Figure 2 , the first gate 16 and second gate 20 together define housings 22 each adapted to receive a blade 24 (figure 6). Each blade 24 is inserted by its foot 26 in a housing 22. such frame 10 allows manipulation of A plurality of vanes 24 and enables more particularly the supply of the blades 24 in a heat treatment furnace. The first grid 16 and second grid 20 each include an inner peripheral wall 28 and an outer peripheral wall 30 defining therebetween a groove 32 on each side of the frame 10.

According to the invention, the first longitudinal bulkheads 16a and 16b cross and the second longitudinal 20a and transverse walls 20b are traversed by support rods and maintaining remote blades of the bottom wall 12 and said longitudinal walls 16a, 20a transverse and 16b, 20b.

As shown in Figures 3 and 4, each housing 22 is traversed by a first, second and third groups of rods, the rods of each group being substantially parallel to each other.

The first group of rods comprises two rods 34 substantially parallel to the bottom wall 12 and extending in the transverse direction (Y axis). These rods 34 of the first group through the first longitudinal partition walls 16a and are arranged symmetrically relative to each other with respect to a median plane YZ housing 22. The rods 34 of the first group through the first longitudinal partitions 16a at notches 36 of said longitudinal walls, the notches 36 opening onto the bottom wall 12 (Figure 4). The second group comprises two rods 38 parallel to the bottom wall 12, extending in the transverse direction (Y axis) and both sides of the rods 34 of the first group. The rods 38 of the second group through the first longitudinal walls 16a at openings 40 in section corresponding to that of the rods, here circular, these openings 40 being formed at a distance from the bottom wall 12. The rods 42 of the third group are oriented parallel to the first and second longitudinal partition walls 16a, 20a and through the first and second transverse walls 16b, 20b. This third group includes four rods 42, two first rods 42a pass through the first transverse partitions 16a and 42b, two second rods pass through the second transverse walls 20b. The first rod 42a of the third group are arranged symmetrical with respect to each other relative to a median plane XZ housing while the second rods 42b of the third group are staggered with respect to one another relative to the axis Z. the first rods 42a and the second rods 42b of the third group through the first and second transverse walls 16b, 20b at circular section holes 44 formed in these walls (Figure 4). Note that the passage openings of the first rods 42a of the third group are positioned along the axis Z between the passage openings 40 of the rods 38 of the second group in the first longitudinal partition walls 16a and the passage openings 44 of the second rods 42b third group in the second transverse walls 20b.

Each vane 24 is arranged in a housing 22 so as to be supported by the rods 34 of the first group, which avoids the contact with the wall of the metal end 12. The rods 38 of the second group ensure maintenance of blade along the X axis avoiding movements according to this axis of the blade root 26. the rods 42a, 42b of the third group ensure maintenance of the blade along the axis Y. specifically, the first rod 42a of the third group provide support for the foot of the blade 26 along the X axis and the second rods 42b of the third group ensure maintenance of the blade 46 of the blade along the axis X (figures 5 and 6). It is understood that the risk of tilting of the blade 46 of the blade 24 along the Y axis are very limited due to the elongated shape of the blade root 26 along the axis X, which explains the absence of rods holding along the Y axis for the blade 46 of the blade 24. However, it would of course be possible to incorporate, if necessary, a fourth group of rods passing through the second longitudinal bulkheads.

According to the invention, each rod 48 is formed of a rigid metal wire 50 on which are engaged ceramic material tubes 52. The rods thus formed are engaged in the orifices of the first and second longitudinal partition walls 16a, 20a and 16b transverse, 20b. The ends of son 50 are fixed to the inner peripheral walls 16, 20 and external 28, 30 of the first and second grids (Figures 1 and 5).

The use of rods 48 having a wire 50 and a plurality of tubes 52 made of thermally insulating material such as ceramic, prevents contact between the blades 24 and the frame 10 in a simple manner while avoiding the problems prior art. The ceramic tube is not deposited on the blades during the various thermal treatments of the blades since the ceramic tube is not deposited in a thin layer on a support which could come loose. On the contrary, the ceramic tubes are made in the mass and are independent of the support.

The metal wire 50 is preferably a material capable of withstanding temperatures up to 1300 ° C and capable of undergoing 350 ° C per minute under an argon pressure of 5 bar absolute. Such a material is for example a stainless steel.

CLAIMS

1. Frame (10) of blades handling comprising a bottom wall (12) carrying a plurality of longitudinal partitions (16a, 20a) and transverse (16b, 20b) intersecting forming a grid (16, 20) defining a plurality of housings ( 22) each adapted to receive a blade (24), characterized in that it comprises rods (48) supporting and retaining blades (24) remote from the bottom wall (12) and said longitudinal walls (16a , 20a) and transverse (16b, 20b), these rods (48) passing through the longitudinal partitions (16a, 20a) and transverse (16b, 20b) and extending into the housing (22) and being formed at least externally in a thermally insulating material.

2. Frame according to Claim 1, characterized in that the rods (48) extend substantially parallel to the longitudinal walls (16a, 20a) or transverse (16b, 20b).

3. Frame according to Claim 1 or 2, characterized in that each housing (22) is crossed by three rods groups, each formed by at least two substantially parallel rods to one another, the rods (34) a first group being arranged so as to support and maintain the blades (24) remote from the bottom wall (12), the rods (38) of a second group being arranged to hold off the blades ( 24) of the longitudinal partitions (16), the rods (42a, 42b) of a third group being arranged to hold off the blades of the transverse bulkheads.

4. Frame according to one of claims 1 to 4, characterized in that each rod (48) is formed of a wire (50) rigid metal around which are engaged tubes (52) of ceramic material.

5. Frame according to one of claims 1 to 4, characterized in that the bottom wall (12) comprises orifices (14) and is in contact with a first grid (16) formed of first longitudinal partition walls (16a) and transverse (16b) and connected by perpendicular arm (18) to the bottom wall (12) to a second gate (20) formed of second longitudinal partition walls (20a) and transverse (20b).

6. Frame according to one of claims 1 to 5, characterized in that the thermally insulating material is a ceramic material.

7. A heat treatment method of a blade, comprising:

a) providing a frame (10) according to one of claims 1 to 6,

b) inserting of the blades (24) in at least some of the housings (22) of the frame (10) so that they come into contact with the rods (48) supporting and holding,

c) inserting the frame (10) carrying the blades (24) in a heat treatment furnace of the blades (24).