Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D5/00—Supports, screens, or the like for the charge within the furnace
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/0006—Details, accessories not peculiar to any of the following furnaces
  • C21D9/0025—Supports; Baskets; Containers; Covers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D5/00—Supports, screens, or the like for the charge within the furnace
  • F27D5/0006—Composite supporting structures

Definitions

• Loading device for supporting parts to be heat treated in an oven.
• the present invention relates to a loading device, or tool, for supporting parts in a heat treatment oven.
• a particular, but not exclusive, field of application of the invention is that of tools for supporting parts to be treated in a cementation furnace.
• the most commonly used tools are metallic. They have two main drawbacks:
• thermostructural composite material in place of a metallic material, for producing hearths for heat treatment ovens.
• Several floors can be provided, spaced from each other by spacers also made of thermostructural composite material.
• the composite material used is a carbon / carbon composite material (C / C) or a ceramic matrix composite material (CMC) whose mechanical properties make them suitable for constituting structural elements and which retain these properties up to high temperatures. .
• the loading device described in document EP-A-0 518 746 does not prove to be suitable for achieving optimal loading, as may be desired when a relatively large number of identical parts have to be processed.
• this device known does not lend itself to the robotization of loading and unloading of parts.
• the object of the present invention is to remedy the aforementioned drawbacks of the devices of the prior art and for this purpose proposes a loading device made of thermostructural composite material and comprising: a base; a load pylon integral with the base, projecting from a central part of the base, and extending over at least the entire height of the loading device; a plurality of loading platforms provided with a central passage to allow the passage of the loading mast; each loading plate carrying several columns allowing the successive assembly of the plates at predetermined intervals, the columns carried by each plate being in the same number and being aligned so as to constitute, after the assembly of the plates, load take-up columns extending on the height of the loading device, and at least one of the columns carried by each plate having a disposition and / or a dimension different from that of the other columns carried by the same plate in order to allow an indexing of the plates during their assembly .
• the loading device due to its realization in thermostructural composite material, and the presence of indexing means of the plates, makes it possible to satisfy the conditions of dimensional stability and precision required for robotization of the loading and unloading operations of parts treat.
• each tray has means for positioning parts in predetermined locations.
• the loading device comprises first plates on which the parts positioning means occupy a first position relative to the balusters, and second plates on which the parts positioning means occupy a second position, different from the first, compared to the balusters. These first plates alternate with the second plates, so that the parts positioning means are not all vertically aligned.
• Each tray has means for receiving posts suitable for receiving ends of posts carried by a tray located below.
• a at least one baluster On each tray, a at least one baluster has an arrangement relative to the axis of the mast different from that of the other balusters and at least one baluster has a different dimension compared to the other balusters, so that two identical trays cannot be mounted one at a time - above the other and that the plates can only be mounted in the required angular positions around the axis of the mast.
• the positioning means can comprise at least part of the columns.
• Each tray has means for receiving posts suitable for receiving ends of posts carried by a tray situated below.
• On each plate at least one column has an arrangement relative to the axis of the mast different from that of the other columns, and / or a different dimension from that of the other columns, so that the plates can only be mounted in predetermined angular positions relative to the axis of the mast.
• FIG. 1 is a partial perspective view of a first embodiment of a loading device according to the invention
• - Figure 2 is a perspective view of a second embodiment of a loading device according to the invention.
• the loading device or tool, partially illustrated in FIG. 1, is intended for loading a set of identical parts, for example steel pinions 10 (shown diagrammatically by rings) for motor vehicles, in order to subject them to a carburizing treatment in an oven.
• steel pinions 10 shown diagrammatically by rings
• the loading device comprises a horizontal base 20, from the center of which projects a vertical load mast 30 and a plurality of horizontal plates 40 spaced along the mast 30 and separated from each other by means of columns 50 forming spacers.
• the base 20, which supports the entire load, has a circular shape and is provided with openings 21 which make it possible to lighten it and facilitate the circulation of gas.
• the load mast 30 is terminated at its free end by a gripping head 31 connected to the rest of the mast by a portion of reduced diameter 32 forming a groove, the head 31 allowing the entire load to be gripped by a tool or machine automatic handling.
• the plates 40 (not all shown), of thickness substantially less than that of the base 20, are inscribed in a circular contour having substantially the same diameter as the base.
• Each tray has a central passage 41, for the passage of the mast 30, and openings 42. These openings open the tray, reducing its mass and its thermal inertia, and promote the circulation of gas over the entire height of the stack. .
• the openings 42 of the plates are not exactly aligned in order to avoid a "chimney" effect for the circulation of gases.
• the parts 10 to be treated (not all shown) are arranged on each plate in predetermined locations.
• groups of pins 45 are mounted in orifices formed in the plates.
• the pins 45 for example three in number, fit inside the internal circumference of a part 10.
• the balusters 50 are carried by the base and each plate, and integral with these, for example by gluing and / or insertion of their lower end into orifices formed in the base or each plate.
• the columns 50 are terminated by a cylindrical part, or head, 51 of reduced diameter which engages in an orifice of corresponding diameter formed in the immediately upper plate, this engagement being facilitated by the frustoconical shape given to the heads 51 at their upper ends.
• the base and each plate carry 4 small columns distributed at regular angular intervals around the axis, but their number could be different, while being at least equal to 3.
• the small columns carried by the base can be reduced height, when the base has no workpiece support means.
• the plates are of two types 40a, 40b arranged alternately. They differ from each other by the position of the workpiece supports relative to the balusters.
• the plates 40a have eight coin supports arranged at regular intervals around the axis of the plate, each coin support being on a radius making an angle of ⁇ / 8 with the radius on which is located. the nearest baluster.
• the plates 40b have eight coin supports arranged at regular intervals around the axis of the plate, each coin support being on a radius making an angle of 0 ° or ⁇ / 4 with the radius on which the baluster is located. the closest.
• Keying and indexing means make it possible to mount the plates by means of robots in the desired order (40a, 40b, 40a, 40b, ...) from the base and in respecting the desired angular position around from the axis of the mast 30.
• the column heads As a coding means, it is possible to give at least one of the column heads a diameter different from that of the other column heads carried by the same plate or base.
• two opposite columns 50 . , 50 2 carried by a plate 40a have heads of diameter greater than that of the heads of the other columns 50 3 , 50 4
• the two opposite columns 50 ⁇ , 50 2 carried by the base or a plate 40b have heads with a diameter smaller than that of the heads of the other balusters 50 3 , 50 4 .
• the loading consists of mounting the plates 40a, 40b successively on the base and, each time a plate is mounted, filling it with pieces 10 by placing these around each group of pins 45.
• the trays can be furnished with parts 10 before mounting.
• the first and the last plate of the assembly mounted on the base are of the same type, for example 40a, as in the example illustrated. In this way, in the case where the trays must be transferred one by one from a first base to a second, the first tray removed is also the first reinstalled. The total number of trays is therefore odd.
• the angular positions of the plates are such that all of the posts carried by the base and each plate is in the same arrangement, so that the posts are aligned, and form columns extending over the entire height of the load.
• Each plate then only has to support its own load (and not also that of the plates located above), so that the plates can have the same thickness less than that of the base.
• the workpiece supports are then not aligned vertically, being angularly offset by ⁇ / 8 between two successive trays. In this way, the parts to be treated are better distributed in the oven and the formation of gas streams capable of causing inhomogeneous treatment of the parts is avoided.
• the dimensional stability of the main components of the loading device (base 20, mast 30, trays 40, balusters 50), necessary to obtain the precision required for the robotization of loading and unloading, is obtained by producing these elements in thermostructural composite material.
• the composite materials that can be used are carbon / carbon composite materials (C / C) and ceramic matrix composite materials (CMC).
• the C / C composites are obtained by making a fibrous preform of carbon fibers and densifying the preform by forming a carbon matrix within its porosity.
• the carbon matrix can be obtained by liquid means, that is to say by impregnation of the preform by means of a liquid composition (such as a resin) carbon precursor and heat treatment to transform the precursor into carbon, or by gas, that is to say by chemical vapor infiltration.
• CMCs are obtained by making a fiber preform of refractory fibers, for example carbon or ceramic fibers, and densification of the preform by forming a ceramic matrix within its porosity.
• the ceramic matrix for example made of silicon carbide (SiC) can be obtained by the liquid route or by chemical vapor infiltration.
• the surfaces of these parts in contact can be coated with a metal strip or provided with a non-stick coating, for example made of nitride.
• the BN coating can be obtained by chemical vapor deposition, the surface parts not to be coated being masked.
• the pins 25 constituting the workpiece supports can be made of metal, for example steel. They are advantageously cold crimped in their housings.
• the pins can be coated with copper, for example by electrolytic copper plating to avoid sticking with the steel parts to be treated.
• FIG. 2 illustrates another embodiment of a loading device according to the invention, more particularly intended for the support of parts 110 of revolution of elongated shape, such as hollow steel transmission shafts for motor vehicles, in order to subject them to a case hardening treatment in an oven.
• parts 110 of revolution of elongated shape such as hollow steel transmission shafts for motor vehicles
• Horizontal plates 140 are mounted at predetermined intervals around the mast 130, being spaced from one another by means of balusters 150 (not all shown) also forming supports for the parts 110 (not all shown).
• the columns 150 are in the form of independent rods which are plugged at their base into orifices formed in the plate which supports them and whose frustoconical free end engages in a socket 143 formed under an upper plate.
• the plates 140 are of two types
• the total number of plates is preferably odd, as in the first embodiment.
• each baluster 150 with a part 110 engaged on that, extends between two plates occupying the same angular position (for example two plates 140a), passing through openings or cutouts 142 formed in the plate (140b) angularly offset and located between these two plates (140a).
• each column extends over a height substantially equal to twice the distance between consecutive plates, which allows to support parts of relatively large length, while optimizing the loading.
• balusters extending between two plates between which are arranged a number n of plates.
• the plates are then distributed into a number of different groups equal to n, the plates of the same group occupying the same particular angular position different from that of the other groups.
• the base and the lower plate 140a carry special columns 151 which make it possible to respectively support the lower plate 140a and the lower plate 140b in desired angular positions.
• the arrangements of the columns 150 (and of the sockets 143) carried by a plate 140a or 140b are different, in particular with respect to the axis of the mast 130, so as to impose the angular position of the plate of the same type situated above.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Furnace Charging Or Discharging (AREA)
• Heat Treatments In General, Especially Conveying And Cooling (AREA)
• Packages (AREA)
• Vending Machines For Individual Products (AREA)
• Drying Of Solid Materials (AREA)
• Heat Treatment Of Articles (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=9514591

Family Applications (1)

Country Status (11)

Cited By (1)

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• 1997
  • 1997-12-15 FR FR9715842A patent/FR2772467B1/fr not_active Expired - Fee Related
• 1998
  • 1998-12-15 KR KR1020007006486A patent/KR100562459B1/ko not_active IP Right Cessation
  • 1998-12-15 EP EP98959989A patent/EP1042517B1/de not_active Expired - Lifetime
  • 1998-12-15 DE DE69810662T patent/DE69810662T2/de not_active Expired - Lifetime
  • 1998-12-15 AT AT98959989T patent/ATE230804T1/de active
  • 1998-12-15 WO PCT/FR1998/002732 patent/WO1999031284A1/fr active IP Right Grant
  • 1998-12-15 JP JP2000539180A patent/JP3977595B2/ja not_active Expired - Fee Related
  • 1998-12-15 ES ES98959989T patent/ES2190124T3/es not_active Expired - Lifetime
  • 1998-12-15 US US09/581,492 patent/US6318571B1/en not_active Expired - Lifetime
  • 1998-12-15 CA CA002315169A patent/CA2315169C/en not_active Expired - Fee Related
  • 1998-12-15 RU RU2000118817/02A patent/RU2220394C2/ru not_active IP Right Cessation

Non-Patent Citations (1)

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