EP0785402B1 - Heat treatment installation for metallic article loads - Google Patents

Abstract

An installation for the heat treatment of a charge of metal components comprises: (a) a first assembly (1) of elements (2 - 7, 9) arranged in an upper line, at least two of these elements being furnaces open at the bottom; (b) some elements (3 - 7, 9) able to move on lateral tracks (27A - 27F) with respect to the longitudinal axis of the upper line, allowing the sliding of these elements of the first assembly from a working position to a transfer position and back, the working position for each moving furnace (3 - 7) incorporating a hoist (30) acting on a stopper on the furnace; (c) a second assembly (11) of elements (12 - 14) of which at least one is a quenching vat, these elements fitted with hoists (34) being able to move on an horizontal track (15) and arranged in a lower position under the transfer position of the first assembly, and allowing, for any number of the elements of the two assemblies, the bringing together of each element of the second assembly (11) with respect to each chosen element of the first assembly (1); and (d) a manipulator (17) for charging and discharging, moving on a vertical track (16) extending the length of the first assembly (1) and allowing the charging and discharging of all the elements of the first assembly (1).

Description

The need for different branches of industry to use more and more frequently produced parts in series goes on increasing and also the use of different heat treatments as well as alloys or other special materials forming said parts. The need has therefore increased the use of facilities allowing perform various heat treatments including several elements, such as ovens or quenching tanks, all allowing easy access to be able, on the one hand, arrange the facilities in a rational manner and, on the other hand, allow the automation of the processes of treatment.

An installation for carrying out treatments thermal loads of metal parts with a rational arrangement of essential elements is defined in the preamble of claim 1 and described in the Patent EP-B-0 296 102 by the same applicant.

Application EP-A-0 533 615 of the same is also known. applicant, describing a facility for treatment thermal of successive charges including a vertical arrangement open downwards, this oven being able to slide in a sliding plane placed at the height of the oven between a position above a rack and a position above from a bin. This patent application only describes an oven arranged above a quench tank. This sliding oven the advantage of being able to push the load from a position under the oven in a position above a tray without the need to hang or unhook the load in the or from the oven.

Market conditions forcing industry, on the one hand, to increase the quality of their products or processes and, on the other hand, to lower prices, an object of the present invention is to provide an installation of heat treatment even more flexible than that indicated first, while maintaining the quality made possible with the second installation cited above. This goal is achieved by the installation described in the independent claim.

La figure 1

est une vue en élévation longitudinale schématique de l'installation selon l'invention,

la figure 2

est une vue en plan de dessus schématique de l'installation de la figure 1,

la figure 3

est une coupe à plus grande échelle selon la ligne III-III de la figure 2,

la figure 4

est une coupe à plus grande échelle selon la ligne IV-IV de la figure 2,

la figure 5

est une coupe en agrandie selon la ligne V-V de la figure 2,

la figure 6

est une coupe à plus grande échelle selon la ligne VI-VI de la figure 2,

la figure 7

est une vue en plan de dessus du manipulateur et

la figure 8

est une vue en plan de dessus du chariot d'une station à laver.

The invention will be explained in detail with reference to the accompanying drawings showing by way of example an embodiment of the object of the invention.

Figure 1

is a schematic longitudinal elevation view of the installation according to the invention,

figure 2

is a schematic top plan view of the installation of FIG. 1,

figure 3

is a section on a larger scale along line III-III of FIG. 2,

figure 4

is a section on a larger scale along line IV-IV of FIG. 2,

figure 5

is an enlarged section along line VV in FIG. 2,

figure 6

is a section on a larger scale along the line VI-VI of FIG. 2,

figure 7

is a top plan view of the manipulator and

figure 8

is a top plan view of the cart of a washing station.

Figures 1 and 2 schematically show a relatively complex installation to be able to demonstrate different applications and handling possibilities for various loads in heat treatment. It is understood and it will appear from this description that FIGS. 1 and 2 only show a few of the many possibilities of an installation according to the invention and that the user is able to modify this installation in a large measure to adapt it to their needs. In other words, thanks to the installation according to the invention, the user can, from a very wide range of combinations and possibilities, choose and define the optimal installation that best meets these needs.

Figures 1 and 2 show, in analogy to an installation according to European patent no. 296 102, a first set 1 on the upper line with a group of ovens 2-7 as well as at one end a washing station 9. This installation was initially planned with an arrangement symmetrical with respect to oven 5, but for reasons of presentation, the second oven similar to oven 2 and the second washing station similar to station 9 have not been represented.

In the example according to FIGS. 1 and 2, the oven 2 is a tempering furnace described in more detail using the figure 5, this oven being movable vertically by through a gallows and training mechanical. Austenitization, case-hardening or carbonitriding are described in more detail in Figure 3.

Ovens 3 and 7 are the same as ovens 4, 5 or 6 with the difference that heating at low temperature is integrated in their heating chamber. The machine washing 9 is explained in more detail in Figures 6 and 8. All the elements of the first set, except the vertically movable oven, can move laterally with respect to the longitudinal axis of the two together, as shown in Figure 2.

The second set 11, see FIG. 3, is arranged on the bottom line and has, in this example execution, three treatment stations, 12, 13 and 14. The station 12 is an oil cooling tank, the station 13 is a salt cooling tank and the station 14 is a water cooling tank. The treatment stations 12, 13 and 14 are arranged on a horizontal track 15 consisting of two rails, so analogous to that described in European patent no. 296 102. The treatment tanks, here cooling, are freely movable on this horizontal track for be able to come next to any oven.

It is obvious that in a given installation, the bins are arranged in such a way that the path traveled by these bins is minimum. That means that in a installation determined and designed for one or more sequences of determined work, it is not necessary that each tray comes next to each oven but of course only next to the oven (s) provided for the treatments considered.

Loads are loaded and unloaded using a manipulator 17 mounted on a longitudinal track 16 consisting of two rails whose plane is perpendicular to that formed by the channels 15. This manipulator, on which we will come back in more detail in support of Figures 3 and 7, can move along the installation to load or unload any element from the first set, after have taken charge to process on storage stations before treatment 18 to file it, after treatment desired, on storage stations after treatment 19. This is indicated symbolically by the arrows M.

Figure 3 shows a section along line III-III of the Figure 2 with, in the upper line, the oven 5 and, in line lower, the tray 13 of the assembly 11 as well as the manipulator 17. The oven 5 is similar to the disclosed oven and described in detail in European patent application no. 533 615, to which explicit reference is made. The oven 5 is a bell oven 20 having in its base a opening 21 limited by a belt 22. Bodies of heater 23, a turbine 24 and a double jacket 25 ensure the uniformity of the speeds of the process gases in charge 40 by forced circulation inside and around the bell 20.

The oven 5 is movable from left to right and from right to left in the plane of the drawing in figure 3, the position from the oven on the right, above tray 13, being indicated by dotted line. The oven stroke is indicated by the arrow CF. For this, it is carried by rollers 26 which run on a side track 27D, and is driven by a rack and pinion reduction motor 10.

In the position of Figure 3, the oven 5 is closed at by means of a plug 28 which is supported by the plate 29 an elevator 30, guided by a bracket 31 and driven by a reduction motor 32 and rack 32A. The order of motor allows the oven 5 to be hermetically sealed. arrangement allows a rapid rise in temperature of the load and has the advantage of ensuring a heat treatment of high precision where the temperature dispersion in the whole load is reduced.

This oven 5 as well as ovens 4 and 6 allow various treatments such as austenitization, case hardening, accelerated carburizing, carbonitriding, nitriding, annealing and income.

By moving the oven 5 to the right in Figure 3, it located above the quenching or cooling tank 13, in this case a salt or water cooling tank. When the oven is moved, the rollers 26 roll on the lateral track 27D formed for example by rails. The drive can be rack and pinion. This quench tank 13 is a container known per se and is rectangular in shape plan, closed by a cover 33 and containing an elevator 34 consisting of a bracket 35, a support arm 36 and of a tray or handling grid 37 (see also Fig. 2). The stem is equipped with a reduction motor and of a rack 38. The cover 33 of the tray is movable using a displacement mechanism 68 comprising a piston acting on a shaped part, see Fig. 2.

Inside the tank, a fluid guide ring 39 delimits a channel which allows a homogeneous flow of the liquid of cooling through charge 40 via a circulator or a stirring pump 41. The cover 33 is provided with an opening through which can pass the tray 37 of the elevator 34.

The manipulator 17, provided for transporting the load 40, is attached to the rear of the installation by moving on the loading track 16 comprising a rail upper support 42 and a lower rail 43 on which roll the rollers 44 of the manipulator. This one can therefore reach each element of the set 1 of the line upper part of the installation as well as stations 18, 19. The manipulator comprises a box 45 enclosing a riser 46 consisting of a bracket 47 fitted with a motor electric reducer and an eccentric 48 acting on a support arm 49.

On the support arm 49 is mounted a transfer plate lateral 50 driven by a reduction and rack motor 51 allowing the load to be moved laterally. The race of this side plate is indicated by an arrow CM. We see in Figure 7 that one end of this plate 50 is in the shape of a semicircle, suitable for receiving a basic grid 52 of a load 40 made up of loose parts in baskets stacked. This arrangement makes it possible to use only one single manipulator for loading and unloading stations 18 at stations 9-2-3-4-5-6-7-8 and 19 (Fig. 2).

The manipulator allows to deposit a load on the surface sliding plane 8 of the plug 28 placed on the plate 29 brought to the intermediate position. This operation of transfer being carried out, it is understood that the manipulator 17 can be evacuated and that the riser 30 can be driven so as to charge load 40 by descent and return and at the same time close the oven with the plug 28. The charge transfer operation after a heat treatment at high temperature and in an atmosphere controlled is analogous to that described in the request for European patent no. 533 615. The elevator 30 of the oven is actuated so as to come into position intermediate between the closed position of the oven visible in Figure 3 and the lower position of loading described previously. In this position intermediate, the plug 28 is extracted from the bell of the oven and its flat upper surface 8 is flush with the upper plane of cover 33 of container 13.

The oven is then moved from left to right, and the base belt 22 of the oven pushes the base rack 52 on the sliding face 8 of the plug 28 and slides this grill until it reaches the cover 33. The oven movement continues until the rack 52 is located on the upper face of the tray 37 of the elevator 34 of the tank which has been brought into a position where this upper surface is also flush with the surface 33. It is therefore sufficient to operate the elevator 34 so as to lower the load in the tank, then load a new charge on the plug 28 by through the manipulator 17 and bring back the oven in its original position and close it with the elevator 30 and the plug 28.

This part of the installation is therefore ready for new treatment cycle. It turns out that these ovens lateral movement does not require any hooking of the load and there are no moving mechanical parts exposed to heat, allowing immersion of the charge in less than 5 seconds, permanently under gas protection. So no air penetration, and by therefore no oxidation is possible.

The cooling tank 13 with the charge after quenching and before drip is moved in front of a washing station, in this case the washing station not shown in the right of Figure 2, for washing after quenching in the salt from tank 13. As will be described later using in Figure 8, the quenched charge is extracted from the liquid by the ferry elevator, then drained and then transferred in the washing station to be evacuated by the manipulator 17 which will deposit the load on the stations storage after treatment 19.

In the installation according to FIGS. 1 and 2, the oven 5 of Figure 3 is similar to oven 4 and 6 while the oven 3 is shown diagrammatically in FIG. 4, this furnace being similar to oven 7. Oven 3 (or 7) differs from oven 5 described above using FIG. 3 with a low temperature heating 53 integrated in the heats 54. Since this oven is at low temperature, the walls 55 are slightly thinner than those of ovens 4, 5 or 6. The other elements of the bell oven as well as the elevator 30 are the same, just like the motor 56 of the rack drive 57 of the oven 3 (7) on the track lateral 27B (27F).

Figure 5 schematically shows another type of oven, know a preheating oven 2. This oven 2 is movable in height via a jib 58 and a mechanical drive 59. In this embodiment, the plug 60 is fixed and when the oven is in the upper position, the load 40 can be deposited on the cap by the manipulator 17 and then the oven goes back down on the load and the heat treatment cycle starts. Cap stationary is equipped with a gas circulation turbine 61. The manipulator 17 is the same as described above. For unload the oven after heat treatment, the oven is brought into its upper position and the load can be discharged by the manipulator.

Figure 6 shows the section along line VI-VI of the figure 2 with in addition the section (in dotted line) of manipulator and one of the cooling tanks described previously using Figure 3. The washing machine 9 includes two water tanks 66 with two water circuits independent 62 and 63, and above a sealed chamber 64 which can be moved up so that the load can be transferred either by means of the manipulator 17, either by means of the carriage 65 moving along a track lateral 27A using a reduction motor 67 and rack. This cart also has a semicircle tray 65A suitable for pushing a circular grid 52 supporting the load (Fig. 7).

After the load has cooled down in the cooling 13, the quenched charge extracted from the liquid by the elevator 34 of the tank is drained. After dripping, the washing station is open in the high position, the industrial truck 65 pushes the load in question the washing station. After the wash cycle, the manipulator 17 picks up the load for a cycle of income, possibly in station 2, or then for be deposited on storage stations after treatment 19.

• pour l'austénitisation-cémentation-carbonitruration sous azote jusqu'à 750° C,
• sous méthanol (+azote) au-dessus de 750° C max. 1'100° C sous gaz ou max. 1'230° C sous gaz,
• carbonitruration avec une adjonction de 3 à 5 % NH₃,
• Dispositif de refroidissement rapide des charges sous atmosphère par une ventilation extérieure au moufle.

To give an example among many other possibilities of handling various loads in heat treatment, we will consider case hardening and quenching. The manipulator 17 takes the load 40 to be treated on the storage stations before treatment 18 and introduces the load into the washing machine 9. After washing, the manipulator unloads the station 9 then goes into the waiting position in front of the work station for the case hardening treatment, namely one of the ovens 4, 5 or 6. These are ovens with the following possibilities:

• for austenitization-carburization-carbonitriding under nitrogen up to 750 ° C,
• under methanol (+ nitrogen) above 750 ° C max. 1'100 ° C under gas or max. 1'230 ° C under gas,
• carbonitriding with an addition of 3 to 5% NH ₃ ,
• Device for rapid cooling of loads in an atmosphere by ventilation outside the muffle.

• un bac à eau
• un bac à huile, max. 100° C
• un bac à huile, max. 200° C
• un bac à sel, max. 600° C
• un bac de refroidissement sous azote, basse ou haute pression
• ou d'autres bacs connus en soi.

If the station is in the process of processing an old load, it is necessary to wait for the end of the treatment and the discharge of the load by quenching in one of the tanks 12, 13 or 14. As described above, these bins can be

• a water tank
• one oil tank, max. 100 ° C
• one oil tank, max. 200 ° C
• salt container, max. 600 ° C
• a cooling tank under nitrogen, low or high pressure
• or other tanks known per se.

With the oven moved backwards, the load by via the manipulator 17 is placed on the plug 28 resting on the elevator 30 then immediately lowered to the low position and the oven returns to the of work. The charge is introduced into the oven for the heat treatment cycle through the elevator 30 of the oven.

At the end of the cycle, the cooling tank 12, 13 or 14, according to the operator's choice, is positioned in front of the furnace in question when moving on the horizontal track 15. A new charge is pending on the manipulator 17.

The operator controls the quenching operation, the oven is partially opened and immediately moved by driving the reduction motor on one of the tracks side 27 C, D or E with the load at temperature and under gaseous atmosphere on elevator 34 of the ferry then immediately immersed in the coolant where forced circulation of the coolant ensures good homogeneity of tempering. Immediately, the manipulator 17 deposits a new load 40 on the plug 60 of oven 2 which is moved to the high position. The oven then returns to the initial position and the new charge is introduced into the furnace and a new cycle of heat treatment restarts.

Then the cooling tank with the load after quenching before drip is moved in front of the station wash 9 or in front of the other wash station. Station 9 is intended for washing after soaking in the oil tank and the other station is intended for washing after quenching in the salt pan. The quenched charge is extracted from the liquid by the tank elevator and drained. After drip, the washing station is open in position high, the handling trolley 65, see Figures 6 and 8, pushes the load in question into the washing station. After the washing cycle, the manipulator 17 picks up the charge washed for a possible income cycle in the oven 2 or the other similar oven or so to be deposited on storage stations after treatment 19.

It appears from the description that this installation allows on the one hand, great flexibility with regard to the various planned treatments and offers the possibility of aligning very different heat treatment ovens, such as austenitization, carburizing, carbonutriation, nitrocarburization or oxynitriding on the one hand and preheats, annealing and tempering on the other hand, as well as various types of cooling tanks, such as tanks oil, water, salt or gas, as well as washing of different designs and this in one installation allowing rational treatment, thanks to concept of aligning the two sets, namely the ovens and the washing stations on an upper line, and other elements such as cooling tanks on a lower line, to provide only one manipulator integral with the installation and capable of loading and unloading each oven and each washing station, and providing ovens that can be moved on a side track, allowing thus avoiding the expensive operation of hooking the load in the oven for more reliable heat treatment and faster. Such an installation allows automation of certain manipulations only, desired by the user, i.e. a partial automation, or full automation.

Claims (4)

1. Installation for the thermal treatment of a batch of metallic pieces, comprising a first set (1) of components (2-7, 9) which are disposed in an upper row, at least two of these components being furnaces (2-7) which are open toward the bottom, and a second set (11) of components (12-14) at least one of which is a hardening vat, these elements provided with elevators (34) being displaceable on a horizontal track (15) and disposed in a lower position under the transfer position of displaceable components (3-7, 9) of the first set, and allowing, for any number of components of the two sets, to bring each component of the second set (11) in front of each selected component of the first set (1), and a displaceable loading/unloading manipulator (17), characterised in that components (3-7, 9) of the first set (1) are displaceable on lateral tracks (27A-27F) with respect to the longitudinal axis of the upper row, thus allowing to slide the components of the first set from a working position to a transfer position and vice-versa, the working positions comprising for each displaceable furnace (3-7) an elevator (30) acting on a plug (28) of the furnace, and in that the loading/unloading manipulator (17) is displaceable on a vertical track (16) extending along the first set (1) and allows to load/unload all components of the first set.
2. Installation according to claim 1, characterised in that the manipulator (17) is guided by an upper supporting rail (42) and comprises rollers (44) running on a lower rail (43), and in that it is provided with an elevator (46) acting upon a supporting arm (49) receiving a lateral displacing plate (50).
3. Installation according to claim 1 or 2, characterised in that the washing station (9) is provided with a tight chamber (64) which is upwardly displaceable and horizontally displaceable by a car (65) running on a lateral track (27A).
4. Installation according to one of claims 1 to 3, characterised in that the elevators (30, 34) and the means for laterally displacing the displaceable components (3-7, 9) are provided with gear motors with toothed racks (32, 32A, 38; 10, 67).

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