DE2163858A1 - Method and device for heat treatment - Google Patents

Description

RIV-SKP Officine di Villar Perosa S.p.A., Turin (Italy)

Method and device for heat treatment

The invention relates to a method for the heat treatment of workpieces, especially of bearing rings, whereby the workpieces are preheated, then quenched, washed and dried and then tempered. In addition, the The subject matter of the invention is a device for carrying out this method.

It is known, for example, to heat-treat rolling bearing rings so that these are first heated in an oven above the austenite point, then be quenched in a separate oil bath, then in a container with v / poor water to which a detergent has been added, washed into a Dry pre-seal introduced and finally in a spatially separate Oven can be read.

The necessary to carry out the heat treatment just described known devices are very bulky due to their length, a fact those with the requirements of modern production plants in which space problems have to be solved to an ever greater extent is incompatible. the space-consuming spatial expansion of the known devices is in particular caused by the ovens, which are tunnel ovens with a large area in horlzon-

Page 2 -

20 9 8 2 9/0636 BAD ORIGINAL

valley direction are formed; however, this also applies to the devices for quenching, which generally consist of a long tank filled with oil or a similar liquid. ·.

Another major disadvantage of the known devices is that the workpieces have to be removed from the ovens or the baths by several complicated transport devices. In addition, the known devices do not meet the requirements of a modern series production, because an inclusion in a flow production is possible only with difficulty. The performance of the known devices is not adapted to the constantly increasing performance of cutting machine tools. The known ψ and initially described devices for the heat treatment in a Flio3fe; actuating .- "having to be able to include this must be provided with several parallel running through to be able to cope with the coming from the machining industry large numbers.

The invention is based on the object of ^{driving a v r} ex * and of creating a device for the heat treatment of workpieces, in particular bearing rings, which meet the technical requirements of modern production. Above all, a heat treatment should be possible within a flow production, so that the device for heat treatment can be inserted in line between the upstream and downstream processing stages. In addition, it should be possible to manufacture such a device for heat treatment at the lowest possible cost, so that many devices, such as flow lines, can be created without great investment outlay.

With the method and the device to be created according to the invention, however, it should also be possible to create an end product whose material properties those As far as possible, exceed those of products manufactured using conventional means. Finally, the hardness of the workpieces should be increased while reducing the hardening time will.

According to the invention, this object is achieved in a method for the heat treatment of

through this
Workpieces, in particular from bearing rings, / solved that the workpieces continuously pass through the heat zone vertically, then continuously in the same cycle

Sheet - 5 -

209 829/0636 _BAD original

be pushed horizontally through the cut-off, washing and drying zone and then run vertically again continuously through the tempering zone.

The advantage of this method according to the invention is that the workpieces no longer treated in batches as with known methods in the individual phases but go through the individual treatment stages almost continuously, so that they are connected to one another by only a few transport devices can be. This is a continuous heat treatment possible in the individual stations without before, ■ between or after these Buffers must be provided.

Furthermore, the stated object is thereby achieved with a device for carrying out this process s'ir heat treatment of workpieces, consisting of a heating furnace, which is followed by means for quenching, washing and drying, a subsequent tempering furnace and means for transporting the workpieces through the device solved in that the heating furnace and the annealing furnace from in each case at least one vertically extending in substantially channel for the continuous passage of the workpieces are made, wherein means are provided that press a medium for heat exchange through the channels opposite the throughput direction of the workpieces.

The advantage of this device is that both the heating furnace and the tempering furnace are arranged vertically, so that a considerable amount of space can be saved eiusr satzweicen feed bckarui ter ovens are required. The circulation of the medium for heat exchange against the direction of flow of the workpieces ensures optimal energy utilization.

According to another feature of the invention, this optimum utilization is still thereby achieved increased that the heating furnace is provided with an inlet opening, open at the top or bottom inner chamber for the passage of the to be heated Workpieces and an outer chamber surrounding the inner chamber, with an intermediate space between the two chambers for circulating the medium for heat

Sheet -

209829/0636 ORIGINAL BATHROOM

Exchange is provided by suitable means, for example a Fan in which the chambers are circulated in countercurrent. The medium for heat exchange is preferably a non-oxidizing gas, especially nitrogen, which first passes through a conduit into the outer chamber and from there into the inner chamber of the heating furnace.

According to a further feature, the invention is characterized in that a or several reciprocating slides or pistons move the workpieces continuously push through the insertion opening into the heating furnace and that the same slide push the heated workpieces out of the heating furnace. In further Embodiment of the invention are the workpieces on the ground in the heat in the oven, advanced vertically towards obexi and again at the upper end pushed out. This makes it possible, in an advantageous manner, to have only one irar / sports facility to have to provide that both pushes the work pieces into the heating furnace and takes over their continuous further transport therein.

According to another feature of the invention, the Vorfichtung is characterized by an input device through which the workpieces reach a table arranged under the floor, a vertical channel connected to the insertion opening, under whose lower opening the workpieces lying on the table move horizontally - and movable slides are pushed, and a vertically reciprocating piston that pushes the workpieces up through the channel into the insertion opening. In this case, the wedge-shaped slide which both ψ for horizontal displacement of the workpieces on the table and z \ sn holding the workpieces contained in the input device is used, be connected via a rod with a ^ nal horizontally displaceable below the K support which in the support phase engages between the legs of the U-shaped piston.

In addition, the device according to the invention is distinguished by an ejection device at the upper end of the heating furnace, which consists of at least one of the heating furnace horizontally continuous guide, each with a slide for ejecting the Each upper work piece consists on a horizontal sliding plane. In a further embodiment of the invention, the means for quenching, washing and drying are

Sheet - 5 -

0 9 8 29/0636 ^BAD ORlGiNAL

one behind the other above the sliding plane connecting the heating furnace to the tempering furnace arranged for receiving the workpieces, and those on the sliding plane Workpieces lying on the ground are pressed cyclically into the inlet opening of the tempering furnace by the slide. The particular advantage of this design is that

that only a single slide is required to remove the workpieces from the Heating furnace, then through the quenching, washing and drying device conveyed and finally pushed into the tempering furnace.

According to other features of the invention, the means for quenching include Work pieces. Sprayer for a corresponding liquid, each made up of two coaxially arranged one inside the other at a distance, in the direction of the workpieces open bushings exist, with spacing in the annular gap between the bushings to both a ring is arranged. If the workpieces to be quenched are ring-shaped, the inside diameter corresponds to the outer sleeve essentially the outer diameter of the annular workpiece and the outer diameter of the inner sleeve is substantially the same as the inner diameter of the annular Workpiece. Thanks to this design of the sprayer, the liquid becomes optimally guided around the ring-shaped workpiece for quenching.

In a further embodiment of the invention, the device is characterized in that that the tempering furnace from one provided with an inlet opening, upwards or a chamber open at the bottom for the passage of the workpieces stacked to form one or more columns, the columns mutually by suitable means and spaced apart with respect to the side walls of the chamber are. The workpieces are preferably fed into the chamber from above introduced, with the pillars on the top with openings for the passage of the medium for heat exchange provided floor of the chamber rest. With such an execution is the medium for heat exchange in an advantageous manner by a Fan or the like pressed from below through the openings into the chamber, sucked off at the top and fed back through a line to the fan or the like. The dwell time of the workpieces in the tempering furnace is thereby advantageously shortened according to a further feature of the invention that in the upper Part of the chamber means for heating the medium for heat exchange, for example electrical resistors are provided.

Sheet - 6 2 0 9 8 2-9 / 0636 ^BAD ORIGINAL

If the tempering furnace is only partially loaded with workpieces, one is good utilization of the amount of heat in the medium for heat exchange is possible, that means for dividing the medium are provided under the base provided with openings.

Finally, according to another feature of the invention, at the lower part of the Tempering furnace a slide can be arranged for ejecting the lowest workpieces in each case from the tempering furnace.

The invention is described below on the basis of an exemplary embodiment of a device for the heat treatment of bearing rings described, which is shown in the drawings ■. These show in:

W j

Figure 1 shows a section through the entire device for heat treatment,

Figure 2 is a partially sectioned view of the upper part of the heating furnace,

FIG. 3 shows a section through the tempering furnace,

Figure h shows a section along the line IV-IV of Figure 3,

Figure 5 shows a cross section along the line V-V of Figure 3 *

FIG. 6 shows a view from below of a sprayer for quenching,

FIG. 7 shows a longitudinal section according to the line VII-VII of FIG. 6,

Figures 8-12 on the basis of sections through the input device and the Inlet opening of the heating furnace different phases of the Transport of the workpieces into the heating furnace,

FIG. 13 is a qualitative diagram to illustrate the hardness in Function of the tempering time at different temperatures.

BAD ORJGfNAL ^sheet " ⁷ ~

2 0 9 8? 9 / Π ß 3 B

The heating furnace 1 shown in FIGS. 1 and 2 is used to harden the workpieces 19 * which, in the exemplary embodiment, are bearing rings for roller bearings. In the chamber 2 of the heating furnace 1 there is arranged a second chamber 3 which ^{is delimited by walls 4 and 5 from} the outer chamber 2. The inner chamber 3 has an opening 6 at its lower end. Between the walls 4 and 5 of the inner chamber 3 and the outer walls 7 and 8 of the chamber 2 there is an intermediate space 9. Suitable heating devices 10, in the embodiment shown electrical resistors, are attached to the outer walls 7 and 8. In the lower area, the walls 4 and 5 of the inner chamber 3 are provided with openings 11 and 12.

A non-oxidizing gas, for example nitrogen, flows out of a gas container 15. Via a connection piece l4 through the line 13 into the space 9 · A In the upper area of the chamber 2 arranged fan 16, which is driven via a shaft 18 by an electric motor 17, pushes the in the space 9 upward flowing gas in the inner chamber 3 downward, so that also in the inner Chamber 3 is a protective gas atmosphere.

The bearing rings 19 to be hardened are stacked one on top of the other in the heating furnace 1 and run through it in the form of several columns 2o arranged next to one another. The bearing rings 19 to be hardened pass through input devices 23, the number of which corresponds to the number of columns 2o, onto a table 24 arranged under the bottom 21 of the heating furnace 1, from which they are worked one after the other through channels into the bottom 21 of the heating furnace 1 Insertion openings 22 are pushed in. After passing through the chamber 3 in the vertical direction upwards (arrow F), the respective uppermost ring 19 of each column 2o, which here has the desired hardening temperature, is ejected by slides 26 running in guides 27. The slide 26 press in the same cycle in which the rings 19 are introduced from below into the heating furnace 1, these through channels 25 on a horizontally extending sliding plane 28. Above the sliding plane 28, which connects the heating furnace with the tempering furnace 69, there are means arranged for quenching, washing and drying the bearing rings 19.

Sheet --8 -

BAD ORIGINAL 209 8-2 9 / (1636

In the following, the device attached under the floor 21 will first be discussed in more detail entered the heating furnace 1 for feeding the workpieces 19. As can be seen from FIGS. 8 to 12, an input device is located above the table 24 23 is provided, in which the workpieces 19 following the chip-lifting Processing to be filled. The input device 23 consists essentially of several cylinders arranged next to one another, the number of which corresponds to the number of columns 2o (see FIG. 2). Between the input device 23 and the table 24 is a space 29 that something is larger than the width of a bearing ring 19. A wedge-shaped slide 3 ° is driven by a hydraulic drive 32 via a rod 31 pushed into the space 29 in cycles.

"As can be seen in Figure 3, the slide holds 3 ° in the input device 23 located bearing rings 19. As soon as the slide 3o moves to the left, a ring 19 slips out of the input device 23 onto the table 24 (FIG lo).

The slide J> o is connected via a further rod 33 to a horizontally directed support 34, which penetrates in the same cycle as the slide 3o into the space 35, which is located between the channel J> 6 and the table 24 and is of the same size is like the gap 29 · As already mentioned, the support 34 works in phase with the slide 3o, so that the support 34 holds the column 2o pushed through the channel 36 into the heating furnace 1 at the moment when the slide 3 ° to the left moves (figure lo).

Below the channel 36, the table 24 has an opening> 3, the diameter of which is slightly larger than the outer diameter of the bearing rings 19. With each upward movement of the piston 37, a bearing ring 19 is pushed into the channel 36. The piston 37 is U-shaped in longitudinal section, so that it can reach around the support 34 with the legs 39 during its upward movements. The piston 37 is driven by a hydraulic 4o via a rod 4l.

BAD ORiGiNAL

'Sheet - 9 -

20 98 29.7 0636

4 ^{; w} ^ \

The operation of the method just described and shown in FIGS. 8 to 12 Device is the following:

j "

As soon as the wedge-shaped slide 3o moves to the left, a bearing ring falls 19 from the input device 23 onto the table 24. During this process, the column 2o is held in the channel 36 by the legs 39 of the piston 37, while the support 34 engages between the legs 39 (Figures 9 and lo). In the next cycle see the piston 37 pulls back down, whereupon the Slide 3o moves back to the right together with the support 34, so that a another bearing ring 19 is pushed under the opening of the channel j? 6 (Figures 11 and 12). As can be seen in FIG. 12, the sliding movements of the wedge-shaped slide 3 ° to the right also the one in the input device 23 located bearing rings 19 held. Then press in the next bar again the piston 37 another bearing ring 19 in the channel 36 (Figure 9)

As already mentioned above, the from the heating furnace 1 are on the sliding plane 28 pushed bearing rings 19 initially quenched. The besti ^ airte for this and in Figure 1 indicated device is shown in Figures 6 i * nd shown in more detail. The bearing rings 19 are quenched one after the other by an oil jet 42 under a sprayer. In Figure 1 it can be seen that the Bearing rings 19 collected dripping oil in a container 44 and from there a pump 45 through lines 46 and an oil cooler 47 back into the sprayer is pressed. Above the sprayer 43 a hood 48 is attached, in the . the oil vapors are collected and sucked off through the can & l 49.

The sprayer 4 consists essentially of two coaxially spaced apart arranged bushings 5 ° and 53 * the down, in the direction of the bearing rings 19 are open. In the annular gap 55 between the inner sleeve 53 wd the outer sleeve 5 ° a ring 56 is arranged at a distance from both, that the Annular gap 55 is divided into two concentric annular gaps 55a and 55b. At several points of the circumference are the two sleeves 50 and 53 and the ring 56 connected to one another by screws 54. The sizes of the two cans 50 and 53 are chosen so that the inner diameter of the outer sleeve 50 is substantially with the outer diameter and the outer diameter of the inner sleeve

Leaf - io -

20 9 8 29/0636

essentially corresponds to the inner diameter de3 underlying bearing ring 19 to be deterred. Through a line 57 the oil is in the chamber 5l ^! sswischen the two bushes 5o and 53, from where it enters the annular gap 55. Here it is divided into two annular, concentric oil jets 42a and 42b, which then deter the bearing ring 19 inside and outside. A tube 58 connects the inner sleeve 5j5 to the outer sleeve 50 and is used to discharge the oil vapors which are formed in the spray zone to the extractor hood 48 and to equalize the pressure between the spray zone and the external pressure.

On. the sliding plane 28, the quenched bearing rings 19 are caused by the movement of the slide 26 pushed under the device for washing. As can be seen in Figure 1, this device consists of sprayers 60, which over a pipe 6l can be fed with running water. The water sprayed over the bearing rings 19 runs into a container 62 and through an outlet 63 into a non further illustrated collection container.

After this treatment, the bearing rings 19 are washed in the next station with warm water at a temperature of about? O ° C. The device required for this purpose consists of a sprayer 64 to which the warm water passes through a line 65. The washing water that drips off the bearing rings 19 runs into a collecting container 66, in which it is heated down to the required temperature by a suitable heater 67. A centrifugal pump 68 conveys the water through line 65 back to the sprayers 64.

Before the bearing rings 19 then move onto the sliding plane 28 in the avalanche furnace 69 are pushed, they are dried under air nozzles 70 »ni! i compressed air.

One embodiment for the tempering furnace 69 is shown in FIG. 1 and in particular in the figures J5 »4 and 5 shown in more detail. The tempering furnace 69 consists of one downwardly open chamber 74, which is at the level of the sliding plane 28 with an insertion opening 72 is provided, through which the bearing rings 19 are pushed into the chamber 74 by the slide 26. The chamber 74 is defined by insulating side walls 73 and 75 and a ceiling 76 and a floor 77 are formed. As in Figure 5 can be seen, the bearing rings 19

Sheet - 11 -

209829/0636 ORIGINAL BATHROOM

formed columns 78 inside the tempering furnace 69 by corrugated support walls and 80 spaced from one another and with respect to the side walls 73 and 75 and supported.

The floor 77 * which supports the columns 78 is provided with openings 88 through which warm air is blown into the chamber Jk. The warm air flows through the chamber Ik from bottom to top and thus opposite to the direction of advance of the bearing rings 19, which pass through the tempering furnace 69 in a cycle from top to bottom. The warm air is circulated by a fan 89, which sucks it out of the upper area of the tempering furnace 69, in which electrical resistors 90 are installed for heating the warm air, via lines 91. In the space 92 under the floor 77 provided with openings 88, a regulating flap 93 is attached, with which the hot air flow can be divided if necessary. The control flap can be operated via a handwheel 9 ^ attached to a shaft 95.

The lower bearing ring 19 of each column 78, the desired at this point Tempering temperature is reached by a slide 83 by a Opening 81 pushed out of tempering furnace 69. Serves to drive the slide 83 a hydraulic device 85 provided with a rod 84. Behind the Opening 81, which can be closed by a flap 82, the bearing rings 19 pass on a slide 86 into a collecting container 87.

With the device according to the invention for heat treatment, a system is created been, which takes up only a small area and in which the Processes aura hardening and tempering take place in the vertical direction. The turn-off and Wasehbchandlunser? are no longer, as with known methods and devices, made by immersing the workpieces in baths, but through Spraying continuously through the stations between the heating furnace and the tempering furnace.

The fact that the workpieces in several columns arranged side by side of the same Are subjected to treatment, there is the possibility of including the device in a flow production, so that several types of workpiece

Sheet - 12 -

09829/0636

with different dimensions, those of upstream stations of the machining Production come, can be subjected to the heat treatment at the same time.

The invention also makes it possible to modify the material properties, and in particular to improve the hardness of the workpieces compared to conventionally heat-treated ones. This is not least due to the fact that the workpieces Only take up a small amount of space in the ovens and are surrounded by a warming medium so that there is only a negligibly small temperature drop in the ducts of the ovens at the various heights. Based on these uniform temperature in the whole tempering furnace, it is possible to produce a desired and to realize very specific hardship. With the uni Hardening fixtures are always a large and disorderly amount next to each other lying workpieces have been heated, so that the outer workpieces due to the heat losses are different from the inner workpieces Have demonstrated hardness.

The larger prairie islon with which, according to the invention, the tempering temperature can hold evenly for all workpieces in the furnace, allowed, to use higher temperatures for tempering than previously usual. This has the advantage that, for the same final hardness, a shorter tempering time at temperature is required so that a greater workpiece throughput can be achieved. It must be noted, however, that a slight deviation from the required Temperature also result in noticeable deviations from the desired final hardness value to have.

At this point, the diagram shown in Figure 15 should be briefly discussed. in which the hardness is plotted on the ordinate and the tempering time is plotted on the abscissa. The curves A, B, C apply to different starting temperatures as a parameter, the tempering temperature being A in conventional methods and devices is less than the tempering temperature C, which with the invention Process in the tempering furnace 69 is realized.

BAD ORIGINAL sheet - 15 -

20982970 636

2183858

From the diagram it can be seen that to achieve a certain Hardness range S at the tempering temperature C a which can be achieved according to the invention

A significantly shorter tempering time R _{2 is} required than in the case of a lower tempering temperature A realized in conventional systems, at which the tempering period R is much longer.

i '

209829/0636

Claims (19)

Claims 1. Process for the heat treatment of workpieces, in particular bearings, 'whereby the workpieces are heated, then quenched, washed and dried and are finally tempered, characterized in that the workpieces (19) continuously pass through the heating zone vertically, then be pushed continuously horizontally through the quenching, washing and drying zone in the same cycle and then again continuously vertically the start-up zone is running. 2. Apparatus for performing the method according to claim 1, consisting of a heating furnace followed by means for quenching, washing and drying, a subsequent tempering furnace and means for transporting the workpieces through the device, characterized in that the heating furnace (l) and the tempering furnace (69) each consisting of at least one substantially vertical running channel for the continuous passage of the workpiece (l?) exist, wherein means are provided that a medium for heat exchange Push through the channels against the flow direction of the workpieces (19). , J. Apparatus according to claim 2, characterized in that the heating furnace (1) consists of an inner chamber (3) which is provided with an insertion opening (22) and is open at the top or bottom for the rotation of the workpieces (19) to be heated and an inner chamber (3) surrounding outer chamber (P.) , with an intermediate space (9) being provided between the two chambers (2, 3) for storing the medium for heat exchange, which is provided by suitable means, for example a fan (16) , is circulated in the chambers (2, 3) in countercurrent. 4. Apparatus according to claim 3 * characterized in that the medium for .Wärmexausch * for example a non-oxidizing gas, especially nitrogen, passes through a line (13) first into the outer chamber (2) and from there into the inner chamber (3). BAD sheet - 2 - 209329/0638 -,; A "216385a 5. Apparatus according to claim 3 or 4, characterized in that one or several reciprocating slides (Jo) or pistons (37) the work • pieces (l9) continuously to the insertion opening (22) and through this into the Slide the heating furnace (1) and that the same slide (26) lifts the heated workpieces Slide (19) out of the heating furnace (l). 6. Device according to one of claims 3 to 5 »characterized in that the workpieces (19) on the bottom (21) are pushed into the heating furnace (l), In it move vertically upwards in time and are pushed out again at the upper end. 7. Vorrichtiing according to one of claims f> or 6, characterized by an input device (23) t through which the workpieces (19) reach a table (24) arranged under the floor (21), one connected to the insertion opening (22) , vertical channel (36), under the lower opening of which the workpieces (19) lying on the table (24) are pushed by the horizontally reciprocating slide (3 °), and a vertically reciprocating piston (37) which pushes the workpieces (19) upwards through the channel (36) into the insertion opening (22). 8. The device according to claim J, characterized in that the wedge-shaped slide (30), which is used both for the horizontal displacement of the workpieces (19) on the table (24) and for holding the workpieces (19) located in the input device (23) ) serves, via a rod (33) '■' ■ it is connected to a support (34) which can be moved horizontally under the channel (36) and which engages between the legs (39) as a U-shaped piston (37) during the support phase » 9. Device according to one of claims 5 to 8, characterized by an ejector device at the upper end of the heating furnace (l), consisting of at least one guide (27) running horizontally through the heating furnace (l), each with one Slide (26) for ejecting the respective upper workpieces (19) onto a horizontal one Slip plane (28). . BAD ORlQiHAL sheet - 3 - -2 O 9 8 2 9; /; 0 β 3 β 10. Device according to one of claims 2 to 9, characterized in that the means for quenching, washing and drying one behind the other above the sliding plane (28) connecting the heating furnace (l) to the tempering furnace (69) for receiving the workpieces (19) are arranged, the means for ^: frightening and washing sprayers (43, βο, 64) for the corresponding liquids and the means for drying contain air nozzles (7o). 11. The device according to claim lo, characterized in that the sprayer (4j5) for quenching consists of two at a distance coaxially arranged one inside the other, downwardly open bushings (50, 53), with in the annular gap (55) between the bushings (5o, 53) a ring (56) is arranged at a distance from both of them. 12. Device for quenching ring-shaped workpieces according to claim 11, characterized in that characterized in that the inner diameter of the outer sleeve (50) is substantially the outer diameter of the annular workpiece (19) and the outer diameter of the inner sleeve (53) essentially the inner diameter of the ring-shaped workpiece (19) corresponds to 13. Device according to one of claims 2 bLs 12, characterized in that the starting furnace (69) consists of a chamber (74), which is provided with an inlet opening (72) and is open at the top or bottom, for the passage of the to one or more Columns (78) of stacked workpieces (19), the columns (78) by suitable means (79 »80) mutually and in relation to the side walls (73 * 75) of the chamber (74) are arranged at a distance from one another. 14. The device according to claim 13, characterized in that the workpieces (19) are introduced from above into the chamber (74), the columns (78) being provided on the with openings (88) for the passage of the medium for heat exchange The bottom (77) of the chamber (74) rest. 15 · Device according to claim 13 or 14, characterized in that the medium for heat exchange through a fan (89) or the like from below pushed through the openings (88) into the chamber (74), sucked out of this at the top and through a line (91) to the fan (89) or the like again is fed. Sheet - 4 - 20-9 8 2.9 / 0636 16. Device according to one of claims 13 to 15 »characterized in that that in the upper part of the chamber (89) means for heating the medium for heat exchange, for example electrical resistors (9o), are provided are. 17. Apparatus according to claim 15 or l6, characterized in that below the bottom (77) provided with openings (88) means (93) for dividing the Med3-uras for heat exchange are provided. 18. Device according to one of claims 9 to 17 *, characterized in that the workpieces (19) lying on the sliding plane (28) are pressed into the inlet opening (72) of the tempering furnace (69) by the slide (26) will. 19. Device according to one of claims 13 to l8, characterized in that a slide (83) is arranged on the lower part of the tempering furnace (69) for ejecting the lowest workpieces (19) from the annealing furnace (69). 209829/0636 A? Blank page