DE69815108T2 - Heat treatment plant for a batch of metallic workpieces - Google Patents

Abstract

Installation for thermal treatment of metallic parts comprises: a first assembly with at least one furnace, and a second assembly with at least one jig; one of the two assemblies is attached to a fixed structure (12) and the other assembly is connected to a moving structure (13) relatively to the fixed structure; couplings (16,17,18) are arranged between the two assemblies for placing one jig (6,7) facing one furnace while avoiding oxidation of the metallic part surface.

Description

The present invention relates to a plant for thermal treatment of a batch of Metal pieces, the plant has at least one furnace under inert gas or under Vacuum and at least one Abschreckbad according to the preamble of the claim 1 has.

The ones available on the market known systems have the disadvantage that the system for vacuum treatments a batch of pieces of metal cold be loaded and then put under vacuum, to evacuate the oxygen from the heating chamber of the furnace. After The treatment must include the entire contents of the oven including the batch chilled become. An operation with a hot stove is without a lock chamber and loading container not possible, as even small amounts of oxygen would damage the heating elements.

A plant for heat treatments is known from EP-A-806 485 known. This application discloses a system with a lock and seals for one dense transfer of the batch from the oven to a container or vice versa. Besides being a lock chamber required is, in this plant, neither the surface oxidation of the pieces of Charge still the pollution and cooling of the furnace throughout Duty cycle avoided.

EP-A-893 510, which is not for The prior art, the date of the application, discloses a system for automatic heat treatments with seals. However, the two units of this plant stationary, and thus it is not possible, any container over one To arrange oven. Moreover, in this construction, the tightness the ovens and the container during the Duty cycle not guaranteed.

Based on this known state of Technology is an object of the present invention is a plant for heat treatments to create, in which the oven does not need to be cooled, and which while the entire work cycle the treatment and the transfer of the pieces without Oxidation and without contamination of the treatment gases in the oven or without impairment the vacuum allowed in the oven.

There are also furnaces or Pusher for long Batches are known, their installation a very large area and especially a great length requires, and which also long working cycles for loading and Have unload the furnace.

Based on this known state of Technique is a further object of the present invention, both the length to shorten such a plant as well as their treatment time.

These goals are set by those in the independent claim 1 described means achieved.

The invention will now be described with reference to attached Drawings of exemplary embodiments thereof explained in more detail.

1 shows a schematic side view of an embodiment of the inventive system,

2 shows a schematic view of the system according to 1 from above,

3A - 3L show a working cycle of the plant according to 1 .

4 shows a schematic view of a second embodiment according to the invention,

5 shows a schematic view of the system according to 4 from above,

6A - 6K show schematically a duty cycle of the system according to 4 and 5 .

7 shows a schematic view of a third embodiment of the inventive system,

8A - 8L show schematically a duty cycle of the system according to 7 .

9 shows a schematic view of another inventive system,

10A - 10L show schematically a duty cycle of the system according to 10 .

11 shows a schematic view of another inventive system,

12A - 12P show schematically a duty cycle of the system according to 11 .

13 shows a schematic view of a plant with a furnace and four containers,

14 shows a schematic view of the system according to 13 from above,

15 shows a transverse view of a linear system according to the invention,

16 shows a schematic longitudinal view of the system according to 15 .

17 shows a view of the system according to 15 from above,

18 shows a schematic longitudinal view of a system with Durchstossofen for long batches,

19 shows a schematic end view of a furnace of the system according to 18 .

20 shows an end view of a container according to the installation 18 .

21 shows a schematic view of the system according to 18 from above, and

22 shows an excerpt from 21 ,

1 and 2 schematically show a first embodiment of an inventive system with a treatment furnace for a maximum temperature of 1100 ° C and two mounted on a rotatable table containers. For example, this facility allows austenitizing, annealing, annealing, sintering and brazing treatments. The oven 1 has a heating chamber 2 with atmospheric circulation turbine 3 , a locking pin 4 as a carrier of the batch to be treated 5 and two containers, ie two feed or Abkühlkammern 6 and 7 , The plug which carries the charge is through the two reciprocating pistons 8th and 9 vertically displaceable, as indicated by the two double arrows. The reciprocating pistons serve to load or remove batches in the oven or in the containers, as will be apparent from the description of a duty cycle of the plant. The oven also has a heating element 10 and an insulated coat 11 according to known technology.

The oven 1 is on an upper table 12 fastened while the containers, ie the feed or Abkühlkammern 6 and 7 with the reciprocating pistons 8th and 9 , on a rotatable table 13 are attached. The solid table 12 is on a rack 14 assembled. The rotatable table 13 is from a motor 15 driven. Between the fixed and the rotatable table two sets of seals are arranged, namely an outer seal 16 , which produces the seal against gas and negative pressure, as well as two inner seals 17 and 18 which form a first sealing barrier between the containers and the upper, fixed table. All seals are inflatable seals known per se in the art, which are partially deflated when the rotatable table is rotated, and then inflated to seal.

The loading and unloading chambers 6 and 7 each have an atmospheric circulation turbine 19 and 20 and a common vacuum pump 21 on which via slider 22 and 23 with the mentioned charging or cooling chambers 6 and 7 connected is. The containers 6 and 7 each have a nitrogen supply line 25 on, and the furnace has a gas supply line 26 on.

The upper table has a door 27 with a seal 28 for introducing the batch into one of the containers. A filling, for example, with nitrogen or another gas allows the transfer of the charge to be treated in the oven under inert gas or vacuum. The oven, always kept at temperature, allows one of the above mentioned treatments to be carried out. At the end of the heating cycle, the batch is removed for cooling in one of the two chambers. Before the rotation for transfer and cooling, a new batch to be treated has been prepared in the empty container. In this way, an alternate treatment of pieces without surface oxidation and without cooling of the furnace and without affecting the treatment gases or the vacuum in the oven is possible.

Of course, also a plant possible, in which the containers, d. H. the charging and cooling chambers (with gas or oil) attached to the frame and the upper table and a rotatable oven or several rotatable ovens are provided.

The 3A to 3L show schematically a duty cycle. 3A shows the preparation of the batch 5 , and it can be seen that the door 27 is open. B shows the conditioning of the batch by means of vacuum, and C Lowering the left-hand plug 4 to open the oven. D shows the rotation of the container, the batch 5 is placed under the oven before being placed in it ( e ) and the treatment cycle begins. F shows the preparation of a second batch 5A during the treatment of the first, and G the conditioning of this batch 5A by means of vacuum. H shows the opening of the oven and the lowering of the batch 5 , and I the rotation of the containers with immediate cooling of the batch 5 , K shows the introduction of the batch 5A in the oven to carry out the treatment cycle during the cooling of the batch 5 , L finally shows the batch 5A during the treatment cycle and the removal of the batch 5 as well as the placement of a new batch 5B ,

The cycle of operations shows the great advantage of the plant according to the invention, which on the one hand allows the preparation of one batch while the other is in the oven, but above all the charging and removal of the batch from the oven without affecting the vacuum or the gas in the oven and without oxidation of the batches. All operations described are carried out under sealing against the outside through the outer seal 16 and the inner seals 17 and 18 ,

The 4 and 5 show a second embodiment of the inventive system with a furnace and three containers. The oven 29 is similar to the oven 1 of the preceding example with the same parts, ie the heating chamber, the turbine and the plug 4 who carries the batch. Also the system with the upper fixed table 12 and the frame 14 is the same as in the previous example, while the rotatable table 30 is designed for three containers and three inner gasket sets 31 . 32 and 33 having. The outer seal 16 is similar to the embodiment described above, and also the door 27 with the associated seal 28 ,

The first container is a feed chamber 34 similar to the chamber 6 , the second container a cooling chamber under gas 35 and the third container a cooling chamber with a liquid 36 , for example, oil 37. The charging chamber and the gas cooling chamber have turbines 38 and 39 while the oil cooling chamber is an oil pump 40 for the oil circulation. This system also has a vacuum pump with sliders for evacuation of the feed and oil cooling chamber and gas supply lines for the chambers and the oven. Each chamber also has a reciprocating piston 41 respectively. 42 respectively. 43 ,

An exemplary working cycle of this plant is based on the 6A to 6K described. 6A shows the preparation of the batch 5 under the charging chamber 34 with open door 27 , 6B shows the conditioning of the batch, even currently by means of vacuum, with the door closed 27 , and C shows the situation after the rotation of the chambers by 120 °, at which the batch 5 placed under the oven. According to D the batch is placed in the oven and the treatment cycle in the oven begins. According to e After the heat treatment, the locking pins are brought to the height of the rotatable table in order to create an in F execute shown rotation. During this rotation, the batch slides on the table and then the oil chamber is under the batch or under the oven. G shows the lowering of the batch and the immediate cooling of the same in the oil. In H is the preparation of the second batch 5A which is possibly pre-treated with vacuum, and the cooling of the first batch 5 in the oil. I shows a re-rotation of the chamber in which the second batch 5A is brought under the oven to introduce them into the same. 6K finally shows the situation in which the treatment cycle of the second batch 5A is completed while the first batch 5 is taken to the situation of 6E to return.

7 shows a third embodiment of an inventive system with a vacuum hot wall oven 44 with graphite heating 45 , an isolation 46 , a circulation turbine 3 for low treatment temperatures and the plug 49 . 49A which the batch 5 wear. The system with the fixed upper table 12 with door 27 and seal 28 by the engine 15 powered rotatable table 13 and the two seal units with external seal 16 and inner seals 17 and 18 is the same as before. The containers suspended from the rotatable table are two loading and unloading chambers 47 and 48 with built-in cooling, including the two turbines 19 and 20 the first embodiment.

The 8A to 8L illustrate an exemplary duty cycle of the system according to 7 , 8A shows the preparation of the batch 5 with the door open, and 8B shows the conditioning of the batch by means of vacuum. C shows the lowering of the plug 49 and the opening of the oven with subsequent rotation of the chambers according to D for positioning the batch 5 under the oven. e shows the introduction of the batch into the oven, which starts the treatment cycle. At the same time according to F the second batch 5A prepared and according to G pretreated with vacuum. H shows the opening of the furnace and the lowering of the first batch with subsequent rotation of the chambers and immediate cooling of the first batch in the cooling chamber 47 ( I ), whereupon the second batch according to K is introduced into the furnace to carry out the treatment cycle while the first batch is still being cooled. 8L shows the removal of the first batch during the treatment of the second batch and the placement of the third batch 5B on the plug for subsequent conditioning and treatment.

The same treatment cycle can be applied to a system in which it is in accordance with a Variant is a cold wall furnace with Graphitisolation.

9 shows a variant of the system according to 7 where the oven 50 is similar to the previous, but in addition four mechanical stops 51 with associated operation, which is the batch 5A hold or release, as is clear from the description of 10A to 10L will emerge. The fixed upper table 12 is similar to the previous case, with the door 27 and their seals 28 as well as the frame 14 of the table. Between the fixed table 12 and the rotatable table 13 the same sealing system is arranged as described above, and the rotatable table is from the engine 15 driven. At the rotatable table are at least one oil chamber 53 with associated pump system 40 and at least one gas cooling tank 54 with turbine 20 suspended.

The container 54 is a pressure chamber, and therefore here is a lifter instead of provided for the other containers reciprocating 55 with batch carrier 56 used with a carrying pillar 57 is connected, whose spindle 58 over a chain by a motor 59 is driven to move the lift up and down. The entire lifting device is arranged within the pressure chamber. At the top is the pressure chamber with a lower door 60 closed, which with seals 61 is sealed. The loading and the removal of the pieces can be done by this pressure chamber, or the plant has except the pressure chamber and the oil chamber a feed chamber of the type described in the preceding examples.

The 10A to 10L show schematically a possible treatment cycle of the system according to 9 , 10A shows the preparation of the batch 5 , also here with the door open, and 10B the conditioning by vacuum, with the door closed 27 , with subsequent rotation of the chambers to bring the batch under the oven ( 10C ). Thereafter, the batch is according to D placed in the oven and the treatment cycle begins, and at the end of the cycle the batch becomes e lowered, and the hooks 51 are closed to hold them while the plug through the lifter 55 is lowered. Thereafter, the chambers are rotated in accordance with F to bring the oil chamber under the oven, and according to G, the batch carrier is raised and the hooks are opened. The batch on the batch carrier is lowered and submerged in the oil for immediate cooling ( H ), wherein the cooling is intensified by a forced circulation channel. According to I will be the second batch 5A prepared and pretreated with vacuum, then according to K rotated and placed under the oven for a treatment cycle according to L while the first batch is taken after dripping and a new cycle is made according to the situation D follows.

11 shows a further embodiment of a system according to the invention with an oven 62 similar to the oven 29 according to 4 , but in addition two slide halves 63 . 63A which form the closure pin and of mechanical elements 64 be operated. The whole thing is on the firm upper table 12 attached, which is formed similar to the previous versions and the frame 14 is appropriate. Below the fixed table is a rotatable table of a similar kind as in the previous embodiments, with the same outer and inner sealing system. The containers, ie the oil chamber and the cooling chamber (s), are the same as in the embodiment according to 4 ,

The 12A to 12P show a working cycle of the plant according to 11 and explain the function of the two slider halves 63 . 63A , 12A shows the preparation of the batch 5 , Figure B whose vacuum conditioning, and C shows the rotation of the chambers to bring the batch under the oven. Thereafter, according to D, the slide halves are moved to open the oven before the charge is introduced into it and the slide halves are a little closed, as is out e evident. In F is the batch carrier 56 lowered to the batch on the plug 63 . 63A store. In G the oven is closed and the treatment cycle begins. Meanwhile, the chambers are rotated and the oil containers are placed under the oven, and at the same time I becomes the second batch 5A prepared and conditioned by vacuum. According to K a pre-opening of the closure pin, ie the slide halves, and the batch carrier is raised. According to L the oven is completely opened, and in M The batch is immersed in the oil chamber with forced circulation channel and immediately cooled. Subsequently, the chambers are according to N shot again, and the second batch 5A is under the stove. In O will be the batch 5A placed in the oven and the treatment cycle in the oven according to C to G starts while the first batch 5 is removed after draining. According to P Finally, the chambers are rotated to bring the oil container under the oven while a new batch 5B is prepared, which according to the cycle 12A ff. goes through.

In this embodiment, it should be noted that the closure pin in the form of two slide halves 63 and 63A not vertically shifted as in the first versions, but horizontally pushed or pulled.

The 13 and 14 schematically show an embodiment variant, which has, for example, a furnace and four suspended on the rotatable table container. The furnace may be designed in the manner of one of the ovens described above, while two containers are provided for charging and removal and two for cooling by means of gas or by means of a liquid, for example oil. All combinations are possible, ie, in principle, neither the number and type of ovens nor the number and type of containers is limited in a system according to the invention.

In the in the 1 to 14 disclosed embodiments are plants with a fixed table and a rotatable table with seals. Preferably, the oven or ovens are arranged on the fixed table and the suspended container connected to the rotatable table. However, it is also a reverse arrangement possible, in which the furnace or ovens arranged on the rotatable table and the containers are suspended from a fixed table. In all these solutions or arrangements, the tightness between the fixed and the rotatable table is made by an inflatable outer seal and by a number depending on the number of containers different number of inflatable inner seals, whereby a perfect tightness is ensured, which is a treatment of pieces on the one hand without Surface oxidation and without affecting the treatment gases or the vacuum in the oven and on the other hand allowed without cooling the furnace during work.

In principle, the displacement of the furnace (s) relative to the container (s) with complete tightness does not necessarily have to be by rotation and is not limited to a rotatable table but can also be transferred to a linear displacement system. The 15 to 21 show two embodiments of ovens and containers with linear mutual displacement.

The 15 to 17 show a first embodiment of such a linearly displaceable plant with a furnace and two containers. The oven is the same as the oven 1 the execution according to 1 , with the same parts as heating chamber, turbine and plug, and is on an upper table 65 fixed on a rack 66 rests. Analogous to the rotatable version is under the upper table a sliding table 67 arranged, the two formed as a loading or Abkühlkammern container 68 and 69 carries, each with a reciprocating piston 8th and 9 and equipped with gas supply lines and connected to a vacuum pump for evacuating the chambers. To seal are an outer seal 70 and two inner seals 71 and 72 provided, which are inflatable as the aforementioned seals.

The operation of this system corresponds those of rotary type installations, and when working with a linear type installation, the same working cycles can be used as in a rotary type installation, where only the term "rotation" needs to be replaced by "linear displacement". Of course, instead of in the 15 to 17 The plant described also applies analogously to the plants described in the preceding examples.

How 16 shows, the linear solution requires two tight loading doors 73 and 74 ,

The 18 to 21 show a system with a piercing furnace for long batches. The batch may for example consist of 6 m long pipes which are to be annealed under vacuum or under atmosphere. Of course, here offers a smaller overall length of such a system in which the furnace must have the same length, a significant advantage.

The piercing furnace 75 for long batches is known per se and has a dense channel or a dense furnace housing 76 and an atmospheric circulation turbine 78 as well as a heating chamber 77 and a gas supply line 79 , where all parts in a shell 80 are arranged. The two loading / unloading chambers 81 . 82 are each with a cooling 83 and a gas circulation turbine 84 equipped. The system also has a fixed circuit board connected to the oven 85 with two loading and unloading doors 86 for baskets or other objects, such as pipes. These doors are provided with gaskets. The loading and unloading chambers are connected to a movable board mounted on a rail. The seal is made via a seal 88 around the feed chambers, which are as before inflatable seals. The charging or removal chambers each have a drive system 89 for the introduction and removal of the batch 90 in the cooling channel and in the oven. In addition, a vacuum pump allows the pumping of the gases or the oxygen from the chamber in the Ladebzw. Unloading. In this way, even the smallest oxidation or contamination of the atmosphere are excluded.

The arrangement of the system components permitted the shortening the space requirement of the system by one or two batch lengths, and Above all, the feed chamber is during the cooling of the batch not blocked. This is when comparing the inventive system with previously known and sold by different companies plants clear seen.

Claims (14)

A plant for the thermal treatment of a batch of pieces of metal comprising a first unit with at least one furnace and a second unit with at least one container, one unit being displaceable relative to the other, and at least one seal arranged between the two units, one Unit on a fixed structure ( 12 ; 65 . 85 ) and the other unit on a structure which can be displaced with respect to the stationary structure ( 13 . 30 ; 67 . 87 ), the structure comprising at least one container ( 6 . 7 ; 34 . 35 . 36 ; 47 . 48 ; 68 . 69 ; 81 . 82 ) at the location of each container with an inner seal extending around the container ( 17 . 18 ; 31 . 32 . 33 ; 71 . 72 ; 88A . 88B ) and between the two structures near the periphery of the structures a continuous outer seal ( 16 . 70 . 88C ), the outer and inner seals the optional placement of one of the containers ( 6 . 7 ; 34 . 35 . 36 ; 47 . 48 ; 68 . 69 ; 81 . 82 ) opposite one of the ovens ( 17 . 18 ; 31 . 32 . 33 ; 70 . 71 . 72 ; 75 ) and at the same time ensuring a double seal and the surface oxidation of the pieces of the batch ( 5 . 5A . 5B ), Impurities and cooling of the furnace during the working cycle. Plant according to claim 1, characterized in that the respective inner seal extending around the containers ( 17 . 18 ; 31 . 32 . 33 ; 71 . 72 ; 88A . 88B ) and / or the outer seal ( 16 . 70 . 88C ) is inflatable or are. Installation according to claim 1 or 2, characterized in that the furnace or ovens ( 17 . 18 ; 31 . 32 . 33 ; 70 . 71 . 72 ; 88 ) on the stationary structure and the containers ( 6 . 7 ; 34 . 35 . 36 ; 47 . 48 ; 68 . 69 ; 81 . 82 ) are attached to the displaceable structure. Installation according to claim 3, characterized in that the stationary structure is a table ( 12 ), the furnace or ovens ( 1 . 29 . 44 . 50 ) and on a frame ( 14 ) and that the movable structure is a rotatable table ( 13 ), the containers ( 6 . 7 ; 34 . 35 . 36 ; 47 . 48 ) wearing. Plant according to claim 3, characterized in that the stationary structure is a fixed table ( 65 ), the furnace or ovens ( 17 . 18 ; 31 . 32 . 33 ; 70 . 71 . 72 ; 88 ) and that the displaceable structure is a linearly displaceable table ( 67 ), the containers ( 68 . 69 ) wearing. Plant according to claim 4, characterized in that the fixed table ( 12 ) a door ( 27 ) with a seal ( 28 ) for loading / unloading the batch ( 5 . 5A . 5B ) having. Plant according to claim 4 or 6, characterized in that the containers ( 6 . 7 ; 34 . 35 . 36 ; 47 . 48 ) on the rotatable table ( 13 ) are suspended, and that the containers each have a reciprocating piston ( 8th . 9 ; 41 . 42 . 43 ) for moving the batch ( 5 . 5A . 5B ), wherein the closure pin ( 4 . 4A ) of the oven forms the batch carrier. Plant according to one of claims 1 to 4 or 6, characterized in that at least one container a cooling liquid ( 53 ) and that another container is a pressure vessel ( 54 ), which is a lifter ( 55 ) with batch carrier ( 56 ) and a tight lower door ( 64 ) having. Installation according to claim 8, characterized in that the furnace ( 50 ) mechanical stops ( 51 ), which the batch ( 5 ) during rotation of the rotatable table ( 13 ) hold tight. Installation according to one of claims 1 to 4, 6 or 7, characterized in that the furnace ( 1 . 29 . 44 ) a closure pin consisting of two slide halves ( 63 . 63A ), which perform a horizontal movement. Installation according to one of claims 1 to 4 and 6 to 10, characterized in that the second unit at least one loading and unloading container ( 6 ; 34 ; 47 . 48 ), a cooling unit under gas ( 35 . 54 ) and a cooling unit with liquid ( 36 . 53 ) having. Installation according to claim 5, characterized in that the furnace or ovens ( 64 ) is mounted on an upper table, and that the containers ( 68 . 69 ) on a sliding table ( 67 ) are hung, the upper table on both sides of the oven a door ( 73 . 74 ) having. Installation according to claim 5, characterized in that the furnace is a piercing furnace ( 75 ) for long batches and a circuit board ( 85 ) having two loading or unloading doors, and that two loading or unloading chambers ( 81 . 82 ) are fastened to a movable board mounted on a rail, the chambers each having a seal ( 88 ) respectively. Plant according to claim 13, characterized in that the chambers ( 81 . 82 ) each a drive system ( 89 ) for the batch ( 90 ) respectively.