DE1758629A1 - Heat treatment process and apparatus - Google Patents

Description

Patent application ALCO STANDARD CORPORATION, 1 Indian Lane, Valley Forge, Pennsylvania, U.S.A. Heat treatment process and apparatus

The invention relates to the treatment of workpieces under given conditions by first placing the workpieces in a carefully controlled atmosphere in a furnace chamber heated to high temperatures and then cooled in a quenching chamber are «In particular, the invention relates to the treatment of workpieces under given conditions, which by a loading canal can be inserted into the oven and then from the furnace kettle into the quenching chamber through the same Loading kamner are forwarded.

According to the main object of the invention is a uniform Heating the workpieces by moving them back and forth over a limited area in the furnace scanner, in order to prevent the radiating from heating elements in the chamber intense heat is constantly concentrated on the same particular surfaces of the workpieces and overheated areas varuiööchto The invention is characterized in this regard through a new device that not only removes the workpiece "in d <* v Offcükalütter moved back and forth, but ulo also In dl ο u4 auu the Oifenkananer directs.

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The invention is also based on the principle that the given state of the atmosphere in the furnace chamber both during the introduction of the workpieces in the furnace and when forwarding the Workpieces are received from the furnace chamber into the cutting chamber That is to say, the invention has, in sum, a contamination of the furnace name ar both with vapors from the chamber as well as also with oxygen from the immediate Qagebung see pages prevent su, during which the furnace must be open to allow the insertion and forwarding of the workpieces su. Su The invention sees the treatment of the workpieces at this point under given conditions at Veng a veeserten device by a new method, in which the Furnace chamber during the introduction of the workpiece · into the Besohickungalr wmmer remains tightly closed, the Beechlekungs-Irammitr is cleaned with a non-oxidizing gas in order to prevent impurities from penetrating into the oven chamber when the workpiece is inserted into the oven chamber, the heated workpieces are returned to the furnace while it is still in the cleaned state and the furnace chamber is tightly closed again, before the workpieces from the Beschlokungslr smir to the Abschreckkammar be forwarded in order to prevent steam escaping from the Abaohreddcanmer when forwarding in penetrate the furnace chamber

An example of the invention is shown in the figures shown and described below!

Flg. 1 is a fractional basic rlA of a device sur treatment under given conditions which embodies the features of the invention.

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Fig. 2 is a similar view to Pig. 1 and seigt

schematically the device for treatment under given conditions.

Fig. 3 is an enlarged, fragmentary cross-section taken substantially on line 3-3 of Fig. I.

FIG ₀ 4 is an enlarged, fragmentary sectional view taken substantially on line 4-4 of FIG · I.

Fig. 5 is a substantially bridge-like cross-section on line 5-5 of Fig. 3

Fig. 6 is an enlarged, bruohatelike cross-section substantially on line 6-6 of FIG. 3.

FIG _o 7 is an elevational view schematically showing the reciprocating workpieces "

Figure 8 is an _o bruohstuckartige perspective view of the reciprocating and relaying device, and

Fig. 9 is a schematic view and includes Circuit diagram.

As shown in the figures for purposes of illustration the invention is in a device for heat treatment under given conditions of metallic workpieces

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embodied that are carried in baskets Io that gradually given by a multitude of connoisseurs sur treatment under Conditions are moved on. In which the successive » the steps la wax treatment process are carried out, to improve the physical properties of the metal of the workpieces. In this case the device contains one Oven 11 for preheating the cold workpieces, one with a larger one Heat working furnace 13 sun heating the work pieces to a high temperature in a chosen nature of the atmosphere, and a quench duct 14 which was used to cool the heated workpieces in a water or oil bath. Each basket of workpieces is loaded after initial heating in the preheating furnace 11 on a trolley 15 and on a rail 16 for Forwarding transported to the high-temperature furnace 13

The high-temperature furnace 13 contains an airtight container or jacket 17 which surrounds an inner lining which defines a heating chamber 20 (FIG. 3) and which is formed by insulated upper, lower and side walls made of heat-resistant material. One of the side walls has an opening which defines a passage 21 for the inlet of each basket into the chamber · Two of the other rare walls are encompassed by a frame (Flg _e 3 and 8) which serves to support the basket and in this case a plurality of side by side lying ceramic rollers 23, which are each rotatably mounted about a horizontal axis by means of bearing pins 23a, which are mounted in the two side walls and extend upward through them. The workpieces are heated to high temperatures while the basket is being carried on the frame rollers by means of radiant heaters that can be optionally activated, for example electrical heating pipes 24 iFig «, 3) that are horizontal

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through the Kanaer 2o above the rollers run »Oi a Prevent the workpieces from oxidizing when they are heated a Vakuunpunpvorrlchtung associated with the container 17 and indicated generally at 25 in Fig. 1, the Atmosphere in the container and the chamber 2o before the workpieces are heated to maximum temperature.

After the workpieces have been heated, the basket Io is turned off the Ofonkammer 2o passed through the passage 21 and su the Quenching channel 14 transported · This is through a wall cladding determined, which on one side has an inlet opening 25 (Fig. 5) which is at right angles to the furnace passage 21 is arranged · Each through the inlet opening 26 into the The basket transported to the quenching chamber is placed on spaced-apart, parallel balls 27 (Fig. 4) of a lifting platform 29 are loaded and lowered into a bath with cooling liquid, which is fed into a lower the opening 26 arranged tank 3o is included. The stage is cantilevered on a hanging yoke 31 that is vertical Guide rails 33 is slidable in the tank, and is according to Mafigabe the supply of pressure fluid in the opposite Ends of a hydraulic actuator 34 connected to the top of the yoke are raised and lowered. While the basket is immersed in the bath, the cooling liquid is brought over the workpieces by a recessed pump 35 in Oalauf, which is driven by a motor 36 mounted above the tank 3o. After the workpieces have cooled down, the basket is removed from the lifting device lifted out of the bath and removed through an exit opening 37 (FIGS. 2 and 4) controlled by a door 38 which is to be opened by a hydraulic actuator 39 and su close. The outlet opening 37 1st

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! Arranged on one side of the drive bend 16, and thus The basket can old the treated workpieces and continue to be transported su another area can be reloaded onto the trolley 15

One aspect of the invention is the furnace chamber and the ironing chamber 14 over a sealing chamber 4o (Fig. 3 and 5) In connection with one another »the on novel Way is used «un importing the workpieces into the Oven chamber 2o and the forwarding of the workpieces from the Ofenkamer sur Absc & recldcammer 14 su enable without danger the pollution of the furnace - he old the anaic atmosphere or with steam escaping from the quenching chamber 4o The Off never isolates me from the deterrent and is made of oxygen and vapors

cleaned in the periods. In which the furnace chamber The introduction and forwarding of the workpieces must be opened constant burning of the furnace chamber without the risk of Contamination of either the parts of the furnace or the workpieces

In the present case, the fitting comb is 4o through upper and lower walls 41 and 43 (Fig. 3) and four crosswinds 44 to 47 (Flg. 3 and 5) and is with the side wall 44 on the Abschreckkanmer 14 and with the side wall 45 on a wall (Fig. 3) of the vacuum filter 17, so that the three Chambers 14, 2o, 4o form a generally L-shaped arrangement, as seen in Flg · 1 and 2. The side wall 46 is

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arranged along the running rail 16 and has an entry passage 5o (Fig. 3) through which the baskets Io from the trolley 15 can be forwarded to the loading channel. A TUr 51 is up and down above the entry passage 5o slidably mounted and operated by a hydraulic actuator 53, which is connected between the door and the upper part of the side wall 46, is optionally open and closed Baskets which have been introduced into the loading chamber through the entry passage 5o are placed on a Conveyor provided, which consists of a series of horizontal Bollen 54 (Fig. 3 and 8) between the side walls 44 and 47 extend and have bearing journals 54a which support the rollers rotatably about their longitudinal axes. From the loading chamber 4o the workpieces are transported to the furnace chamber 2o through a passage 55 (FIG. 3), which is connected to the passage 21 of the furnace chamber is aligned and is determined by an opening through the side wall 45 of the loading channel and the adjacent wall 49 of the vacuum container 17 is formed. A horizontal pair of rollers 56 (Fig. 8) is arranged between the two passages 21, 55 to guide the baskets as they move from the conveyor rollers 54 to the frame rollers 23 to be supported.

A double door arrangement is advantageously used, as shown in FIG the also pending application P 15 33 954.5 of the applicant is disclosed to produce an airtight seal between the loading chamber 4o and the vacuum container 17 and to prevent heat from escaping from the oven chamber 2o. In this case one of the doors is a vacuum door 57 (Fig. 3), which is formed by a relatively light sheet metal plate, which is arranged in the loading chamber and for opening and

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Closing the passage 55 can be operated optionally. slide Vacuum tetr is connected by a set of parallel links 59 to a track 6o which slides up and down in channels 61 is performed on the side walls 44 and 4? the loading barn are attached. At its upper find is the frame attached to the piston rod of a hydraulic actuator 63, which is on the upper wall 41 of the Besohiokungikkammer is appropriate. As disclosed in more detail in the aforementioned application, the initial downward movement of the Frame 6o in accordance with the operation of the operating device 63 a downward movement of the vacuum door 57 along the side wall and in alignment with passage 55. On continued downward movement of the frame, the vacuum door shifts to the passage 55 and into firm engagement with the side wall 45 sur Establish an extremely tight seal between the loading chamber 40 and the vacuum container 17. When the frame is moved upwards, the vacuum door is first removed from the side wall 45 sucked away in order to interrupt the seal, and is then lifted upwards on a path parallel to the side wall 45, and thereby the passage 55 is opened.

Since the vacuum door 57 is made of a light material in order to facilitate opening and closing of the door, it must be protected against the intense heat radiating from the furnace chamber 20 through the passage 21. Su this purpose LSI: a mountains from a thick plate of hitsebeständigem Material * put heat door 64 (FIG _e 3) up in front of the passage 21 and downwardly slidable, and causes not only a shielding of the vacuum door 57, but also keeps the heat in the furnace chamber ·

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The retaining door 64 is operated by a hydraulic actuator 65 and is opened immediately after opening the va ** The vacuum door is opened and immediately before the vacuum door is closed closed so that the latter is always shielded by the hitst door and is never exposed to the heat radiating from the passage 21.

After the workpieces have been heated, the basket Io is transported back out of the furnace chamber 2o and through the passages 21 and 55 into the loading chamber / and passed from the loading chamber into the quenching chamber 14 through a passage 66 (Fig. _N 5), which is defined by an opening formed in the side wall 44 of the load chamber and aligned with the inlet opening 26 in the quench chamber downwardly slidably to the feed chamber from the quenching chamber seal, Zua transport of the basket to quench 1st an actuated by a pneumatic actuator 71 slide 7o (Fig _o 2} forth in the Beschickungekammer and backward movably guided on a path about the transversely to the conveyor rollers 54, and is operable to remove the basket from the bolls 54 and a to hit the leveling castors 27.

With the above arrangement, a basket Io is placed in the loading chamber 4o introduced through entry passage 5o while door 67 is closed to quench chamber 14 to seal and while the double doors 57 and 64 are closed

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are in order to prevent the outside atmosphere from passing through the loading chamber can penetrate into the furnace chamber 2o. The loading chamber is then cleaned of air, which is opened by of the entry passageway 5o, and of all vapors previously emitted from the quench chamber into the loading kaoner have penetrated. In the present case, this is done by the influx of a non-oxidizing gas, for example Nitrogen or hydrogen into the lock chamber a tube 73 (Fig. 2) to pass through the air and vapors in the chamber to be driven out through an AusIaBrohr 74. When the loading chamber is cleaned, the double doors 57 and 64 can be opened to transport the basket into the oven chamber 2o without Risk of contamination of this chamber to allow old oxidizing gases

After the basket Io has been retracted, doors 57 and 64 are closed, and the furnace chamber 2o is evacuated and brought to a high temperature of approximately lo93 ° C. When the The vacuum container 17 is heated by the influx of a non-oxidizing gas into the container through a pipe 75 (Fig. 2) pressurized to break the vacuum and open a of doors 57 and 64 to enable »Then these doors are opened and the basket is in the loading»! inwnr 4o returned ^ while this is still in a purified state in order to maintain the given state of the atmosphere in the furnace chamber · Before the one leading to the quenching chamber 14 Door 67 is opened, the double doors 57 and 64 are closed to prevent the ingress of vapors the quenching chamber into the furnace chamber. Sohllefilich

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the door 67 is opened, and the basket Io from the loading canal to the Abeohreckkanmer · A new basket can then be moved into the loading chamber

From the above it can be seen that it is practically impossible is that the furnace chamber 20 old contaminates air or fumes is, since the loading chamber 4o is always cleaned State is held when the furnace chamber is open, and the furnace chamber is closed inside when one of the doors 51 or 67 is open. By cleaning the loading scanners and controlling the order in which the; different doors are opened, the furnace chamber is protected against all dirty gases. By keeping dirty gases away from the chamber, the workpieces can and the parts of the furnace, for example the heating pipes 24 do not oxidize, and consequently the oven chamber can be heated continuously. Instead of the Hexzrohre completely between cycles switching off only needs to reduce the output of the raw and the stove to be lowered to a temperature that is here is in the range of approximately 482-593 ° C.

In another aspect of the invention, an advantage and Moving back the workpieces in the Ofenkanmer 2o provided to the concentration of heat radiating from the heating tubes 24 to avoid the same surfaces of the workpieces and thus an even «heating of the workpieces over their whole Ensure surfaces. In addition, a new drive device 76 (Fig. 8) is provided that can move back and forth the workpieces in the furnace can be operated, and at the same time is operable to transport the workpieces into and out of the furnace chamber.

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In these Sweden there are sliding rollers 23 a with the drive device 76 connected to optionally OberelnstiisBend fiber a · given · angular distance rotatable, tm a basket lo in to and from the furnace chamber 20 to one through the passage 21 running path su drive · Maohdam the basket in the Keaeer moved «order 1st, the Aollen Ober a · curier Wlnkelstreok · ta her · own JMiIiIeIi in front and surttok swings whether thereby the basket on the sloped path in Fig. 7 and surflok see below and constantly move the surfaces of the workshop locomotive directly opposite the hot pipes 24

The drive device 76 here especially has a reversible one Electric motor 77 {Fig. 8) which is actuatable sun Rotation of a well 79 in the selected direction by means of a son corner 8o which is carried by the drive shaft of the motor and meshes with a worm wheel 81 which is keyed to the shaft 79, the latter being supported in bearings 83 (FIG. 5) is, which are attached to a «Stfitssockel 84, the the BeechickungskaBsrar 4o is arranged next to the side wall 47 » The drive motor 77 rotates not only the frame rollers 23, but also the conveyor rollers 54, in the next move the basket Io from the conveyor rollers to the frame rollers and then move the basket in the Beechlckungekasmter and in alignment with the passage 66 SurttcKsuffahren and transport to the deterrent box 14. Iu This "Iweok is an end" of the wave 79 through a chain of drives 85 (Fig. 8) «it is coupled to an extension shaft 86 which passes through the side wall 47 of the lesohlckungili —ir protrudes inward and it is connected to the bearing pin 54 of the last conveyor roller 54 1st · Bin · Hsihe of drive chains 87 are around on the bearing journals of the remaining conveyor rollers fixed sprockets 89 sucked and

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carry the rotation from the last roll to the other rolls. When the motor is operated in one direction, the conveyor rollers 54 are rotated clockwise (FIG. 8) in order to advance the basket onto the frame rollers 23 and when the motor reverses, the rollers 54 are turned in opposite directions; Direction twist to accommodate the basket when it moves away from the rack rollers and move it into alignment with the passageway 66 ₉

To rotate the frame rollers 23 is a light 9o (Fig. 8) the opposite end of the shaft 79 is coupled via a magnetic coupling 91 and to the frame rollers via a drive chain 93 tied together. This is drawn around a chain wheel 94 at the free end of an extension shaft 95 which passes through the vacuum container 17 protrudes inward and connected at its other end to the bearing journal 23a of the first roller of the series of frame rollers is. A sealed bearing 96 (Fig. 6) is mounted in the wall of the vacuum vessel and supports the shaft 95 rotatable. The drive imparted to the first frame roller via the chain 93 and the shaft 95 is via a single endless chain 97, which runs around sprockets 98 on the bearing journals of the rollers, is transferred to the other Gostell rollers · When energized of the clutch 91, the motor 77 rotates the shaft 9o with the shaft 79, around the frame rollers and the conveyor rollers via a selected one Angular distance and to be rotated in a direction related to the working direction of the motor · With this arrangement, a Basket by the conveyor rollers 54 from the loading chamber 4o and moved forward through the passage 55, taken up by the frame rollers 23 and through the passage 21 to a centrally located one

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Place in the furnace chamber (see PIg. 3) moved and after completion The heating cycle from the rack rollers to the conveyor rollers can be returned by driving the rollers in the opposite direction

The drive device 76 is never shown in FIG also a hydraulic actuator loo to the Rack rollers 23 over a limited area of their own Swivel axes back and forth and thereby the basket Io move back and forth in the oven chamber 2o. Beer contains the Actuating device a piston lol (Fig. 9) which is inserted into a Cylinder Io3 according to the specifications for the supply of hydraulic fluid slides back and forth in opposite ends of the cylinder. A piston rod Io4 is carried by the piston and faces at its free end a row of rack teeth loosens, which are in engagement with a pinion lo6 (Flg. t) fixed on a shaft Io7 in order to offset the shaft Swivel directions around its axis while the piston rod is moved back and forth · The shaft Io7 is on the Stützeoekel 84 stored in a suitable manner and can optionally be coupled to the shaft 9o when a magnetic coupling Io9 arranged between the two shafts is excited Coupling lo9 is the reciprocating motion of the shaft Io7aif the Shaft 9o and then over the chains 93 and 97 onto the frame rollers 23 transferred so that the frame rollers coincide about their axes can be moved back and forth to move the basket back and forth in the oven chamber. The workpieces are thus constantly shifted with respect to the heating pipes 24 in order to avoid the formation of overheated areas on the workpieces.

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Om the working direction of the hydraulic actuating device * loo in correct ·!) KeIIr atrst Hn 4tfi to reverse and regulate the stroke length of the piston rod Io4 su control «in pairs on the base 84 attached · Limit switches LS-I and Lfl-2 (Fig. Β« id 9) "in solenoid Ho, the actuatable let, w" in Vlegvall in for alternating supply of pressure fluid in opposite ends of the cylinder Io3 from a pressure medium source, not shown. Specifically, by energizing the solenoid, the valve is switched to "in" position, by directing pressure fluid into the head end of the cylinder and thus extending the piston rod, and when the solenoid is de-energized, a spring 113 puts the valve in its starting position, un pressure fluid da · guide the rod end of the cylinder su and retract the piston rod. After a basket Io has been moved onto the frame rollers 23 and correctly positioned in the oven compartment 2o, a switch is closed by an automatic control (not shown) which responds to the position of the Xorbes. The normally closed limit switch LS-I energizes a relay 115 and closes a normally open switch 116 and a switch 117 which establishes a holding circuit for the relay via the normally closed limit switch LS-2

Closing the switch HC causes the solenoid Ho to be excited, which the valve 111 switches to the Vomftrtshub the Start piston rod Io4 see below. When the piston rod advances moves, it engages switch bedding device 119 of the limit switch LS-I, and is located under it, around the Open switch. However, the relay 115 remains on the dated Switch 117 established holding circuit energized and with £ «

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Solenoid energized via switch 116. If the piston rod continues to move forward, the end of the rod comes with it of the actuating device I2o of the limit switch LS-2 engages, whereby this switch is opened · The relay de-energized to open switch 116 and de-energize the solenoid As a result, the spring 113 switches the valve to direct pressure fluid into the rod end of the cylinder Io3 and thus retract the piston rod then the retracting rod moves away from the actuator I2o, about a blank shot of the limit switch LS-2 in preparation for the next cycle. If the piston rod is the Near the end of its retraction stroke, it moves under the switch actuator 119 in order to enable a new bottom reading of the limit switch IS-I and thus again the To excite solenoid Ho to reverse the direction of the rod movement

switched off The coupling JLo9. around the shafts 9o and Io7 to be uncoupled when the basket Io is in and out of the oven kawmer 2o is moved by the motor 77 so that the hydraulic actuator loo does not delay the rotation of the shaft 9o Likewise, the clutch 91 - when the basket is reciprocated by the actuator to thereby to uncouple shafts 79 and 9o and to prevent that Transmission 8o, 81 interferes with the reciprocating movement of the shaft 9o. In addition, the * of the clutch 91 is used during the

Back and forth movement of the frame rollers 23 to avoid unnecessaryx μ -,. ·· «. * -" Decay

Back and forth of the conveyor rollers 54. Excitement and

the two couplings to the correct control points can be achieved by the same control that responds to the position, which is used to view switch 114.

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Claims (1)

Claims 1. Heat treatment device, characterized by an oven, the βina made of walls facing has a Heating chamber intended to use a series of horizontal rollers Supporting a workpiece in the chamber with the rollers in the chamber arranged side by side and around theirs Longitudinal axis are rotatably mounted, a drive device, those with <ien rollers for the optional rotation of each roller a predetermined angular distance is coupled to the workpiece to move on a straight path running into the Xamner, and means that are optionally batfitigbar to to swivel each roller back and forth over a shorter angular distance around the said axis, thereby removing the workpiece tick on the way to move back and forth. 2 _e tub treatment device according to claim 1, characterized in that that the drive device has a reversible motor, which is optionally b-actuatable to turn the rollers in opposite directions for transporting the workpiece in opposite directions on the way " 3c goods handling device according to claim 2, characterized in that that the means comprise an actuator, the one has reciprocating piston rod that moves back and forth on a predetermined stroke and with the rollers is coupled - 13 - 109812/0668 -ie - 4. Warabehandlungsvorrlohtung nadb claim 3, dadorafa marked _f that the. Engine and the piston rod · «it is a WsXIe are coupled, which is in drive connection ait the Bollen, and a pair of clutches are optionally operable to uncouple the motor and the piston rods from the shaft see below 5. Waxabehandlungsvorriehtung according to one of the preceding claims, characterized by a Beschiokangskanmer, the upper and lower winch and a variety of. Cross winds is determined, the inside of the furnace being connected to the soling channel through a first opening in a first wall of the walls of the soling channel, a housing which has a quenching channel and "it the loading channel through a" wide opening in a " wide wall of the walls of the charging cashier is connected, a third wall of the walls of the charging ** iw η r having a third opening, whereby a workpiece is introduced into the Besohlk ~ kungskaner through the third opening in the third wall and optionally sur Heizkaner or . the retainer can be transported through the first and second opening, three doors, one for each opening and each optionally operable to close and seal off the respective openings. Means for maintaining a selected atmospheric level in the heating chamber, and means for purging a non-oxidizing gas into the heating chamber, while all three doors are closed, in order to purify the heating chamber of air and vapors before the workpiece is transported from the heating chamber into the heating chamber . - 19 - 109812/0668 BATH ORIGINAL 6, Wannbeadlngvchtung according to claim 5, characterized in that that the chambers form an L-shaped arrangement, the noble Loading chamber In the corner of the L * a is arranged, and the quenching channel has an exit opening that opens up on the same side of the L * as the opening in the third wall 7ο heat treatment device according to claim 5 or 6, characterized marked, that a “wide series of side-by-side rolls is stored in the loading chamber and with the first opening is aligned between the pickling and loading chamber and the first row of rollers, and the drive device is also coupled to the second row of rollers and operable to raise the studs to move the workpiece to twist a continuation of the straight path. 8 · Method for treating a workpiece under given conditions using a device according to a of claims 5 to 7, characterized by the following process steps « Introducing the workpiece into the loading chamber through the third opening while the first opening is closed, around the furnace chamber against penetrating through the third opening Protecting air, purging a non-oxidizing gas into the loading chamber when all openings are closed, to clean air and vapors from the loading chamber, open the first opening with the loading chamber cleaned - 2o - 109812/0668 - 2ο - and while the other two openings remain closed and forwarding the workpiece into the furnace chamber through the first opening. Sealing the first opening and heating the Workpiece in the furnace chamber in a selected atmospheric state, opening the first opening and returning it of the workpiece into the Beschiokungskammer through the first opening, while the other two openings are closed remain and the loading chamber is in a cleaned state. Open the second opening * after the first the first opening is closed against the furnace chamber, escaping from the quenching chamber through the second opening Protect vapors, and transport the work piece · to the quenching chamber through the wide opening 9. The method according to claim 8, characterized in that that the furnace chamber in the periods in which the workpiece is passed into and out of the furnace chamber is constantly heated will. lo _B method according to claim 8, characterized in that UbB the furnace chamber is maintained at a temperature of approximately 538 ° C when the workpiece is transported in the one furnace chamber, and is brought to a temperature of approximately lo93 ° C, after the workpiece in the furnace chamber has been transported 109812/0668 BAD ORiGtNAL