WO1986002104A1 - Method and installation for heat treatment, especially case-hardening - Google Patents

Method and installation for heat treatment, especially case-hardening Download PDF

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Publication number
WO1986002104A1
WO1986002104A1 PCT/SE1985/000377 SE8500377W WO8602104A1 WO 1986002104 A1 WO1986002104 A1 WO 1986002104A1 SE 8500377 W SE8500377 W SE 8500377W WO 8602104 A1 WO8602104 A1 WO 8602104A1
Authority
WO
WIPO (PCT)
Prior art keywords
furnace
articles
heat treatment
installation
ring
Prior art date
Application number
PCT/SE1985/000377
Other languages
French (fr)
Inventor
Tomas Barkman
Original Assignee
Ab Volvo
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=20357207&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO1986002104(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Ab Volvo filed Critical Ab Volvo
Priority to DE1985905124 priority Critical patent/DE198871T1/en
Priority to AT85905124T priority patent/ATE39949T1/en
Priority to DE8585905124T priority patent/DE3567479D1/en
Publication of WO1986002104A1 publication Critical patent/WO1986002104A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0037—Rotary furnaces with vertical axis; Furnaces with rotating floor

Definitions

  • the present invention relates to a method of heat treatment, especially case-hardening, of articles with varying requirements as to heat treatment time.
  • the invention also relates to a heat treatment instal- lation particularly suited to carrying out said method,
  • continuous case hardening up to now pusher type installations have been used, in which the articles to be hardened are placed on metal skidding pallets, which are inserted through a feed-in opening at one end of the heat treatment furnace, and after heat treatment has been completed, are taken out through an exit opening at the opposite end of the furnace.
  • the articles are heated to the heat treatment temperature and kept at this temperature as long as is required to achieve the desired carbonization depth.
  • the method is based on the principle: first in - first out, and presupposes that all the articles inserted at the same time into the furnace are to have the same carbonization depth and therefore the same heat treatment time. If the assortment of articles in the heat treatment installa ⁇ tion contains articles requiring different carboniza ⁇ tion depths, which is often the case, these cannot be mixed in the furnace, since those articles requiring a short heat treatment time cannot be taken out before those requiring a longer treatment time. The result will be low utilization of capacity, when a few articles are to have a long heat treatment time and the available furnace space cannot at the same time be used for articles requiring a shorter treatment time.
  • the purpose of the present invention is to achieve a method which makes it possible to better utilize available capacity by making it possible to treat at the same time articles which are to have differing carbonization depths.
  • An installation particularly suited to carrying out the method according to the invention comprises a ring furnace known per se with a rotatable carrier for the articles and is characterized in that the discharge opening from a separate heating-up furnace is connected directly to the input opening of the ring furnace.
  • all the articles are heated in the heating-up furnace to the heat treatment temperature of the heat treatment furnace.
  • the articles to be heat-treated for 1.5 hours can be inserted into the heat treatment furnace after the articles to be treated for 3.5 hours, and be taken out before these, without requiring a change in the temperature or atmosphere of the heat treatment furnace.
  • a ring furnace this can be done quite simply.
  • Each article is time-monitored, preferably via a computer system, and is advanced to the exit point from the ring furnace after heat treatment has been completed.
  • 1 designates a feeding station for articles to be case-hardened.
  • the articles are placed on metal skidding pallets 2, on which the artic ⁇ les are then transported through the installation.
  • the pallets are transferred to a conveyor 4 and are conveyed thereon through a washing station 5 and back to the conveyor 3 via a conveyor 6, and from there to a conveyor 7, by means of which the skidding pallets 2 are fed into the heat treatment furnace 8.
  • the pallets are advanced to a heating up furnace 9, in which the articles are heated up to their heat treatment temperature, e.g. ca 900°C.
  • the heating-up furnace 9 is attached directly to a ring furnace 10, in which the pallets after heat ⁇ ing of the articles are placed on a turn-table (as is indicated by the arrows in the figure). Regardless of the order in which the pallets are fed into the furnace 10, anyone of the pallets can now be removed by virtue of the fact that the turn-table can be advanced as many steps as are desired in either direction in order to place the selected pallet at the outlet 11 of the furnace 10. .
  • the articles After treatment has been completed in the ring furnace 10, the articles are.transferred to a diffusion furnace 12 and from there either directly to a packing robot 13 or to an oil bath 14. From the oil bath 14, the articles are conveyed via conveyors 3 and 4 once again through the washing station 5 and finally to a tempering furnace 15, from which the articles are conveyed out to the conveyor 3»
  • the heat treatment installation shown and described is suitably controlled by a computerized control system which keeps track of where each indi ⁇ vidual pallet is at each moment and times the various operations, so that all of the articles receive the proper heat treatment period independently of the order in which they are fed into the installation.

Abstract

Method and installation for heat treatment in connection with case-hardening of articles with varying requirements as to heat treatment time. The articles are first heated up in a heating-up furnace (9) to the heat treatment temperature. Thereafter the articles are heat-treated in a ring furnace (10). The articles are removed from the ring furnace after a predetermined holding time independently of the order in which they are inserted, by advancing each article to the discharge opening (11) of the furnace.

Description

Method and installation for heat treatment, especially case-hardening
The present invention relates to a method of heat treatment, especially case-hardening, of articles with varying requirements as to heat treatment time. The invention also relates to a heat treatment instal- lation particularly suited to carrying out said method, In continuous case hardening, up to now pusher type installations have been used, in which the articles to be hardened are placed on metal skidding pallets, which are inserted through a feed-in opening at one end of the heat treatment furnace, and after heat treatment has been completed, are taken out through an exit opening at the opposite end of the furnace. In the furnace, the articles are heated to the heat treatment temperature and kept at this temperature as long as is required to achieve the desired carbonization depth. The method is based on the principle: first in - first out, and presupposes that all the articles inserted at the same time into the furnace are to have the same carbonization depth and therefore the same heat treatment time. If the assortment of articles in the heat treatment installa¬ tion contains articles requiring different carboniza¬ tion depths, which is often the case, these cannot be mixed in the furnace, since those articles requiring a short heat treatment time cannot be taken out before those requiring a longer treatment time. The result will be low utilization of capacity, when a few articles are to have a long heat treatment time and the available furnace space cannot at the same time be used for articles requiring a shorter treatment time. The purpose of the present invention is to achieve a method which makes it possible to better utilize available capacity by making it possible to treat at the same time articles which are to have differing carbonization depths.
This is achieved according to the invention by a plurality of articles being heated up at the same time in a separate heating-up furnace to a predeter- mined temperature, the articles being thereafter inserted into and kept in a heat treatment furnace for heat treatment, the holding time for each article in the heat treatment furnace being monitored individu¬ ally and the articles being removed individually from the furnace after a predetermined holding time independently of the sequence of insertion.
An installation particularly suited to carrying out the method according to the invention comprises a ring furnace known per se with a rotatable carrier for the articles and is characterized in that the discharge opening from a separate heating-up furnace is connected directly to the input opening of the ring furnace.
In the method according to the invention, all the articles are heated in the heating-up furnace to the heat treatment temperature of the heat treatment furnace. The articles to be heat-treated for 1.5 hours, for example, can be inserted into the heat treatment furnace after the articles to be treated for 3.5 hours, and be taken out before these, without requiring a change in the temperature or atmosphere of the heat treatment furnace. By using a ring furnace, this can be done quite simply. Each article is time-monitored, preferably via a computer system, and is advanced to the exit point from the ring furnace after heat treatment has been completed.
The invention will be described in more detail with reference to an example shown in the accompanying drawing, which shows schematically a heat treatment installation, particularly suited for carrying out the method according to the invention.
In the figure, 1 designates a feeding station for articles to be case-hardened. The articles are placed on metal skidding pallets 2, on which the artic¬ les are then transported through the installation. From a conveyor 3 , the pallets are transferred to a conveyor 4 and are conveyed thereon through a washing station 5 and back to the conveyor 3 via a conveyor 6, and from there to a conveyor 7, by means of which the skidding pallets 2 are fed into the heat treatment furnace 8. After preheating, the pallets are advanced to a heating up furnace 9, in which the articles are heated up to their heat treatment temperature, e.g. ca 900°C.
The heating-up furnace 9 is attached directly to a ring furnace 10, in which the pallets after heat¬ ing of the articles are placed on a turn-table (as is indicated by the arrows in the figure). Regardless of the order in which the pallets are fed into the furnace 10, anyone of the pallets can now be removed by virtue of the fact that the turn-table can be advanced as many steps as are desired in either direction in order to place the selected pallet at the outlet 11 of the furnace 10. .
After treatment has been completed in the ring furnace 10, the articles are.transferred to a diffusion furnace 12 and from there either directly to a packing robot 13 or to an oil bath 14. From the oil bath 14, the articles are conveyed via conveyors 3 and 4 once again through the washing station 5 and finally to a tempering furnace 15, from which the articles are conveyed out to the conveyor 3»
The heat treatment installation shown and described is suitably controlled by a computerized control system which keeps track of where each indi¬ vidual pallet is at each moment and times the various operations, so that all of the articles receive the proper heat treatment period independently of the order in which they are fed into the installation.

Claims

1. Method of heat treatment, preferably case- hardening, of articles with varying requirements as to heat treatment time, characterized in that a plurality of articles are heated up at the same time in a separate heating-up furnace (9) to a predetermined temperature, that the articles are thereafter inserted into and kept in a heat treatment furnace (10) for heat treatment, that the holding time for each article in the heat treatment furnace is monitored individually and that the articles are removed individually from the furnace after a predetermined holding time independently of the sequence of insertion.
2. Method according to Claim 1, characterized in that the articles after heating up are placed on a rotary carrier in a ring furnace (10) and that each article, when the predetermined holding time has expired, is advanced to a discharge opening in the furnace by rotation of the carrier.
3. Method according to Claim 2, characterized in that the articles, after heat treatment in the ring furnace (10), are fed into a diffusion furnace (12) directly connected to the ring furnace.
4. Installation for heat treatment, preferably case-hardening, of articles with varying requirements as to heating-up time, said installation comprising a ring furnace with a rotary carrier for the articles, characterized in that the discharge opening from a heating-up furnace (9) is directly connected to the feeding opening of the ring furnace (10).
5. Installation according to Claim 4, characterized in that the ring furnace has a discharge opening (11) placed diametrically opposite to its feed-in opening and is directly connected to the feed-in opening of a diffusion furnace (12).
PCT/SE1985/000377 1984-10-02 1985-09-30 Method and installation for heat treatment, especially case-hardening WO1986002104A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DE1985905124 DE198871T1 (en) 1984-10-02 1985-09-30 METHOD AND DEVICE FOR HEAT TREATMENT, ESPECIALLY FOR USE HARDENING.
AT85905124T ATE39949T1 (en) 1984-10-02 1985-09-30 METHOD AND DEVICE FOR HEAT TREATMENT, ESPECIALLY FOR CASE HARDENING.
DE8585905124T DE3567479D1 (en) 1984-10-02 1985-09-30 Method and installation for heat treatment, especially case-hardening

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8404926A SE450389B (en) 1984-10-02 1984-10-02 METHOD AND PLANT FOR HEAT TREATMENT OF DETAILS WITH VARIOUS REQUIREMENTS FOR HEAT TREATMENT TIME
SE8404926-1 1984-10-02

Publications (1)

Publication Number Publication Date
WO1986002104A1 true WO1986002104A1 (en) 1986-04-10

Family

ID=20357207

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1985/000377 WO1986002104A1 (en) 1984-10-02 1985-09-30 Method and installation for heat treatment, especially case-hardening

Country Status (5)

Country Link
EP (1) EP0198871B1 (en)
JP (1) JPS62500529A (en)
DE (1) DE3567479D1 (en)
SE (1) SE450389B (en)
WO (1) WO1986002104A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3441338A1 (en) * 1984-11-13 1986-05-15 Ipsen Industries International Gmbh, 4190 Kleve Process for heat-treating metallic workpieces, using a straight-flow or continuous pusher-type furnace, and equipment for carrying out this process
FR2607231A1 (en) * 1986-11-26 1988-05-27 Ipsen Ind Int Gmbh THERMAL TREATMENT INSTALLATION OF METALLIC PARTS WITH FUEL ATMOSPHERE
US5187670A (en) * 1990-11-05 1993-02-16 Caterpillar Inc. Control system for scheduling parts in a heat-treating process
EP2186916A1 (en) 2008-11-17 2010-05-19 LOI Thermprocess GmbH Process and installation for continuous case hardening

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE29505496U1 (en) * 1995-03-31 1995-06-01 Ipsen Ind Int Gmbh Device for the heat treatment of metallic workpieces under vacuum
ES2163791T3 (en) * 1996-08-30 2002-02-01 Franz Hillingrathner ROTARY OVEN FOR THE TREATMENT OF WORK PIECES.
DE19635257C1 (en) * 1996-08-30 1998-03-12 Franz Hillingrathner Compact orbital heat treatment furnace

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE971225C (en) * 1943-10-13 1958-12-31 Aeg Rotary hearth furnace with attached cooling chamber
GB920150A (en) * 1961-03-28 1963-03-06 Salem Brosius Inc Rotary hearth furnace control
DE1201380B (en) * 1958-05-07 1965-09-23 Lee Wilson Method and device for the heat treatment of loosened metal tape reels
DE2301958B2 (en) * 1972-02-28 1975-02-13 Morgan Construction Co., Worcester, Mass. (V.St.A.) Continuous furnace for heating wire or sheet metal coils to rolling temperature
EP0098344A1 (en) * 1982-06-09 1984-01-18 Daidotokushuko Kabushiki Kaisha Heat-treatment system and process

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2013905A (en) * 1933-02-04 1935-09-10 Jr James L Adams Circular ingot heating furnace
CA980040A (en) * 1971-09-07 1975-12-16 John P. Stallings Homogeneously colored low profile unsaturated polyester moldings and preparations thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE971225C (en) * 1943-10-13 1958-12-31 Aeg Rotary hearth furnace with attached cooling chamber
DE1201380B (en) * 1958-05-07 1965-09-23 Lee Wilson Method and device for the heat treatment of loosened metal tape reels
GB920150A (en) * 1961-03-28 1963-03-06 Salem Brosius Inc Rotary hearth furnace control
DE2301958B2 (en) * 1972-02-28 1975-02-13 Morgan Construction Co., Worcester, Mass. (V.St.A.) Continuous furnace for heating wire or sheet metal coils to rolling temperature
EP0098344A1 (en) * 1982-06-09 1984-01-18 Daidotokushuko Kabushiki Kaisha Heat-treatment system and process

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3441338A1 (en) * 1984-11-13 1986-05-15 Ipsen Industries International Gmbh, 4190 Kleve Process for heat-treating metallic workpieces, using a straight-flow or continuous pusher-type furnace, and equipment for carrying out this process
FR2607231A1 (en) * 1986-11-26 1988-05-27 Ipsen Ind Int Gmbh THERMAL TREATMENT INSTALLATION OF METALLIC PARTS WITH FUEL ATMOSPHERE
BE1002059A4 (en) * 1986-11-26 1990-06-12 Ipsen Ind Internat Ges Mit Bes INSTALLATION FOR HEAT TREATMENT OF METAL PARTS IN A CARBON CEMENTATION ATMOSPHERE.
US5187670A (en) * 1990-11-05 1993-02-16 Caterpillar Inc. Control system for scheduling parts in a heat-treating process
EP2186916A1 (en) 2008-11-17 2010-05-19 LOI Thermprocess GmbH Process and installation for continuous case hardening
WO2010055163A1 (en) * 2008-11-17 2010-05-20 Loi Thermprocess Gmbh Method and system for continuous case hardening

Also Published As

Publication number Publication date
EP0198871A1 (en) 1986-10-29
JPS62500529A (en) 1987-03-05
DE3567479D1 (en) 1989-02-16
SE8404926L (en) 1986-04-03
EP0198871B1 (en) 1989-01-11
SE450389B (en) 1987-06-22
SE8404926D0 (en) 1984-10-02

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