JPS60141863A - Method and device for continuous heat treatment - Google Patents

Abstract

PURPOSE:To improve remarkably productivity and workability by providing plural independent and individual chambers for an atmosphere heat treatment vertically and horizontally in parallel and performing the continuous atmosphere heat treatment under different conditions. CONSTITUTION:A material to be heat-treated is charged into a prepurging chamber 22 and after prepurging, a door 23 is opened and the material is transferred into a heating chamber 24 where the material is subjected to a heating treatment. A door 25 is then opened and the material is transferred into an atmosphere heating chamber 27 where the material is subjected to shallow carburization and thereafter a door 31 is opened and the material is transferred into a hardening and holding chamber 33. On the other hand, a part of the material to be treated in the chamber 24 is transferred into an atmosphere heating chamber 28 after a door 26 is opened and the material is subjected to deep carburization then a door 32 is opened and the material is transferred into the chamber 33. A door 34 is opened and the material is put into an oil tank 35a in a hardening and post purging chamber 35; at the same time the inside of the chamber 35 is purged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous heat treatment method and a continuous heat treatment apparatus that allow atmospheric heat treatment to be performed simultaneously and continuously under different conditions.

Atmospheric heat treatments include surface hardening treatments such as carburizing, carbonitriding, and nitriding. These atmospheric heat treatments are used to harden the surface of the heat-treated product while maintaining its internal toughness, such as gears, Shafts and bearings, gauges, tools,
It is used in the manufacture of various sliding parts, etc.

For example, in the gas carburizing of the various parts mentioned above, a tray conveyance type continuous carburizing and quenching apparatus is sometimes used, but in this case, a tray pusher type as shown in FIG. 1 is often used.

The Trebutscher type continuous carburizing and quenching equipment shown in Fig. 1 is as follows:
The heat-treated products pretreated in the pre-cleaning chamber 1 are transferred to the pre-purge chamber 2, and then the heat-treated products are loaded into the heating furnace 4 by the tray transfer pusher 3. The product to be heat-treated is sequentially moved to a heating chamber, a carburizing (diffusion) chamber, and a quenching holding chamber in a heating furnace 4, and then transferred to a quenching chamber 6 by a tray unloading pusher 5 to be quenched, and then a post-purge chamber 7, A desired heat-treated product is obtained through a tempering furnace 8 and a post-cleaning chamber 2.

This type of tray pusher type continuous carburizing and quenching equipment has the advantages of simple transportation, fewer failures of the drive unit, which is a particular problem in continuous heat treatment equipment, and the ability to perform stable heat treatment continuously. Although it has characteristics,
There were also some problems as shown below. In other words, ■Since it is not possible to provide an intermediate door between the heating chamber, carburizing (diffusion) chamber, and quenching holding chamber in the heating furnace 4, carbon precipitation (suction) occurs in the heating chamber and quenching holding chamber. ■ The heating chamber in the heating furnace 4, carburizing (
Since it is not possible to individually change the passing speed and time of the workpiece in the diffusion chamber and the quenching holding chamber, a considerable amount of waiting time occurs when changing processing conditions such as carburization depth, which significantly reduces processing efficiency. ■It is not possible to perform heat treatments with different processing conditions on the product to be heat treated, such as carburizing and quenching, deep carburizing and shallow carburizing at the same time, ■Heating at different temperatures in one heating furnace There were problems such as a heat transfer zone, a carburizing (diffusion) zone, and a quench retention zone, which caused heat to move between the zones, resulting in a considerable decrease in thermal efficiency.

On the other hand, a batch type carburizing and quenching apparatus as shown in FIG. 2 is also often used in place of the two continuous type carburizing and quenching apparatus.

The batch type carburizing and quenching apparatus shown in FIG. Carburizing (carburizing) is carried out at high temperature to promote diffusion during
After that, the temperature is lowered to 830 to 850°C, and then quenching is performed. Batch-type carburizing and quenching equipment has the advantage of being highly flexible in processing, as it is a batch process and the processing conditions can be changed each time. There are some problems. In other words, ■ The time and thermal energy losses are extremely large due to the heating and cooling of the heating furnace; ■
There were problems such as continuous processing was not possible and the processing time tended to be long, resulting in poor productivity.

This invention was made by focusing on the problems of the conventional methods as described above, and it is possible to simultaneously and continuously perform atmospheric heat treatment under different conditions in one unit of atmospheric heat treatment system, and it is possible to simultaneously and continuously perform atmospheric heat treatment under different conditions. It is possible to stabilize the atmosphere and suppress carbon precipitation (sooting) during each process, and since continuous processing is possible, time and thermal energy losses are extremely small, improving productivity and workability in atmospheric heat treatment. The object of the present invention is to provide an extremely superior continuous heat treatment method and continuous heat treatment apparatus.

This invention provides a method for performing atmospheric heat treatment such as carburizing and nitriding on a product to be heat-treated through a pre-ambient heating stage, an atmospheric heating stage, and a post-ambient heating stage, in which at least a plurality of the atmospheric heating stages are provided in parallel, and each of the atmospheric heating stages is performed in parallel. The continuous heat treatment method according to the present invention is characterized in that it is continuous with the pre-stage and the post-atmosphere heat treatment stage to enable continuous atmospheric heat treatment under different conditions in a single atmosphere heat treatment system, and the continuous heat treatment method according to the present invention is directly used to carry out the continuous heat treatment method. The heat treatment apparatus includes a front purge chamber, a plurality of atmosphere heating chambers adjacent to the front purge chamber in a manner that allows communication and isolation, and a rear purge chamber adjacent to the plurality of atmosphere heating chambers in a manner that allows communication and isolation. It is characterized in that the indoor conditions of the pre-purge chamber, atmosphere heating chamber, and post-purge chamber can be individually controlled.

FIG. 3 is an explanatory plan view of a continuous heat treatment apparatus showing an embodiment of the present invention. a plurality of atmosphere heating chambers (e.g., carburizing chambers) 27, 28, which are capable of communicating with the heating chamber 24 through doors 25, 26, ie, two atmosphere heating chambers (for example, carburizing chambers) 27, 28 as shown in the illustrated example; The quenching holding chamber 33 is connected to each of the atmosphere heating chambers 27 and 28 through doors 31 and 32, and the quenching holding chamber 33 is connected to and disconnected from the quenching holding chamber 33 through the door 34. A heating chamber 24, an atmosphere heating chamber 27.28, a quenching holding chamber 3'5, and a quenching and post-purging chamber 35 are installed.
6.31.

32 is integrally surrounded by a heat insulating wall 36, and tRzs, 3+ is also formed by a heat insulating wall.

In this case, the pre-purge chamber 22 and the heating chamber 2 become the atmosphere heating chamber 27.28, that is, the atmosphere heating pre-stage for the atmosphere heating stage, and the quenching holding chamber 33 and the quenching/post-purging chamber 35 become the atmosphere heating chamber 27.28. That is, the atmosphere heating step is a post-atmosphere heating step, and the pre-atmosphere heating step, the atmosphere heating step, and the after-atmosphere heating step are configured to be continuous in the same atmosphere heat treatment system.

Further, a heater 44 is provided in the heating chamber 24, and heaters 27a, 27b, and 2 are provided in the atmosphere heating chambers 27 and 28, respectively.
8a28b, and a heater 53 is provided in the quenching holding chamber 33.
Each room is equipped with a system that allows the temperature, atmosphere, and other conditions in each room to be individually controlled.

In the figure, reference numeral 51 denotes a door for loading the article to be heat treated, 52 a drive device for moving the article to be treated loaded into the front purge chamber 22, 54 a drive device for moving the article to be treated in the heating chamber 24, Reference numerals 57 and 58 are drive devices for moving the objects to be processed within the atmosphere heating chambers 27 and 28, respectively.

Temperature and atmosphere control in such a heat treatment apparatus 21 are controlled by each door 23, 25, 26, 31.

Each chamber 22.24.27°28.33 by 32.34
．． Since it is possible to block 35, this can be done separately for each room without affecting each room. Control in this case can be easily performed using a simple computer; for example, by calculating backwards from the final stage, the control program for the timing of transporting the heat-treated products to the pre-purge chamber 22 and other stages can be determined. Determine automatically. and,
If necessary, the processing pattern at each processing stage is recorded on a magnetic tape or the like, multiple lots of products to be heat treated are prepared, and the heat treatment is performed in a fully automatic manner according to the recorded processing pattern for each loft, It is also possible to achieve full automation and unmanned heat treatment work.

Next, a mode of performing atmospheric heat treatment such as carburizing, nitriding, carbonitriding, etc. using the continuous heat treatment apparatus 21 having the above-described configuration will be described.

In FIG. 4(a), after the article to be heat-treated is charged into the pre-purge chamber 22 and pre-purged, the door 23 is opened and the article to be heat-treated is transferred into the heating chamber 24 and heated. Next, the door 25 is opened and a part or all of the heat-treated product is transferred into the atmosphere heating chamber 27 to perform shallow carburization, and then the door 31 is opened and the heat-treated product after carburization is transferred to the quenching holding chamber 33. Move inside. On the other hand, the other part or all of the heat-treated product in the heating chamber 24 is moved into the atmospheric heating chamber 28 by opening the door 26, and deep carburization is performed, and then the door 31 is opened and the heat-treated product after carburization is transferred. It is transferred into the quenching holding chamber 33.

Next, the layer 34 is opened and the article to be heat-treated in the quench holding chamber 33 is put into the oil tank 35a in the quench/post-quench purge chamber 35, and the inside of the quench/post-purge chamber 35 is purged.

Therefore, the single continuous heat treatment apparatus 21 can perform shallow carburization and deep carburization of the heat-treated product at the same time as necessary, which is an excellent effect that has never been seen before.

Further, FIG. 4(b) shows a case where the inside of the quenching holding chamber 33 is also made into a carburizing atmosphere, and quenching and holding of the workpiece after carburizing is omitted. This mode is suitable when the carburizing temperature is low or when there is little problem of distortion even when the carburizing temperature is high, and in this case also it is possible to vary the carburizing treatment conditions in the atmosphere heating chambers 27 and 28. It is.

Furthermore, FIG. 4(C) shows a case where one of the atmosphere heating chambers 27 is not set to a carburizing atmosphere, and in this case, the product to be heat-treated cannot be moved into one of the atmosphere heating chambers 27. Normal quenching is performed by this method, and carburizing and quenching is performed by moving the product to be heat treated into the other atmosphere heating chamber 28, so that different heat treatments can be performed simultaneously as needed in a single heat treatment device 21. It is possible to perform a unique heat treatment that has never been seen before, and it can be performed continuously.

FIG. 4(d) shows a case where neither of the atmosphere heating chambers 27 and 28 is set to a carburizing atmosphere, and only normal heating and quenching is performed.

In this way, by using the heat treatment apparatus 21 according to the present invention illustrated in FIG.
．． 28.33.35 is the door 23.25, 26.31.32
．． 34, each chamber 22, 24, 27 has a different temperature, atmosphere, or pressure depending on the case.
28.33.35 can be controlled, a stable atmosphere can be obtained, and carbon precipitation (sooting) can be suppressed. ■Even though it is a continuous furnace, it can be used for heat treatment with different processing conditions, such as immersion. It must be possible to simultaneously process charcoal quenching and heat quenching, or deep carburizing and shallow carburizing, etc.; ■Heating chamber 24. Atmosphere heating chamber 27, 28, baking sample holding chamber 3
3 are installed separately, and the temperature increases and decreases only for the items to be heat-treated, so the loss of time and thermal energy is extremely small. ■Each room 24, 27, 28. .2
6, 31, 32, 34, so there is significantly less heat transfer between each room, significantly improving thermal efficiency. Because it can be precisely controlled, it is suitable not only for shallow carburizing but also for high-temperature carburizing. ■It is possible to process many products in small lots, but it is basically a continuous furnace, so it is less effective than a batch-type heat treatment furnace. It has remarkable advantages such as: 1) simple structure and less chance of failure; 2) efficient use of space, requiring less installation space. It is possible to make a profit.

In addition, in the above explanation, the case where the inside of the atmosphere heating chamber 27, 28 is mainly a carburizing atmosphere or a normal atmosphere was described, but it is not limited to a carburizing atmosphere, but can also be a carbonitriding atmosphere, a nitriding atmosphere,
A sulfurizing atmosphere can also be used, and atmospheric heat treatment can be performed using an appropriate metamorphic gas.

As explained above, according to the continuous heat treatment method and continuous heat treatment apparatus of the present invention, a method of performing atmospheric heat treatment such as carburizing and nitriding on a product to be heat treated through a pre-atmosphere heating stage, an atmosphere heating stage, and a post-atmosphere heating stage. At least a plurality of the atmosphere heating stages are provided in parallel, each of which is continuous with the atmosphere heating stage and the atmosphere heating stage,
In order to enable continuous atmospheric heat treatment under different conditions in a single atmosphere heat treatment system, in the equipment directly used for carrying out this method, the pre-purge chamber is adjacent to the pre-purge chamber so as to be able to communicate with or shut off from the above-mentioned pre-purge chamber. a plurality of atmosphere heating chambers, and a rear purge chamber adjacent to the plurality of atmosphere heating chambers so as to be able to communicate with and shut off, and each of the front purge chamber, the atmosphere heating chamber, and the rear purge chamber can be individually controlled. Because of this, it is possible to simultaneously and continuously perform atmospheric heat treatments under different conditions in one unit's atmospheric heat treatment system, which stabilizes the atmosphere for each atmospheric heat treatment and suppresses carbon precipitation (sooting). Since it is possible to perform continuous processing, the loss in time and thermal energy is extremely small, and it is possible to significantly improve productivity and workability in heat treatment, something that has never been seen before. It has a significant effect.

[Brief explanation of drawings]

FIG. 1 is an explanatory plan view of a conventional continuous heat treatment apparatus, FIG. 2 is an explanatory plan view of a conventional batch type heat treatment apparatus, and FIG. 3 is an explanatory plan view of a continuous heat treatment apparatus according to an embodiment of the present invention.
FIGS. 4(a), 4(b), 4(c), and 4(d) are explanatory diagrams showing how the continuous heat treatment apparatus according to the present invention is used. 21...Heat treatment device, 22...Pre-purge chamber, 23, 25, 26, 31.32.34...Door, 24.
...Heating chamber, 27.28... Atmosphere heating chamber, 33... Quenching holding chamber, 35... Quenching and post-purging chamber, 35a... Oil tank. Patent Applicant Sanchik Co., Ltd. Patent Attorney Yutaka Koshio 325- Procedural Amendment February 1980 2El Commissioner of the Japan Patent Office Kazuo Wakasugi■, Case Description 1982 Patent Application No. 247931 2, Title of Invention Continuous Heat Treatment Relationship between the method, continuous heat treatment device 3, and the case of the person making the amendment Patent applicant address (residence) Name: 7, 1610 Omaki, Urawa City, Saitama Prefecture (
Name) Santic Co., Ltd. Representative Yoshiaki Yokoyama 4, Agent address (residence) Kobikikan Ginza Building, 2-8-9 Ginza, Chuo-ku, Tokyo 104 Telephone 03 (587) 2781 (Representative) 6, Increase due to amendment Number of inventions 7, Claims of the specification to be amended 9 Detailed description of the invention column 8, Contents of the amendment As attached 1, Claims of the specification, page 1, lines 4 to 18 shall be corrected as follows. [2. Claims (1) 1. A heat treatment method, characterized in that the heat treatment under the bamboo fork to be heat treated can be carried out in the same way as the kiln method. (2) A front purge chamber and a rear purge chamber that is adjacent to the front purge chamber in communication with the front purge chamber and can be disconnected from the ambient air heating chamber, and the indoor conditions of the front purge chamber, the atmosphere heating chamber, and the rear purge chamber are adjusted respectively. A continuous heat treatment device characterized by being individually controllable. ” 2, page 5, line 17 to page 6, line 11 of the specification
Correct the line as follows. [This invention is characterized in that, in a method for atmospheric heat treating a product to be heat treated, a plurality of independent individual chambers for atmospheric heat treatment are provided in parallel vertically and horizontally to enable continuous atmospheric heat treatment under different conditions. The continuous heat treatment apparatus according to the present invention, which is used directly to carry out a heat treatment method, includes a pre-purge chamber, and an atmosphere heating chamber in which a plurality of independent chambers are arranged in parallel in a row and a column, adjacent to the pre-purge chamber so as to be able to communicate with and shut off from the pre-purge chamber. , comprising a rear purge chamber adjacent to the plurality of atmosphere heating chambers so that communication φ can be cut off, and the indoor conditions of the front purge chamber, the atmosphere heating chamber, and the rear purge chamber can be individually controlled. . ” 3. The following amendments have been made to page 6, lines 17 to 18. "Atmosphere heating chambers (e.g. carburizing chambers) arranged vertically and horizontally in parallel, consisting of a plurality of individual chambers, each with a communication φ that can be shielded and are individually independent (for example, two carburizing chambers)" 4, page 7, line 4 of the same article. ``heating chamber 24, atmosphere heating chamber'' is corrected to ``heating chamber 24, atmosphere heating chambers independently provided in parallel''. 5. On page 7, line 16, "so that it is continuous within the system" is corrected to "so that it is continuous in parallel within the system". 6. On page 8, line 13, "can be shut off" is corrected to "can be shut off to create independent rooms." 7. "Conditions that differ depending on the conditions for the heat-treated product...at φ" on page 13, line 9 to page 14, line 4 are corrected as follows. "In a method for atmospheric heat treatment of products to be heat treated, a plurality of independent chambers for atmospheric heat treatment are arranged in parallel vertically and horizontally to enable continuous atmospheric heat treatment under different conditions, and equipment used directly to carry out this method. In the above, a pre-purge chamber, an atmosphere heating chamber in which a plurality of individually independent chambers that are adjacent to the pre-purge chamber so as to be able to communicate with and be disconnected from each other and are arranged in parallel vertically and horizontally, and a plurality of atmosphere heating chambers that can be communicated with and disconnected from The above-mentioned front purge chamber is equipped with an adjacent rear purge chamber.Since the atmosphere heating chamber and the after purge chamber are each configured to be individually controllable, different conditions can be generated in one atmosphere heat treatment facility.'' Yutaka 329-

Claims (2)

[Claims] (1) In a method of performing atmospheric heat treatment such as carburizing and nitriding on a product to be heat-treated through a pre-atmosphere heating stage, an atmosphere heating stage, and a post-atmosphere heating stage, at least a plurality of the atmosphere heating stages are provided in parallel, and each stage is performed before the atmosphere heating. A heat treatment method characterized in that the step and the post-atmosphere heating step are made continuous to enable continuous atmospheric heat treatment under different conditions in a single atmosphere heat treatment system. (2) comprising a front purge chamber, a plurality of atmosphere heating chambers adjacent to the front purge chamber so as to be able to communicate with and be shut off, and a rear purge chamber adjacent to the plurality of atmosphere heating chambers so as to be able to communicate with and shut off,
A continuous heat treatment apparatus characterized in that the indoor conditions of the pre-purge chamber, atmosphere heating chamber and post-purge chamber can be controlled individually.