JPS62247021A - Heat treatment furnace - Google Patents

Abstract

PURPOSE:To permit treatment of articles to be treated for which treatment conditions for hardening, etc., are different by successively providing plural auxiliary chambers respectively provided with cooling vessels via openable and closable doors adjacently to a heating chamber provided with heating means. CONSTITUTION:A heat treatment furnace 1 opens and closes an intermediate door 8 and transfers the articles to be treated into an elevator 20 in the 1st auxiliary chamber 6 if the articles to be treated heated by a heater 2 in the heating chamber 3 have poor hardenability. The articles to be treated descend into the cooling vessel 4 where the articles to be treated are quickly cooled and hardened by the hardening oil kept at about a room temp. The articles to be treated are shifted into an elevator 21 is the 2nd auxiliary chamber 7 if the articles to be treated are lowered into the cooling chamber 5 and are slowly cooled by the preheated hardening oil, by which the articles to be treated are hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in a heat treatment furnace used to heat treat various objects to be treated.

(Prior Art) Conventionally, for example, batch operation type heat treatment furnaces often
A heating chamber is provided behind the front chamber with a quenching tank on the lower side, and an openable and closable intermediate door is provided between the front chamber and the heating chamber. A cooling agent such as oil, molten salt, or water for quenching is stored inside the quenching tank. Also,
The front chamber has a front door on the front that opens and closes the inside and outside of the furnace, and has an elevator inside that can go up and down with respect to the quenching tank.

In such a heat treatment furnace, a workpiece heated in a heating chamber is transferred to an elevator located in a front chamber, and the elevator is lowered into a quenching tank to harden the workpiece.

(The problem that Ming is trying to solve) Here, when hardening the workpiece as described above, it is important to note that, for example, the workpiece may be made of a material with poor hardenability or may have a large amount of distortion. If the product is a material, use oil or water at a temperature of approximately 60 to 80°C as a coolant to increase the cooling rate, and remove the material that is likely to cause quench cracking. In cases where the material is heated to about 100 to 200°C or molten salt is used as a coolant to prevent the cooling temperature from becoming excessive. . However, in conventional heat treatment furnaces, it is almost impossible in actual operation to change the coolant each time depending on the properties and shape of the product to be treated, and in a single heat treatment furnace, it is almost impossible to change the coolant each time depending on the properties and shape of the product being treated. The current situation is that processing of other or similar items to be processed is carried out intensively. Therefore, in order to meet the demands of improving productivity and handling workpieces with different quenching conditions, multiple heat treatment furnaces are required, resulting in an enormous amount of space and equipment costs. There was a problem.

(Object of the Invention) The present invention has been made by focusing on the above-mentioned problems, and it is possible to easily deal with processed products having different processing conditions such as quenching in one heat treatment furnace. The purpose of this project is to provide a heat treatment furnace that can save the area occupied by the heat treatment furnace itself and equipment costs even when expansion of the equipment is required in order to improve the productivity of processed products. There is.

[Structure of the Invention] (Means for Solving the Problems) The heat treatment furnace according to the present invention has a plurality of sub-chambers each equipped with a cooling tank, which has a door that can be opened and closed, adjacent to a heating chamber equipped with a heating means. It is characterized by being connected through the

(Example) The present invention will be explained below based on the drawings.

The accompanying drawings are diagrams illustrating a heat treatment furnace according to an embodiment of the present invention.

That is, in the heat treatment furnace 1, a first sub-chamber 6 and a second sub-chamber 7 each having cooling tanks 4 and 5 on the lower side are connected to each other on both sides of a heating chamber 3 equipped with a heater 2 serving as a heating means. Internal doors 8 and 9, which open and close in the vertical direction, are provided between the heating chamber 3 and each sub-chamber 6, 7, and each sub-chamber 6, 7 is provided with an internal door 8.9.
An external groove 10.11 is provided which faces the internal door 8.9 and opens and closes the inside and outside of the furnace.

Inside the heating chamber 3, a stirring device 12 for stirring the atmosphere and a thermocouple 13 for measuring room temperature are provided. Inside each of the cooling tanks 4 and 5, there is a stirring device 14, 15 used to make the temperature distribution of the coolant uniform;
Heaters 16, 17 for heating the coolant and heat exchanger 18.1
In this embodiment, the cooling tank 4 in the first subchamber 6 stores quenching oil at about room temperature (for example, the temperature for cold quenching), and the second subchamber 7 stores quenching oil at about room temperature (for example, the temperature for cold quenching). Cooling tank 5
Inside, quenching oil is stored which is adjusted to a predetermined temperature (for example, hot quenching temperature) by a heater 17. In addition, each of the auxiliary chambers 6 and 7 also serves as an air exchange chamber to prevent explosions caused by the atmosphere inside the furnace, and each of the subchambers 6 and 7 serves as an air exchange chamber to prevent explosions caused by the atmosphere inside the furnace.
, 5 are provided with elevators 20, 21 that go up and down. Each elevator 20.21 consists of two stages of upper and lower roller conveyors 20a, 20b, 21a, 21b, and a cylinder 22.
23. Incidentally, the stirring device 14.15 and heater 16.17 in each cooling tank 4.5 are naturally located at a position where they do not interfere with the elevator 20.21. Furthermore, charging tables 24.25 are provided outside the external J% 10.11 of each subchamber 6, 7, respectively, in view of the roller conveyor, and below each charging table 24.25, as shown in the figure, Although omitted, a snaking chain or the like is provided for carrying in and carrying out the items to be processed.

In the heat treatment furnace 1 having the above configuration, when the workpiece heated in the heating chamber 3 is made of a material with poor hardenability, the intermediate door 8 is opened and closed, and the workpiece is moved to the first
Move to the elevator 20 in the auxiliary room 6, and this elevator 20
By lowering the workpiece into the cooling tank 4, the workpiece is rapidly cooled and hardened using hardening oil kept at about room temperature. In addition, if the item to be processed is made of a material that does not like distortion or has a high possibility of cracking, the item to be processed is moved to the elevator 21 in the second auxiliary chamber 7, and this elevator 21 is moved. By lowering the workpiece into the cooling tank 5, the workpiece is slowly cooled and hardened using preheated hardening oil. Furthermore, while hardening is being carried out as described above, the next workpiece is also transported from either side of the charging table 24 or 25 via the upper stage of the elevator used for hardening or the lower stage of the elevator that is not being driven. It can be carried into the heating chamber 3.

In other words, it is clear that the heat treatment furnace 1 described in the above embodiment can handle workpieces with different quenching conditions with just one heat treatment furnace 1. It is also possible to use it for martempering and austempering.

It goes without saying that the structure of the heat treatment furnace according to the present invention is not limited to the above-mentioned embodiments, and that the detailed structure including the heating means, etc., the type of coolant, etc. can be changed as appropriate. Although the number and arrangement of sub-chambers in the heat treatment furnace can be freely selected, if the sub-chambers 6 and 7 are provided on both sides of the heating chamber 3 as explained in the above embodiment,
For example, when a plurality of process lines for processing objects to be processed are provided in parallel in a factory layout, the heat treatment furnace can be installed between the two lines for even more rational utilization.

[Effects of the Invention] As explained above, according to the heat treatment furnace of the present invention, a plurality of auxiliary chambers each equipped with a cooling tank are opened and closed through openable and closable doors adjacent to a heating chamber equipped with a heating means. Because of the structure in which they are connected in series, one heat treatment furnace can easily handle products with different processing conditions such as quenching, and for example, equipment expansion is required to improve the productivity of processed products. Even in such a case, the area occupied by the heat treatment furnace itself and the equipment cost can be significantly reduced.

[Brief explanation of drawings]

The attached drawing is a sectional view illustrating a heat treatment furnace based on an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Heat treatment furnace, 2... Heater (heating means), 3... Heating chamber, 4.5... Cooling tank, 6... First sub-chamber, 7... Second sub-chamber , 8.9...Inner door.

Claims (1)

[Claims] (1) A heat treatment furnace characterized in that a plurality of auxiliary chambers each having a cooling tank are connected to each other through an openable/closable door adjacent to a heating chamber equipped with a heating means.