KR980009500A - Apparatus and method for plasma carburizing a metal object to be treated - Google Patents

Abstract

The present invention provides a method and apparatus for plasma carburization of a mechanical component part, which can reduce the manufacturing cost of the equipment, facilitate the maintenance of the process and the equipment, maximize the production efficiency of the carburized product, and improve the quality of the heat treatment. The apparatus according to the present invention is an apparatus for plasma carburizing a material to be processed of a mechanical element part, comprising: a plasma carburizing chamber of the object to be connected to which a pipe from a vacuum device and a gas supply source for carburizing is connected; A lid for covering the upper portion of the carburizing chamber to seal the object to be carburized during the carburization process of the object to be processed and for placing the object to be processed directly on the upper portion of the cooling vessel, A target to be processed integrally formed with the lid by a connecting shaft at a lower portion of the lid and a lid provided apart from an upper portion of the carburization treatment chamber and the cooling bath to vertically lift and lower And a vertically lifted lid and an enemy tooth which are capable of being reciprocated, And an overhead crane capable of horizontally reciprocating between the crane and the crane.

Description

Apparatus and method for plasma carburizing a metal object to be treated

The present invention relates to a vacuum and plasma carburizing method and apparatus for treating a metal object, and more particularly, to a quenching technology for vacuum and plasma carburization, which is felt in the limelight by a high-quality surface hardening heat treatment technique, .

Generally, in a high temperature plasma diffusion surface hardening heat treatment technique such as carburization, direct quenching process above AC3 temperature is indispensable process for surface hardening, so that a cooling method that is simpler and facilitates control of process parameters is continuously required Has come. When this innovative cooling method is used, high quality carburizing technology of various mechanical elements such as various gears, axial flow and driving parts applied to existing carburizing products is applied, and the durability life such as excellent mechanical properties, abrasion resistance and fatigue resistance is remarkably improved It is expected to contribute. Especially, when applying this cooling method to various power transmission parts such as heavy equipment operating at high load and low speed, it is possible to drastically improve processing cost and durability life, and contributes greatly to the localization of heat treatment equipment production and design technology. .

The general construction of vacuum and plasma carburizing equipment is schematically illustrated in FIG. 1 of the accompanying drawings. The equipment 10 shown in Figure 1 has a two chamber structure as a heating chamber 11 and a cooling chamber 12 and a heating chamber 11 is connected to a manifold 14 And an auxiliary heater 15 and a vacuum system 16 are provided. On the other hand, the cooling chamber 12 is provided with a vacuum system 16a, a gas cooling fan 17, an oil heater 18 and an oil circulator 19.

2. Description of the Related Art At present, the development and application of a two-chamber type plasma carburizing facility as shown in FIG. 1 is being actively applied to mass production lines worldwide. However, such conventional equipment has a complicated form in which the structure of the cooling chamber is heat-treated while keeping the vacuum state. In the case of such existing equipment, the overall system configuration is quite complex, and this complexity has the following problems. Firstly, due to the complexity of the equipment, the cost of the equipment is very high. This means that the heating chamber should be kept in a vacuum state and the cooling oil should also be used in an expensive product which can be used in a vacuum state.

Thus, these expensive equipment prices are causing many consumers to hesitate to apply such equipment. Another problem is that many unnecessary devices are included in the equipment. These unnecessary devices cause difficulties in maintenance of the equipment due to various factors such as interference, noise, electromagnetic wave and the like with the increase of the equipment cost, and it is making the work of the general worker more difficult than the skilled expert. In addition to the above two factors, there is a problem in equipment such as an increase in maintenance cost, a limit of installation place of the facility, a problem of contamination of the carburizing treatment chamber during cooling, excessive use of public facilities, And a reduction in the quality of heat treatment due to time.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method and apparatus for reducing the manufacturing cost of equipment, facilitating maintenance of process and equipment, improving the production efficiency of carburizing products, and improving the quality of heat treatment And to provide a method and apparatus for plasma carburizing treatment of a metal object to be treated.

FIG. 1 is a schematic diagram illustrating a typical configuration of a conventional vacuum and plasma carburizing equipment; FIG.

FIG. 2 is a schematic view showing a configuration of an apparatus for carburizing a metal object to be treated according to an embodiment of the present invention; FIG.

FIG. 3 is a graph showing a temperature change according to a transport time of a metal object to be processed according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

11: Heating chamber 12: Cooling chamber

13: gas supply system 15: auxiliary heater

16, 16a: Vacuum system 18: Oil heater

19: Circulator 30: Carburizing and cooling device of the present invention

31: object to be treated 32: carburizing chamber

33: cooling chamber 34:

35: support frame 36: overhead crane

37: Shaft 38: Cap

39: Red tooth 40: Connecting axis

According to a first aspect of the present invention, there is provided an apparatus for plasma carburizing a metal object to be treated, the apparatus comprising: a vacuum chamber capable of generating plasma to carburize the metal object; And a transporting unit for separating the metal object to be processed from the vacuum chamber into a normal temperature state and moving the metal object to be processed into the cooling chamber. .

According to a second aspect of the present invention, there is provided a method of plasma carburizing a metal object to be treated, comprising the steps of: generating a plasma in a vacuum chamber to carburize the metal object to be processed; A second step of separating the object to be processed into a room temperature state, and a third step of causing the object to be processed to be quenched in a cooling bath.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a schematic view showing a configuration of a plasma carburizing and direct quenching apparatus for a metal object to be processed according to an embodiment of the present invention.

In the second figure, the carburizing and direct quenching device of the mechanical component parts is shown at 30. The carburizing and direct quenching apparatus 30 is provided with a carburizing treatment chamber 32 for carburizing the object 31 which is a mechanical element part and carburizing gas and pressure increasing inert gas are supplied to the carburizing treatment chamber 32 (Not shown) for supplying the water. In addition, a cooling chamber 33 is provided in the vicinity of the carburizing process chamber 32. In addition, at the position spaced apart from the upper surfaces of the two chambers, the horizontal transfer rods 34 are supported by the support rods 35. An overhead crane 36 is provided on the lower surface of the horizontal transfer table 34 to reciprocate along the horizontal shaft 34. A shaft 37 vertically movable up and down is installed on the lower surface of the overhead crane 36 have. The upper end of the shaft 37 is covered with the upper portion of the carburizing chamber 32 during the carburizing process of the object 31 and the upper surface of the lid 38 located at the upper portion of the cooling chamber 33 during cooling. Is connected. A lower end of the lid 38 is integrally formed with a connecting shaft 40 to receive an object to be processed 31 thereon. Therefore, the lid 38 and the enemy tooth 39 integrally move up and down reciprocally according to the operation of the shaft 37.

The operation of the carburizing and cooling apparatus having the above configuration will be described as follows.

When the object 31 is to be carburized, the object to be processed 31 is loaded on the enemy tooth 39, and the object 31 is placed on the upper part of the carburizing chamber 32 using the overhead crane 36 . Thereafter, the shaft 37, to which the reel base 39 and the lid 38 are integrally connected, is moved downward until the lid 38 covers and hermetically closes the top of the carburizing treatment chamber 32, And the enemy tooth 39 on which the water 31 is loaded is placed inside the carburizing chamber 32.

Subsequently, the carburizing treatment chamber 32 is kept in a vacuum state, and the subject 31 is plasma-carburized at an appropriate temperature and time according to a suitable process variable according to the chemical composition of the substance to be treated. Gas is injected into the carburizing chamber 32 and the pressure inside the chamber is raised to 1 atm. Then, when the shaft 37 is moved upward, the lid 38 and the knurled tooth 39 connected thereto are also raised so that the carburized object 31 loaded on the knurled tooth 39 is transferred to the chamber 32 . Thereafter, the overhead crane 36 is moved horizontally along the transfer table 34 to transfer the target tooth 39 loaded with the object 31 to the upper position of the cooling chamber 33, The shaft 37 of the shaft 37 is moved downward to introduce the enemy tooth 39 into the inside of the cooling chamber 33 so that the object 31 to be loaded on the enemy tooth 39 is directly quenched.

However, at this time, what is important is how long the exposed object 31 is exposed to the atmosphere, which is an important factor in ensuring the quality of the heat treatment. If the surface temperature of the object 31 does not fall below the AC3 temperature It does not affect the quality of the heat treatment at the time of direct ingress, but rather reduces the total amount of heat treatment deformation. This can be seen in FIG. 3, which is a graph showing the temperature change of the material to be treated according to the transfer time. As can be seen in FIG. 3, the surface temperature does not drop below the AC3 temperature when the overall feed rate is within about 2 minutes, preferably within about 1.5 minutes.

In addition, formation of an oxide film on the surface layer, which is a concern due to exposure to the atmosphere, is insignificant compared to the case of gas carburization, and thus was not an object of concern.

The above-described process provides a basis for using a simple transfer device and an object to be processed, as compared with a conventional two-chamber plasma carburizing furnace, to use a plasma heat treatment technique, which is a better heat treatment method, for surface hardening of various machine parts.

This series of processes can be controlled by simple software. All processes are automatically progressed by pressing the start button by inputting various process variables such as process temperature, process time, cooling condition, etc., and the surface hardening heat treatment is completed This enables to reduce the ratio of labor cost included in the process cost and to construct a system that can be easily maintained by simple cooling system configuration.

As described above, the plasma carburization apparatus according to the present invention can improve the direct finishing method after the carburizing treatment, thereby reducing the manufacturing cost of the equipment, facilitating the process, and facilitating maintenance. We have opened a way to supply carburizing facilities at a relatively low price. In particular, we can maximize the improvement of production efficiency of carburizing products and improvement of heat treatment quality. Particularly, the apparatus according to the present invention can provide a possibility of light design by reducing the processing cost by shortening the processing time in the heat treatment of power transmission mechanical parts, and maximizing wear resistance and fatigue resistance.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the gist of the invention.

Claims (4)

An apparatus for plasma carburizing a metal object to be treated, the apparatus comprising: a vacuum chamber for generating a plasma to carburize the metal object to be processed; a cooling chamber for quenching the metal object to be carburized; And transport means for separating the metal object to be processed from the chamber into a room temperature state and moving the metal object to be processed into the cooling chamber. The apparatus as claimed in claim 1, wherein the vacuum chamber has an aperture for mounting the metal object, and a lid for opening and closing the vacuum chamber, wherein the aperture and the cover are integrally formed. 3. The apparatus according to claim 2, wherein the moving time of the carburized material from the vacuum chamber to the cooling chamber is about 2 minutes or less. A method of plasma carburizing a metal object to be treated, the method comprising: a first step of generating a plasma in a vacuum chamber to carburize the metal object to be processed; and a second step of separating the object to be processed from the vacuum chamber And a third step of dewatering the object to be treated in a cooling bath. ※ Note: It is disclosed by original contents.