JPH0517817A - Hardening device - Google Patents

Abstract

PURPOSE:To allow the hardening treatments of different targets without changing the kind of a cooling liquid by controlling the atm. pressure in a hardening chamber at the time of hardening when various kinds of metals are going to be hardened. CONSTITUTION:A heated metallic member W to be hardened is imposed on an elevator 13 and is carried into the hardening chamber 2. This chamber is maintained in a hermetic state and the inside thereof is evacuated by a vacuum pump 17. The elevator 13 is then lowered to immerse the metallic member W into the cooling agent 9 for hardening in a cooling chamber 8 to harden the member. The metal W to be hardened is subjected to the hardening treatment while the atm. pressure of the hardening chamber 2 communicating with the hardening and cooling chamber 8 is adequately controlled by a program controller 22 inputted with pressure conditions for satisfying the quality required for the above-mentioned member under the opening and closing of a supply valve 18 and a work valve 21. Different hardening effects are obtd. without replacing the cooling agent 9 by the regulation of the of the atm. pressure in the hardening chamber 2 even if the materials of the metal W to be hardened and the physical properties after the hardening treatment are many and diversified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quenching device which is continuously installed on a heating device of a metal heat treatment device.

[0002]

2. Description of the Related Art Conventionally, when there are many kinds of objects to be heat-treated, the material, size, shape, etc. of each object to be processed and each object to be processed are required. Depending on the quality such as hardness, metal structure and amount of strain, prepare multiple quenching cooling liquid tanks containing liquid cooling agents of different types and temperatures, and use the cooling agent suitable for each workpiece. I was quenching.

However, the conventional method has a problem that the equipment cost and the operating cost are high and a large installation space is required. Moreover, in the case of a fully automatic line, there is a problem that the transport route becomes complicated.

Further, even by the conventional method, the state after quenching of the object to be treated is determined by the kind of the cooling agent, so that the quality such as hardness, metallographic structure and strain amount cannot be finely adjusted. There was a problem. That is, these qualities are determined by a cooling curve that represents the relationship between cooling time and temperature. For example, as shown by the solid line (A) in FIG. 3, in the first stage (X) of cooling, the vapor film of the coolant covers the entire surface of the object to be treated, so that the cooling rate is slow, and then the predetermined characteristic temperature is reached. The cooling rate increases sharply after shifting to the second stage (Y), and then to the third stage (Z) where cooling proceeds by convection, the cooling rate becomes the slowest (part C). The quality is changed by changing the time of each stage, the cooling rate, and the start or end temperature. However, since the cooling curve is determined by the type of coolant, it is not possible to delicately adjust the quality such as hardness, metallurgical structure and strain amount.Therefore, in order to solve this problem, the coolant is agitated or jetted to flow. It is considered that the temperature of the coolant is changed in advance, or that the concentration of the water-soluble coolant is changed when the coolant is used.

However, the method (1) has a problem that a uniform flow velocity of the coolant cannot be obtained and the strain of the object to be treated becomes large. The method (1) has a problem that it takes a long time to change the temperature and the degree of curing is limited. This method is the same as changing the type of the coolant, and has a problem that it cannot be applied to each object to be treated.

An object of the present invention is to provide a quenching device that solves the above problems.

[0007]

In a quenching apparatus according to the present invention, a quenching cooling liquid tank is provided in a quenching chamber having a closed structure, and a pressure control device for controlling the pressure in the quenching chamber. Is provided.

[0008]

When the pressure in the quenching chamber is changed during quenching, the cooling curve can be arbitrarily changed without changing the kind of the coolant.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of a quenching apparatus according to the present invention.

In FIGS. 1 and 2, the quenching apparatus includes a quenching chamber (2) which is connected to the heating chamber (1) of the heating device and has a closed structure. Exit (1) of heating chamber (1)
a), the entrance (2a) and the exit (2b) of the quenching chamber (2) are provided with movable doors (3), (4) and (5), respectively. The movable doors (4) and (5) provided at the entrance (2a) and the exit (2b) of the quenching chamber (2) are
It is designed to be pressed against the peripheral portions of the inlet (2a) and the outlet (2b) by the lock device (6) when closed.
At this time, the quenching chamber (2) is sealed by the O-ring (7) arranged between the inlet (2a) and the peripheral edge of the outlet (2b).

At the bottom of the quenching chamber (2) is a quenching cooling liquid tank (8)
Is provided in which the liquid coolant (9) is placed. The quenching cooling liquid tank (8) is provided with a stirrer (11) for flowing the coolant (9). Although not shown, the quenching cooling liquid tank (8) is provided with a temperature control device for the coolant (9). In the quenching chamber (2), there is provided an elevator (13) which moves up and down between the upper space (12) and the quenching cooling liquid tank (8).

The quenching chamber (2) has a space (1) above the quenching chamber (2).
2) A pressure adjusting device for adjusting the pressure inside is provided.
As shown in FIG. 1, the pressure adjusting device includes a pressure sensor (15) for detecting the pressure in the upper space (12) of the quenching chamber (2) and a quenching chamber (2).
A vacuum pump (17) connected to (2) via an exhaust valve (16) with an actuator, and a high pressure inert gas also connected to the quenching chamber (2) via an inert gas supply valve (18) with an actuator. Gas tank (19) and leak valve with actuator (2
1) and are provided. The pressure sensor (15), the exhaust valve (16), the inert gas supply valve (18) and the leak valve (21) are connected to the program controller (22). The program controller (22) is input with pressure conditions for obtaining a cooling curve satisfying the required quality of the object to be processed (W), which is obtained in advance by a small-sized experimental device. A safety valve (23) is installed in the quenching chamber (2).
Is provided.

In such a structure, the movable doors (3) and (4) at the outlet (1a) of the heating chamber (1) and the inlet (2a) of the quenching chamber (2) are opened to heat the heating chamber (1). The processed object (W) is carried into the upper space (12) of the quenching chamber (2) and placed on the elevator (13) in the raised position. And movable door (3) (4)
Is closed and the quenching chamber (2) is sealed. Then, the elevator (13) descends and the object to be processed (W) becomes the coolant.
(9) Immersed in. After the inside of the quenching chamber (2) is sealed, before or after the workpiece (W) is immersed in the coolant (9), the quenching chamber (2) is kept at a predetermined pressure with a pressure regulator. The pressure is maintained for a predetermined time. After that, the exhaust valve (16), the inert gas supply valve (18) and the leak valve are
(21) is opened and closed to pressurize and / or depressurize, and the quenching chamber
(2) The pressure inside is changed. When the cooling is completed, the elevator (13) rises and the movable door (5) at the exit (2b) is opened to carry it out.

In the above, the inside of the quenching chamber (2) is at normal pressure (1 ba
r), the cooling curve of the object to be processed (W) is shown by the solid line (A) in Fig. 3.
As shown in. When the pressure in the quenching chamber (2) is increased, the cooling rate in the first stage (X) increases and the first stage
The time of (X) becomes shorter and the cooling rate of the third stage (Z) becomes smaller. The cooling curves at 2 bar and 5 bar are shown by solid lines (B) and (C). Conversely, the quenching room
(2) As the pressure inside is reduced, the cooling rate in the first stage (X) decreases, the time in the first stage (X) becomes longer, and the cooling rate in the third stage (Z) increases. .. 0.5 bar
And the cooling curves at 0.1 bar are shown by the solid lines (D) and (E).
As shown in. Then, by adjusting the pressure in the quenching chamber (2) until the cooling is completed so that the pressurized state and the depressurized state are properly combined, the cooling curve is shown in FIG. Can be changed arbitrarily. Therefore, the required quality can be imparted to the object to be processed (W).

In the above embodiment, a bypass pipe is connected to the pipe connecting the quenching chamber (2) and the vacuum pump (17) so as to straddle the exhaust valve (16), and the exhaust valve is connected to this bypass pipe.
It is better to provide a valve with an actuator that has a smaller capacity than (16). Further, a bypass pipe is connected to the pipe connecting the quenching chamber (2) and the high-pressure inert gas tank (19) so as to straddle the supply valve (18), and the supply valve (1
It is better to install a valve with an actuator that has a smaller capacity than 8). These valves are also program controllers (22)
Connected to. This allows fine adjustment of the pressure inside the quenching chamber (2).

[0017]

According to the quenching apparatus of the present invention, the cooling curve can be arbitrarily changed without changing the kind of the coolant. Therefore, even when there are many kinds of objects to be processed, it is possible to give quality to each object to be processed.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of a quenching apparatus of the present invention.

FIG. 2 is a schematic side view showing an embodiment of the quenching apparatus of the present invention.

FIG. 3 is a graph showing a cooling curve when the pressure in the quenching chamber is changed.

[Explanation of symbols]

 2 Quenching room 8 Quenching cooling liquid tank

Claims (1)

Claim: What is claimed is: 1. A quenching cooling liquid tank is provided in a quenching chamber having a closed structure, and a quenching chamber is provided with a pressure control device for controlling the pressure in the quenching chamber. Input device.