JPH04337022A - Method and device for low-temperature heat treatment - Google Patents

Abstract

PURPOSE:To improve the uniformity of temps. by subjecting a work to a heating treatment by the hot water in a treating chamber, then cooling the work to a required temp. and taking out the work. CONSTITUTION:The treating chamber 1 which can house the work and is provided with a hermtically closable open/close cap 10, a hot water storage chamber 2, a boiler 3, a feed water pump 5, a hot water circulating pump 6, a hot water transfer pump 7, a hot water heating or cooling pipe 8, and a cooling water supplying pump 9 are provided. The work is treated in the hot water and taken out after a temp. fall.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low temperature heat treatment method and apparatus for heat treating objects to be treated, such as metal materials and products, in a low temperature range (80 to 250 DEG C.).

0002

[Prior Art] In general, low-temperature heat treatment of metal products such as molds, etc. is carried out using a hot air circulation heating method and an oil bath (oil bath).
(oil bath) heating method is adopted. Conventionally, many heat treatment specialists have adopted an oil bath heating method from the viewpoint of uniformity of heating temperature and efficiency of heat treatment time.

0003

[Problems to be Solved by the Invention] In the conventional oil bath heating method, high viscosity oil is heated and the object to be treated is immersed in the oil for heat treatment.
It takes time and effort to remove the oil from the processed material after the treatment is completed, resulting in poor post-treatment efficiency, and there are other problems, such as the constant use of oil and the risk of fire.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to eliminate the need for post-treatment after heat treatment, improve temperature uniformity, and reduce the risk of fire. An object of the present invention is to provide a low-temperature heat treatment method and an apparatus for the same, which can solve the problem.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention takes the following technical measures. That is, in the method of the present invention, the object to be treated is directly heated to the required temperature using hot water in the treatment tank in a treatment tank equipped with a sealable lid, and after the treatment is completed, the inside of the treatment tank is heated to the required temperature. The feature is that the object to be processed is taken out after cooling to a certain temperature and discharging the hot water.

[0006] The apparatus of the present invention also includes a processing tank that can accommodate the object to be processed and is equipped with a sealable opening/closing lid, a means for supplying water to the processing tank, a means for heating hot water, and a means for lowering the temperature inside the tank. It is characterized in that it is equipped with the following features and is capable of processing the object to be processed in hot water. Furthermore, the apparatus of the present invention is characterized by comprising a hot water storage tank for temporarily storing hot water, and a hot water transfer means for transferring hot water between the processing tank and the hot water storage tank.

[0007] Note that hot water circulation stirring means may be provided within the processing tank.

[0008]

[Operation] According to the present invention, the object to be treated is housed in the treatment tank and sealed with an opening/closing lid, water or hot water is injected into the treatment tank,
The water in the tank is heated to the heat treatment temperature and maintained at that temperature for the required time. Therefore, when the heat treatment is finished, the temperature of the hot water in the treatment tank is lowered, and even if the object to be treated is taken out, it will not change color (oxidation).
When the temperature has reached such a temperature that no oxidation occurs, the hot water is discharged from the treatment tank and stored in the hot water storage tank. When the hot water in the treatment tank disappears and the pressure becomes equal to atmospheric pressure, the lid is opened and the material to be treated is removed. Remove from treatment tank. When the workpiece is taken out of the treatment tank, its residual heat (around 100°C) quickly evaporates the adhering moisture and dries it quickly, so there is no risk of rusting in the case of metal, and no post-processing is required. It is.

[0009] Next, when performing heat treatment, the object to be treated is placed in the treatment tank, the opening/closing lid is sealed, the hot water in the hot water storage tank is supplied into the treatment tank, and the above-mentioned operation is repeated. It can be processed efficiently.

0010

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is a flow sheet showing an example of the present invention.
is a treatment tank, 2 is a hot water storage tank, 3 is a boiler, 4 is a water tank,
5 is a water supply pump, 6 is a hot water circulation pump, 7 is a hot water transfer pump, 8 is a hot water heating or cooling pipe, and 9 is a cooling water supply pump.

The processing tank 1 has a lid 10 that can be opened and closed.
The sealing state can be confirmed by a limit switch 11, and a one-touch clutch door is adopted as the opening/closing lid 10, so that it can be opened and closed in a short time. The hot water heating or cooling pipe 8 is disposed inside the processing tank 1, and a temperature indicating controller 1 is provided.
2. Temperature recorder 13, pressure switch 14, full water level switch 15, low water level switch 16, hot water blow valve 1
7. A pressure relief valve 18, a pressure gauge 19, and a safety valve 20 are installed, and a hot water circulation pipe 21 with a hot water circulation pump 6 interposed therein is connected. Further, to the treatment tank 1, a water supply pipe 23 having the water supply pump 5 and a water supply source valve 22 is connected to constitute a water supply means, and the hot water transfer pump 7, hot water discharge valves 24, 25, and A hot water transfer pipe 28 with hot water supply valves 26 and 27 interposed therebetween is connected to constitute a hot water transfer means. Note that a hot water blow valve 29 is provided in the middle of the hot water transfer pipe 28.

The hot water storage tank 2 includes the hot water transfer pipe 2.
8 is connected via the stop valve 30, and the full water level switch 3
1. A pressure relief valve 32, a pressure switch 33, a pressure gauge 34, and a safety valve 35 are provided to temporarily store hot water and reduce heating costs through effective use of heat.
By shortening the heating time of the internal hot water, the processing time for the material to be processed is shortened. When the internal pressure of the hot water storage tank 2 exceeds the set pressure, the pressure switch 33 is activated and the pressure relief valve 32 is opened. , the internal pressure of the storage tank 2 is prevented from rising above a predetermined value.

Steam generated in the boiler 3 is supplied to the inlet 8A of the hot water heating or cooling pipe 8 through a steam pipe 36 via a steam source valve 37 and an on-off valve 38. 3 and a heating or cooling pipe 8, etc. constitute a hot water heating means. And steam pipe 36
A cooling water supply pipe 39 is connected between the inlet 8A of the cooling pipe 8 and the on-off valve 38, and the cooling water supply pipe 39 is led to the water tank 4, and the cooling water supply pump 9, A cooling water source valve 40 and an on-off valve 41 are interposed to constitute an in-tank temperature lowering means.

Two drain pipes 42 and 43 are connected to the outlet 8B of the hot water heating or cooling pipe 8, one drain pipe 42 is provided with a cooling release valve 44, and the other drain pipe 42 is provided with a cooling release valve 44. 43 is provided with a main valve 45 and a steam trap 46. 47 is a control panel. In the above embodiment,
When heat-treating objects to be treated, open/close lid 1 of treatment tank 1
0 is opened and the material to be treated is placed in the processing tank 1 in the absence of hot water. When the opening/closing lid 10 is closed and the limit switch 11 is activated to confirm the sealed state, the water supply source valve 22 is opened. The water supply pump 5 is operated to inject water into the treatment tank 1, and the water supply pump 5 is stopped by operating the full water level switch 15, and at the same time, the water supply source valve 22 is closed. next,
Steam from the boiler 3, which has started operation in advance, is passed through the hot water heating or cooling pipe 8 by opening the steam source valve 37 and the on-off valve 38.
At the same time, the hot water circulation pump 6 is operated to heat the water in the treatment tank 1 to make the temperature distribution of the water in the tank 1 uniform. The valve 37 repeats opening and closing, and heat treatment is performed at a constant temperature for a certain period of time. When the pressure inside the processing tank 1 exceeds the set value, the pressure relief valve 18 is opened by a signal from the pressure switch 14, and the pressure inside the tank 1 is controlled to be below the set value.

When the heat treatment of the object to be treated is completed, the steam source valve 37 is closed, the cooling water supply pump 9 is started, and at the same time, the cooling source valve 40 and the open valve 44 are opened (the on-off valve 41 was opened in advance). ), cooling water is supplied to the hot water heating or cooling pipe 8, and the steam in the cooling pipe 8 is replaced with cooling water, and the material to be processed is quickly heated to a temperature at which it will not discolor (oxidize) even if it is taken out into the air. The temperature drops. When the temperature of the hot water in the treatment tank 1 drops to a predetermined temperature, the hot water transfer pump 7 starts operating, and at the same time, the hot water discharge valves 24 and 2
5 is opened, the hot water is transferred to the hot water storage tank 2 and temporarily stored, and the hot water in the treatment tank 1 becomes low and the low water level switch 16 is activated, and the signal from the switch 16 turns on the hot water transfer pump. 7 stops and the hot water discharge valves 24, 2
5 is closed, and at the same time, the blow valve 17 is opened and the pressure inside the processing tank 1 is lowered until it becomes equal to atmospheric pressure. Processing tank 1
When the pressure inside becomes equal to atmospheric pressure, the opening/closing lid 10 is opened and the object to be processed is taken out.

The objects to be treated taken out from the treatment tank 1 are 1
Since it has self-heat (its own residual heat) that reaches 00°C, moisture adhering to the object to be processed evaporates rapidly.
Since it dries quickly immediately after being taken out, there is no risk of rusting on metal objects, and post-treatment is not necessary. Subsequently, when heat-treating the object to be treated, the object to be treated is placed in the treatment tank 1 and the opening/closing lid 10 is closed. At the same time, the hot water transfer pump 7 is started and the hot water supply valve 26 is closed.
, 27 are opened, the hot water in the storage tank 2 flows into the treatment tank 1.
The pressure relief valve 18 is opened by the signal from the pressure switch 14, and the hot water supply continues until the signal from the full water level switch 15 is output. When the operation of the hot water circulation pump 6 is started, the steam source valve 37 is opened, heating is started, and the above-described operation is repeated.

[0017] Note that the bright tempering treatment can be carried out by mixing an oxygen scavenger with the hot water. In addition, in the case of tempering treatment for forming molds, it may be necessary to repeat the tempering process two or three times depending on the steel type, but in the above example, the process can be repeated multiple times automatically by program control. . Furthermore, in order to increase the temperature increase efficiency, the treatment tank 1
Steam can be directly introduced into the water to heat it.

In the above embodiment, there is one treatment tank 1 and one hot water storage tank 2, but for objects that require time to cool down after the treatment, two treatment tanks 1 and two hot water storage tanks are used. By using only one storage tank 2, processing efficiency can be improved. The hot water heating means can be provided outside the processing tank 1 , for example, inside the hot water storage tank 2 , or it can be provided on the outer periphery of the processing tank 1 for external heating. Further, instead of steam, a heat source such as electricity, gas, kerosene, etc. can be used.

In the processing tank 1, hot water circulation stirring means is provided.
(For example, stirring blades, etc.) can be provided to ensure uniformity of the temperature of the hot water so that the heat treatment can be performed evenly. FIGS. 2 and 3 show a batch-type embodiment of the apparatus of the present invention, in which an electric heater 48 is arranged around the outer periphery of the processing tank 101.
The hot water in the treatment tank 101 is heated from the outside to raise the pressure and temperature.The opening/closing lid 110 is tightly sealed by bolts 49, and is surrounded by heat insulation covers 50, 51. In addition, 52 is a water supply and drainage pipe, 53 is a flow control valve, 54 is a thermocouple, 55 is a safety valve, 56 is a pressure gauge, 5
7 is a terminal cover of the heater 48, and the processing tank 1
A hot water circulation stirring blade (not shown) is installed inside the chamber to ensure uniform temperature.

In this embodiment as well, similarly to the embodiment shown in FIG.
01, and after sealing the opening/closing lid 110, hot water or water is supplied into the processing tank 101 from the water supply/drainage pipe 52, and the water is heated by the electric heater 48 and maintained at a predetermined temperature for a certain period of time. After finishing, drain the hot water and open/close the lid 110.
Open and take out the object to be processed.

Note that the electric heater 48 is connected to the processing tank 1.
Further, hot water heated to a required temperature by a separately provided hot water heater (for example, a boiler) may be supplied to the processing tank 101 . The present invention is not limited to the above embodiments, and the design can be modified as appropriate.

[0022]

[Effects of the Invention] As described above, the method of the present invention involves directly heat-treating the object to be treated in a treatment tank equipped with a sealable opening/closing lid to a required temperature using hot water in the treatment tank. After the heat treatment is completed, the inside of the processing tank is cooled to the required temperature, the hot water is discharged, and then the processed material is taken out. Therefore, there is no need for post-processing of the processed material after the heat treatment is completed, which is different from conventional methods. Compared to the oil bath heating method described above, temperature uniformity can be further improved, the risk of fire can be eliminated, and workability can be improved.

As described above, the apparatus of the present invention includes a processing tank capable of accommodating objects to be processed and equipped with a sealable opening/closing lid, a means for supplying water to the processing tank, a means for heating hot water, and a means for lowering the temperature inside the tank. Since the method is characterized in that the object to be treated can be treated in hot water, it is possible to efficiently and automatically heat treat the object to be treated, and furthermore, Discoloration of the object to be treated can be prevented, and the heat treatment cycle time can be shortened.

Furthermore, the apparatus of the present invention is characterized in that it is equipped with a hot water storage tank for temporarily storing hot water, and a hot water transfer means for transferring hot water between the treatment tank and the hot water storage tank. Therefore, hot water can be reused, fuel and electricity can be saved through effective use of heat, and the time of the heat treatment cycle can be shortened. Furthermore, since the apparatus of the present invention is equipped with a hot water circulation stirring means in the treatment tank, the temperature distribution of the hot water in the treatment tank can be made uniform, and good and uniform heat treatment is possible. .

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing an example of the present invention.

FIG. 2 is a front view showing another embodiment of the device of the present invention.

FIG. 3 is a plan view of FIG. 2;

[Explanation of symbols]

1 Processing tank 2 Hot water storage tank 3 Boiler 4 Aquarium 5 Water supply pump 6 Hot water circulation pump 7 Hot water transfer pump 8 Hot water heating or cooling pipe 9 Cooling water supply pump 10 Opening/closing lid 48 Electric heater 52 Water supply and drainage pipes 101 Processing tank 110 Opening/closing lid

Claims (4)

[Claims] Claim 1: The object to be processed is directly heated to a desired temperature using hot water in the processing tank in a processing tank equipped with a sealable lid, and after the processing is completed, the processing tank is cooled to the required temperature. A low-temperature heat treatment method characterized by removing the object to be treated after discharging the hot water. 2. A treatment tank that is capable of accommodating the object to be treated and has a sealable opening/closing lid, a means for supplying water to the treatment tank, a means for heating hot water, and a means for lowering the temperature inside the tank. A low-temperature heat treatment device characterized in that it is capable of treating in hot water. 3. The low-temperature heat treatment apparatus according to claim 2, further comprising a hot water storage tank for temporarily storing hot water, and hot water transfer means for transferring hot water between the processing tank and the hot water storage tank. 4. The low-temperature heat treatment apparatus according to claim 2 or 3, wherein the treatment tank is provided with hot water circulation stirring means.