JP2006183874A - Heat treating apparatus and method of manufacturing heat treated parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treating apparatus capable of performing heat treatment of higher quality by obtaining higher cooling speed, and to provide a method of manufacturing heat treated parts. <P>SOLUTION: This heat treating apparatus 1 has a heating means 6 for heating a heat treated object W; a cooling tank 2c containing a cooling liquid 4 for cooling the treated object heated by the heating means; a pressure chamber 2 storing at least the cooling tank; a pressurizing means 12 for pressurizing the inside of the pressure chamber; and a put-in means 10 for putting the treated object heated by the heating means, into the cooling tank stored in the pressure chamber pressurized by the pressurizing means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat treatment apparatus and a method for manufacturing a heat treated part, and more particularly to a heat treatment apparatus for cooling a heated object to be processed with a coolant and a method for manufacturing the heat treated part.

  Currently, heat treatment is widely performed in manufacturing processes of various machine parts. In particular, quenching in which a part to be heat-treated is heated and then rapidly cooled is widely performed. As a cooling medium for rapidly cooling a heated part to be heat-treated when quenching, liquids such as heat-treated oil and cooling water, gases such as inert gas, salt, and the like are known. In addition, as a cooling method using a cooling liquid such as heat-treated oil or cooling water, there are known methods such as putting a heated part into a cooling tank containing a cooling liquid, and causing the cooling liquid to flow down to the heated part. It has been.

  The effect of heat treatment such as quenching varies depending on the temperature at which the part is heated, the temperature of the coolant, and the cooling rate of each part of the part to be heat-treated. In particular, in quenching, in order to cure the object to be processed without causing quenching cracks or quenching distortion, an appropriate cooling rate according to the material of the object to be processed is required, and various heat treatment methods have been tried. ing. When the heat treatment method is not appropriate, there arises a problem that the heat treated parts are deformed and the effect of the heat treatment varies between parts in the same lot. A quenching method in which a part to be heat-treated is put into a cooling tank containing a cooling liquid is widely adopted. In this method, the temperature of the cooling liquid in the cooling tank is made uniform to cool the part. In order to increase the speed and make the cooling speed of each part of the parts uniform, the cooling liquid is stirred by a propeller stirrer or a jet stirrer. Japanese Patent Application Laid-Open No. 2003-286517 discloses a quenching apparatus in which a vibration stirrer is used in combination with a jet stirrer in a cooling tank to suppress variation in heat-treated parts in a lot.

  Further, in the heat treatment method in which the parts to be heat treated are put into the cooling tank, there is a limit to the cooling rate of the parts to be heat treated. FIG. 3 is an example of a cooling curve when a component to be heat-treated is put into cooling oil in a conventional heat treatment apparatus. As shown in FIG. 3, the temperature of the heat-treated component first decreases to a linear shape with a relatively gentle slope after being put into the cooling bath, and then reaches a temperature at point M called a characteristic temperature. The temperature drops while drawing an exponential curve. Immediately after being put into the cooling bath, the temperature difference between the heat-treated parts and the coolant is the largest, so the maximum cooling rate should be obtained. However, the actual cooling rate is relatively slow, and after reaching the M point, the cooling rate Is the maximum. It is known that this phenomenon occurs when the heat-treated component is covered with a vapor film of a cooling liquid evaporated by the heat immediately after the heated heat-treated component is put into the cooling bath. That is, when the heat-treated component is covered with the vapor film, heat is transferred by heat conduction and radiation cooling of the vapor film, but the vapor film, which is a gas, has a low density and high heat insulation, so the cooling rate decreases. .

Next, when the temperature of the heat-treated component is lowered to the M point, the vapor film around the heat-treated component is not formed, and the coolant comes into direct contact with the heat-treated component. When the coolant comes into direct contact with the heat-treated component, the coolant is boiled, and the heat of the heat-treated component is taken away by convection of the coolant in the cooling bath. Thus, the cooling rate is maximized immediately after the coolant comes into direct contact with the heat treated component. When the temperature further decreases and the coolant directly in contact with the heat treated component does not boil, the heat of the heat treated component is taken away by convective heat transfer and heat conduction. At this stage, the temperature of the heat-treated component is lowered, and the temperature difference between the heat-treated component and the cooling liquid is reduced, so that the cooling rate is reduced.
Also, in the heat treatment of large parts, the cooling rate is greatly different in each part of a single heat treatment part, such as the part is surrounded by a vapor film and the other part is cooled by cooling liquid convection. In some cases. In such a case, a large quenching distortion may occur in the heat-treated component due to the difference in the cooling rate of each part.

  Therefore, by suppressing the phenomenon that the heat-treated component is covered with the vapor film immediately after the heat-treated component is put into the cooling bath, it becomes possible to increase the cooling rate of the heat-treated component and to suppress the occurrence of quenching distortion. In order to make the phenomenon that the heat-treated parts are covered with the vapor film less likely to occur and to increase the cooling rate, the cooling liquid in the cooling tank is agitated as described above.

JP 2003-286517 A

However, although it is possible to increase the cooling rate by agitating the cooling liquid in the cooling bath as in the conventional heat treatment apparatus, it is not possible to sufficiently satisfy the increasing demand for heat treatment in recent years. There's a problem. Further, in the method of stirring the cooling liquid, the flow rate of the cooling liquid around the heat-treated parts is not necessarily uniform, so it is difficult to keep the cooling rate at each part of the heat-treated parts constant and prevent quenching distortion. is there.
Therefore, the present invention provides a heat treatment apparatus capable of obtaining a higher cooling rate than a conventional heat treatment apparatus and capable of performing a heat treatment with higher quality than a conventional heat treatment apparatus, and a method of manufacturing a heat treatment component. The purpose is to do.

  In order to solve the above-described problems, the heat treatment apparatus of the present invention includes a heating unit that heats a workpiece, a cooling tank that contains a coolant for cooling the workpiece heated by the heating unit, and A pressure chamber containing at least a cooling tank, a pressurizing means for pressurizing the inside of the pressure chamber, and an object heated by the heating means were accommodated in a pressure chamber pressurized by the pressurizing means. And a charging means for putting in the cooling tank.

In the present invention configured as described above, the workpiece is heated by the heating means and immersed in the cooling liquid in the cooling tank accommodated in the pressure chamber pressurized by the pressurizing means. The coolant around the object to be processed placed in the cooling tank is evaporated by the heat of the object to be processed. However, since the cooling tank is accommodated in the pressurized pressure chamber, the formation of the vapor film of the cooling liquid around the object to be processed is suppressed, or the formed vapor film becomes thin.
According to the present invention configured as described above, the formation of the vapor film around the object to be processed is suppressed, or the thickness of the formed vapor film is reduced, so that the cooling rate of the object to be processed is increased. Can do. In addition, the action of suppressing the formation of the vapor film by pressurization or reducing the thickness of the vapor film to be formed works uniformly around the object to be processed, so that the uneven cooling rate due to the influence of the vapor film is greatly reduced. Can be reduced.

In the present invention, the pressurizing means preferably has a gas container containing a high-pressure gas, and pressurizes the pressure chamber by introducing the high-pressure gas from the gas container into the pressure chamber.
According to the present invention configured as described above, it is possible to easily increase the pressure in the pressure chamber by simply connecting a commercially available gas container without using a special device.

In the present invention, it is preferable to further have a stirring means for stirring the coolant in the cooling bath.
According to the present invention configured as described above, the temperature of the cooling liquid in the cooling tank can be made uniform, and the formation of a vapor film around the object to be processed is obstructed. The cooling rate can be further increased.

Further, in the present invention, preferably, a granular material is mixed in the cooling liquid in the cooling tank.
According to the present invention configured as described above, since the particulate matter mixed in the cooling liquid interferes with the formation of a vapor film around the object to be processed, the cooling rate of the object to be processed is further increased. Can do.

Preferably, in the present invention, the charging means puts the workpiece into the cooling tank in a state where the pressure in the pressure chamber is 0.1 to 30 MPa (1.02 to 306 kgf / cm ² ) in terms of gauge pressure.
According to the present invention configured as described above, the formation of the vapor film around the object to be processed can be effectively suppressed, or the thickness of the formed vapor film can be effectively reduced.

  The method for manufacturing a heat-treated component according to the present invention includes a step of forming a component to be heat-treated, a step of heating the formed component by a heating means, and a cooling tank containing a coolant into which the component has been carried. It is characterized by having a step of pressurizing the pressure in the accommodated pressure chamber by a pressurizing means, and a step of putting the heated component into the cooling liquid of the cooling tank.

  According to the present invention configured as described above, the formation of the vapor film around the heat-treated component is suppressed or the thickness of the formed vapor film is reduced, so that the cooling rate of the heat-treated component is increased. High quality heat-treated parts can be obtained. In addition, the action of suppressing the formation of the vapor film by pressurization or reducing the thickness of the vapor film to be formed works uniformly around the object to be processed, so that the uneven cooling rate due to the influence of the vapor film is greatly reduced. Can be reduced.

  Furthermore, the method for manufacturing a heat-treated component of the present invention includes a step of forming a component to be heat-treated, a step of carrying the formed component into a pressure chamber, a step of sealing the pressure chamber, and a pressure in the pressure chamber. The step of pressurizing by the pressurizing means, the step of heating the parts to be heat-treated carried in the pressure chamber, the stage of heating by the heating means, and the heated parts are placed in the cooling tank containing the coolant contained in the pressure chamber. And a step of entering.

  According to the present invention configured as described above, the formation of the vapor film around the heat-treated component is suppressed or the thickness of the formed vapor film is reduced, so that the cooling rate of the heat-treated component is increased. High quality heat-treated parts can be obtained. In addition, the action of suppressing the formation of the vapor film by pressurization or reducing the thickness of the vapor film to be formed works uniformly around the object to be processed, so that the uneven cooling rate due to the influence of the vapor film is greatly reduced. Can be reduced.

  According to the heat treatment apparatus and the method for producing a heat treated component of the present invention, a higher cooling rate and higher quality heat treatment can be performed.

Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
First, a heat treatment apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of the heat treatment apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the heat treatment apparatus 1 of the present embodiment includes a pressure vessel 2 that is a pressure chamber, a heater 6 that is a heating means disposed therein, and a heat insulating material 8 that surrounds the heater 6. And an elevator 10 that is an input means that extends from the outside to the inside of the pressure vessel 2 and can support a workpiece W as a workpiece at the tip. Furthermore, the heat treatment apparatus 1 of the present embodiment includes a gas container 12 containing high-pressure nitrogen gas, and a pressure reducing valve 14 and an opening / closing valve 16 provided in a pipe line connecting the gas container 12 and the pressure container 2. Have. The gas container 12, the pressure reducing valve 14, and the on-off valve 16 constitute a pressurizing means. In addition, the heat treatment apparatus 1 of the present embodiment includes a propeller 18 that is disposed at the bottom of the pressure vessel 2 and that stirs the coolant, and a motor 20 that drives the propeller 18 to rotate. The propeller 18 and the motor 20 constitute stirring means.

The pressure vessel 2 includes a generally cylindrical body 2a and hemispherical end plates 2b and 2c attached to the upper and lower sides thereof. The lower end plate 2c contains heat treatment oil 4 as a cooling liquid, and the lower part of the pressure vessel 2 functions as a cooling tank. The lower end plate 2c is formed with a cylindrical propeller mounting portion 2d extending in the horizontal direction. The shaft of the propeller 18 extends to the outside of the pressure vessel 2 through the propeller attachment portion 2 d and is coupled to the output shaft of the motor 20. Furthermore, the upper end plate 2b includes a safety valve 22 for preventing the pressure vessel 2 from rupturing due to an abnormally high pressure inside the pressure vessel 2, and a gas release valve 26 for releasing the gas in the pressure vessel 2. Is installed. In addition, two observation windows 23 for observing the cooling state of the workpiece W are provided in a portion where the heat treatment oil 4 at the lower part of the pressure vessel 2 is placed (only one is shown by an imaginary line). Further, a water cooling jacket (not shown) is provided around the lower portion of the pressure vessel 2, and a heat treatment oil heater (not shown) is provided at the lower portion of the pressure vessel 2, so that the heat treatment oil in the pressure vessel 2 is heat treated. It can be cooled to a temperature suitable for the heating or heating. In the present embodiment, the pressure vessel 2 is made of SUS304 and is designed to be used at an internal pressure of 3 MPa (30.6 kgf / cm ² ).

The heater 6 is a coil-shaped electric heater and is supported so as to be positioned above the inside of the pressure vessel 2. The heater 6 is configured to heat the workpiece W when the elevator 10 rises and the workpiece W supported by the elevator 10 is positioned inside the heater 6.
The heat insulating material 8 is supported above the inside of the pressure vessel 2 so as to surround the heater 6. A hole for passing the shaft 10a of the elevator 10 is provided on the upper surface of the heat insulating material 8, and an opening for taking in and out the workpiece W is formed on the bottom surface. The other part of the heat insulating material 8 is formed so as to surround the periphery of the heater 6, so that the heat of the heater 6 does not easily escape to the outside of the heat insulating material 8. In the present embodiment, the heat insulating material 8 is made of ceramic fiber.

  The elevator 10 serving as the charging means has a shaft 10a extending from the outside to the inside of the pressure vessel 2, and a work W is attached to the tip of the shaft 10a. Further, the shaft 10 a is configured to be movable from an ascending position where the workpiece W is located inside the heater 6 to a descending position where the workpiece W is immersed in the heat treatment oil placed in the lower portion of the pressure vessel 2. ing. Further, a seal 24 is disposed at a portion through which the shaft 10 a of the pressure vessel 2 passes, and the airtightness of the pressure vessel 2 is maintained. In this embodiment, the shaft 10a is made of SUS304 and is moved up and down by the driving force of the air cylinder. In the present embodiment, the workpiece W is directly attached to the tip of the shaft 10a. However, depending on the type of the workpiece W, the workpiece W may be suspended from the tip of the shaft 10a. A suitable basket may be suspended at the tip, and the workpiece W may be placed therein. In the present specification, the input means means all means for putting the work W into the heat treatment oil, such as means for immersing the work W in the heat treatment oil by an elevator and means for dropping the work W into the heat treatment oil. Means.

The gas container 12 contains high-pressure nitrogen gas. By sending nitrogen gas from the gas container 12 into the pressure container 2, the inside of the pressure container 2 is brought to a predetermined high pressure. In addition, a pressure reducing valve 14 and an on-off valve 16 are provided in series in the middle of a conduit for introducing nitrogen gas from the gas container 12 into the pressure container 2. By opening the on-off valve 16, nitrogen gas can be sent into the pressure vessel 2 and the pressure in the pressure vessel 2 can be increased to a predetermined pressure set by the pressure reducing valve 14. In the present embodiment, when the workpiece W is rapidly cooled, the pressure in the pressure vessel 2 is increased to 3 MPa as a gauge pressure. The pressure in the pressure vessel 2 can be set to a gauge pressure of about 0.1 to 30 MPa (1.02 to 306 kg / cm ² ) depending on the workpiece W to be heat-treated and the required heat treatment conditions. Considering the effect of pressurization and the economical efficiency of the heat treatment equipment, it is more preferable to set the gauge pressure to about 0.3 to 3 MPa (3.06 to 30.6 kg / cm ² ).

  The propeller 18 is disposed in a portion that functions as a cooling tank containing heat-treated oil at the lower portion of the pressure vessel 2. Further, the propeller 18 is driven by a motor 20 and is configured to make the temperature of the heat treatment oil in the cooling tank uniform when the heat treatment oil is stirred to rapidly cool the workpiece W.

  Next, the operation of the heat treatment apparatus 1 according to the first embodiment of the present invention will be described. First, the shaft 10a of the elevator 10 is pulled out from the pressure vessel 2, and the workpiece W is attached to the tip of the shaft 10a. In the present embodiment, the workpiece W is attached to the tip of the shaft 10a by screwing. Next, the shaft 10a to which the workpiece W is attached is inserted into the pressure vessel 2, and the pressure vessel 2 is sealed.

  After inserting the shaft 10 a into the pressure vessel 2, the elevator 10 is lowered until the workpiece W is positioned inside the heater 6. Next, a current is passed through the heater 6 to heat the workpiece W inside the heater 6. After a current is passed through the heater 6 for a predetermined time to heat the workpiece W to a predetermined temperature, the current passed through the heater 6 is turned off at an appropriate timing. Although the temperature at which the workpiece W is heated depends on the material of the workpiece W, in the present embodiment, the workpiece W is heated to 850 ° C. Next, the motor 20 is started and the propeller 18 is rotated to stir the heat-treated oil.

On the other hand, nitrogen gas in the gas container 12 is introduced into the pressure vessel 2 by opening the on-off valve 16 while stirring the heat-treated oil. Although nitrogen gas having a pressure of about 15 MPa is accommodated in the gas container 12, the nitrogen gas is decompressed to about 3 MPa (30.6 kg / cm ² ) by the pressure reducing valve 14 and flows into the pressure container 2. When the pressure in the pressure vessel 2 rises to about 3 MPa due to the inflow of nitrogen gas, the inflow stops and the on-off valve 16 is closed.

  If the pressure in the pressure vessel 2 rises to a predetermined pressure, the elevator 10 is lowered and the workpiece W is immersed in the heat treatment oil. When the high-temperature work W is immersed in the heat treatment oil, the heat treatment oil around the work W is heated by the heat of the work W. In the heat treatment apparatus 1 of the present embodiment, since the inside of the pressure vessel 2 is maintained at a high pressure, the heat treatment oil is not easily vaporized even when the heat treatment oil is heated, and a vapor film of the heat treatment oil is formed around the workpiece W. It becomes difficult. Even if a vapor film of heat-treated oil is formed around the workpiece W, the pressure inside the pressure vessel 2 is much higher than the atmospheric pressure. Is much thinner than if Furthermore, since the inside of the pressure vessel 2 is at a high pressure, the density of the steam of the heat-treated oil that forms the steam film becomes larger than when the ambient pressure is atmospheric pressure, and the amount of heat conducted through the steam film also increases. . Further, the stirring of the heat-treated oil by the propeller 18 also acts to hinder the formation of a vapor film of the heat-treated oil around the workpiece W.

As a result, the point M of the cooling curve shown in FIG. 3 moves to the upper left, and the vapor film stage becomes very short or disappears. Thereby, the boiling stage or the convection stage starts immediately after the work W is immersed in the heat treatment oil, and the work W is cooled at a very high speed. Moreover, since the effect of pressurizing the inside of the pressure vessel 2 extends uniformly over the entire work W, the difference in the cooling rate at each part of the work W is reduced. Further, in the cooling by the heat treatment apparatus of the present embodiment, the M point of the cooling curve is eliminated or the influence thereof is almost eliminated, so that the cooling curve does not occur in the cooling curve while using the heat treatment oil as the cooling medium. It is similar to gas cooling or salt bath cooling.
Subsequently, when the temperature of the workpiece W is lowered to a predetermined temperature, the heat treatment of the workpiece W is completed. Next, the gas release valve 26 is opened to reduce the pressure in the pressure vessel 2 to atmospheric pressure, and then the shaft 10a is pulled out from the pressure vessel 2 and the heat-treated workpiece W is taken out.

  According to the heat treatment apparatus of the first embodiment of the present invention, since the formation of a vapor film around the work W immediately after the start of cooling is suppressed, the amount of heat transferred from the work W to the heat treatment oil immediately after the start of cooling can be increased. The cooling rate of the workpiece W can be increased. This makes it possible to perform high-quality heat treatment.

In addition, according to the heat treatment apparatus of the present embodiment, the effect of pressurizing the inside of the pressure vessel is uniformly applied to the entire work W. Therefore, the difference in the cooling rate in each part of the work W is reduced, and quenching distortion is reduced. Occurrence can be suppressed.
Furthermore, according to the heat treatment apparatus of the present embodiment, while using the heat treatment oil as a cooling medium, its cooling curve is similar to that of gas cooling or cooling by a salt bath, so that the coolant, cooling gas, salt, etc. Heat treatment that combines the advantages of cooling with can be realized.

In the above-described embodiment, a part of the pressure vessel is used as a cooling tank. However, the cooling tank may be configured separately and disposed in the pressure vessel. In the present specification, the “cooling tank accommodated in the pressure chamber” includes a case where a part of the pressure chamber is used as a cooling tank as in the present embodiment.
Furthermore, in the above-described embodiment, after heating the workpiece, the inside of the pressure vessel is pressurized, and the workpiece is put into a cooling liquid to be rapidly cooled. However, after the inside of the pressure vessel is pressurized, the workpiece is heated. Anyway.

In the above-described embodiment, the workpiece is heated by the electric heater. However, the workpiece may be heated by a combustion gas, a high-frequency coil through which a high-frequency current is passed, or the like. In the above-described embodiment, the coolant is stirred by the propeller, but any stirring means such as a jet stirrer or a vibration stirrer can be used.
Furthermore, in the embodiment described above, the temperature of the heat treatment oil is adjusted by a water cooling jacket (not shown) and a heat treatment oil heater (not shown), but the heat treatment oil is circulated to an external heat exchanger. It is also possible to adjust the temperature.

  In the above-described embodiment, the inside of the pressure vessel is pressurized by flowing nitrogen gas, but as introduced gas, inert gas such as argon gas, air, carbon dioxide gas, nitrogen and hydrogen, nitrogen and Carbon monoxide, a mixed gas of nitrogen and carbon dioxide, or the like can be used. In addition, when using an active gas mixed with an inert gas, it is good to mix and use them in the ratio within an explosion limit. In the above-described embodiment, the pressure in the gas container is used as a means for pressurization. However, when a liquefied gas is used, or depending on the type of gas used and the pressure used, a booster or the like is used. The pressure vessel can be pressurized.

  Alternatively, the inside of the pressure vessel can be pressurized without using a gas vessel or a booster. That is, when the gas is heated in the sealed pressure vessel, the gas expands due to the temperature rise, and the pressure in the pressure vessel rises. In this case, the heater for heating the gas acts as a pressurizing means. In the present specification, the term “gas container” is used as a general term for containers containing gas, such as small containers and medium containers.

  Furthermore, in the above-described embodiment, the heat treatment oil is used as the cooling liquid. However, in addition to the heat treatment oil, various liquids such as martemper oil, water, and a water-soluble coolant can be used as the cooling liquid. When heat-treated oil is used as the coolant, the heat-treated oil is adjusted to hot (100 to 200 ° C), semi-hot (100 to 130 ° C), or cold (room temperature to 80 ° C) for heat treatment. When using martemper oil, heat treatment is often carried out by adjusting the temperature to about 150-300 ° C, and when using water, about 10-35 ° C. Can also be done.

  Further, the heat treatment apparatus of the present embodiment is subjected to various heat treatments such as gas carburization and bright quenching. For example, the heat treatment apparatus according to the present embodiment is used for heat treatment of metal products such as clutch plates, thin gears, shafts, crankshafts, bearings, tappets in automobile-related parts, and in construction machines, such as gears, shafts, gears, etc. in machine tools. Then, it can be used for heat treatment such as Caterpillar (trademark). Furthermore, the heat treatment apparatus of this embodiment can also be used for heat treatment of tools such as dies, gauges, bolts, drills, metal bats, bows, golf equipment, and the like. Moreover, according to the heat treatment apparatus of the present embodiment, heat treatment can be performed on any ferrous and non-ferrous metal parts such as an alloy such as carbon steel and stainless steel, an aluminum alloy, and the like.

  Furthermore, in the heat treatment apparatus according to the first embodiment of the present invention described above, only the heat treatment oil is put in the cooling tank. However, as a modification, it is possible to mix particulate matter in the heat treatment oil. good. According to this modified example, when the heat-treated oil mixed with the particulate matter during the rapid cooling of the workpiece is stirred in the cooling tank, the particulate matter collides with the workpiece together with the heat-treated oil, so that the vapor film around the workpiece is more destroyed. Since it becomes easy, the cooling rate of a workpiece | work can be raised. As the particulate matter mixed in the heat-treated oil, for example, particles having an average particle diameter of about 0.1 μm to 3 mm and a bulk specific gravity of about 0.5 to 16 can be used. Moreover, iron, iron oxide, sand, tungsten, silicon carbide, silicon oxide, carbon fiber, etc. can be used as the material of the granular material.

  Next, a heat treatment apparatus according to the second embodiment of the present invention will be described with reference to FIG. The heat treatment apparatus according to the second embodiment of the present invention is different from the first embodiment of the present invention in that it includes a large pressure chamber and can heat a large amount of workpieces W or large workpieces W. Accordingly, here, only the points of the second embodiment of the present invention that are different from the first embodiment will be described, and description of similar points will be omitted.

  FIG. 2 is a schematic cross-sectional view of a heat treatment apparatus according to the second embodiment of the present invention. As shown in FIG. 2, the heat treatment apparatus 100 of this embodiment includes a pressure vessel 102 that is a pressure chamber, a heater 106 that is a heating means, a heating chamber 108 that is formed of a heat insulating material, and a downstream side of the pressure vessel 102. And an elevator 110 that is an input means for supplying the workpiece W, which is an object to be processed, into the heat treatment oil 104 accommodated in the lower part. Furthermore, the heat treatment apparatus 100 of this embodiment includes a gas container 112, a pressure reducing valve 114, and an on-off valve 116. The gas container 112, the pressure reducing valve 114, and the on-off valve 116 constitute a pressurizing means. Further, the heat treatment apparatus 100 of the present embodiment includes a propeller 118 that stirs the coolant and a motor 120. The propeller 118 and the motor 120 constitute stirring means.

  The pressure vessel 102 has a generally cylindrical main body 102a extending in the horizontal direction, a carry-in port 102b and a carry-out port 102c formed at both ends thereof, a cooling tank 102d extending vertically downward from the downstream side of the main body 102a, Have The cooling tank part 102d is a cylindrical container formed continuously with the main body part 102a of the pressure vessel 102, and heat treatment oil 104 as a cooling liquid is placed therein, and functions as a cooling tank. A propeller 118 and a motor 120 are provided at the bottom of the cooling bath 102d so that the heat treatment oil 104 in the cooling bath 102d can be stirred.

Further, on the upstream side and the downstream side of the pressure vessel 102, a rupture desk 122 that is a safety valve for preventing the pressure vessel 102 from bursting when the pressure in the pressure vessel 102 rises excessively is attached. . Further, on the upstream side and the downstream side of the pressure vessel 102, when releasing the carry-in port 102b or the carry-out port 102c, etc., gas is released to release the gas inside the pressure vessel 102 and return the pressure vessel 102 to atmospheric pressure. Valves 123 are respectively attached.
Furthermore, inside the pressure vessel 102, a number of conveying rollers 124 for conveying the workpiece W from the carry-in port 102b to the carry-out port 102c are arranged in the horizontal direction. The conveyance roller 124 supports the workpiece W at both ends of the workpiece W and is driven to rotate, thereby conveying the workpiece W from the carry-in port 102b to the carry-out port 102c (from the upstream side to the downstream side).

  Further, a hawk loader 126a and a hawk unloader 126b are disposed on both sides of the heating chamber 108 in the pressure vessel 102, respectively. The hawk loader 126a is disposed between the conveying rollers 124 on both sides, and is configured to rise above the conveying rollers 124 when the workpiece W is put into the heating chamber 108. When the workpiece W is put into the heating chamber 108, the fork loader 126a is raised, the workpiece W is placed on the fork of the fork loader 126a, and acts like a forklift, so that the workpiece W is moved into the heating chamber 108. It is comprised so that it may mount on the support stand 128 of this. Similarly, the hawk unloader 126 b is configured to act like a hawk lift so that the workpiece W on the support base 128 is placed on the conveyance roller 124 on the downstream side of the heating chamber 108.

  The heating chamber 108 formed of a heat insulating material has an entrance door 108a and an exit door 108b to which the heat insulating material is attached. When the workpiece W is heated, the heating chamber 108 is closed, and the heat in the heating chamber 108 is externally applied. To avoid running away. Further, a plurality of heaters 106 are inserted into the heating chamber 108 and are configured to heat the workpiece W carried into the heating chamber 108 to a predetermined temperature. In addition, an in-furnace stirring means 129 is disposed above the heating chamber 108. The in-furnace stirring means 129 rotates the paddle 129a disposed inside the heating chamber 108, stirs the gas in the heating chamber 108, and raises the temperature of the workpiece W uniformly.

Further, a partition wall 130 is provided inside the pressure vessel 102 so as to be adjacent to the cooling tank portion 102d and separate the upstream side and the downstream side of the pressure vessel 102. The partition wall 130 is provided with an oil smoke prevention door 132 that is opened when the workpiece W is carried into the cooling bath 102d. Since oil smoke generated when the workpiece W is heat-treated in the cooling bath 102d is blocked by the partition wall 130 and the oil smoke prevention door 132, contamination of the equipment on the upstream side of the pressure vessel 102 due to oil smoke is prevented.
Further, the elevator 110 is disposed adjacent to the partition wall 130 on the cooling tank portion 102 d side of the pressure vessel 102. A number of transport rollers are provided on the upper surface of the elevator 110, and the workpiece W that has passed through the partition wall 130 is moved to the center of the elevator 110 by the transport rollers. In addition, the elevator 110 is configured to drop the workpiece W into the heat treatment oil 104 after the workpiece W is placed thereon, and is lowered to a position indicated by an imaginary line by an elevator mechanism (not shown).

  The propeller 118 is disposed at the bottom of the cooling tank portion 102d of the pressure vessel 102. The motor 120 is disposed below the cooling bath portion 102d, and when the propeller 118 is driven, the heat treatment oil is stirred, and when the workpiece W is rapidly cooled, the temperature of the heat treatment oil 104 in the cooling bath portion 102d is increased. It is configured to be uniform. Further, a water cooling jacket 134 is attached to the outside of the cooling tank portion 102d of the pressure vessel 102, and the temperature of the heat treatment oil 104 is maintained at a predetermined temperature.

  Further, high-pressure nitrogen gas is put in the gas container 112, and the entire inside of the pressure container 102 is brought to a predetermined high pressure by sending the nitrogen gas to both sides of the partition wall 130. Further, the pressure reducing valve 114 and the on-off valve 116 are provided in the middle of a conduit for introducing nitrogen gas into the pressure vessel 102 and are configured to introduce the gas in the gas vessel 112 into the pressure vessel 102 at a predetermined pressure. Has been.

  Next, the operation of the heat treatment apparatus 100 according to the second embodiment of the present invention will be described. Here, as an example, a case will be described in which a metal gear is heat-treated as an object to be processed. First, a workpiece in which a large number of gears formed by cutting or the like and subjected to pretreatment such as degreasing and cleaning are accommodated in a heat treatment basket is prepared as a workpiece to be heat treated. Next, the carry-in port 102b of the pressure vessel 102 is opened. Furthermore, after the conveyance roller 124 is operated and the workpiece W is moved into the pressure vessel 102, the carry-in port 102b is closed. Further, with each gas release valve 123 opened, nitrogen gas is introduced from the gas container 112 into the pressure container 102, and the air in the pressure container 102 is discharged out of the pressure container 102. After introducing nitrogen gas for a predetermined time, each gas release valve 123 is closed to seal the pressure vessel 102.

  The workpiece W moved into the pressure vessel 102 is conveyed by the conveying roller 124 to above the hawk loader 126a. When the workpiece W reaches above the fork loader 126a, the fork loader 126a rises upward from between the conveyance rollers 124 on both sides, and raises the workpiece W slightly above the conveyance rollers 124. When the workpiece W is lifted and separated from the conveying roller 124, the hawk of the fork loader 126 a moves toward the heating chamber 108 with the workpiece W placed thereon, and carries the workpiece W into the heating chamber 108. When the hawk of the hawk loader 126a moves and the workpiece W reaches above the support table 128 in the heating chamber 108, the hawk is lowered. When the hawk of the hawk loader 126a is lowered, the hawk is received in a groove (not shown) provided on the upper surface of the support base 128. As a result, the workpiece W is supported on the upper surface of the support table 128 by the surface that is not in contact with the hawk on the bottom surface, and is placed on the support table 128. When the workpiece W is placed on the support stand 128, the hawk loader 126 a pulls the hawk out of the heating chamber 108 and lowers it below the conveying roller 124.

  When the workpiece W is placed on the support stand 128, the entrance door 108a and the exit door 108b of the heating chamber 108 are closed. Next, the heater 106 is energized, and the workpiece W is heated. The in-furnace stirring means 129 rotates the paddle 129a in the heating chamber 108 and stirs the nitrogen gas in the heating chamber 108 so that the entire workpiece W is heated uniformly. When the workpiece W is heated for a predetermined time and reaches a predetermined temperature, the energization to the heater 106 is stopped and the outlet door 108b is opened. When the exit door 108b is opened, the hawk unloader 126b acts in the same manner as the hawk loader 126a to take out the workpiece W from the heating chamber 108 and remove the workpiece W on the conveying roller 124 on the downstream side of the heating chamber 108. Put it on.

  The workpiece W placed on the conveyance roller 124 is moved up to the elevator 110 by the conveyance roller 124. When the workpiece W is placed on the elevator 110, the on-off valve 116 is opened, and nitrogen gas is introduced into the pressure vessel 102. When nitrogen gas is introduced into the pressure vessel 102, the pressure in the pressure vessel 102 rises to a predetermined pressure defined by the pressure reducing valve 114 because the gas release valve 123 is closed. When the pressure in the pressure vessel 102 reaches a predetermined pressure, the on-off valve 116 is closed.

  Next, the elevator 110 on which the workpiece W is placed starts to descend, and the oil smoke prevention door 132 is closed. After the oil smoke prevention door 132 is closed, the workpiece W is immersed in the heat treatment oil 104 in the cooling tank portion 102d of the pressure vessel 102 and cooled. Since the effect | action which the workpiece | work W is cooled with heat processing oil is the same as that of 1st Embodiment, description is abbreviate | omitted. Further, steam (oil smoke) of heat-treated oil generated when the workpiece W is cooled is isolated to the downstream side of the pressure vessel 102 by the partition wall 130 and the oil smoke prevention door 132, and the heating chamber 108 disposed in the upstream side and the heater therein It is possible to prevent the equipment such as 106 from being contaminated by oil smoke.

  When the workpiece W is cooled to a predetermined temperature, the elevator 110 raises the workpiece W to the original position. Next, the gas release valve 123 is opened, and the pressure in the pressurized pressure vessel 102 is reduced to atmospheric pressure. After the pressure in the pressure vessel 102 is reduced to atmospheric pressure, the carry-out port 102c is opened, and the work W is carried out from the carry-out port by the carrying roller 124.

  According to the heat processing apparatus of 2nd Embodiment of this invention, the cooling rate of the workpiece | work W can be raised, or each gear accommodated in the basket can be cooled uniformly. In addition, according to the heat treatment apparatus of the present embodiment, it is possible to sequentially heat a large number of parts.

  In the above-described embodiment, the pressure vessel containing the heating means and the cooling tank is pressurized. However, as a modification, in the heat treatment apparatus shown in FIG. It is also possible to adopt a structure in which only the cooling tank portion 102d is pressurized as a pressure chamber. In this case, the portion other than the portion to be pressurized does not necessarily need to be airtight, and may be open to the atmosphere depending on the application.

  As mentioned above, although preferable embodiment of this invention was described, a various change can be added to embodiment mentioned above.

It is a schematic sectional drawing of the heat processing apparatus of 1st Embodiment of this invention. It is a schematic sectional drawing of the heat processing apparatus of 2nd Embodiment of this invention. It is a graph which shows the cooling curve of the to-be-processed object in the conventional heat processing apparatus.

Explanation of symbols

W Work 1 Heat treatment apparatus according to the first embodiment of the present invention 2 Pressure vessel 4 Heat treatment oil 6 Heater 8 Heat insulating material 10 Elevator 12 Gas container 14 Pressure reducing valve 16 Open / close valve 18 Propeller 20 Motor 22 Safety valve 23 Observation window 24 Seal 26 Gas release valve DESCRIPTION OF SYMBOLS 100 Heat processing apparatus by 2nd Embodiment of this invention 102 Pressure vessel 102a Main part 102b Carry-in inlet 102c Carry-out outlet 102d Cooling tank part 104 Heat-treatment oil 106 Heater 108 Heating chamber 108a Inlet door 108b Outlet door 110 Elevator 112 Gas container 114 Pressure reducing valve 116 On-off valve 118 Propeller 120 Motor 122 Rupture desk 123 Gas release valve 124 Transport roller 126a Hawk loader 126b Hawk unloader 128 Support stand 129 In-furnace stirring means 129a Paddle 130 Bulkhead 13 Oily smoke prevention door

Claims (7)

A heating means for heating the workpiece;
A cooling tank containing a coolant for cooling the object heated by the heating means;
A pressure chamber containing at least the cooling tank;
A pressurizing means for pressurizing the inside of the pressure chamber;
A charging unit that puts an object heated by the heating unit into the cooling tank accommodated in the pressure chamber pressurized by the pressurizing unit;
The heat processing apparatus characterized by having.   The heat treatment apparatus according to claim 1, wherein the pressurizing means has a gas container containing a high-pressure gas, and pressurizes the pressure chamber by introducing the high-pressure gas from the gas container into the pressure chamber.   Furthermore, it has a stirring means which stirs the cooling liquid in the said cooling tank, The heat processing apparatus of Claim 1 or 2 characterized by the above-mentioned.   The heat processing apparatus of Claim 3 with which the granular material is mixed in the cooling fluid of the said cooling tank.   The heat treatment apparatus according to any one of claims 1 to 4, wherein the charging means puts an object to be processed into the cooling bath in a state where the pressure in the pressure chamber is 0.1 to 30 MPa as a gauge pressure. Forming a part to be heat-treated;
Heating the formed part by a heating means;
A step of pressurizing the pressure in the pressure chamber containing the cooling tank containing the cooling liquid in which the above-mentioned components are carried, by a pressurizing unit;
Placing the heated part in the coolant of the cooling bath;
A method for producing a heat-treated component, comprising: Forming a part to be heat-treated;
Carrying the formed parts into a pressure chamber;
Sealing the pressure chamber;
Pressurizing the pressure in the pressure chamber by a pressurizing means;
Heating the component to be heat-treated carried into the pressure chamber by a heating means;
Placing the heated part in a cooling bath containing a coolant, contained in the pressure chamber;
A method for producing a heat-treated component, comprising:

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