Water-cooled quenching system

Abstract

This mechanism prevents water vapor generated when a heated workpiece is rapidly cooled by immersion in water or a cooling solution from entering the furnace from the quenching chamber, thereby reducing the carbon potential of the atmospheric gas inside the furnace. It also prevents atmospheric gas from entering the quenching chamber when the temperature and pressure inside the quenching chamber decrease. [Solution] A workpiece W heated in the furnace 1 is introduced into the quenching chamber 10 through the introduction door 11, the heated workpiece is cooled by immersion in water c contained in a cooling liquid tank 13 located at the bottom of the quenching chamber, and the cooled workpiece is removed from the quenching chamber through the removal door 12. A pressure adjustment device 20 is provided to adjust the pressure inside the quenching chamber. When the pressure inside the quenching chamber becomes high, the atmosphere A1 and water vapor A3 inside the quenching chamber are exhausted, while when the pressure inside the quenching chamber becomes low, exhaust gas A2 is drawn into the quenching chamber to adjust the pressure inside the quenching chamber to a predetermined pressure.

Description

【Technical Field】 【0001】 The present invention relates to a quenching apparatus that introduces a workpiece heated in a furnace into a quenching chamber by opening an introduction door of the quenching chamber, immerses the heated workpiece in a coolant contained in a coolant tank provided at the lower part of the quenching chamber for cooling, and takes out the cooled workpiece from the quenching chamber by opening an extraction door of the quenching chamber. The present invention also relates to a water-cooled quenching apparatus that introduces a workpiece heated in a furnace into a quenching chamber by opening an introduction door of the quenching chamber, immerses the heated workpiece in water or a cooling aqueous solution contained in a coolant tank provided at the lower part of the quenching chamber for cooling, horizontally moves the cooled workpiece in the water or the cooling aqueous solution, and then raises it to take it out from the quenching chamber. In particular, in a water-cooled quenching apparatus using water or a cooling aqueous solution as the coolant contained in the coolant tank, when the heated workpiece is immersed in the water or the cooling aqueous solution for rapid cooling, the pressure in the quenching chamber rises due to the water vapor generated, and the water vapor enters the furnace through the gap of the introduction door of the quenching chamber and reacts with the atmospheric gas in the furnace, resulting in a decrease in the carbon potential of the atmospheric gas in the furnace, thereby preventing the workpiece in the furnace from being oxidized or decarburized. When the workpiece is cooled and the pressure in the quenching chamber decreases, the atmospheric gas in the furnace enters the quenching chamber, preventing changes in the environment in the furnace and the quenching chamber. 【Background Art】 【0002】 Conventionally, a workpiece heated in a heat treatment furnace has been immersed in a coolant contained in a coolant tank provided at the lower part of a quenching chamber to cool and quench the workpiece. 【0003】 Here, when quenching a heated workpiece by immersing it in a cooling liquid contained in a cooling liquid tank located at the bottom of the quenching chamber, Patent Document 1 shows a method in which the heated workpiece is guided from the furnace outlet door into a quenching chamber filled with an inert gas such as nitrogen gas, the heated workpiece is immersed in quenching oil contained in a cooling liquid tank located at the bottom of the quenching chamber, the workpiece is moved through the quenching oil to cool it, and the workpiece is removed from the cooling liquid tank. 【0004】 Furthermore, Patent Document 2 describes a method in which a heated workpiece is guided into a quenching chamber, immersed in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the heated workpiece is rapidly cooled by moving it through the water or cooling aqueous solution, and then the workpiece is removed from the cooling liquid tank. 【0005】 Furthermore, since water has a higher heat transfer coefficient than oil, as shown in Patent Document 2, rapidly cooling a heated workpiece by immersing it in water or a cooling aqueous solution has the advantage of being more efficient than cooling it by immersing it in quenching oil, resulting in increased surface hardness of the workpiece and a shorter processing time. 【0006】 On the other hand, as shown in Patent Document 2, when a heated workpiece is rapidly cooled by immersing it in water or a cooling aqueous solution, a large amount of steam (water vapor) is generated because water has a lower boiling point than oil. This increases the pressure inside the quenching chamber, and the water vapor enters the furnace through gaps in the quenching chamber's inlet door and reacts with the atmospheric gas inside the furnace. This reduces the carbon potential of the atmospheric gas inside the furnace, leading to oxidation or decarburization of the workpiece inside the furnace. Furthermore, when the temperature inside the quenching chamber decreases and the pressure inside the quenching chamber drops, the atmospheric gas inside the furnace enters the quenching chamber, causing changes in the furnace and the environment inside the quenching chamber. [Prior art documents] [Patent Documents] 【0007】 [Patent Document 1] Publication number 2-41156 [Patent Document 2] Japanese Patent Publication No. 2002-97520 [Disclosure of the Invention] [Problems that the invention aims to solve] 【0008】 The present invention aims to solve the aforementioned problems in a water-cooled quenching apparatus in which a workpiece heated in a furnace is introduced into the quenching chamber by opening the introduction door of the quenching chamber, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the cooled workpiece is removed from the quenching chamber by opening the removal door of the quenching chamber, and a water-cooled quenching apparatus in which a workpiece heated in a furnace is introduced into the quenching chamber by opening the introduction door of the quenching chamber, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the cooled workpiece is moved horizontally through the water or cooling aqueous solution before being raised and removed from the quenching chamber. 【0009】 In other words, the present invention aims to prevent the workpiece from being oxidized or decarburized in the furnace by increasing the pressure inside the quenching chamber due to the steam generated when the heated workpiece is cooled by immersion in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber. This steam enters the furnace through a gap in the introduction door of the quenching chamber and reacts with the atmospheric gas inside the furnace, reducing the carbon potential of the atmospheric gas inside the furnace. Furthermore, it aims to prevent the atmospheric gas inside the furnace from entering the quenching chamber and changing the furnace environment when the temperature inside the quenching chamber decreases and the pressure inside the quenching chamber decreases. [Means for solving the problem] 【0010】 In the first water-cooled quenching apparatus according to the present invention, in order to solve the above problems, a workpiece heated in a furnace is introduced into the quenching chamber by opening the introduction door of the quenching chamber, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the cooled workpiece is removed from the quenching chamber by opening the removal door of the quenching chamber. In this water-cooled quenching apparatus, a pressure adjustment device is provided to adjust the pressure inside the quenching chamber. When the introduction door and the removal door are closed, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in the cooling liquid tank. The pressure adjustment device is configured to exhaust gas from inside the quenching chamber when the pressure inside the quenching chamber becomes high, and to draw exhaust gas into the quenching chamber when the pressure inside the quenching chamber becomes low, thereby adjusting the pressure inside the quenching chamber to a predetermined pressure. 【0011】 Furthermore, in the second water-cooled quenching apparatus according to the present invention, in order to solve the above problems, a workpiece heated in a furnace is introduced into the quenching chamber by opening the introduction door of the quenching chamber, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the cooled workpiece is moved horizontally through the water or cooling aqueous solution before being raised and removed from the quenching chamber. In this water-cooled quenching apparatus, a pressure adjustment device is provided to adjust the pressure inside the quenching chamber. When the introduction door is closed and the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in the cooling liquid tank, the pressure adjustment device is configured to exhaust gas from inside the quenching chamber when the pressure inside the quenching chamber becomes high, and to draw exhaust gas into the quenching chamber when the pressure inside the quenching chamber becomes low, thereby adjusting the pressure inside the quenching chamber to a predetermined pressure. 【0012】 As in the first and second water-cooled quenching apparatuses according to the present invention, a pressure adjustment device is provided to adjust the pressure inside the quenching chamber. When a heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in the cooling liquid tank, a large amount of steam is generated and the pressure inside the quenching chamber rises. The pressure adjustment device exhausts the gas inside the quenching chamber, adjusting the pressure inside the quenching chamber to a predetermined pressure. This prevents steam from entering the furnace through the gap in the quenching chamber's inlet door and reacting with the atmospheric gas inside the furnace. Furthermore, when the temperature inside the quenching chamber decreases and the pressure inside the quenching chamber drops, exhaust gas is drawn into the quenching chamber to adjust the pressure inside the quenching chamber to a predetermined pressure. This prevents atmospheric gas from entering the quenching chamber, and since exhaust gas is drawn into the quenching chamber, costs are reduced compared to drawing in an inert gas such as nitrogen gas. 【0013】 In the first and second water-cooled quenching apparatuses according to the present invention, a combustion device is provided at the intake and exhaust port of the intake and exhaust section, which exhausts the gas inside the quenching chamber and draws the exhaust gas into the quenching chamber, as the pressure adjustment device. When the pressure inside the quenching chamber increases, the gas inside the quenching chamber is exhausted from the intake and exhaust port, while when the pressure inside the quenching chamber decreases, the exhaust gas burned by the combustion device is drawn into the quenching chamber from the intake and exhaust port. 【0014】 Furthermore, in the first and second water-cooled quenching apparatuses according to the present invention, a second introduction door can be provided upstream of the quenching chamber, and the space between the introduction door and the second introduction door can be used as a buffer chamber. 【0015】 Furthermore, when the second inlet door, located upstream of the buffer chamber, is closed as described above, even if a large amount of steam flows into the quenching chamber at once when the heated workpiece is cooled by immersing it in the water or cooling aqueous solution contained in the cooling liquid tank, it is further prevented from the steam entering the furnace and reacting with the atmospheric gas inside the furnace. In addition, even if the temperature inside the quenching chamber decreases and the pressure inside the quenching chamber drops, it is further prevented from the atmospheric gas inside the furnace entering the quenching chamber. 【0016】 Furthermore, in the first and second water-cooled quenching apparatuses according to the present invention, it is preferable to use a porous material for the second introduction door provided upstream of the buffer chamber, for example, insulating bricks or ceramic fibers can be used. [Effects of the Invention] 【0017】 In the first and second water-cooled quenching apparatuses of the present invention, a pressure adjustment device is provided to adjust the pressure inside the quenching chamber as described above. When a heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, a large amount of steam is generated and the pressure inside the quenching chamber rises. In such cases, the pressure adjustment device exhausts the gas inside the quenching chamber to adjust the pressure inside the quenching chamber to a predetermined pressure. Conversely, when the temperature inside the quenching chamber decreases and the pressure inside the quenching chamber drops, exhaust gas is drawn into the quenching chamber to adjust the pressure inside the quenching chamber to a predetermined pressure. 【0018】 As a result, in the first and second water-cooled quenching apparatuses of the present invention, even if a large amount of steam is generated when the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, it is prevented that the steam will enter the furnace through the gap in the introduction door of the quenching chamber and react with the atmospheric gas inside the furnace. This reduces the carbon potential of the atmospheric gas inside the furnace, preventing oxidation or decarburization of the workpiece inside the furnace. Furthermore, when the temperature inside the quenching chamber decreases and the pressure inside the quenching chamber drops, exhaust gas is drawn into the quenching chamber to adjust the pressure inside the quenching chamber to a predetermined pressure, preventing the atmospheric gas inside the furnace from entering the quenching chamber. Also, since exhaust gas is drawn into the quenching chamber, the cost is reduced compared to the case where an inert gas such as nitrogen gas is drawn in. [Brief explanation of the drawing] 【0019】 [Figure 1]In the water-cooled quenching device according to Embodiment 1 of the present invention, when a workpiece heated in a furnace is introduced into a quenching chamber by opening and closing an introduction door of the quenching chamber and the heated workpiece is immersed in water contained in a coolant tank for cooling, it is a schematic cross-sectional explanatory view showing a state in which the gas in the quenching chamber is exhausted from the quenching chamber. [Figure 2] In the water-cooled quenching device according to the above Embodiment 1, when the workpiece is cooled in the coolant tank and returned to the quenching chamber, and the pressure in the quenching chamber decreases, it shows a state in which exhaust gas is sucked into the quenching chamber. Then, it is a schematic cross-sectional explanatory view showing a state in which the cooled workpiece is taken out from the quenching chamber by opening and closing the take-out door of the quenching chamber. [Figure 3] In the water-cooled quenching device according to the above Embodiment 1, a modified example is shown in which a second introduction door is provided upstream of the quenching chamber, and a buffer chamber is formed between the introduction door and the second introduction door. A workpiece heated in a furnace is introduced into the buffer chamber by opening and closing the second introduction door of the buffer chamber, and then introduced into the quenching chamber by opening and closing the introduction door of the quenching chamber. When the heated workpiece is immersed in water contained in a coolant tank for cooling, it is a schematic cross-sectional explanatory view showing a state in which the gas in the quenching chamber is exhausted from the quenching chamber. [Figure 4] In the above modified example, when the workpiece is cooled in the coolant tank and returned to the quenching chamber, and the pressure in the quenching chamber decreases, it shows a state in which exhaust gas is sucked into the quenching chamber. Then, it is a schematic cross-sectional explanatory view showing a state in which the cooled workpiece is taken out from the quenching chamber by opening and closing the take-out door of the quenching chamber. <酬 [Figure 5] It is a schematic top view showing an intake and exhaust port and a combustion device for performing air supply and exhaust in the quenching chamber. [Figure 6] In the water-cooled quenching device according to Embodiment 2 of the present invention, when a workpiece heated in a furnace is introduced into a quenching chamber by opening and closing an introduction door of the quenching chamber, the heated workpiece is immersed in water contained in a coolant tank for cooling, and after horizontally moving the water and then raising it, it is taken out from the quenching chamber, it is a schematic cross-sectional explanatory view showing a state in which the gas in the quenching chamber is exhausted from the quenching chamber. [Figure 7]In the water-cooled quenching device according to the above-described Embodiment 2, when the work is cooled in the coolant tank and returned to the quenching chamber, and the pressure in the quenching chamber decreases, exhaust gas is drawn into the quenching chamber, and then, after the cooled work is horizontally moved in water and then raised, it is a schematic cross-sectional explanatory view showing a state of being taken out from the quenching chamber to the outside. 【Best Mode for Carrying Out the Invention】 【0020】 Hereinafter, the water-cooled quenching device according to an embodiment of the present invention will be specifically described based on the accompanying drawings. Note that the water-cooled quenching device according to this invention is not limited to that shown in the following embodiments, and can be appropriately modified and implemented within a range not changing the gist of the invention. 【0021】 (Embodiment 1) In the water-cooled quenching device in Embodiment 1, as shown in FIGS. 1 and 2, the work W heated in the furnace 1 is introduced from the furnace 1 into the quenching chamber 10 by opening and closing the introduction door 11 of the quenching chamber 10, and the work W quenched in the quenching chamber 10 is taken out from the quenching chamber 10 to the outside by opening and closing the take-out door 12 of the quenching chamber 10. 【0022】 Further, in the water-cooled quenching device in this Embodiment 1, a coolant tank 13 containing water (or a cooling aqueous solution) c for cooling the heated work W is provided below the quenching chamber 10. On the other hand, as a pressure adjusting device 20 for adjusting the pressure in the quenching chamber 10, an air supply and exhaust part 21 is provided at the upper part of the quenching chamber 10, and at the air supply and exhaust port 22 of the air supply and exhaust part 21, as a combustion device 23, a combustion device (disk burner) 23 having a circular shape as shown in FIG. 5 and having a nozzle 24 arranged outward is provided. The fuel is burned by this combustion device 23 to form a flame F, and exhaust gas A2 is generated at the air supply and exhaust port 22 of the air supply and exhaust part 21. 【0023】 In this embodiment 1, as shown in Figure 1, the workpiece W heated in the furnace 1 is introduced into the quenching chamber 10 by opening and closing the introduction door 11 of the quenching chamber 10, and then the heated workpiece W is cooled (rapidly cooled) by immersing it in water c contained in a cooling liquid tank 13 located at the bottom of the quenching chamber 10. 【0024】 Here, when the heated workpiece W is introduced into the quenching chamber 10 as described above, the temperature of the atmosphere A1 inside the quenching chamber 10 rises and it expands. Then, when the heated workpiece W is immersed in the water c contained in the cooling liquid tank 13 located at the bottom of the quenching chamber 10, the heat from the heated workpiece W causes the water c to evaporate, generating steam A3, and the pressure inside the quenching chamber 10 increases. 【0025】 Then, when the pressure inside the quenching chamber 10 increases to a level higher than atmospheric pressure, the atmosphere A1 and water vapor A3 inside the quenching chamber 10 are exhausted through the intake and exhaust port 22 on the outer circumference of the combustion device 23 via the intake and exhaust section 21, and the pressure inside the quenching chamber 10 is adjusted to a predetermined pressure (atmospheric pressure). 【0026】 As a result, the pressure inside the quenching chamber 10 increases, preventing the atmosphere A1 containing water vapor A3 from entering the furnace 1 through the gap in the introduction door 11 in the quenching chamber 10. This prevents the atmosphere A1 containing water vapor A3 from reacting with the atmospheric gas inside the furnace 1, reducing the carbon potential of the atmospheric gas inside the furnace 1, and preventing oxidation or decarburization of the workpiece W inside the furnace 1. 【0027】 Furthermore, as described above, after exhausting the atmosphere A1 inside the quenching chamber 10 containing water vapor A3 to the outside through the supply and exhaust port 22, the workpiece W, which has been cooled by being immersed in water c, is returned to the quenching chamber 10 as shown in Figure 2, and the removal door 12 of the quenching chamber 10 is opened and closed to remove the workpiece W from inside the quenching chamber 10 to the outside. 【0028】 Here, immediately after immersing the workpiece W in water c, the temperature inside the quenching chamber 10 decreases, the pressure inside the quenching chamber 10 decreases, and the exhaust gas A2 generated at the intake and exhaust port 22 on the outer circumference of the combustion device 23 of the intake and exhaust section 21, when the fuel is burned by the combustion device 23 as described above, is drawn into the quenching chamber 10 through the intake and exhaust section 21, and the pressure inside the quenching chamber 10 is adjusted to a predetermined pressure (atmospheric pressure). 【0029】 As a result, even if the temperature inside the quenching chamber 10 decreases, the pressure inside the quenching chamber 10 also decreases, preventing atmospheric gases from the furnace 1 from entering the quenching chamber 10. Furthermore, since oxygen-free exhaust gas A2 is drawn into the quenching chamber 10, costs are reduced compared to drawing in expensive inert gases such as nitrogen gas. 【0030】 In this embodiment 1, the water-cooled quenching apparatus is introduced directly from the furnace 1 into the quenching chamber 10 by opening and closing the introduction door 11 of the quenching chamber 10. However, as shown in the modified examples in Figures 3 and 4, a second introduction door 31 can be provided upstream of the quenching chamber 10, and the space between the introduction door 11 and the second introduction door 31 can be made into a buffer chamber 30. 【0031】 Furthermore, if a second introduction door 31 is provided upstream of the quenching chamber 10, and the space between the introduction door 11 and the second introduction door 31 is made into a buffer chamber 30, as shown in Figures 3 and 4, the workpiece W heated in the furnace 1 is introduced from inside the furnace 1 into the buffer chamber 30 by opening and closing the second introduction door 31. Then, the heated workpiece W introduced into the buffer chamber 30 is introduced from inside the furnace 1 into the quenching chamber 10 by opening and closing the introduction door 11 of the quenching chamber 10, as in the embodiment described above. The workpiece W heated in the quenching chamber 10 is then cooled by immersing it in water c contained in a cooling liquid tank 13 located at the bottom of the quenching chamber 10, as described above. After the cooled workpiece W is returned to the quenching chamber 10, the removal door 12 of the quenching chamber 10 is opened and closed to remove the workpiece W from inside the quenching chamber 10 to the outside. 【0032】 Thus, when a second introduction door 31 is provided upstream of the quenching chamber 10, and the space between the introduction door 11 and the second introduction door 31 is designated as a buffer chamber 30, as shown in Figure 3, when a heated workpiece W is introduced into the quenching chamber 10 from the buffer chamber 30, the atmosphere A1 inside the quenching chamber 10 expands as described above. Furthermore, when the heated workpiece W is immersed in water c contained in a cooling liquid tank 13 located at the bottom of the quenching chamber 10, the heat from the heated workpiece W causes the water c to evaporate, generating water vapor A3, and increasing the pressure inside the quenching chamber 10. 【0033】 Then, when the pressure inside the quenching chamber 10 becomes higher than atmospheric pressure, the atmosphere A1 and water vapor A3 inside the quenching chamber 10 are exhausted through the supply and exhaust section 21 and the supply and exhaust port 22, similar to the embodiment described above, and the pressure inside the quenching chamber 10 is adjusted to a predetermined pressure (atmospheric pressure). 【0034】 Here, as shown in this example of modification, if a second inlet door 31 is provided upstream of the quenching chamber 10, and the space between the inlet door 11 and the second inlet door 31 is made into a buffer chamber 30, then even if the pressure inside the quenching chamber 10 increases as described above, and the atmosphere A1 containing water vapor A3 inside the quenching chamber 10 leaks out through the gap in the inlet door 11 in the quenching chamber 10, the leaked atmosphere A1 containing water vapor A3 will only flow into the buffer chamber 30, preventing it from flowing into the furnace 1. 【0035】 Furthermore, if insulating bricks or ceramic fibers are used for the material of the second introduction door 31, the atmosphere A1 containing water vapor A3 that flows into the buffer chamber 30 will be absorbed by the surface of the insulating bricks or ceramic fibers, preventing it from flowing into the furnace 1. 【0036】 As a result, even if the pressure inside the quenching chamber 10 increases further, the atmosphere A1 containing water vapor A3 inside the quenching chamber 10 is prevented from entering the furnace 1, preventing the atmosphere A1 containing water vapor A3 from reacting with the atmospheric gas inside the furnace 1, which reduces the carbon potential of the atmospheric gas inside the furnace 1 and prevents oxidation or decarburization of the workpiece W inside the furnace 1. 【0037】 Furthermore, after exhausting the atmosphere A1 and steam A3 inside the quenching chamber 10 to the outside through the intake / exhaust port 22 as described above, the workpiece W, which has been cooled by being immersed in water c, is returned to the quenching chamber 10 as shown in Figure 4, and the removal door 12 of the quenching chamber 10 is opened and closed to remove the workpiece W from inside the quenching chamber 10 to the outside. 【0038】 Here, immediately after immersing the workpiece W in water c, if the temperature inside the quenching chamber 10 decreases and the pressure inside the quenching chamber 10 drops, then, as in the above embodiment, the exhaust gas A2 generated at the intake and exhaust port 22 of the intake and exhaust section 21 when the fuel is burned by the combustion device 23 is drawn into the quenching chamber 10 through the intake and exhaust section 21, and the pressure inside the quenching chamber 10 is adjusted to a predetermined pressure (atmospheric pressure). 【0039】 As a result, as shown in this example of modification, by providing a buffer chamber 30 between the furnace 1 and the quenching chamber 10, when the pressure inside the quenching chamber 10 drops as described above, the buffer chamber 30 more reliably prevents the atmospheric gas from inside the furnace 1 from entering the quenching chamber 10. Furthermore, since exhaust gas A2 is drawn into the quenching chamber 10, the cost is reduced compared to the case where an inert gas such as nitrogen gas is drawn in. 【0040】 (Embodiment 2) In the water-cooled quenching apparatus of Embodiment 2, when removing the workpiece W cooled in the cooling liquid tank 13 from the quenching chamber 10, instead of the removal door 12 shown in Embodiment 1, as shown in Figure 6, the cooling liquid tank 13 is extended in the direction of the workpiece W's movement, and the lower end 41 of the water seal wall 40 provided at the bottom of the quenching chamber 10 is immersed in water c, thereby creating a structure that isolates the inside of the quenching chamber 10 from the outside air. As shown in Figure 7, the workpiece W immersed in water c is moved horizontally through the water c, passing under the lower end 41 of the water seal wall 40, and then the cooled workpiece W is raised and removed from the quenching chamber 10. 【0041】 In the case where an extraction door 12 is provided as in Embodiment 1 above, when the extraction door 12 is opened, outside air randomly enters the quenching chamber 10, causing the temperature distribution of the workpiece W to vary before it is moved out of the quenching chamber 10. However, with the structure shown in Embodiment 2, the inside of the quenching chamber 10 can always be completely isolated from the outside air, and when the workpiece W is removed from the water c, the workpiece W can be exposed to the outside air all at once, thereby reducing the variation in the temperature distribution of the workpiece W and improving the accuracy of the quenching process. 【0042】 Although not shown in the figures, in the water-cooled quenching apparatus of Embodiment 2, as shown in the modified example of Embodiment 1, a second introduction door 31 can be provided upstream of the quenching chamber 10, and the space between the introduction door 11 and the second introduction door 31 can be made into a buffer chamber 30. [Explanation of symbols] 【0043】 1: Furnace 10: Hardening chamber 11: Introduction Door 12: Retrieval door 13:Cooling liquid tank 20: Pressure Regulator 21: Intake and exhaust section 22: Intake and exhaust vents 23: Combustion device 24: Nozzle 30: Buffer chamber 31: Second entrance door 40: Water seal wall 41: Bottom edge A1: Atmosphere A2: Exhaust gas A3: Water vapor W: Work c: Water (cooling aqueous solution) F:Flame

Claims

[Claim 1] In a water-cooled quenching apparatus in which a workpiece heated in a furnace is introduced into the quenching chamber by opening the introduction door of the quenching chamber, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the cooled workpiece is removed from the quenching chamber by opening the removal door of the quenching chamber, a pressure adjustment device is provided to adjust the pressure inside the quenching chamber, and when the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in the cooling liquid tank with the introduction door and the removal door closed, the pressure adjustment device is characterized in that when the pressure inside the quenching chamber becomes high, it exhausts the gas inside the quenching chamber, and when the pressure inside the quenching chamber becomes low, it draws in the exhaust gas into the quenching chamber to adjust the pressure inside the quenching chamber to a predetermined pressure. [Claim 2] A water-cooled quenching apparatus according to claim 1, wherein a combustion device is provided at the intake and exhaust port of the intake and exhaust section, which exhausts the gas in the quenching chamber and draws the exhaust gas into the quenching chamber, as the pressure adjustment device, and when the pressure in the quenching chamber increases, the gas in the quenching chamber is exhausted from the intake and exhaust port, while when the pressure in the quenching chamber decreases, the exhaust gas burned by the combustion device is drawn into the quenching chamber from the intake and exhaust port. [Claim 3] A water-cooled quenching apparatus according to claim 1 or claim 2, characterized in that a second introduction door is provided upstream of the quenching chamber, and the space between the introduction door and the second introduction door is a buffer chamber. [Claim 4] A water-cooled quenching apparatus according to claim 3, characterized in that a heat insulating brick or ceramic fiber is used for the second introduction door in the buffer chamber. [Claim 5] In a water-cooled quenching apparatus, a workpiece heated in a furnace is introduced into the quenching chamber by opening the introduction door, the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in a cooling liquid tank located at the bottom of the quenching chamber, and the cooled workpiece is moved horizontally through the water or cooling aqueous solution before being raised and removed from the quenching chamber, the apparatus is equipped with a pressure adjustment device for adjusting the pressure inside the quenching chamber, and when the heated workpiece is cooled by immersing it in water or a cooling aqueous solution contained in the cooling liquid tank with the introduction door closed, the pressure adjustment device is characterized in that when the pressure inside the quenching chamber becomes high, it exhausts the gas inside the quenching chamber, and when the pressure inside the quenching chamber becomes low, it draws in the exhaust gas to adjust the pressure inside the quenching chamber to a predetermined pressure. [Claim 6] A water-cooled quenching apparatus according to claim 5, wherein a combustion device is provided at the intake and exhaust port of the intake and exhaust section, which exhausts the gas in the quenching chamber and draws the exhaust gas into the quenching chamber, as the pressure adjustment device, and when the pressure in the quenching chamber increases, the gas in the quenching chamber is exhausted from the intake and exhaust port, while when the pressure in the quenching chamber decreases, the exhaust gas burned by the combustion device is drawn into the quenching chamber from the intake and exhaust port. [Claim 7] A water-cooled quenching apparatus according to claim 5 or claim 6, characterized in that a second introduction door is provided upstream of the quenching chamber, and the space between the introduction door and the second introduction door is a buffer chamber. [Claim 8] A water-cooled quenching apparatus according to claim 7, characterized in that a heat insulating brick or ceramic fiber is used for the second introduction door in the buffer chamber.

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