JP3596930B2 - Quench furnace - Google Patents

Description

[0001]
[Industrial applications]
TECHNICAL FIELD The present invention relates to a quenching furnace capable of performing rapid cooling such as quenching effectively.
[0002]
[Prior art]
As a method for performing rapid cooling such as quenching, a method using a cooling gas has been established conventionally. In configuring such a gas cooling mechanism, it is essential to install a fan inside the furnace, connect it drivably to a motor outside the furnace, and arrange cooling means on the gas circulation path. Conventionally, an inexpensive stainless steel alloy fan is used for such a cooling fan, and the cooling means is provided at a position where heat can be simply exchanged on the gas circulation path.
[0003]
[Problems to be solved by the invention]
However, the strength of the stainless steel alloy is poor despite its high specific gravity. Therefore, in order to have a certain strength, the fan must be heavy, and since such a fan is driven by a motor, the large inertia of the fan causes the motor to start up at startup. There was a problem that it took time and it was difficult to quench quickly. Then, due to such a problem, the quality of the heat treatment is reduced and the motor is increased in size.
[0004]
The present invention has been made in view of such a problem, and provides a quenching furnace that shortens the motor start-up time during quenching, thereby improving the quality of heat treatment and miniaturizing the motor. It is intended to be.
[0005]
[Means for Solving the Problems]
The present invention employs the following configuration in order to achieve the above object.
[0006]
That is, the quenching furnace according to the present invention includes a fan in which a cooling gas is circulated in the furnace, wherein the fan is made of a titanium alloy or an aluminum alloy and housed in a scroll casing. And a cooling pipe through which a cooling medium flows is provided in the scroll casing.
[0007]
[Action]
Titanium alloys and aluminum alloys have much lower specific gravity and higher strength than stainless steel alloys. Therefore, when making a fan of constant strength, such an alloy can make a thinner and lighter fan than before. In addition, titanium alloys and aluminum alloys have a disadvantage that heat resistance is lower than that of stainless steel.However, as in the present invention, a fan is housed in a scroll casing, and a cooling means is provided at a position where the fan can be directly cooled. With this arrangement, it is possible to prevent the temperature from rising due to heat during the heat treatment and maintain the strength of the fan at an effective value.
[0008]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0009]
As shown in FIGS. 1 and 2, the quenching furnace has a furnace body 1 in which a furnace body 1 is provided with a heat insulating body 2 having a housing shape and heat insulating lids 3 and 4 for opening and closing both ends of the heat insulating body 2. And a processing space S2. The processing object W is detached by opening and closing one of the heat insulating lids 3 together with the furnace door 1a, and the inserted processing object W is subjected to heating by a heater 5 provided in the processing space S1. The in-furnace space S2 includes a cooling gas transfer system S21 defined between the top plate 21 of the heat-insulating body 2 and the furnace body 1, and between the bottom plate 22 of the heat-insulating body 2 and the furnace body 1, respectively. , S22, and gas outlet spaces S24, S25 closed between one of the heat insulating lids 3 and the furnace body 1 and between the other heat insulating lid 4 and the furnace body 1, respectively. The two gas outlet spaces S24 and S25 are communicated with each other through a gas return path S26 closed between the side plate 23 of the heat insulating main body 2 and the furnace body 1.
[0010]
The top plate 21 and the bottom plate 22 of the heat insulating main body 2 are provided with a large number of gas outlets 2a for discharging a cooling gas to the processing space S1 in the thickness direction. Of the cooling gas transfer passages S21 and S22.
[0011]
On the other hand, at one end of the furnace, a scroll casing 6 including a bottom wall 61, a peripheral wall 62, and a lid 63 is disposed at a position penetrating the furnace body 1 as shown in FIGS. Is housed. The fan 7 is driven by a motor M provided outside the furnace. More specifically, the suction side of the fan 7 is communicated with the gas outlet space S25 through a suction hole 6a provided in the center of the cover 63 of the scroll casing 6, and the discharge side is large in size. The cooling gas transfer system passages S21 and S22 are communicated with each other through a discharge hole 6b provided in a diameter portion. The material of the fan 7 is a titanium alloy or an aluminum alloy, and can be directly cooled by a cooling means 8 provided inside the scroll casing 6 to prevent a temperature rise. The cooling means 8 is provided with a copper cooling pipe 81 laid in multiple layers along the peripheral wall 62 of the scroll casing 6, and copper plates 82 and 83 opposed to each other at a position closing the end of the flow path, and a cooling medium. After flowing in from one copper plate 82 and flowing through the cooling pipe 81, it flows out from the other copper plate 83. During this time, the cold heat of the cooling medium is transmitted to the cooling pipe 81 and the copper plates 82 and 83, and the cold heat is transmitted to the fan 7 from these portions by transmission or convection. The cooling capacity is designed so that when the fan 7 is made of a titanium alloy, the fan 7 can be kept at 500 ° C. or less even during the heat treatment in the processing space S1. . When the fan 7 is made of an aluminum alloy, the fan 7 is designed so as to obtain a higher effect.
[0012]
Gas outlets 3a, 4a are opened in the heat insulating lids 3, 4, and the gas outlets 3a, 4a are sealed by the weight of the open / close plates 3b, 4b suspended and supported upward. It has become. Further, a heat exchanger 9 for cooling the gas immediately before being sucked into the cooling fan 7 is arranged in front of the suction portion 6a.
[0013]
Next, the operation in the quenching furnace will be described. In a process such as quenching, it is customary to heat the workpiece W disposed in the processing space S1 by the heater 5 at a high temperature, then stop the heater 5 and activate the fan 7 for rapid cooling. Therefore, in this embodiment, in order to prevent the temperature of the fan 7 from being increased by heat mainly transmitted by radiation from the heat insulating body 2 and the heat insulating lids 3 and 4 during the heat treatment, the cooling means 8 is also provided during the heat treatment. A cooling medium is supplied. When the heating process is completed, the heater 5 is turned off, the fan 7 is started by the motor M, and a cooling gas such as an inert gas is introduced from a position (not shown). During this time, the cooling means 8 is continuously supplied with the cooling medium. Then, the cooling gas discharged from the fan 7 is discharged from the discharge port 6b through the internal flow path of the scroll casing 6, and the cooling gas flows from the upper and lower cooling gas transfer paths S21 and S22 from one end to the other end. Flowing towards. During this time, since a large number of gas outlets 2a are opened along the system path S21, gas flows sequentially from the upstream gas outlets 2a through the gas outlets 2a into the processing space S1 as shown in FIG. Spouts. When the cooling gas is spouted without interruption and the internal pressure of the processing space S1 gradually increases, the lids 3b and 4b are pressed to rotate to a position where the rotational moment due to its own weight and the pressure received by the cooling gas are balanced. Then, the gas outlets 3a and 4a are opened. As a result, the cooling gas ejected into the inside is led out to the gas lead-out spaces S24 and S25 via these gas lead-out portions 3a and 4a. The led out cooling gas passes through the gas return passage S26 and collects in the gas outlet space S25, where it is cooled by the heat exchanger 9 and then flows into the scroll casing 6 again through the suction port 6a, and then the fan It is sucked into 7. Since the gas is further cooled while flowing through the scroll casing 6, the gas becomes a lower temperature gas and is discharged again.
[0014]
In this way, the cooling gas is spouted without interruption to the processing object W disposed in the processing space S1, and the processing object W is subjected to rapid cooling. In the case of the quenching furnace as in the present embodiment, the titanium alloy and the aluminum alloy used as the material of the fan 7 have a much lower specific gravity and a higher strength than the stainless alloy. When making the fan 7 of high strength, it can be made much lighter and thinner than a conventional stainless steel alloy fan. For this reason, the problem that the inertia of the fan 7 hinders the start of the motor M is reduced, and a quick start-up characteristic of the motor M that is less than half as compared with the related art is obtained, thereby enabling the rapid cooling of the processing object W. be able to. This makes it possible to effectively perform a process such as quenching and to surely improve the quality of the heat treatment. Further, since the load on the motor M can be reduced in this manner, the motor M can be covered with a smaller capacity. Further, it goes without saying that the cooling means 8 is effective in enhancing the cooling effect on the cooling gas in cooperation with the heat exchanger 9. Furthermore, titanium alloys and aluminum alloys have a lower heat resistance than stainless steel, and have the property that their strength and shape are destroyed when subjected to heat more than necessary during the heat treatment. Since the fan 7 is housed in the housing 7 and the fan 7 is directly cooled by the cooling means 8 during the heat treatment to prevent the temperature from rising due to heat, when the titanium alloy or the aluminum alloy is used as the material of the fan 7, Inconvenience can be prevented in advance.
[0015]
The specific configuration of each part is not limited to only the above-described embodiment. For example, a cooling pipe with fins may be used, or a scroll casing having a double furnace copper structure capable of flowing cooling water into the scroll casing. For example, various modifications can be made without departing from the spirit of the present invention.
[0016]
【The invention's effect】
The present invention, as described in detail above, uses a titanium alloy or an aluminum alloy as its material to make the fan lightweight, and at the same time, attaches a scroll casing and cooling means to protect the fan from overheating. It is a thing. Therefore, it is possible to improve the start-up characteristics of the motor that starts the fan and to perform processing such as quenching, thereby improving the quality of the heat treatment and effectively reducing the motor capacity. Excellent effects are achieved.
[Brief description of the drawings]
FIG. 1 is a schematic overall longitudinal sectional view showing one embodiment of the present invention.
FIG. 2 is a cross-sectional view of FIG.
FIG. 3 is a front view of a scroll casing used in the embodiment.
FIG. 4 is a front sectional view of the same.
FIG. 5 is a sectional side view of the same.
[Explanation of symbols]
7 Fan 8 Cooling means

Claims (2)

In a quench furnace with a fan that circulates cooling gas inside the furnace,
The fan is made of a titanium alloy or an aluminum alloy, and is housed in a scroll casing to surround it,
A quenching furnace, wherein a cooling pipe through which a cooling medium flows is provided in the scroll casing. A copper plate is provided in the vicinity of a discharge port from which gas that has passed through the internal flow path of the scroll casing is discharged, and the cold heat possessed by the cooling medium is transmitted to the cooling pipe and the copper plate, and further transmitted from these to the fan. The quenching furnace according to claim 1, wherein the quenching furnace is configured to perform the quenching.

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