WO2022054437A1

WO2022054437A1 - Batch-type heat treatment furnace

Info

Publication number: WO2022054437A1
Application number: PCT/JP2021/027867
Authority: WO
Inventors: 規輝永井; 朋哉大久保; 淳一臼田
Original assignee: 中外炉工業株式会社
Priority date: 2020-09-09
Filing date: 2021-07-28
Publication date: 2022-03-17
Also published as: JP2021071284A; JP6903205B2

Abstract

The technical problem addressed by the present invention is to provide a batch-type heat treatment furnace which, when cooling variation occurs in a workpiece, can suppress the cooling variation and enable easier and more uniform workpiece cooling by changing the cooling capacity for each area and cooling only specific parts.　This technical problem is solved by a batch-type heat treatment furnace that comprises, disposed inside of a casing (2), an inner chamber (3) which constitutes a heat treatment chamber, a cooling space (S), multiple ventilation flow paths (10) which allow communication between the inside of the inner chamber (3) and the cooling space (S), and lids (11) which are provided in each ventilation flow path (10), wherein each of the lids (11) can individually open and close the ventilation flow paths (10) in a manner allowing adjustment of the degree of opening thereof so as to differ the amount of air flowing from the cooling space (S) into the inner chamber (3) for each ventilation flow path (10); each of the ventilation flow paths (10) is provided with discharge holes (10a), and the discharge holes (10a) allow communication with the inner chamber (3); the multiple ventilation flow paths (10) include ventilation flow paths (10) that are arranged in a branching manner and ventilation flow paths that have different numbers and arrangements of the discharge holes (10a).

Description

Batch type heat treatment furnace

INDUSTRIAL APPLICABILITY The present invention makes it possible to suppress the cooling variation by changing the cooling capacity for each area or cooling only a specific part when the cooling variation occurs in the work, making the work easier and easier. The present invention relates to a batch type heat treatment furnace capable of cooling more uniformly.

Conventionally, Patent Documents 1 to 5 are known as techniques and devices for cooling by a batch type heat treatment furnace provided with an inner chamber. The "gas-cooled single-chamber heat-treating furnace" of Patent Document 1 is provided with a cooling gas vent that is opened and closed by a damper on the facing wall of the inner chamber forming the processing chamber, and the cooling gas vent is provided during gas cooling. In a gas-cooled single-chamber heat-resistant furnace that circulates cooling gas in an open state, a grid-like rectifying member made of a heat-resistant material is installed in a ventilation port for cooling gas of the inner chamber.

The "gas cooling method for metal materials" in Patent Document 2 is a gas cooling method for metal materials in which a metal material heated to a quenching temperature is forcibly convected-cooled in a furnace atmosphere, and a set cooling curve and a furnace atmosphere temperature or a furnace are used. Compared with the internal metal material temperature, the rotation speed of the cooling fan drive motor is controlled based on the deviation, and when the output of the motor reaches the limit, the maximum limit is reached regardless of the load fluctuation due to the temperature change. The output keeps the cooling fan drive motor rotating.

The "heat treatment furnace" of Patent Document 3 is a heat treatment furnace for heat-treating a work, and has a heat treatment chamber in which the work to be heat-treated is arranged, a cooling fan for circulating a cooling fluid for cooling the work, and a cooling fluid. The opening / closing damper is provided so as to have an angle with respect to the facing wall surface of the heat treatment chamber arranged facing the cooling fan at the opening position of the opening / closing damper. ing.

In the "vacuum heat treatment furnace" of Patent Document 4, the gas outlets of the two gas flow paths arranged along the heat insulating wall and the opening of the heat insulating wall are communicated with each other and passed through both gas flow paths. The cooling gases collide with each other and then flow through the opening into the storage space. By changing the ratio of the amount of gas passing through both gas flow paths, the direction of the cooling gas flowing into the storage space changes.

That is, in the vacuum container having a space for storing the object to be processed inside, a heat insulating wall surrounding the space is provided, and the heat insulating wall has an opening for sending cooling gas toward the space. In the formed vacuum heat treatment furnace, two gas flow paths are arranged along the heat insulating wall between the inner surface of the container and the heat insulating wall inside the vacuum container, and both gas flows. The gas outlet of the road and the opening are communicated with each other so that the cooling gas passing through both gas flow paths collides with each other and the colliding gas flows into the space through the opening. Both gas flow paths are provided with a changing means for changing the ratio of the amount of gas passing through each gas flow path.

In the "vacuum heat treatment furnace" of Patent Document 5, a heating chamber surrounded by a heat insulating material is formed in the furnace body, and the heated material is vacuum-heated in the heating chamber and then gas-cooled. In the heat treatment furnace, an attachment is attached to the tip of a nozzle for ejecting the cooling gas into the heating chamber, and the attachment is configured to change the ejection direction of the cooling gas.

That is, the gas is cooled by circulating the cooling gas cooled by the heat exchanger, and a plurality of cooling gases are introduced into the heating chamber between the furnace body and the heat insulating material forming the heating chamber. Pipes are arranged side by side, and a plurality of nozzles inserted into the heating chamber through the heat insulating material are attached to each of the pipes, and the cooling gas ejection direction is provided at the tip of each of the nozzles. An attachment that regulates the temperature is attached so that the direction of ejection of the cooling gas can be changed by the attachment.

Japanese Patent Application Laid-Open No. 2002-333277 Japanese Unexamined Patent Publication No. 2002-249819 Japanese Unexamined Patent Publication No. 2019-190801 Japanese Unexamined Patent Publication No. 6-100928 Japanese Unexamined Patent Publication No. 63-255319

Even if the cooling fluid that is circulated in the inner chamber in which the work is arranged and cools the work is circulated in the furnace as in Patent Documents 1 to 3, it is difficult to uniformly cool the work having a complicated shape. ..

Therefore, in Patent Document 4, the ratio of the amount of gas passing through the two gas flow paths arranged between the heat insulating wall surrounding the space is changed in the vacuum container having the space where the object to be processed is arranged. It is supposed to be.

However, it is difficult to cool the work sufficiently uniformly because two gas flow paths are provided only on one side of the heat insulating wall surrounding the space.

In Patent Document 5, an attachment made of a cylindrical part that is in sliding contact with the outer periphery of the tip of the nozzle and whose tip is inclined is fastened with a screw. Therefore, every time the shape of the work changes, the screw holding each attachment is fastened. There was a problem that the work was complicated because the ejection direction from the attachment had to be adjusted individually.

In heat treatment, it is difficult to cool the work uniformly with gas cooling, and a temperature difference always occurs depending on the part of the work. In any of Patent Documents 1 to 5, it is not possible to specify and cool only a portion where cooling is slow.

The present invention has been devised in view of the above-mentioned conventional problems, and when the cooling variation occurs in the work, the cooling capacity is changed for each area or only a specific part is cooled to reduce the cooling variation. It is an object of the present invention to provide a batch type heat treatment furnace which can be suppressed and can cool a work more easily and more uniformly.

The batch type heat treatment furnace according to the present invention has an inner chamber provided inside the furnace and forming a heat treatment chamber, a cooling space provided inside the furnace and provided with a cooling device for cooling air, and the inner inside the furnace. A plurality of airflow channels provided on the outer peripheral portion of the chamber and communicating the inside of the inner chamber with the cooling space, and a lid provided in each of the ventilation channels are provided, and each of the lids is individually provided. The ventilation flow path can be opened and closed so that the amount of air flowing from the cooling space to the inner chamber differs for each ventilation flow path, and each of the ventilation flow paths has a discharge hole. The plurality of airflow channels, which are communicated with the inside of the inner chamber by the discharge holes, include the airflow channels that are branched and arranged, and the airflow channels having different numbers and arrangements of the discharge holes. It is characterized by being.

The lid body is characterized in that it can be opened and closed from the outside of the furnace body.

The discharge hole is characterized in that it is formed with a cross-sectional area smaller than the cross-sectional area of the ventilation flow path.

In the batch type heat treatment furnace according to the present invention, when cooling variation occurs in the work, the cooling variation can be suppressed by changing the cooling capacity for each area or cooling only a specific part. , The work can be cooled more easily and more uniformly.

It is a vertical sectional view which shows one preferable embodiment of the batch type heat treatment furnace which concerns on this invention. It is a schematic perspective view which shows the slide drive mechanism of the block plate provided in the batch type heat treatment furnace of FIG. In FIG. 1, it is a cross-sectional view taken along the line AA. It is a schematic perspective view which shows the opening and closing drive mechanism of the lid provided in the batch type heat treatment furnace of FIG. It is explanatory drawing explaining the state which separated the upper part of the furnace body from the lower part of the furnace body in order to charge a work in the batch type heat treatment furnace of FIG. It is explanatory drawing explaining the state in the heat treatment furnace at the time of cooling in the batch type heat treatment furnace of FIG. It is explanatory drawing explaining an example of the opening and closing state of the lid body at the time of cooling shown in FIG. It is a developed view which developed the inner peripheral side wall in the circumferential direction to explain an example of the arrangement of the ventilation flow path and the discharge hole which can be adopted in the batch type heat treatment furnace which concerns on this invention.

Hereinafter, a preferred embodiment of the batch heat treatment furnace according to the present invention will be described in detail with reference to the attached drawings. As shown in FIG. 1, in the batch type heat treatment furnace 1 according to the present embodiment, an inner chamber 3 forming a heat treatment chamber is arranged substantially in the center of a casing 2 which is a furnace body.

The casing 2 has a cylindrical peripheral side wall (hereinafter referred to as an outer peripheral side wall) 2a, a top portion (hereinafter referred to as an outer top portion) 2b having an arc-shaped portion and swelling upward, and an arc-shaped portion and swelling downward. It has a bottom (hereinafter referred to as an outer bottom) 2c.

The outer bottom portion 2c is integrally formed by being connected to the lower end of the outer peripheral side wall 2a. The outer sky portion 2b is configured to be separable from the outer peripheral side wall 2a, and the outer sky portion 2b is configured to be placed on the upper end of the outer peripheral side wall 2a.

An annular surrounding body 2d protruding downward is provided on the outer periphery of the lower end of the outer sky portion 2b. The annular enclosure 2d is configured to surround the outer periphery of the upper end of the outer peripheral side wall 2a when the outer top portion 2b is placed on the upper end of the outer peripheral side wall 2a.

A motor 4a of a cooling fan 4 provided in the upper part of the casing 2 is provided on the outer top portion 2b. Below the outer bottom portion 2c, a motor 5a of a heating fan 5 provided at the lower portion in the inner chamber 3 is provided.

The inner chamber 3 has a cylindrical peripheral side wall (hereinafter referred to as an inner peripheral side wall) 3a having an outer diameter smaller than the inner diameter of the outer peripheral side wall 2a and a top portion (hereinafter referred to as an inner ceiling portion) covering the upper end of the inner peripheral side wall 3a. It has a 3b and a flat bottom portion (hereinafter referred to as an inner bottom portion) 3c that closes the lower end of the inner peripheral side wall 3a.

The inner bottom portion 3c is connected to the lower end of the inner peripheral side wall 3a and is integrally formed. The inner ceiling portion 3b is connected to the upper end of the inner peripheral side wall 3a and has an inner opening 3e concentric with the inner peripheral side wall 3a. It has an obstruction body 3f that covers.

The peripheral edge top portion 3e and the closing body 3f are configured to be separable, and the inner opening 3d in the state where the closing body 3f is removed serves as an insertion port when the work W to be heat-treated is placed in the inner chamber 3. ..

The closed body 3f has a closed body main body 3h having a rectangular upper opening 3g in the center, and two closing plates 3i capable of closing the upper opening 3g.

The two closing plates 3i are provided so as to be slidable on the closing body main body 3h, and are configured to be abutted at the center of the upper opening 3g and to open and close the upper opening 3g so as to be openable and closable.

As shown in FIG. 2, the two closing plates 3i are pushed and pulled by the actuators 3j provided on the outer periphery of the casing 2, and slid in directions away from each other to open the upper opening 3g. It is configured in.

The obstruction body 3f is provided integrally with the outer heaven portion 2b. The obstructed body 3f is arranged at a distance below the cooling fan 4 provided in the center of the upper part of the outer top portion 2b.

A guide 6 for guiding the flow of the atmosphere in the casing 2 is provided between the cooling fan 4 and the closing body 3f. The guide 6 has a lower end opened so as to surround the outer periphery of the closed body 3f and an upper end opened toward the upper cooling fan 4, and the diameter of the upper end side is narrower than that of the lower end side. It is formed to be.

A cooling device 7 is provided around the cooling fan 4 provided above the upper end of the guide 6 so as to surround the cooling fan 4. When the cooling fan 4 and the cooling device 7 are operated, the air drawn from below the cooling fan 4 moves to the outer peripheral side by the cooling fan 4, is cooled by the cooling device 7, and flows to the outer peripheral side of the inner chamber 3. Guided by the guide 6.

The inner bottom portion 3c is placed on the legs 2e erected from the outer bottom portion 2c, and the inner peripheral side wall 3a is arranged substantially concentrically with the outer peripheral side wall 2a. Therefore, the inner bottom portion 3c and the outer bottom portion 2c are vertically separated from each other, and the inner peripheral side wall 3a and the outer peripheral side wall 2a are separated from each other over the entire circumference.

On the inner bottom portion 3c, a mounting table 8 on which the work W is placed is provided at an interval upward from the inner bottom portion 3c. A heating fan 5 connected to a motor 5a provided under the outer bottom portion 2c is provided between the mounting table 8 and the inner bottom portion 3c.

In the inner chamber 3, a plurality of heaters 9 are arranged along the inner peripheral side wall 3a at appropriate intervals in the circumferential direction of the inner peripheral side wall 3a. The heater 9 is provided so as to surround the space on the mounting table 8 on which the work W is placed.

A plurality of ventilation flow paths 10 are provided on the outer periphery of the inner chamber 3, that is, between the outer peripheral side wall 2a and the inner peripheral side wall 3a.

The ventilation flow path 10 is a square tubular duct pipe having a rectangular cross section, an upper end is open, and a lower end is closed, and each is provided along the vertical direction.

In the present embodiment, as shown in FIG. 3, 16 ventilation flow paths 10 are provided at equal intervals along the circumferential direction on the outside of the inner peripheral side wall 3a.

In FIG. 3, the mechanism for sliding the block plate 3i and the guide 6 are omitted.

As shown in FIG. 1, each ventilation flow path 10 is provided with four discharge holes 10a provided at intervals in the vertical direction. The number of discharge holes 10a is not limited to four, and any number may be provided.

Each discharge hole 10a is provided so as to be drawn into the inner chamber 3 so that the space (cooling space) S above the ventilation flow path 10 provided with the cooling device 7 and the inside of the inner chamber 3 communicate with each other. It is configured in.

The cross-sectional area of the discharge hole 10a is set sufficiently smaller than the cross-sectional area of the ventilation flow path 10. Therefore, the air discharged from the discharge hole 10a through the ventilation flow path 10 is blown into the inner chamber 3 and discharged so as to be blown to the work W.

A lid 11 capable of opening and closing the upper end opening 10b of the ventilation flow path 10 is provided at the upper end portion of the ventilation flow path 10.

As shown in FIG. 4, the lid 11 has a rack and pinion mechanism 3l (see FIG. 4A) on the actuator 3k provided on the outer periphery of the casing 2, or a pinion mechanism 3l on the motor 3k (FIG. 4B). )), The lid 11 is attached to the rotating shaft 3 m connected via the rotation shaft 3 m. Therefore, the lid 11 is rotationally driven by an actuator 3k or the like to fully open / close the upper end opening 10b, or the lid 11 is held at a predetermined angle to arbitrarily open the upper end opening 10b. Can be adjusted.

That is, the air flow passage 10 is blocked by the lid 11 by the actuator 3k or the like, the lid 11 is opened to communicate the cooling space S with the inside of the inner chamber 3, and the angle of the lid 11 is adjusted. Therefore, the amount of inflow of air flowing into the ventilation flow path 10 can be adjusted.

An actuator 3j for sliding the closing plate 3i, an actuator 3k and a motor 3k for opening and closing the lid 11, a motor 4a for the cooling fan 4, a motor 5a for the heating fan 5, and the like, which are provided on the outside of the casing 2. Both the cooling device 7 and the heater 9 can be operated from the outside of the casing 2.

Therefore, for example, the actuator 3k or the like is operated according to the shape of the work W to adjust the angle of the lid 11 of each air flow path 10, or the lid 11 of each air flow path 10 is adjusted with the passage of time. You can change the angle of. The mechanism for sliding the closing plate 3i and the mechanism for opening and closing the lid 11 are not limited to this, and various well-known devices can be used.

The operation of the batch type heat treatment furnace 1 according to the present embodiment will be described. First, as shown in FIG. 5, the upper portion 1a of the furnace body integrated with the outer top portion 2b of the casing 2 is removed, and the work W is placed on the mounting table 8 from the inner opening 3d of the inner chamber 3. After that, the upper part 1a of the furnace body is arranged on the lower part 1b of the furnace body. At this time, the obstruction body 3f is placed on the peripheral edge top portion 3e to close the inner opening 3d.

Next, as shown in FIG. 1, the heating fan 5 and the heater 9 are operated from the outside in a state where the upper opening 3g is closed by the closing plate 3i and each ventilation flow path 10 is closed by the lid 11. It is operated to heat the work W. At this time, the cooling fan 4 and the cooling device 7 are stopped.

After the heating of the work W is completed, the heating fan 5 and the heater 9 are stopped by an external operation, and as shown in FIGS. 6 and 7, the closing plate 3i is slid to open the upper opening 3g, and each of them is opened. The angle of the lid 11 of the ventilation flow path 10 is adjusted.

That is, the lid 11 of the ventilation flow path 10 having the discharge hole 10a facing the portion of the work W that is difficult to be cooled is opened more widely, and the ventilation flow path having the discharge hole 10a facing the portion of the work W that is easily cooled is opened. The lid 11 of 10 is set according to the shape of the work for uniform cooling, such as opening the lid 11 smaller than the others or adjusting the angle of the lid 11 so as to close the lid 11.

After that, the cooling fan 4 and the cooling device 7 are operated by an external operation to cool the work W. In FIG. 7, the portion where the air flow path 10 is shown in black indicates the inside of the air flow path 10 which can be seen from above by opening the lid 11.

According to the batch type heat treatment furnace 1 according to the present embodiment, a plurality of air currents provided on the outer peripheral portion of the inner chamber 3 forming the heat treatment chamber and communicating the inside of the inner chamber 3 with the cooling space S provided with the cooling device 7. Since the air flow path 10 is provided with a lid 11 that can open and close the ventilation flow path 10 individually, the ventilation flow path 10 through which the cooling air flows and the ventilation flow path 10 in which the cooling air does not flow are created or the flow rate is increased. A modified ventilation passage 10 can be created.

Therefore, depending on the shape of the work W to be cooled, for example, the lid 11 of the ventilation flow path 10 having the discharge hole 10a at a position facing the portion that is difficult to be cooled is opened, and the lid 11 is placed at a position facing the portion that is easily cooled. The amount of cooling air ejected toward the work W by closing the lid 11 of the ventilation flow path 10 provided with the discharge hole 10a or by making the opening degree of the lid 11 of the ventilation flow path 10 different. Can be different for each ventilation flow path 10. As a result, the work W can be cooled more uniformly.

That is, by adjusting the angle of the lid 11 to be opened, the inflow amount of the cooling air flowing into the ventilation flow path 10 can be adjusted. As a result, the amount of cooling air discharged from the discharge holes 10a provided in each ventilation flow path 10 can be finely adjusted, so that cooling can be performed more uniformly according to the shape of the work W and the like.

Further, since the cross-sectional area of the discharge hole 10a is sufficiently smaller than the cross-sectional area of the ventilation flow path 10, the cooling air discharged from the discharge hole 10a has a higher flow velocity than the air flowing in the ventilation flow path 10. Therefore, the cooling air can be discharged so as to be blown onto the work W to efficiently cool the work W.

Further, since each lid 11 can be opened and closed from the outside of the casing 2, the lid 11 is opened or the opening angle is set when cooling after the heat treatment or without opening the furnace body upper portion 1a during the cooling treatment. Can be adjusted. Therefore, the work is easy and the work can be carried out efficiently.

Further, when the device capable of monitoring the temperature of the work W is provided, the opening angle of the lid 11 can be adjusted at any time according to the temperature state of the work W, and the work W can be cooled to a more uniform temperature. can.

In the above embodiment, an example in which 16 ventilation flow paths 10 having a rectangular cross section are provided on the outer periphery of the inner peripheral side wall 3a has been described, but the cross-sectional shape and the number thereof are not limited to this.

Further, an example in which the same ventilation flow path 10 is provided along the vertical direction has been described, but the present invention is not limited to this. For example, as shown in FIG. 8, of two airflow passages 10 adjacent to each other, one of the airflow passages 10 is provided only on the upper side and has two discharge holes 10a, and the other airflow passage 10 The shape of the ventilation flow path 10 and the number of discharge holes 10a that each ventilation flow path 10 has, such as being branched and arranged so as to extend to the lower side of the adjacent ventilation flow path 10 and having six discharge holes 10a. Can be arbitrarily set, and the ventilation flow path 10 may include a ventilation flow path 10 having a different number and arrangement of discharge holes 10a.

In detail, FIG. 8 is provided on the outer peripheral portion of the inner chamber 3 in the casing 2, and includes a plurality of air flow paths 10 that communicate the inside of the inner chamber 3 and the cooling space S, and each of the air flow paths 10 is provided. , The ventilation flow path 10 having a discharge hole 10a and being communicated with the inside of the inner chamber 3 by the discharge hole 10a, and being branched and arranged in the plurality of ventilation flow paths 10, and the number of the discharge holes 10a and the number of the discharge holes 10a. The configuration shows that the ventilation flow paths 10 having different arrangements are included.

As described above, the present invention can suppress the cooling variation by changing the cooling capacity for each area or cooling only a specific part when the cooling variation occurs in the work. To provide a batch type heat treatment furnace capable of cooling more easily and more uniformly. "

In order to solve this problem, the present invention includes a plurality of air flow paths 10 that communicate the inner chamber 3 and the cooling space S with a branch arrangement or a different number and arrangement of discharge holes 10a. To be configured, that is, to give a change to the layout of the ventilation flow path 10 communicating in the inner chamber 3 and the layout of the discharge hole 10a provided in the ventilation flow path 10 and communicated in the inner chamber 3. It is configured in.

That is, the present invention is a technique relating to a ventilation flow path 10 for guiding air to a discharge hole 10a, in which the layout of the ventilation flow path 10 is changed or the layout of the discharge hole 10a of the ventilation flow path 10 is changed. When the same amount of air is supplied to each ventilation flow path 10 depending on whether or not the ventilation flow path 10 is branched and the number and arrangement of the discharge holes 10a are different, those are discharged from each ventilation flow path 10. It is possible to change the amount of air ejected from the hole 10a.

The above embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. It goes without saying that the present invention can be modified and improved without departing from the spirit thereof, and the present invention includes an equivalent thereof.

1 Batch type heat treatment furnace 1a Upper part of the furnace body 1b Lower part of the furnace body 2 Casing 2a Outer peripheral side wall 2b Outer top

2c Outer bottom

2d Circular enclosure 2e Leg 3 Inner chamber 3a Inner peripheral side wall

3b Inner top

3c Inner bottom 3d Inner opening 3e Peripheral top 3f Closure

3g Top opening

3h Closure body

3i Closure plate 3j Actuator 3k 3l rack and pinion mechanism or pinion mechanism 3m rotating shaft 4 cooling fan 4a motor 5 heating fan 5a motor 6 guide 7 cooling device 8 mounting stand 9 heater 10 ventilation flow path 10a discharge hole 10b upper end opening 11 lid S cooling space W work

Claims

An inner chamber provided inside the furnace and forming a heat treatment chamber,
A cooling space provided in the furnace body and equipped with a cooling device for cooling air,
A plurality of ventilation channels provided on the outer peripheral portion of the inner chamber in the furnace body and communicating the inside of the inner chamber and the cooling space,
A lid provided in each of the above ventilation channels is provided.
Each of the lids can individually open and close the ventilation flow path so that the amount of air flowing from the cooling space to the inner chamber differs for each ventilation flow path.
Each of the ventilation channels is provided with a discharge hole, and the discharge hole communicates with the inside of the inner chamber.
A batch-type heat treatment furnace characterized in that the plurality of the airflow channels include the airflow channels that are branched and arranged, and the airflow channels having different numbers and arrangements of the discharge holes.
The batch type heat treatment furnace according to claim 1, wherein the lid body can be opened and closed from the outside of the furnace body.
The batch type heat treatment furnace according to claim 1 or 2, wherein the discharge hole is formed with a cross-sectional area smaller than the cross-sectional area of the ventilation flow path.