WO2019087732A1

WO2019087732A1 - Carburization device

Info

Publication number: WO2019087732A1
Application number: PCT/JP2018/038053
Authority: WO
Inventors: 勝俣　和彦
Original assignee: 株式会社Ihi; 株式会社Ｉｈｉ機械システム
Priority date: 2017-11-06
Filing date: 2018-10-12
Publication date: 2019-05-09
Also published as: JP6799173B2; CN209039565U; JPWO2019087732A1

Abstract

A carburization device (A) according to the present disclosure is provided with: a furnace body (1) in which an object to be processed is contained; a plurality of heaters (4a) which extend in the horizontal direction within the furnace body; a plurality of protection members (4b) which cover the plurality of heaters, respectively; support units (5, 6, 7, 8) which are arranged at both ends of the heaters so as to support the heaters; a carburization gas supply unit (13) which supplies a carburization gas into the furnace body; and an air supply unit (11) which supplies an air for burn-out into the spaces between the heaters and the protection members. The support units cool the ends of the heaters in an indirect manner.

Description

Carburizing equipment

The present disclosure relates to a carburizing apparatus.
Priority is claimed on Japanese Patent Application No. 2017-213903, filed Nov. 6, 2017, the content of which is incorporated herein by reference.

Patent Document 1 below describes burnout in a carburizing apparatus. When the object to be treated is carburized by the carburizing apparatus, the carbon content (that is, soot) caused by the carburizing gas adheres to the inside of the carburizing apparatus, but burnout is carburized by introducing air into the carburizing apparatus. It is a process of burning and removing carbon (soot) attached to a heater or the like in the apparatus. Such burnout is also disclosed in Patent Document 2.

Japanese Patent No. 5830586 Japanese Patent Application Publication No. 2007-131936

By the way, since burnout is performed between carburizing treatment objects using a carburizing apparatus, it is a factor that reduces the operation efficiency of the carburizing apparatus, and may act to damage the heater that generates heat to high temperatures. It is also. When the heater of the carburizing apparatus is damaged, the heat generation efficiency is lowered, so that the carburizing temperature can not be set to the desired temperature even if a predetermined power is supplied. The carburizing apparatus is usually provided with a plurality of heaters, but heater damage is a very important issue in maintaining the apparatus performance of the carburizing apparatus.

This indication is made in view of the situation mentioned above, and aims at controlling damage to a heater in a carburizing device.

A carburizing apparatus according to an aspect of the present disclosure includes: a furnace body that accommodates an object to be treated; a plurality of heaters extending in the horizontal direction in the furnace body; a plurality of protection members that respectively cover the plurality of heaters; Support for supporting the heater, a carburizing gas supply unit for supplying carburizing gas into the furnace body, and air for burnout to the gap between the heater and the protective member An air supply, and the support indirectly cools the end of the heater.

In the carburizing apparatus according to the above aspect, the support portion includes a receiving member that contacts the end of the heater, and a support plate that fixes the receiving member to the furnace body, and cools the support plate. May indirectly cool the end of the heater.

In the carburizing apparatus of the above aspect, the support portion may be provided with a refrigerant flow path which is provided in the vicinity of the end portion of the heater and through which a coolant flows.

In the carburizing apparatus according to the above aspect, the plurality of heaters may be provided in upper and lower two stages so as to sandwich the object to be treated.

The carburizing apparatus according to the above aspect may further include a coolant supply unit that adjusts the flow rate of the coolant for each stage.

According to the present disclosure, it is possible to suppress damage to the heater in the carburizing apparatus.

1 is a front sectional view of a carburizing apparatus according to an embodiment of the present disclosure. It is a side cross-section electrogram of the upper electrode part in one embodiment of this indication. FIG. 5 is a top cross-sectional view of the upper electrode portion in an embodiment of the present disclosure. It is a side cross-sectional electrogram of the lower electrode part in one embodiment of this indication. FIG. 7 is a top cross-sectional view of the lower electrode portion in an embodiment of the present disclosure.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.
As shown in FIG. 1, the carburizing apparatus A according to this embodiment includes a furnace body 1, a heat insulating container 2, a hearth 3, a plurality of heater units 4, an upper electrode portion 5, an upper ground portion 6, a lower electrode portion 7, The lower earth unit 8, the carburizing gas pipe 9, the exhaust pipe 10, the air supply unit 11, the gas recovery unit 12, the carburizing gas supply unit 13, the cooling liquid supply unit 14 and the like are provided. Among these components, the upper electrode portion 5, the upper ground portion 6, the lower electrode portion 7, and the lower ground portion 8 correspond to the support portion of the present disclosure.

The carburizing apparatus A carburizes the object X stored in the carburizing chamber P. That is, the carburizing apparatus A causes carbon (carbon atoms) to enter the surface of the object to be treated X by heating the object to be treated X to a temperature close to 1000 ° C. and setting the carburizing chamber P to a carburizing gas atmosphere. Form a carburized layer of a predetermined depth. In addition, the to-be-processed object X which is a process target of the carburizing apparatus A is a metal component to which surface hardness rises by a carburized layer.

The furnace body 1 is a substantially rectangular parallelepiped main body container (metal container), and an open / close door (not shown) is provided on one side surface (surface on the near side in FIG. 1). The furnace body 1 is electrically grounded. The heat insulation container 2 is a container provided with a heat insulation property of a substantially rectangular parallelepiped shape provided in the furnace body 1, and is formed of a predetermined heat insulation material (for example, a ceramic material). The internal space (substantially rectangular parallelepiped space) of the heat insulation container 2 is a carburizing chamber P that accommodates the object X to be treated. The hearth 3 is a mounting table on which the workpiece X is placed, and is provided inside and below the heat insulation container 2. The hearth 3 is formed of a ceramic material (heat insulating material) such as alumina.

Moreover, the heat insulation board which forms one side of the heat insulation container 2 is provided inside the opening-and-closing door mentioned above. That is, the heat insulation container 2 is comprised from the openable-closable heat insulating board provided inside the opening-closing door, and five heat-insulation boards fixedly installed. In the carburizing apparatus A, the object to be treated X is accommodated in the carburizing chamber P by opening the open / close door provided on the front side of FIG.

Here, the left and right direction in FIG. 1 is the width direction of the carburizing apparatus A, that is, the furnace body 1 and the heat insulating container 2, and the vertical direction in FIG. 1 is the height direction of the carburizing apparatus A. The direction orthogonal to the direction is the depth direction of the carburizing apparatus A.

The plurality of heater units 4 are rod-like members having a predetermined length and extending in the horizontal direction, and are vertically disposed to sandwich the object X in the vertical direction. That is, as shown in FIG. 1, the plurality of heater units 4 are provided at the upper and lower portions in the heat insulating container 2 in a posture in which the axial direction is the width direction of the carburizing apparatus A (the furnace body 1 and the heat insulating container 2). . The heater unit 4 is provided at predetermined intervals in the depth direction of the carburizing apparatus A (the furnace body 1 and the heat insulating container 2) as shown in FIGS. 2A and 2B and FIGS. 3A and 3B.

Further, seven heater units 4 are provided in the depth direction of the upper part (upper part of the carburizing chamber P) in the heat insulation container 2 as shown in FIGS. 2A and 2B, and as shown in FIGS. 3A and 3B The same seven are provided in the depth direction of the lower part of. That is, the plurality of heater units 4 are provided in upper and lower two stages so as to sandwich the processing object X.

The seven heater units 4 provided in the upper part of the carburizing chamber P are upper heater units 4A. The upper heater unit 4A is supported at its first end (left end) by the upper electrode portion 5 and at its second end (right end) by the upper ground portion 6. The seven heater units 4 provided in the lower part of the carburizing chamber P are lower heater units 4B. The lower heater unit 4B is supported at its first end (left end) by the lower electrode portion 7 and at its second end (right end) by the lower ground portion 8.

The heater units 4 (upper heater unit 4A and lower heater unit 4B) each include a heater main body 4a and a protective tube 4b. The heater main body 4a has a first end located on the upper electrode portion 5 or lower electrode portion 7 side connected to the power supply, and a second end located on the upper earth portion 6 or lower earth portion 8 side is grounded. The heater main body 4a is a columnar electric heater (resistance heating element) that generates heat when power is supplied from the power supply to the first end, and is, for example, a ceramic heater made of ceramic or a graphite heater made of graphite. The heater main body 4a corresponds to the heater of the present disclosure, and the protective tube 4b corresponds to the protective member of the present disclosure.

The protective tube 4b is a ceramic circular tubular member (straight tube) having an inner diameter larger than the diameter of the heater main body 4a, and is provided so as to cover the heater main body 4a. The inner surface of the protective tube 4b and the surface of the heater main body 4a are an annular surface and a cylindrical surface facing each other in parallel and at predetermined intervals in a concentric manner. Although details will be described later, compressed air K for burnout flows in the gap between the inner surface of the protective tube 4b and the surface of the heater main body 4a.

The upper electrode portion 5 is a structure that mechanically supports the first end (left end) of the upper heater unit 4A. The upper electrode portion 5 is provided at the upper left portion of the furnace body 1 so as to entirely cover the first ends (left ends) of the seven upper heater units 4A as shown in FIG. 1 and FIGS. 2A and 2B. The upper electrode portion 5 includes an enclosing member 5a, a first plate 5b, a second plate 5c, seven supporting plates 5d, seven receiving members 5e, and the like.

The enclosing member 5a is a substantially rectangular metal member whose first surface (right side surface) is released. The enclosing member 5a is provided at the upper left portion of the furnace body 1 so as to entirely surround the first end (left end) of the seven upper heater units 4A. The first plate 5b is a metal plate provided with an opening (round hole) through which the protective tube 4b is inserted, and sealing the first surface of the enclosing member 5a. The periphery of the first plate 5b is welded to the enclosure member 5a so as to seal the first surface of the enclosure member 5a, and the periphery of the opening of the first plate 5b is welded to the protective tube 4b.

Similar to the first plate 5b, the second plate 5c is formed with an opening (round hole) through which the protective tube 4b is inserted, and faces the first plate 5b in parallel with each other at a predetermined distance inside the enclosing member 5a. It is a metal plate provided in The periphery of the second plate 5c is welded and fixed to the enclosing member 5a, and the periphery of the opening of the second plate 5c is welded to the protective tube 4b all around.

That is, the space surrounded by the enclosing member 5a, the protective pipe 4b, the first plate 5b, and the second plate 5c forms a refrigerant flow path 5f (closed space) through which the cooling fluid R flows. A space surrounded by the enclosing member 5a and the second plate 5c is a substantially sealed space, and is an air supply chamber S1 to which the compressed air K for burnout is supplied from the air supply unit 11.

Seven support plates 5d are provided corresponding to the upper heater units 4A, that is, the heater main bodies 4a of the upper heater units 4A. The support plate 5d is a bent plate (L-shaped metal) having a first surface welded and fixed to the outer surface (left surface) of the second plate 5c in a vertical posture and a second surface (horizontal surface) orthogonal to the first surface. Board). Receiving members 5e are respectively installed on the second surface (horizontal surface) of the support plate 5d. That is, the second surface (horizontal surface) of the support plate 5d is the installation surface of the receiving member 5e.

The receiving member 5e is an insulating member provided corresponding to each heater main body 4a of the upper heater unit 4A. The receiving member 5e receives the load of each heater main body 4a by abutting on the first end (left end) of each heater main body 4a of the upper heater unit 4A. The receiving member 5e is a substantially rectangular parallelepiped molded body having a V-shaped groove formed in the upper part as shown in FIG. 2A, and the first V-shaped groove of the first heater main body 4a of the upper heater unit 4A. It is placed with the end (left end) engaged. That is, the first end (left end) of each heater main body 4 a is supported by the furnace body 1 by the upper electrode portion 5.

The upper ground portion 6 is a structure that supports the second end (right end) of the upper heater unit 4A. The upper ground portion 6 is provided on the upper right portion of the furnace body 1 so as to entirely cover the second ends (right ends) of the seven upper heater units 4A as shown in FIG. The upper ground portion 6 includes an enclosing member 6a, a first plate 6b, a second plate 6c, seven supporting plates 6d, seven receiving members 6e, and the like.

The enclosing member 6a is a substantially rectangular metal member whose first surface (left side surface) is released. The enclosing member 6a is provided at the upper right portion of the furnace body 1 so as to entirely surround the second ends (right ends) of the seven upper heater units 4A. The first plate 6b is a metal plate provided with an opening (round hole) through which the protective tube 4b is inserted, and sealing the first surface of the enclosing member 6a. The periphery of the first plate 6b is welded and fixed to the enclosure member 6a so as to seal the first surface of the enclosure member 6a, and the periphery of the opening of the first plate 6b is welded all around the protection tube 4b.

The second plate 6c is a metal plate provided with an opening (round hole) through which the protective tube 4b is inserted, and provided inside the enclosing member 6a so as to face the first plate 6b in parallel at a predetermined distance. is there. The periphery of the second plate 6c is welded and fixed to the enclosing member 6a, and the periphery of the opening of the second plate 6c is welded to the protective tube 4b all around.

That is, a space surrounded by the enclosing member 6a, the protective pipe 4b, the first plate 6b, and the second plate 6c forms a refrigerant flow path 6f (sealed space) through which the cooling fluid R flows. A space enclosed by the enclosing member 6a and the second plate 6c is a substantially enclosed space, and a gas recovery chamber C1 for recovering the burnout gas from the gap between the protective tube 4b and the heater main body 4a in total of seven. It is.

Seven support plates 6d are provided corresponding to the upper heater units 4A, that is, the heater bodies 4a of the upper heater units 4A. The support plate 6d is a bent plate (L-shaped plate material) having a first surface fixed in a vertical posture to the outer surface (right surface) of the second plate 6c and a second surface (horizontal surface) orthogonal to the first surface. It is. Receiving members 6e are mounted on the second surface (horizontal surface) of the support plate 6d. That is, the second surface (horizontal surface) of the support plate 6d is the installation surface of the receiving member 6e.

The receiving member 6e is an insulating material provided corresponding to each heater main body 4a of the upper heater unit 4A. The receiving member 6e receives the load of each heater main body 4a by abutting on the second end (right end) of each heater main body 4a of the upper heater unit 4A. Similar to the receiving member 5e, the receiving member 6e is a substantially rectangular parallelepiped molded body in which a V-shaped groove is formed in the upper part, and the V-shaped groove is used for the second heater main body 4a of the upper heater unit 4A. The two ends (right end) are placed in the engaged state. That is, the second end (right end) of each heater body 4 a is supported by the furnace body 1 by the upper ground portion 6.

The lower electrode portion 7 is a structure that supports the first end (left end) of the lower heater unit 4B. The lower electrode portion 7 is provided at the lower left portion of the furnace body 1 so as to entirely cover the first ends (left ends) of the seven lower heater units 4B as shown in FIGS. 1 and 3A, 3B. The lower electrode portion 7 includes an enclosing member 7a, a first plate 7b, a second plate 7c, seven supporting plates 7d, seven receiving members 7e and the like.

The enclosing member 7a is a substantially rectangular metal member whose first surface (right side surface) is released. The enclosing member 7a is provided at the lower left portion of the furnace body 1 so as to entirely surround the first end (left end) of the seven lower heater units 4B. The first plate 7b is a metal plate provided with an opening (round hole) through which the protective tube 4b is inserted, and sealing the first surface of the enclosing member 7a. The periphery of the first plate 7b is welded and fixed to the enclosure member 7a so as to seal the first surface of the enclosure member 7a, and the periphery of the opening of the first plate 7b is welded all around to the protective tube 4b.

Similar to the first plate 7b, the second plate 7c is formed with an opening (round hole) through which the protective tube 4b is inserted, and faces the first plate 7b in parallel with each other at a predetermined distance inside the enclosing member 7a. It is a metal plate provided in The peripheral edge of the second plate 7c is welded and fixed to the enclosing member 7a, and the peripheral edge of the opening of the second plate 7c is welded all around the protective tube 4b.

That is, the space surrounded by the enclosing member 7a, the protective pipe 4b, the first plate 7b and the second plate 7c forms a refrigerant flow path 7f (closed space) through which the cooling fluid R flows. A space surrounded by the enclosing member 7a and the second plate 7c is a substantially sealed space, and is an air supply chamber S2 to which the compressed air K for burnout is supplied from the air supply unit 11.

Seven support plates 7d are provided corresponding to the lower heater units 4B, that is, the heater bodies 4a of the lower heater units 4B. The support plate 7d is a bent plate (L-shaped metal) having a first surface welded and fixed to the outer surface (left surface) of the second plate 7c in a vertical posture and a second surface (horizontal surface) orthogonal to the first surface. Board). Receiving members 7e are respectively installed on a second surface (horizontal surface) of the support plate 7d. That is, the second surface (horizontal surface) of the support plate 7d is the installation surface of the receiving member 7e.

The receiving member 7e is an insulating member provided corresponding to each heater main body 4a of the lower heater unit 4B. The receiving member 7e receives the load of each heater main body 4a by abutting on the first end (left end) of each heater main body 4a of the lower heater unit 4B. The receiving member 7e is a substantially rectangular parallelepiped molded body having a V-shaped groove formed in the upper part as shown in FIG. 3A, and the first V-shaped groove is used as the first heater main body 4a of the lower heater unit 4B. It is placed with the end (left end) engaged. That is, the first end (left end) of each heater body 4 a is supported by the furnace body 1 by the lower electrode portion 7.

The lower ground portion 8 is a structure that supports the second end (right end) of the lower heater unit 4B. The lower ground portion 8 is provided at the lower right portion of the furnace body 1 so as to entirely cover the second ends (right ends) of the seven lower heater units 4B, as shown in FIG. The lower ground portion 8 includes an enclosing member 8a, a first plate 8b, a second plate 8c, seven supporting plates 8d, seven receiving members 8e and the like.

The enclosing member 8 a is a substantially rectangular metal member whose first surface (left side surface) is released. The enclosing member 8a is provided at the lower right portion of the furnace body 1 so as to entirely surround the second ends (right ends) of the seven lower heater units 4B. The first plate 8b is a metal plate provided with an opening (round hole) through which the protective tube 4b is inserted and sealing the first surface of the enclosing member 8a. The periphery of the first plate 8b is welded and fixed to the enclosure member 8a so as to seal the first surface of the enclosure member 8a, and the periphery of the opening of the first plate 8b is welded all around to the protective tube 4b.

The second plate 8c is a metal plate provided with an opening (round hole) through which the protective tube 4b is inserted, and provided inside the enclosure member 8a so as to face each other in parallel with the first plate 8b at a predetermined distance. is there. The periphery of the second plate 8c is welded and fixed to the enclosing member 8a, and the periphery of the opening of the second plate 8c is welded to the protective tube 4b all around.

That is, the space surrounded by the enclosing member 8a, the protective pipe 4b, the first plate 8b and the second plate 8c forms a refrigerant flow path 8f (sealed space) through which the cooling fluid R flows. A space enclosed by the enclosing member 8a and the second plate 8c is a substantially enclosed space, and a gas recovery chamber C2 for recovering the burnout gas from the gap between the protective tube 4b having a total of seven and the heater main body 4a. It is.

Seven support plates 8d are provided corresponding to the lower heater units 4B, that is, the heater bodies 4a of the lower heater units 4B. The support plate 8d is a bent plate (L-shaped plate material) having a first surface fixed in a vertical posture to the outer surface (right surface) of the second plate 8c and a second surface (horizontal surface) orthogonal to the first surface. ). Receiving members 8e are placed on the second surface (horizontal surface) of the support plate 8d. That is, the second surface (horizontal surface) of the support plate 8d is the installation surface of the receiving member 8e.

The receiving member 8e is an insulating material provided corresponding to each heater main body 4a of the lower heater unit 4B. The receiving member 8e receives the load of each heater main body 4a by abutting on the second end (right end) of each heater main body 4a of the lower heater unit 4B. Similar to the receiving member 7e, the receiving member 8e is a substantially rectangular parallelepiped molded body in which a V-shaped groove is formed in the upper portion, and the V-shaped groove is used for the second heater main body 4a of the lower heater unit 4B. The two ends (right end) are placed in the engaged state. That is, the second end (right end) of each heater body 4 a is supported by the furnace body 1 by the lower ground portion 8.

The carburizing gas pipe 9 is a tubular member for introducing a carburizing gas into the carburizing chamber P. The tip of the carburizing gas pipe 9 opens into the carburizing chamber P, and the rear end of the carburizing gas pipe 9 communicates with the carburizing gas supply unit 13. The carburizing gas pipe 9 discharges the carburizing gas having a predetermined flow rate supplied from the carburizing gas supply unit 13 to the carburizing chamber P. The exhaust pipe 10 is a tubular member having one end opened to the carburizing chamber P and the other end connected to an exhaust device (not shown). The exhaust pipe 10 exhausts the gas in the carburizing chamber P (the carburizing gas or the pyrolysis gas obtained by thermal decomposition of the carburizing gas) to the outside through an exhaust device (vacuum pump).

The air supply unit 11 is connected to the two air supply chambers S1 and S2, and supplies compressed air K for burnout to the air supply chambers S1 and S2. The compressed air K is air pressurized to a predetermined pressure higher than the normal pressure. The gas recovery unit 12 is connected to the two gas recovery chambers C1 and C2, and recovers the burnout gas from the gas recovery chambers C1 and C2. The burnout gas contains, in addition to the compressed air K, carbon dioxide or the like generated by chemical reaction with the soot that a part of the compressed air K is accumulated in the gap between the inner surface of the protective tube 4b and the surface of the heater main body 4a. It is a mixed gas. The carburizing gas supply unit 13 supplies the carburizing gas to the carburizing chamber P via the carburizing gas pipe 9. The carburizing gas is, for example, acetylene gas (C ₂ H ₂ ).

The cooling fluid supply unit 14 supplies the cooling fluid R to the

refrigerant flow paths

5f, 6f, 7f, 8f of the upper electrode unit 5, the upper grounding unit 6, the lower electrode unit 7, and the lower grounding unit 8. The coolant R is, for example, water (cooling water). For example, the coolant supply unit 14 supplies the coolant R to the first end of each of the

coolant flow paths

5f, 6f, 7f, 8f and the coolant from the second end of each of the

coolant flow paths

5f, 6f, 7f, 8f. It is a refrigerant circulating type cooling device which recovers R, cools the cooling fluid R by heat exchange or the like, and then supplies it to the first end of each of the

refrigerant flow paths

5f, 6f, 7f, 8f.

The coolant supply unit 14 has a function of adjusting the flow rate of the coolant R at least for each stage, that is, for each of the upper heater unit 4A and the lower heater unit 4B. That is, in the upper heater unit 4A and the lower heater unit 4B, the calorific value (energization amount) of the heater main body 4a may be made different due to the difference of the upper and lower structures in the furnace body 1 or the like.

For example, since the hearth 3 having a relatively large heat capacity is provided in the lower part of the furnace body 1, the lower part of the furnace body 1 tends to be difficult to heat up unlike the upper part. When this point is taken into consideration, the lower and upper portions of the furnace body 1 are equalized by setting the amount of energization of each heater main body 4a of the lower heater unit 4B larger than the amount of energization of each heater main body 4a of the upper heater unit 4A. Needs to be set to a reasonable temperature. In this case, since the calorific value of each heater main body 4a of lower heater unit 4B is larger than the calorific value of each heater main body 4a of upper heater unit 4A, the cooling capacity of each heater main body 4a is lower than the upper one. Need to improve.

Next, the operation of the carburizing apparatus A according to the present embodiment will be described in detail.
When carburizing the object to be treated X using the carburizing apparatus A, the object to be treated X is accommodated in the carburizing chamber P by opening the opening and closing door provided on the furnace body 1 and placed on the hearth 3 Be placed. Then, the carburizing chamber P is sealed by closing the open / close door. By operating the vacuum pump in this state, the carburizing chamber P is set to a predetermined reduced pressure atmosphere.

Further, in parallel with the evacuation of the carburizing chamber P by the vacuum pump, power is supplied from the heating power source to the heater main bodies 4a of the heater units 4 (upper heater unit 4A and lower heater unit 4B). The chamber P is heated to a predetermined temperature (carburizing temperature). Then, the carburizing chamber P is maintained at the carburizing temperature for a predetermined time (carburizing time), and the carburizing gas supply unit 13 operates during this time to continuously carry carburizing gas from the carburizing gas pipe 9 to the carburizing chamber P at a predetermined flow rate. It is supplied intermittently.

As a result, carbon atoms derived from the carburizing gas penetrate from the surface of the object to be treated X into the inside, and a carburized layer is formed from the surface of the object to be treated X to a predetermined depth (carburized depth). That is, in the carburizing chamber P, carbon atoms and thermal decomposition gas are generated by thermal decomposition of the carburizing gas, and a part of carbon atoms (carbon) generated by the thermal decomposition infiltrate the object X to be carburized. Form a layer.

Then, a part of the pyrolysis gas and the carburizing gas generated by the pyrolysis is exhausted from the exhaust pipe 10 to the outside. For example, when the carburizing gas is acetylene (C ₂ H ₂ ), hydrogen gas (H ₂ ) is generated as pyrolysis gas, and hydrogen gas (H ₂ ) is exhausted from the carburizing chamber P via the exhaust pipe 10.

In the carburizing apparatus A, the upper electrode portion 5, the upper ground portion 6, and the lower electrode portion are operated by the cooling liquid supply unit 14 operating in parallel with the formation (carburizing treatment) of the carburized layer on the object X to be treated The coolant R is supplied to the

refrigerant flow paths

5f, 6f, 7f, 8f of the lower ground portion 8 and the lower ground portion 8. As a result, the portions near both ends of each heater body 4a are indirectly cooled by the cooling fluid R. That is, the

second plates

5c, 6c, 7c, 8c and the support plates 5d, which are metal members excellent in thermal conductivity, are the receiving

members

5e, 6e, 7e, 8e that directly support both end portions of the heater main bodies 4a. , 6d, 7d, and 8d, the heat exchange is performed indirectly with the coolant R, so that both end portions of each heater main body 4a can be effectively cooled.

Therefore, according to the present embodiment, the heat of each heater body 4a is indirectly cooled by the cooling fluid R by indirectly cooling the both ends of each heater body 4a, that is, the supported portions by the receiving

members

5e, 6e, 7e and 8e. It is possible to suppress the damage. According to the present embodiment, it is possible to extend the life of each heater main body 4a, and thus it is possible to realize the reduction of the maintenance cost.

Here, if it is necessary to set the carburizing chamber P to a uniform temperature, the amount of current supplied to each heater body 4a of the lower heater unit 4B and the amount of current supplied to each heater main body 4a of the upper heater unit 4A are different. The unit 14 adjusts the amount of supply of the cooling fluid R to the respective

refrigerant channels

5f, 6f, 7f, 8f according to the amount of electricity supplied. For example, when the amount of current supplied to the lower heater unit 4B is larger than the amount of current supplied to the upper heater unit 4A, the coolant supply unit 14 supplies the amount of coolant R supplied to each of the

coolant channels

7f and 8f as each coolant flow. The cooling capacity of each heater main body 4a of the lower heater unit 4B is improved more than the cooling capacity of each heater main body 4a of the upper heater unit 4A by increasing the amount supplied to the

paths

5f, 6f.

According to the present embodiment, it is possible to eliminate the unbalance of the thermal damage of the heater main bodies 4a of the upper heater unit 4A and the lower heater unit 4B, and thus to improve the maintainability of each heater main body 4a. It is.

Further, in the carburizing apparatus A, each of the

refrigerant flow paths

5f, 6f, 7f, 8f is opposed to a portion near the end of the heater main body 4a through the gap between the protective pipe 4b and the protective pipe 4b and the heater main body 4a. . That is, in the carburizing apparatus A, the

refrigerant flow paths

5f, 6f, 7f, 8f are disposed in the vicinity of the end portion of the heater main body 4a, so that both ends of the heater main body 4a can be cooled also by this. it can.

Here, a part of carbon generated by the thermal decomposition of the carburizing gas intrudes into a gap between the heater main body 4a and the protective tube 4b of each heater unit 4 (upper heater unit 4A and lower heater unit 4B) and hatches. The crucible (carbon) is a substance which is electrically conductive and can change the electric resistance of the heater body 4a. That is, when the carburizing apparatus A is operated for a long time, the electric resistance of the heater main body 4a gradually changes from the initial state due to soot (carbon), so the calorific value of the heater main body 4a may gradually change. . In this case, in the carburizing apparatus A, it becomes difficult to heat the carburizing chamber P to a desired carburizing temperature.

In the carburizing apparatus A, burnout processing is performed regularly or irregularly in order to remove the soot. That is, in the carburizing apparatus A, by supplying the compressed air K to the upper electrode unit 5 and the lower electrode unit 7 from the air supply unit 11, the soot (carbon) existing in the gap between the heater main body 4a and the protective tube 4b Are chemically reacted to cause gasification to carbon dioxide, etc., and are recovered as burnout gas from the gap between the heater main body 4a and the protective tube 4b to the gas recovery chambers C1 and C2, and the gas recovery unit 12 further recovers the gas recovery chambers C1 and C2. Recover from the outside.

According to such a burnout process, soot (carbon) present in the gap between the heater main body 4a and the protective tube 4b is sufficiently removed, and the electric resistance of the heater main body 4a returns to the initial state. That is, according to the present embodiment, the burnout process can more reliably prevent the deposition of soot (carbon) on the heater main body 4a.

In addition, this indication is not limited to the said embodiment, For example, the following modifications are considered.
(1) In the above-mentioned embodiment, although each

refrigerant channel

5f, 6f, 7f, and 8f were provided in the position which counters the end vicinity part of heater main part 4a, this indication is not limited to this. For example, the

refrigerant channels

5f, 6f, 7f, 8f are opposite to the receiving

members

5e, 6e, 7e, 8e in FIG. 1, that is, the left sides of the receiving

members

5e, 7e for the

refrigerant channels

5f, 7f The

paths

6f and 8f may be disposed to the right of the receiving

members

6e and 8e.

(2) In the above embodiment, the flow rate of the coolant R is adjusted for each of the upper heater unit 4A and the lower heater unit 4B, but the present disclosure is not limited to this. For example, instead of adjusting the flow rate of the cooling fluid R for each stage, the flow rate of the cooling fluid R for each support portion, that is, for each of the upper electrode portion 5, the upper ground portion 6, the lower electrode portion 7 and the lower ground portion 8 You may adjust the Further, such adjustment for each stage and each support may be omitted.

(3) Although the number of upper heater units 4A and lower heater units 4B is the same (seven) in the above embodiment, the present disclosure is not limited to this. Since the hearth 3 exists in the lower part in the heat insulation container 2, the lower part of the article to be treated X is more difficult to heat than the upper part. In consideration of such circumstances, the number of lower heater units 4B may be greater than the number of upper heater units 4A.

(4) In the above-mentioned embodiment, although water (cooling water) was adopted as cooling fluid R, this indication is not limited to this. You may employ | adopt the liquid whose heat conductivity is higher than a cooling water as needed.

According to the present disclosure, damage to the heater in the carburizing apparatus can be suppressed.

A carburizing apparatus K compressed air R coolant S1, S2 air supply chamber C1, C2 gas recovery chamber P carburizing chamber X object to be treated 1 furnace body 2 heat insulation container 3 hearth 4 heater unit 4A upper heater unit 4B lower heater unit 4a heater Body (heater)
4b Protective tube (protective member)
5 Upper electrode part (support part)
5a enclosure member 5b first plate 5c second plate 5d support plate 5e support member 5f refrigerant flow path 6 upper ground portion (support portion)
6a enclosure member 6b first plate 6c second plate 6d support plate 6e support member 6f refrigerant flow path 7 lower electrode portion (support portion)
7a enclosure member 7b first plate 7c second plate 7d support plate 7e support member 7f refrigerant flow path 8 lower ground portion (support portion)
8a enclosure member 8b first plate 8c second plate 8d support plate 8e support member 8f refrigerant flow passage 9 carburizing gas pipe 10 exhaust pipe 11 air supply unit 12 gas recovery unit 13 carburizing gas supply unit 14 coolant liquid supply unit

Claims

A furnace body for containing the object to be treated;
A plurality of heaters extending horizontally in the furnace body;
A plurality of protection members that respectively cover the plurality of heaters;
Supporting portions respectively provided at both ends of the heater and supporting the heater;
A carburizing gas supply unit for supplying carburizing gas into the furnace body;
And an air supply unit for supplying air for burnout to a gap between the heater and the protective member.
The support unit indirectly cools an end of the heater.
The support portion is
A receiving member that abuts on the end of the heater;
A support plate for fixing the receiving member to the furnace body,
The carburizing apparatus according to claim 1, wherein the end portion of the heater is indirectly cooled by cooling the support plate.
The carburizing apparatus according to claim 1 or 2, wherein the support portion includes a refrigerant flow path provided near the end of the heater and through which a coolant flows.
The carburizing apparatus according to claim 1 or 2, wherein the plurality of heaters are provided in upper and lower two stages so as to sandwich the object to be treated.
The carburizing apparatus according to claim 3, wherein the plurality of heaters are provided in upper and lower two stages so as to sandwich the object to be treated.
The carburizing apparatus according to claim 5, further comprising a coolant supply unit that adjusts the flow rate of the coolant for each stage.