JP4011768B2 - Heating furnace device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heating furnace apparatus such as an atmosphere furnace or a baking furnace for heat-treating an object to be heated, or a reflow furnace for reflow soldering a printed circuit board on which electronic components are mounted.
[0002]
[Prior art]
In conventional heating furnace devices, in general, the heated object such as a printed circuit board equipped with electronic components is heated by irradiation with an infrared heater, or the entire heated object is heated evenly by circulating hot air. The hot air circulation heating method is adopted. FIG. 7 is a partially cutaway schematic perspective view showing a typical reflow furnace apparatus among conventional heating furnace apparatuses, and FIG. 8A is a schematic cross-sectional view taken along line AA of FIG. In these drawings, the furnace body 1 of the reflow furnace apparatus has a triple wall surface structure in which a heat insulating material 3 is attached to the inner surface of a furnace body outer wall 2 and the furnace body wall 4 is placed inside the heat insulating material 3. . In the heating space 5 inside the furnace body 1, a heater 7 as a heating source is supported on the furnace body wall 4 via a support body (not shown), and a blower fan that is rotationally driven by a motor 8 on the heater 7. 9 is arranged, and a wind tunnel for guiding the circulating wind is constituted by the blower fan 9.
[0003]
The reflow furnace apparatus as described above is generally used for reflow soldering the electronic component 11 mounted on the printed circuit board 10. Cream solder 12 is applied and formed by printing or the like at a predetermined position on the printed circuit board 10 on which the conductor wiring pattern is applied, and the electronic component 11 is mounted on the cream solder 12. The printed circuit board 10 on which the electronic component 11 is mounted is carried into the heating space 5 of the furnace body 1 by the conveying means including the conveying rail 13 and the air 6 circulated by the blower fan 9 is used as the heater 7. The whole is heated evenly by blowing hot air 6a heated in step (b). Thereby, the electronic component 11 is reflow soldered by the cream solder 12 melted by heating.
[0004]
The cream solder 12 is a paste formed by mixing a solder powder having a diameter of about 30 μm and a flux having an action of removing oxides in a volume ratio of about 50%, and when heated, the flux evaporates. Thus, the flux fume 14 is generated inside the furnace body 1. The flux fume 14 is cooled on the inner surface of the wall 4 of the furnace body to form droplets. The droplets may become a considerable amount and flow out to the periphery of the furnace body 1. For this reason, the furnace body 1 has a purpose of preventing the heat insulating material 3 from being contaminated and deteriorated by droplets or gas, and the need to ensure the sealing required for the furnace body 1. It is an essential requirement that a plated steel plate is generally used in the reflow furnace apparatus as the furnace body wall 4. The interior of the furnace body 1 is classified into a plurality of types of heating zones in which the temperature is set stepwise according to the temperature history required for the object to be heated, as shown in FIG. ing.
[0005]
In the above reflow furnace apparatus, the printed circuit board 10 which is an object to be heated is continuously carried into the furnace body 1, the cream solder 12 is melted by heating by blowing hot air, and the cream solder 12 is solidified to form an electronic component. 11 reflow soldering is performed. When the reflow soldering on one surface of the printed circuit board 10 is completed, the printed circuit board 10 is turned upside down, the cream solder 12 is printed on the other surface of the printed circuit board 10, and the electronic component 11 is mounted. Reflow soldering is performed on the other surface of the printed circuit board 10 by bringing the board 10 into the furnace body 1 and heating it again. In the reflow furnace apparatus described above, the hot air circulation heating method is exemplified, but there is an infrared heating method using an infrared heater as a heating source.
[0006]
Further, in the conventional furnace body 1, the temperature T _S1 inside the furnace body 1 is an atmospheric temperature of 200 ° C. to 300 ° C. as shown by the solid characteristic curve in FIG. 8B showing the temperature distribution inside the furnace body 1. In order to prevent this heat from escaping outside the furnace, a heat insulating material 3 having a thickness of about 25 mm to 100 mm is used. On the other hand, as the energy for heating, electric power with good controllability is used in both the hot air circulation heating method and the infrared heating method. Most of the electric power used in the mounting line of the electronic component 11 on the conventional printed circuit board 10 is consumed by a heating furnace device such as the reflow furnace, and there is a desire to reduce this consumed energy as much as possible.
[0007]
[Problems to be solved by the invention]
However, in the conventional heating furnace apparatus, the heat amount of about 20% of the total energy consumption is only utilized for the original use such as reflow soldering, and other heat amounts are indicated by arrows in FIG. As described above, since it is diffused to the outside of the furnace body 1, there is a drawback that the thermal efficiency is extremely poor. In particular, as far as the amount of heat dissipated from the inside of the furnace body 1 to the outside, the wall 4 of the furnace body has rigidity necessary to support a structure such as the heater 7 inside the furnace body 1. Since the end is directly bonded and fixed to the furnace body outer wall 2 as clearly shown in FIG. 8A, the heat insulating material 3 is conducted and diffused to the outside of the furnace body 1. The amount of heat dissipated by direct heat conduction from the furnace body wall 4 to the furnace body outer wall 2 is greater than the amount of heat generated.
[0008]
For example, as shown in the characteristic curve shown by the solid line in FIG. 8B, the wall surface temperature T _S1 of the furnace body wall 4 is 200 ° C. to 300 ° C., whereas the wall surface temperature T _S2 of the furnace body outer wall 2 is 100 ° C. The amount of heat loss through the outer peripheral surface of the furnace body 1 is remarkably large. Therefore, in order to suppress the heat dissipation from the inside of the furnace body 1 to the outside, even if a material having a large thickness or a material having excellent heat insulating performance is used as the heat insulating material 3, there is not much effect, and the above-described consumption. There is a problem that power cannot be reduced.
[0009]
Therefore, the present invention has been made in view of the above-described conventional problems, and with a simple and inexpensive configuration, the amount of heat loss dissipated from the inside of the furnace body to the outside can be greatly reduced, thereby greatly reducing power consumption. An object of the present invention is to provide a heating furnace apparatus that can perform the above.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a heating furnace apparatus of the present invention includes a furnace body that heats an object to be heated that is carried into an internal heating space by a heating means, and the furnace body includes a furnace body wall and a furnace body. It is composed of a triple wall surface structure in which an insulating material is interposed between the outer wall and the outer wall, and both end portions of the furnace body wall and the furnace body outer wall are spaced apart from each other in a non-contact state, and the It has the structure connected through the two heat insulating materials .
[0011]
In this heating furnace apparatus, since the furnace body wall and the furnace body outer wall are connected in a thermally insulated state, heat conduction is not directly conducted from the furnace body wall to the furnace body outer wall to dissipate heat. The amount of heat radiation to the outside can be greatly reduced, and the power consumption is greatly reduced.
[0012]
The connection structure of both ends of each of the furnace inner wall and the furnace body outer wall in the invention, both end portions of each of said furnace body outer wall and the furnace body wall, the second insulation material by metal fastening member Each of the fastening members may be individually fixed, and the fastening member may have a length that does not contact each other in the second heat insulating material .
[0013]
As a result, the furnace body wall is indirectly connected to the furnace body outer wall by fastening a metal fastening member such as a bolt through the second heat insulating material . It will have sufficient rigidity to support it and will not cause any trouble. In addition, since the metal fastening members for fixing the furnace body wall and the furnace body outer wall to the second heat insulating material are set to short dimensions in which the respective front end portions do not contact inside the second heat insulating material , It does not radiate heat while directly conducting heat from the inner wall to the outer wall of the furnace body via the metal fastening member.
[0014]
In the above structure, the insertion hole of the metal fastening member in the furnace inner wall is formed in the long hole to the elongation direction due to thermal expansion of the furnace body wall and longitudinal direction, into the insertion hole, the furnace inner wall It is preferable that a spacer having the same thickness as that is slidably fitted so that the metal fastening member is inserted through the spacer and fastened to the second heat insulating material .
[0015]
As a result, when the furnace body wall extends against the fastening force of the fastening member due to thermal expansion accompanying an increase in the furnace temperature, the hole edge surface of the insertion hole only slides on the fixed spacer. In addition, a force that causes distortion to the outer wall of the furnace body is not applied via the second heat insulating material due to elongation accompanying thermal expansion. Moreover, when the wall of the furnace body extends, the contact surface between the inner surface and the second heat insulating material hardly generates a frictional force due to the fastening of the fastening member, and extends smoothly. Therefore, in this heating furnace apparatus, the thermal expansion of the wall of the furnace body is caused even though a large difference in thermal expansion occurs due to a large temperature difference between the wall of the furnace body and the outer wall of the furnace body because the heat radiation amount is remarkably suppressed. The elongation due to can be effectively absorbed, so that no distortion occurs in the furnace body.
[0016]
Further, the connection structure of both ends of each of the furnace inner wall and the furnace body outer wall in the invention, the second insulation material is, at one end near portion of the furnace inner wall or the furnace outer wall together are fixed at one end portion by the fastening by the metal fastening members, one of said furnace body wall or the other to a fixed holding member and the furnace inner wall or the furnace outer wall of said furnace body outer wall Between the other end portion of the second heat insulating material and the inner wall of the furnace body or the outer wall of the furnace body. A space that can absorb the elongation due to thermal expansion of the furnace body wall may be formed.
[0017]
As a result, in addition to the effect of greatly reducing the amount of heat dissipated by conducting heat directly from the furnace body wall to the outer wall of the furnace body, the power consumption can be significantly reduced, and the furnace temperature increases as the furnace temperature rises. When the body wall expands due to thermal expansion, the holding piece, the holding member, and the second heat insulating material can be displaced toward the outside of the furnace body while relatively sliding due to the presence of the gap. Therefore, in this heating furnace device, the elongation due to the thermal expansion of the wall of the furnace body can be effectively absorbed, and since there is no void during use, the rigidity of the furnace body is further improved. It has sufficient rigidity necessary to support a structure such as a means.
[0018]
In the above configuration, and the holding member and the second heat insulator, with are connected by the metal fastening member which is fastened to the second insulation material by inserting the holding member, the at the retaining member insertion holes of the metal fastening member is preferably a structure formed in the elongated hole of the expanding direction due to thermal expansion of the furnace body wall and longitudinal direction.
[0019]
As a result, when the second heat insulating material is displaced integrally with the furnace wall extending by thermal expansion, the metal fastening member fastened to the second heat insulating material is displaced using the elongated insertion hole as a guide. In addition, it is possible to effectively absorb both the vertical and horizontal thermal expansion of the wall of the furnace body and to further improve the rigidity of the furnace body.
[0020]
Further, in the above invention, the connecting structure of both ends of the furnace body wall and the furnace body outer wall is configured such that both the inner and outer surfaces of the heat insulating material are bonded and fixed to the furnace body wall and the furnace body outer wall by a heat-resistant adhesive, respectively. can do.
[0021]
This prevents direct heat conduction from the furnace body wall to the furnace body outer wall and dissipates heat, greatly reducing the amount of heat dissipated, while maintaining the effect of dramatically reducing power consumption, Since the entire inner surface of each of the body wall and the outer wall of the furnace body is bonded and fixed to the heat insulating material and the second heat insulating material , the wall of the furnace body has a rigidity necessary for supporting a structure such as heating means inside the furnace body. It has enough.
[0022]
Furthermore, the connection structure of both ends of each of the furnace inner wall and the furnace body outer wall in the invention, the furnace each of both end portions of the inner wall and the furnace body outer wall, said second interposed therebetween it may be a configuration that is connected directly by the heat insulating material non-metal fastening member you through the.
[0023]
This prevents direct heat conduction from the furnace body wall to the furnace body outer wall and dissipates heat, greatly reducing the amount of heat dissipated, while maintaining the effect of dramatically reducing power consumption, Since both end portions of the inner wall and the outer wall of the furnace body are directly connected by a non-metallic fastening member, the furnace body has an advantage of extremely high rigidity.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1A is a schematic longitudinal sectional view showing a heating furnace apparatus according to a first embodiment of the present invention, FIG. 1B is an enlarged view of a portion B of FIG. 1A, and FIG. 1C is a right side of FIG. FIG. In this figure, the same or equivalent parts as those in FIG. 7 and FIG. Although the furnace body 17 in this heating furnace apparatus has a triple wall surface structure in which the heat insulating material 3 is interposed between the furnace body wall 18 and the furnace body outer wall 19, the furnace body 17 is similar to the conventional furnace. The body wall 18 and the furnace body outer wall 19 are separated from each other so as not to be in direct contact with each other, and no metal fastening mechanical elements such as bolts and rivets are interposed, that is, thermally insulated. The structure is connected in a connected state. That is, both end portions of the furnace body wall 18 and the furnace body outer wall 19 are provided with hard heat insulating materials 20 having low thermal conductivity in an arrangement spaced apart from each other, and metal bolts 21 are respectively inserted from the inside and outside of the furnace body 17. Each bolt 21 is fixed to the hard heat insulating material 20 by fastening, and the bolt 21 has a short dimension in which the tip portions do not contact each other inside the hard heat insulating material 20.
[0025]
Since the furnace body wall 18 and the furnace body outer wall 19 are connected by the thermally insulated structure as described above, the furnace body wall 18 does not directly conduct heat from the furnace body wall 18 to dissipate heat. Therefore, the amount of heat released to the outside of the furnace body 17 is greatly reduced, and the power consumption can be significantly reduced. Moreover, the furnace body wall 18 is indirectly connected to the furnace body outer wall 19 by fastening bolts 21 with a hard heat insulating material 20 in the form of a block. It has sufficient rigidity to support an object and does not cause any trouble.
[0026]
In the heating furnace apparatus, the heat insulating material 3 is fixed to the outer wall 19 of the furnace body to suppress the heat radiation from the inside of the furnace body 17, and the metal furnace body wall 18 is a droplet generated by cooling the flux fume. As a result, the heat insulating material 3 is prevented from deteriorating and the hermeticity of the furnace body 17 is secured. Since the wall surface temperature T _S1 becomes a high temperature of about 200 ° C. to 300 ° C. as described above, the furnace wall 18 is thermally expanded. On the other hand, the furnace body outer wall 19 is thermally insulated from the furnace body wall 18 as described above, and the heat radiation from the inside of the furnace body 17 is suppressed by the heat insulating material 3, so that FIG. As shown in the characteristic curve shown by the two-dot chain line in b), the wall surface temperature T _S3 is suppressed to 100 ° C. or less and hardly thermally expands. Therefore, the furnace body 17 has a force to generate distortion due to a difference in thermal expansion caused by a large temperature difference between the furnace body wall 18 and the furnace body outer wall 19 connected via the hard heat insulating material 20. Act.
[0027]
Therefore, the heating furnace apparatus is provided with a mechanism for absorbing elongation due to thermal expansion of the furnace body wall 18. That is, as shown in FIGS. 1B and 1C, the insertion hole 22 of the bolt 21 on the furnace body wall 18 is a long hole whose major axis is the extending direction of the furnace body wall 18 indicated by an arrow in FIG. Furthermore, a spacer 23 having the same thickness as the furnace wall 18 and having an insertion hole 24 for the bolt 21 is inserted into the insertion hole 22, and the bolt 21 is inserted through the insertion hole 24 of the spacer 23 to be hard. It is screwed into the heat insulating material 20.
[0028]
Thus, when the furnace wall 18 extends against the fastening force of the bolt 21 due to thermal expansion accompanying an increase in the furnace temperature, the hole edge surface of the insertion hole 22 only slides on the fixed spacer 23. Therefore, a force that causes distortion is not applied to the furnace body outer wall 19 through the hard heat insulating material 20. In addition, when the furnace wall 18 extends due to thermal expansion, the frictional force caused by tightening the bolts 21 hardly occurs on the contact surface between the inner surface of the furnace wall 18 and the hard heat insulating material 20, and the furnace wall 18 extends smoothly. Therefore, this heating furnace apparatus has a structure in which the elongation due to the thermal expansion of the furnace body wall 18 is effectively absorbed and no distortion occurs in the furnace body 17. In the above description, the connection structure between the furnace body wall 18 and the furnace body outer wall 19 at the lower end portion of the furnace body 17 has been described as an example.
[0029]
FIG. 2A is a schematic longitudinal sectional view showing a heating furnace apparatus according to the second embodiment of the present invention, in which the same or equivalent parts as those in FIG. The description is omitted. This embodiment differs from the first embodiment in that the hard heat insulating material 20 is fixed only to the furnace body outer wall 19 by tightening bolts 21, and the holding member 27 and the furnace body wall fixed to the furnace body wall 18. It is only the structure which provided the mechanism which can absorb the expansion | extension by the thermal expansion of the furnace wall 18 by bending 18 and bending | intersecting from the upper and lower sides with the holding piece 18a extended in the horizontal direction, and hold | maintaining slidably.
[0030]
The holding member 27 is fixed to the furnace wall 18 by the mounting piece 27a.
[0031]
FIG. 6B is a diagram showing an extracted portion C of FIG. 6A. At the time of assembly, the hard heat insulating material 20 fixed to the furnace body outer wall 19 by the bolt 21 is attached to the inner surface of the furnace body wall 18. The holding member 27 and the holding piece 18a are slidably held between the holding member 27 and the holding piece 18a in a state of being spaced apart from each other. The gap 28 is set to a width corresponding to the elongation due to thermal expansion of the furnace body wall 18.
[0032]
Therefore, in the mechanism for absorbing the elongation due to the thermal expansion of the furnace body wall 18 in this heating furnace apparatus, when the furnace body wall 18 extends in the arrow direction (b) as the furnace temperature rises, The holding piece 18a and the holding member 27 of the inner wall 18 can be displaced toward the outside of the furnace body 17 while sliding on the hard heat insulating material 20 due to the presence of the gap 28, and as shown in FIG. The inner surface is in surface contact with the inner end surface of the hard heat insulating material 20. Therefore, in this heating furnace apparatus, the elongation due to the thermal expansion of the furnace body wall 18 can be effectively absorbed, and the rigidity of the furnace body 17 is further improved by eliminating the gap 28 when in use. Moreover, since this heating furnace apparatus does not conduct heat directly from the furnace body wall 18 to the furnace body outer wall 19 as in the first embodiment, the amount of heat released to the outside of the furnace body 17 is greatly reduced. The power consumption can be remarkably reduced, and the furnace wall 18 is indirectly connected to the furnace outer wall 19 through the hard heat insulating material 20, so that the structure such as the heater 7 inside the furnace body 17 is supported. It has sufficient rigidity necessary for this.
[0033]
FIG. 3 shows a longitudinal sectional view of a main part of a modification of the second embodiment of the present invention. In the second embodiment, the same holding member 27 as the holding member 27 fixed to the furnace wall 18 is provided. These are fixed to the outer wall 19 of the furnace body through the mounting pieces 27a. The elongation due to the thermal expansion of the furnace wall 18 is such that the hard heat insulating material 20 fixed to the furnace wall 18 is bent at right angles from the end of the holding member 27 and the furnace outer wall 19 and extends horizontally. It is absorbed by displacing outward while sliding, and the same effect as in the second embodiment can be obtained.
[0034]
FIG. 4 shows a longitudinal sectional view of the main part of still another modification of the second embodiment of the present invention. As in FIG. 3, the holding member 27 is fixed to the furnace body outer wall 19 via its mounting piece 27 a, and the difference from FIG. 3 is that the bolt 21 is inserted through the holding member 27 and the hard heat insulating material 20. It is only the structure screwed in. However, although not shown, the insertion hole of the bolt 21 in the holding member 27 is in the same direction as the insertion hole 22 provided in the furnace wall 18 of FIG. It is formed in a long hole whose direction is the long axis. Therefore, in the mechanism for absorbing the elongation due to the thermal expansion of the furnace body wall 18 in the heating furnace apparatus, when the hard heat insulating material 20 is displaced integrally with the furnace body wall 18 that is expanded by the thermal expansion, Since the bolt 21 inserted through the insertion hole and screwed into the hard heat insulating material 20 is displaced using the elongated insertion hole as a guide, the thermal expansion in the horizontal direction as well as the vertical direction of the furnace wall 18 is effectively performed. While being able to absorb, it becomes the structure where the rigidity of the furnace body 1 improved further.
[0035]
FIG. 5 is a longitudinal sectional view of a main part showing a heating furnace apparatus according to the third embodiment of the present invention. In the figure, the furnace body 17 has a structure in which the inner surfaces of the furnace body wall 18 and the furnace body outer wall 19 are bonded and fixed to the heat insulating material 3 and the hard heat insulating material 20 with a heat-resistant adhesive 29, respectively. Also in this heating furnace apparatus, both end portions of the furnace body wall 18 and the furnace body outer wall 19 are separated from each other, and are thermally insulated through the hard heat insulating material 20 having a low thermal conductivity interposed therebetween. It has a structure that is connected in the state. Therefore, since heat is not directly conducted from the furnace body wall 18 to the furnace body outer wall 19 to dissipate heat, the amount of heat radiation can be greatly reduced and power consumption can be significantly reduced. In addition, since the entire inner surfaces of the furnace body wall 18 and the furnace body outer wall 19 are bonded and fixed to the heat insulating material 3 and the hard heat insulating material 20, the furnace body wall 18 has a structure such as the heater 7 inside the furnace body 17. Rigidity with sufficient strength to support the object.
[0036]
FIG. 6 is a longitudinal sectional view of an essential part showing a heating furnace apparatus according to a fourth embodiment of the present invention. In the figure, a furnace body 17 is directly formed by a resin bolt 30 such as polyamide in which a furnace body wall 18 and a furnace body outer wall 19 are inserted in a horizontal direction with respect to a hard heat insulating material 20 interposed between both ends. It is connected to the structure. Here, the resin bolt 30 is inserted from the furnace body wall 18 through the hard heat insulating material 20 and the furnace body outer wall 19, and a nut 31 is fastened to a screw portion exposed to the outside of the furnace body 17. Also in this heating furnace apparatus, the furnace body 17 is separated from both ends of the furnace body wall 18 and the furnace body outer wall 19 with a hard heat insulating material 20 having a low thermal conductivity interposed therebetween, and The structure is connected by a non-metallic resin bolt 30. Therefore, since heat is not directly conducted from the furnace body wall 18 to the furnace body outer wall 19 to dissipate heat to the outside of the furnace body 17, the amount of heat radiation can be greatly reduced and power consumption can be significantly reduced. In addition, since both end portions of the furnace body wall 18 and the furnace body outer wall 19 are directly connected by the resin bolts 30, the furnace body 17 has high rigidity.
[0037]
【The invention's effect】
As described above, according to the heating furnace apparatus of the present invention, the heat insulating material is interposed between the furnace body wall and the furnace body outer wall, and both ends of the furnace body wall and the furnace body outer wall are Since they are separated from each other in a non-contact state and are connected by interposing a second heat insulating material therebetween, heat is not directly transferred from the furnace body wall to the outer wall of the furnace body, to the outside of the furnace body. This greatly reduces the amount of heat released and can significantly reduce power consumption. Therefore, the present invention can provide an energy-saving heating furnace apparatus with high energy efficiency by minimizing the loss of heat energy.
[Brief description of the drawings]
1A is a schematic longitudinal sectional view showing a heating furnace apparatus according to a first embodiment of the present invention, FIG. 1B is an enlarged view of a portion B of FIG. 1A, and FIG. FIG.
FIG. 2A is a schematic longitudinal sectional view showing a heating furnace apparatus according to a second embodiment of the present invention, FIG. 2B is a sectional view showing an extracted portion C of FIG. ) Is a cross-sectional portion of the C portion when the furnace wall is thermally expanded.
FIG. 3 is a longitudinal sectional view of an essential part showing a modification of the embodiment.
FIG. 4 is a longitudinal sectional view of a main part showing still another modification of the embodiment.
FIG. 5 is a longitudinal sectional view of a main part showing a heating furnace apparatus according to a third embodiment of the present invention.
FIG. 6 is a longitudinal sectional view of a main part showing a heating furnace apparatus according to a fourth embodiment of the present invention.
FIG. 7 is a partially broken schematic perspective view showing a conventional reflow furnace apparatus.
8A is a schematic cross-sectional view taken along line AA of FIG. 7, and FIG. 8B is a temperature distribution diagram inside the furnace body.
[Explanation of symbols]
3 Insulation 5 Heating space 7 Heater (heating means)
10 Printed circuit board (object to be heated)
17 furnace body 18 furnace body wall 19 furnace body outer wall 20 hard heat insulating material (hard structural material)
21 bolts (metal fastening members)
22 Insertion hole 23 Spacer 27 Holding member 18a, 19a Holding piece 28 Gap 29 Heat resistant adhesive 30 Non-metallic bolt (non-metallic fastening member)

Claims (7)

A furnace body for heating an object to be heated, which is carried into an internal heating space, with heating means,
The furnace body is composed of a triple wall surface structure in which a heat insulating material is interposed between the furnace body wall and the furnace body outer wall,
Both ends of the furnace body wall and the furnace body outer wall are separated from each other in a non-contact state, and are connected with a second heat insulating material interposed therebetween. . The furnace end portions of each of the inner wall and the furnace body outer wall, each fixed individually to the second insulation material by metal fastening member,
The heating furnace apparatus according to claim 1, wherein the fastening member has such a length that the tip portions thereof do not contact with each other inside the second heat insulating material . The insertion hole of the metal fastening member in the furnace inner wall is formed in the long hole to the elongation direction due to thermal expansion of the furnace inner wall and the major axis direction,
In the insertion hole, a spacer having the same thickness as the wall of the furnace body is slidably fitted,
The heating furnace apparatus according to claim 2, wherein the metal fastening member is inserted into the spacer and fastened to the second heat insulating material . Said second heat insulating material, together with being fixed at one end portion by the fastening by the metal fastening member at one end near portion of the furnace inner wall or the furnace outer wall, the furnace inner wall or the A holding member fixed to the other one of the outer walls of the furnace body and a holding piece extending in a right-angle direction from the vicinity of one end of the inner wall or the outer wall of the furnace body are slidably held. And
A gap capable of absorbing elongation due to thermal expansion of the furnace body wall is formed between the other end of the second heat insulating material and an inner surface of either the furnace body wall or the furnace body outer wall. The heating furnace apparatus according to 2. And the holding member and the second heat insulator, with are connected by the metal fastening member which is fastened to the second insulation material by inserting the holding member, the metal fastening member in the holding member The heating furnace apparatus according to claim 4, wherein the insertion hole is formed in a long hole whose longitudinal direction is an extension direction due to thermal expansion of the wall of the furnace body. The heat insulating material and a heating furnace according to claim 1, wherein the inner and outer surfaces of the second heat insulating material is bonded to each of the furnace inner wall and the furnace outer wall by heat-resistant adhesive. Both end portions of each of said furnace body outer wall and the furnace body wall, according to claim 1, which is directly connected by a non-metal fastening member you through the second heat insulating material interposed between them Heating furnace device.

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