JPH093760A - Production of inorganic fiber cylindrical formed body and producing apparatus therefor - Google Patents

Abstract

PURPOSE: To produce an inorganic fabric formed body capable of shortening curing and forming time and not causing baking unevenness and baking deficiency at the end of a core mold article. CONSTITUTION: In this method for producing an inorganic fiber cylindrical formed body comprising laminating and winding a mat-like raw stock composed of an inorganic fiber to which an uncured binder is dispersed and attached round the mandrel 1 while holding the raw stock between a mandrel 1 for core mold and a press roller to form a core mold article 20 and pressing the core mold article 20 housed into the low mold 8 with the upper mold 7, heating and drying the core mold article 20 while carrying out press molding, forming the cut part in the core mold article 20 by a cut part-forming apparatus, taking out the mandrel 1 from the core mold article 20 and forming the cylindrical formed body, heat-drying is carried out by feeding hot air to both directions between the hollow porous mandrel 1 in which plural small through holes are formed in the circumferential direction and axial direction and the upper mold 7 and the lower mold 8 having an arc-like part contacting with the outer circumference of the core mold article 20 and forming a passage 11 in the interior.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an inorganic fiber tubular molded body used as a heat insulating material for large pipes and a sound absorbing material for air conditioning fans.

[0002]

2. Description of the Related Art Conventionally, a mat-shaped raw cotton made of inorganic fibers to which an uncured binder is dispersed and attached is sandwiched between a mandrel for a core type and a press roller and wound around the mandrel to form a core type product. The core-shaped product that has been formed and stored in the lower mold is heated and dried while being pressed by the upper mold and press-molded, the split part is formed on the core-shaped product by the split-part forming device, and the mandrel is removed from the core-shaped product. There is known a method for manufacturing a cylindrical molded body of inorganic fiber for forming a cylindrical molded body and a manufacturing apparatus therefor (Japanese Patent Laid-Open No. 5-280689).

In this prior art, a core type product is formed as follows. That is, as shown in the manufacturing process diagram of FIG. 4, first, the raw cotton 15 cut to a fixed size is prepared,
The raw cotton 15 is pressed at the front and rear ends by the pressing tool 16 and the inclined portion 1
7 is formed and mounted on the supply conveyor 18, and the raw cotton 15 transferred by the supply conveyor 18 is inserted between the hollow porous mandrel 1 and the press roller 19 to be laminated and wound around the hollow porous mandrel 1, and the press roller 19 presses the raw cotton 15 to the hollow porous mandrel 1 side, and the raw cotton 1
The widthwise ends of the hollow cored mandrel 5 are regulated by the collars 2 and 2 of the hollow porous mandrel 1 and pressed flat to form the core 20. The core-type product 20 is laminated and wound in a state where a portion corresponding to the convex portion 5 of the hollow porous mandrel 1 is swollen.

Next, the core mold 20 is housed in the lower mold 8 and pressed by the upper mold 7 to be press-molded. At the same time, as shown in FIGS. 4 and 5, the hot air from the hot air supply source 21 is passed through the hot air introduction tube 28 to the hollow porous mandrel 1
Is introduced into the through hole 4. The hot air in the through holes 4 passes through the through small holes 6 of the hollow porous mandrel 1, passes through the thick portion of the core type product 20, and heats and drys the raw cotton 15, while ventilating holes 13, 13 of the upper mold 7 and the lower mold 8. , And then into the passages 11, 11. The used hot air in the passages 11 and 11 is returned to the hot air supply source 21 side through the hot air return tubes 29 and 30, respectively, is reheated, is introduced again to the hot air introduction tube 28 side, and is circulated. The core mold product 20 sandwiched between the upper mold 7 and the lower mold 8 is heated and dried by the above hot air flow, and is pressed by the upper mold 7 to be press-molded into a predetermined shape.

Next, the split portion 2 along the radial direction is formed by the split portion forming device 25 on the core type product 20 which has been press-molded and dried.
6 is formed, then the split portion 26 is opened, and the hollow porous mandrel 1 in the core-shaped product 20 is taken out. When the skin material 27 is attached, the skin material 27 is attached to the outer surface and / or the inner surface of the core-type product 20 by an unillustrated skin material supply means. As described above, the tubular molded body 20a is completed. In addition, by the collar portions 2 and 2 of the hollow porous mandrel 1,
The tubular molded body 20a is finished to a fixed size without trimming.

[0006]

Conventionally, the raw cotton fed to the upper mold and the lower mold is folded inward and wound around a hollow porous mandrel in order to effectively utilize the ears of the raw cotton. Therefore, the end of the core type product has a higher density than the other parts, so when supplying hot air from the mandrel to the upper mold and the lower mold, the end of the core type product with high density is cured and molded. However, if the molding time is adjusted to a low-density portion, uneven baking and insufficient baking occur. An object of the present invention is to provide a method for manufacturing an inorganic fiber tubular molded body and a manufacturing apparatus for the same, which shortens the heat-curing molding time of a core type product and prevents uneven burning and insufficient baking at the end of the core type product. To do.

[0007]

In order to achieve the above-mentioned object, the method for producing an inorganic fiber tubular molded body of the present invention comprises a mat-shaped raw cotton made of inorganic fibers having an uncured binder dispersed and attached to the core type. While sandwiched between the mandrel and the press roller for use to form a core-type product by laminating and winding around the mandrel,
The core type product housed in the lower mold is pressed by the upper mold and heated and dried while being press-molded, a split portion is formed on the core type product by a split portion forming device, and the mandrel is removed from the core type product. In the method for manufacturing an inorganic fiber tubular molded body to form a tubular molded body, the heating and drying is a hollow porous mandrel formed with a plurality of through small holes along the circumferential direction and the axial direction, and the core-shaped product outer periphery. Is performed by bidirectionally sending hot air between the upper mold and the lower mold that have an arcuate portion that abuts against the upper mold and the lower mold that forms a passage therein.

As means for sending hot air in both directions, after sending hot air from the mandrel to the upper die and the lower die at high speed,
It is desirable to switch the speed to a lower speed and send the hot air, and then send the hot air from the upper and lower molds at high speed in the mandrel direction.

The apparatus for producing an inorganic fiber tubular molded article of the present invention is a production apparatus suitable for carrying out the above-mentioned production method, and is a mat-like article made of inorganic fibers to which an uncured binder is dispersed and adhered. After the raw cotton is laminated and wound on a mandrel, molded and heated and dried, in a manufacturing apparatus for an inorganic fiber tubular molded body formed by forming a split portion along the radial direction, a mandrel for a core type which winds the raw cotton. A press roller for pressing the raw cotton wound around the mandrel toward the mandrel,
An upper die and a lower die that sandwich a core-shaped product formed by laminating and winding the raw cotton around the mandrel, a heating unit that heats the core-shaped product that is sandwiched between the upper mold and the lower mold, and after molding and heating and drying. And a hollow portion forming device which engages with the core-shaped product and forms a split portion along the radial direction thereof, wherein the mandrel forms a plurality of through small holes along the circumferential direction and the axial direction. It is a porous mandrel, wherein the upper die and the lower die each have an arcuate portion that abuts the outer periphery of the core die product to form a passage therein, and the heating means includes the through small hole of the hollow porous mandrel and the upper die. In the manufacturing apparatus including a hot air supply source communicating with the mold and the lower mold passage, a hot air flow passage from the hot air supply source has an air blow passage and an exhaust air passage by a movable damper provided in the flow passage. And is divided into a circulation path.

The air passage is formed between the hot air outlet of the hot air supply source and the passage of the mandrel or the upper and lower molds, and the hot air from the hot air supply source is opened and closed by opening and closing the movable damper. When supplying from the mandrel to the upper mold and the lower mold, the hot air is introduced into the mandrel from the hot air outlet, and when the hot air is supplied from the upper mold and the lower mold to the mandrel direction. A hot air inlet for introducing the hot air into the upper and lower mold passages from the outlet, and the hot air return inlet of the hot air supply source and the upper and lower mold passages or the mandrel. When the hot air from the hot air supply source is supplied from the mandrel to the upper mold and the lower mold by opening and closing the movable damper, the hot air is delivered from the upper mold and the lower mold passages. Hot air said heat When returning to the return inlet, and when supplying the hot air from the upper mold and the lower mold in the mandrel direction, it is a flow path for returning the hot air sent from the mandrel to the hot air return inlet, and The circulation path is formed between the hot air outlet and the hot air return inlet, and the hot air from the hot air outlet does not flow to the mandrel, the upper mold, and the lower mold by opening and closing the movable damper, and the hot air return inlet. It is a flow path to return to.

[0011]

According to the method for producing an inorganic fiber tubular molded body of the present invention, a core type product is obtained by bidirectionally supplying hot air from the mandrel to the upper mold and the lower mold, and from the upper mold and the lower mold to the mandrel. By heating and drying, even if the core type product wound with the raw cotton has uneven density, it can be satisfactorily cured and molded in a short time. First, by supplying high-speed hot air from the mandrel to the upper and lower molds, the mandrel-side end of the core type product is sufficiently baked, and then the speed is switched to a speed lower than that to blow hot air through the same path. By sending, the equipment is protected when the direction of the hot air is reversed, and then the direction of the air is reversed, and high-speed hot air is supplied from the upper mold and the lower mold in the mandrel direction, so that the entire core-shaped product is baked well.

Further, unlike the case where hot air is first supplied from the upper mold and the lower mold in the mandrel direction by first supplying hot air from the mandrel toward the upper mold and the lower mold, the core is moved by the initial high-speed hot air. The surface of the die will not be crushed. When hot air is first supplied from the upper mold and the lower mold in the mandrel direction, it is necessary to first gradually cure and mold the surface with a low-speed hot air and then switch to a hot air having a higher speed than that. Further, according to the manufacturing apparatus of the present invention, the hot air flow passage formed by opening and closing the movable damper provided in the flow passage of the hot air from the hot air supply source preferably performs the above manufacturing method, and By forming the hot air circulation path so that air is not blown to the mandrel, the upper mold and the lower mold by opening and closing, it is not necessary to stop the operation of the hot air supply source when removing the obtained core mold product from the mold.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First, in order to explain a manufacturing apparatus for manufacturing a tubular molded body, a hollow porous mandrel, a press roller,
For upper mold, lower mold, heating means, split part forming device, etc.,
The same one as described in JP-A-5-280689 is used. That is, the hollow porous mandrel 1 is shown in FIG.
As shown in FIG. 2, the collar portions 2 and 2 at both ends, the shaft portion 3 formed between the collar portions 2 and 2, the through hole 4 penetrating the collar portions 2 and 2 and the shaft portion 3, A convex portion 5 formed at an intermediate portion of the body portion 3 and a through-hole 6 for passing hot air, which is formed along the circumferential direction and the axial direction of the shaft body portion 3 and the convex portion 5 and communicates with the through hole 4. Formed from. The dimension between the inner side surfaces of the flange portions 2 and 2 corresponds to the axial length of the tubular molded body, and the outer diameter of the flange portions 2 and 2 corresponds to that of the raw cotton laminated and wound on the shaft body portion 3 and the convex portion 5. It is formed at least larger than the outer diameter dimension after molding. Further, a tapered surface 2a is formed on the inner surface side of the collar portion 2 so that both side edges of the raw cotton can easily enter the shaft body portion 3 side. Further, the convex portion 5 is formed in a shape that matches the concave portion of the tubular molded body.

As shown in FIG. 2, the upper mold 7 and the lower mold 8 each include an arcuate portion 9, a mold matching portion 10, and a frame body 12 having a passage 11 in the form of a closed space therein. ,
A large number of ventilation holes 13 are formed through the arc-shaped portion 9 so as to communicate with the inside of the passage 11. A mold matching portion 10 of the upper mold 7 and the lower mold 8,
A cylindrical space formed by bringing 10 into contact with each other substantially coincides with the outer contour shape of the tubular molded body. The passage 11 and the ventilation holes 13 form a hot air passage 14.

Further, as shown in FIG. 4, the raw cotton 15 cut into a predetermined size is pressed at its front and rear ends by a pressing tool 16 or the like to form an inclined portion 17. The raw cotton 15 is transferred to the hollow porous mandrel 1 by a supply conveyor 18.
A press roller 19 is arranged above the hollow porous mandrel 1, and the raw cotton 15 wound around the hollow porous mandrel 1
To the hollow porous mandrel 1 side. The hollow porous mandrel 1 is rotationally driven and controlled by a driving means (not shown). Through the above steps, the core product 20 is formed. Regarding the heating means, the hot air supply source 21 introduces hot air to the core mold 20 side sandwiched between the upper mold 7 and the lower mold 8 and returns the used hot air to reheat it. It is provided. As shown in FIG. 3, the hot-air supply source 21 has its hot-air outlet 21a communicated with the through hole 4 of the mandrel 1 through a flow path 22, and through the flow paths 23 and 24, respectively. It is communicated with the mold passages 11, 11. Channels 22, 2
As shown in FIG. 3, the movable dampers a ...
h is provided, and the flow path of the hot air from the hot air supply source 21 is divided into a blower path, an exhaust path, and a circulation path by opening and closing these movable dampers.

The air passage is formed by the hot air outlet 21a of the hot air supply source 21 and the through hole 4 of the mandrel 1 or the upper mold 7 and the lower mold 8.
Of the movable dampers a to h formed between the passages 11 and 11.
When the hot air from the hot air supply source 21 is supplied from the mandrel 1 toward the upper die 7 and the lower die 8 by opening and closing the hot air, the hot air is introduced from the hot air outlet 21a into the through hole 4 of the mandrel 1, and the hot air is also introduced. When air is supplied from the upper die 7 and the lower die 8 in the direction of the mandrel 1, the hot air is introduced into the passages 11, 11 of the upper die 7 and the lower die 8 from the hot air outlet 21a. The exhaust path is the hot air return port 21 of the hot air supply source 21.
b and the passages 11 and 11 of the upper die 7 and the lower die 8 or the mandrel 1, and by opening and closing the movable dampers a to h,
When the hot air from the hot air supply source 21 is supplied from the mandrel 1 to the upper mold 7 and the lower mold 8, the hot air sent out from the passages 11 of the upper mold 7 and the lower mold 8 is returned to the hot air return inlet 21b. , The hot air from the upper mold 7 and the lower mold 8 to the mandrel 1
When supplying in the direction, the hot air blown out from the through hole 4 of the mandrel 1 is returned to the hot air return inlet 21b. The circulation path is a flow path in which the hot air from the hot air outlet 21a of the hot air supply source 21 returns to the hot air return inlet 21b of the hot air supply source 21 without flowing to the mandrel 1, the upper mold 7, and the lower mold 8. .

That is, the movable dampers a to h provided in the flow path
The hot air from the hot air supply source 21 is introduced into the through hole 4 of the mandrel 1 through the opening / closing of the mandrel 1, passes through the through small holes 6 of the mandrel 1 and passes through the hot air passages 14 and 14 of the upper mold 7 and the lower mold 8, and the hot air supply source 21 First hot air flow path for returning to the hot air supply source 21
Through the hot air passages 14, 14 of the upper mold 7 and the lower mold 8 and through the small through holes 6 and the through holes 4 of the mandrel 1 to the hot air supply source 2
A second hot air flow path returning to the hot air supply source 21 and a third hot air flow path returning to the hot air supply source 21 without flowing from the hot air supply source 21 to the mandrel 1, the upper mold 7, and the lower mold 8 are formed. The first hot air flow path is formed by opening the movable dampers a to d and h and closing the remaining movable dampers e, f and g,
The second hot air flow passage is formed by opening the movable dampers b to g and closing the remaining movable dampers a and h, and the third hot air flow passage opens the movable dampers a and g and the remaining movable dampers. It is formed by closing b to f and h.

Further, the split portion forming device 25 shown in FIG. 4 forms the split portion 26 on the core type product 20 which has been molded and heated and dried, and is formed, for example, along the radial direction of the hollow porous mandrel 1. It has a structure in which the split portion 26 is formed while guiding the slitter (circular saw etc.) to the narrow slit groove. Further, as the splitting section 26, various types such as half-splitting, half-splitting, and half-splitting are used as necessary. In order to attach the skin material 27 to the outer surface and / or the inner surface of the completed core product 20 or the core product 20 in the middle of the process after heating and drying, the skin material sent from the skin material supplying means (not shown) is used. This is performed by applying an adhesive and contactingly engaging the core product 20. In the case of the core-type product 20 during the heating and drying process, the adhesive may not be used.

Next, a method of manufacturing the cylindrical molded body 20a of the present invention will be described with reference to FIGS. As described above, the core mold product 20 is formed according to the process diagram of FIG. 4, and then the core mold product 20 is housed in the lower mold 8 and pressed by the upper mold 7 to perform press molding. At the same time, the movable dampers a to d and h are opened, and the remaining movable dampers e, f, and g are set to be closed, and hot air at a high speed of 200 m / min and a high temperature of 330 ° C. from the hot air supply source 21 is passed through the flow path 22. , Φ5 mm, pitch 6 mm, 1 in the through hole 4 of the mandrel 1 with a porosity of 35%.
Supply for minutes. The hot air in the through holes 4 passes through the through small holes 6 of the mandrel 1, passes through the thick portion of the core type product 20, and heats and drys the raw cotton 15, while ventilating holes 13 of the upper mold 7 and the lower mold 8,
It is sent to the passages 11 and 11 via 13. Passages 11, 1
The used hot air in 1 returns to the hot air supply source 21 via the flow paths 23 and 24. If desired, it is reheated according to the degree of curing and blown again through the flow path 22.

Next, the same route for 10 seconds, low speed 100m
After supplying hot air having a high temperature of 330 ° C./minute, the movable dampers b to g provided in the hot air flow path are opened and the remaining movable dampers a and h are closed. And high speed 200m /
Minute, hot air with a high temperature of 330 ° C. is sent to the passages 11 and 11 of the upper die 7 and the lower die 8 through the flow passages 23 and 24, and then through the ventilation holes 13 and 13 to the thick portion of the core die product 20. Through the through small hole 6 of the mandrel 1 to the through hole 4 for 1 minute and 50 seconds. The used hot air is returned to the hot air supply source 21 via the flow path 22.

When the core die 20 is removed from the mold after molding, the movable dampers a and g in the hot air flow path are opened, and the remaining movable dampers b to f and h are closed so that the hot air flows to the mandrel 1. Through-hole 4, passageway 11 of upper die 7 and lower die 8,
A hot air circulation path is formed so that air is not blown to 11, so that the core mold product is removed from the mold without stopping the operation of the hot air supply source. The core-type product obtained according to the above method had neither uneven baking nor insufficient baking. After the above-described series of molding operations are completed, the next core-shaped product 20 is set, the movable dampers a to h of the flow path are set and changed as described above, and the molding operation is repeated as described above to obtain the target product. obtain.

For comparison of the hot air supply from the hot air supply source, in the case shown in FIG. 5, the hot air from the hot air supply source 21 is passed through the hot air introduction pipe 28 into the through hole 4 of the hollow porous mandrel 1. And the hot air in the through holes 4 is passed through the through small holes 6 of the hollow porous mandrel 1 and through the thick portion of the core type product 20, while the raw cotton 15 is heated and dried, the upper mold 7 and the lower mold 8 are ventilated. The used hot air in the passages 11 and 11 is sent into the passages 11 and 11 through the holes 13 and 13, and the hot air return pipe 2 is used.
A molding operation was performed for 5 minutes so as to return to the hot air supply source 21 side via 9 and 30. Burning unevenness and insufficient burning were observed at the end of the obtained core type product. When hot air is sent in the reverse flow path, the air is blown first for 1 minute at a low speed and then at a higher speed for 2 minutes 30 seconds so as not to crush the surface of the core type product. I went. Burning unevenness and insufficient burning were observed on the inner end of the obtained core type product. Thus, according to the manufacturing method and the manufacturing apparatus thereof of the present invention,
The heat-curing molding time can be shortened by about 14% or more, and uneven burning and insufficient burning of the end portion of the core type product can be eliminated.

In the above embodiments, the hollow porous mandrel 1 has the convex portion 5 as shown in the drawing, but it may have another shape or concave portion. It is of course possible to use a straight one having no convex portion or concave portion. Further, the hot air passages 14 formed in the hollow porous mandrel 1 and the upper mold 7 and the lower mold 8 are not limited to those shown in the drawings. Further, in the present embodiment, the description has been made such that the skin material 27 is attached to the outer surface and / or the inner surface of the core type product 20, but the skin material 2
7 may be omitted.

[0024]

EFFECTS OF THE INVENTION According to the method for producing an inorganic fiber tubular body and the apparatus for producing the same of the present invention, the heat-curing molding time can be shortened and uneven burning or insufficient burning of the end portion of the core type article does not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a hollow porous mandrel according to the present invention.

FIG. 2 is a side view showing an example of an upper mold and a lower mold in the present invention.

FIG. 3 is a diagram for explaining a heating and drying step in the present invention.

FIG. 4 is a process diagram for explaining a manufacturing method and a manufacturing apparatus for a cylindrical molded body according to a conventional technique.

FIG. 5 is a diagram for explaining a heating and drying step of the steps of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow porous mandrel 2 Collar part 2a Tapered surface 3 Shaft body part 4 Through hole 5 Convex part 6 Through small hole 7 Upper mold 8 Lower mold 9 Arc part 10 Mold mating part 11 Passage 12 Frame body 13 Vent hole 14 Hot air passage 15 Raw cotton 16 Pressing Tool 17 Inclined Part 18 Supply Conveyor 19 Press Roller 20 Core Type Product 20a Cylindrical Formed Body 21 Hot Air Supply Source 21a Hot Air Outlet 21b Hot Air Return Inlet 22 Flow Path 23 Flow Path 24 Flow Path 25 Split Section Forming Device 26 Split Section 27 Skin material 28 Hot air introduction pipe 29 Hot air return pipe 30 Hot air return pipe

Claims (4)

[Claims] 1. A core type product is formed by sandwiching and winding a mat-like raw cotton made of inorganic fibers to which an uncured binder is dispersed and attached between a mandrel for a core type and a press roller, and winding the laminated layer around the mandrel. Then, the core type product stored in the lower mold is heated and dried while being pressed by the upper mold and press-molded, a split portion is formed on the core type product by a split portion forming device, and the mandrel is formed from the core type product. In the method for manufacturing an inorganic fiber tubular molded body which is removed to form a tubular molded body, the heating and drying are
Between a hollow porous mandrel having a plurality of through-holes formed along the circumferential direction and the axial direction, and the upper die and the lower die having an arcuate portion abutting the outer periphery of the core die and forming a passage therein. The method for producing an inorganic fiber tubular molded article is characterized in that it is carried out by sending hot air in both directions. 2. As the means for sending hot air in both directions, after sending hot air from the mandrel to the upper die and the lower die at a high speed, the hot air is sent at a speed lower than that.
Next, the method for producing an inorganic fiber tubular molded body according to claim 1, wherein hot air is sent from the upper mold and the lower mold in the mandrel direction at a high speed. 3. An inorganic fiber tube formed by laminating and winding a mat-like raw cotton made of inorganic fibers to which an uncured binder is dispersed and attached on a mandrel, molding and heat-drying, and then forming a split portion along the radial direction. In a device for manufacturing a shaped body, a mandrel for a core type for winding the raw cotton, a press roller for pressing the raw cotton wound on the mandrel to the mandrel side, and the raw cotton laminated and wound on the mandrel. An upper die and a lower die for sandwiching the core die product, heating means for heating the core die article sandwiched by the upper die and the lower die, and engaging the core die article after molding and heating and drying, A split portion forming device that forms a split portion along the radial direction thereof, wherein the mandrel is a hollow porous mandrel in which a plurality of through small holes are formed along the circumferential direction and the axial direction, the upper mold and the lower mold. Each mold is on the outer circumference of the core type product. The manufacturing, wherein the heating means comprises a hot air supply source having an abutting arcuate portion and forming a passage therein, and wherein the heating means communicates with the through small hole of the hollow porous mandrel and the upper and lower die passages. In the apparatus, a flow path of hot air from the hot air supply source is divided into a blower path, an exhaust path and a circulation path by a movable damper provided in the flow path, of an inorganic fiber tubular molded body. Manufacturing equipment. 4. The air passage is formed between the hot air outlet of the hot air supply source and the passage of the mandrel or the upper mold and the lower mold, and is opened and closed from the hot air supply source by opening and closing the movable damper. When supplying hot air from the mandrel to the upper die and the lower die, the hot air is introduced from the hot air outlet to the mandrel, and the hot air is fed from the upper die and the lower die to the mandrel direction. The time is a flow path for introducing the hot air from the outlet to the upper and lower mold passages, and the exhaust passage is the hot air return inlet of the hot air supply source and the upper and lower mold passages or Formed between the mandrel and the movable damper, the hot air from the hot air supply source is fed from the mandrel toward the upper and lower molds through the upper and lower mold passages. The hot air that has been heated When returning to the wind return inlet, and when supplying the hot air from the upper mold and the lower mold in the mandrel direction, there is a flow path for returning the hot air sent from the mandrel to the hot air return inlet, and The circulation path is formed between the hot air outlet and the hot air return inlet, and when the movable damper is opened and closed, the hot air from the hot air outlet does not flow to the mandrel, the upper mold, and the lower mold, and the hot air returns. The inorganic fiber tubular molded body manufacturing apparatus according to claim 3, wherein the channel is a flow path that returns to the inlet.