JP2015004503A - Flexible duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a pressure loss caused by a fold at bending.SOLUTION: An air conditioning flexible duct D has a cylindrical inner coat material 1, a cylindrical heat insulation material 3 and a cylindrical outer coat material 4 on a cylindrical entire peripheral face of a strip reinforcing body 2 which is spirally and cylindrically wound. Fold promotion means 10 along a spiral direction of the reinforcing body is arranged at the inner coat material. The fold promotion means is constituted by pasting reinforcing tapes 11 or the like (Fig. (a), (b) and (c)), or providing folded lines 13 (Fig. (c), (d)). By arranging the fold promotion means, the number of folds a along the spiral direction in the inner coat material of a center portion between the opposing reinforcing bodies is increased, and when the number of the folds is increased, a diameter difference of internal/external peripheries at bending and elongation/contraction is absorbed by the protrusion of the folds, and a degree of the protrusion is lowered. That is, as compared with a conventional flexible duct in which the fold promotion means is not arranged, and the center portion is protruded, a protrusion amount of each fold a is small, and thereby a pressure loss is reduced more than before.

Description

  The present invention relates to a flexible duct used for general air conditioning and moisture resistance in a bathroom or the like.

For example, as shown in FIG. 5 (a) and FIG. 6 (a), this type of flexible duct is formed by winding a belt-like polyester nonwoven fabric, a polyethylene terephthalate film (PET) 1a, or the like with its side edges overlapped in a spiral tube shape. The endothelium material 1 is formed by turning, and a thread 1b such as nylon is attached to the entire length of the overlapping side edge part, and the overlapping side edge part and the thread 1b are wrapped with a steel strip 2a having a C-shaped cross section and reinforced. Insulating material 3 such as glass wool is provided in a cylindrical shape on the outer peripheral surface of the inner skin material 1, and an outer skin material 4 made of a polyethylene resin film or the like is provided on the outer peripheral surface of the heat insulating material 3. It is a structure (refer patent document 1 paragraph 0011, FIG. 1, FIG. 3).
As shown in FIGS. 5 (b) and 6 (b), the flexible duct D having this structure has an outer skin such as a polyethylene-based resin film (aluminum PET) on which aluminum is further deposited on the outer peripheral surface of the outer skin material 4. Some have improved heat resistance and weather resistance by providing a material 5 (see Patent Document 1, paragraphs 0011 and 0012, FIG. 1, FIG. 3, etc.).
The flexible duct D using a hygroscopic material such as a non-woven fabric for the endothelium material 1 is usually used for general air conditioning, and for a humid gas (air) such as a bathroom, the endothelium material 1 has a polyethylene terephthalate film or the like. The one with moisture resistance is used.

Japanese Patent Laid-Open No. 11-257725

The arrangement of the flexible duct D is not only linear but also bent at various angles (curvatures). Since the outer peripheral curvature and the inner peripheral curvature are different at the time of bending, the inner skin material 1, the heat insulating material 3 and the like on the inner peripheral side contract as shown in FIG. 7, and correspond to the bending. At this time, the endothelial material 1 or the like has a ridge a that is irregularly bent and protrudes inside the duct (flow channel side), and the ridge a usually protrudes most in the center between the reinforcing bodies 2 and 2 facing each other. Further, the heel a is not along the spiral direction of the reinforcing body 2 but is oriented in an arbitrary direction.
The protrusion of the ridge a becomes a protrusion into the flow path of the flexible duct D, and the ridge a directed in an arbitrary direction directs the flow of fluid in the arbitrary direction, thereby causing a pressure loss (pressure loss). . Pressure loss leads to a decrease in gas (air) transport efficiency.

  This invention makes it a subject to aim at reduction of the said pressure loss under the above condition.

In order to achieve the above object, the present invention aims to reduce the pressure loss by reducing the protruding amount of the ridge a. Specifically, the inventor found that the pressure loss depends on the size (the amount of protrusion) compared to the number of protrusions, and bends the above-mentioned endothelial material in the length of the helical tube. When this is done, wrinkle promoting means is provided along the spiral direction of the reinforcing body for promoting wrinkles associated with the bending.
If the wrinkle promoting means along the spiral direction of the reinforcing body is provided, the number of wrinkles a along the spiral direction in the endothelial material between the reinforcing bodies facing each other increases. If the number of ridges increases, the difference in diameter between the inner and outer circumferences at the time of bending will be absorbed by the increased ridge protrusion, and the degree of protrusion will also be reduced. That is, from the above discovery, the pressure loss depends on the size of the protrusions compared to the number of protrusions. Therefore, when the wrinkle promoting means is provided, the conventional central part without the protrusions protrudes. For example (see FIG. 7), the protrusion amount of each ridge a is low (for example, FIG. 3A), and therefore pressure loss is reduced as compared with the conventional case.

  As a configuration of the present invention, a filament reinforcing body wound in a spiral cylindrical shape, a cylindrical endothelial material provided on the entire cylindrical peripheral surface of the reinforcing body, and a cylindrical shape provided on the outer peripheral surface of the endothelial material A flexible duct for air conditioning having a heat insulating material and a tubular outer skin material provided on the entire outer peripheral surface of the heat insulating material, and when the inner skin material is bent or stretched in the spiral cylindrical length direction, The structure provided with the wrinkle promotion means along the spiral direction of the said reinforcement body for promoting the wrinkle accompanying the bending or expansion / contraction can be employ | adopted.

As the wrinkle promoting means, various modes for promoting wrinkles associated with bending or expansion / contraction can be considered. For example, in the spiral direction of the reinforcing body, the endothelial material between the reinforcing bodies facing each other in the spiral cylindrical length direction is used. A configuration in which a reinforcing tape is attached can be adopted.
In this configuration, the bending of the endothelial material is suppressed by the reinforcing tape, and the generation of wrinkles other than the portion to which the reinforcing tape is attached is promoted.
At this time, if the affixing portion of the reinforcing tape is an endothelium material at the opposite central portion between the reinforcing bodies, the central portion between the reinforcing bodies is difficult to bend. As a result, the number of ridges increases and the protruding amount of each ridge decreases.

Moreover, as another aspect of the wrinkle promoting means, a configuration is adopted in which a plurality of fold lines along the spiral direction of the reinforcing body are formed on the endothelial material between the reinforcing bodies facing each other in the spiral cylindrical length direction. be able to. The fold line can be formed using a conventionally known streak forming roller, a ruler, or the like, and can also be a ballpoint pen.
The bend line surely promotes the generation of wrinkles with the line as the apex, and the wrinkles also extend along the helical length direction of the reinforcing body. It is effectively absorbed and the degree of protrusion is low.
At this time, since the fold line is plural (a plurality of lines), a mountain-shaped fold that folds inward and a valley-shaped fold that folds outward can be generated. The difference in diameter between the inner and outer circumferences is absorbed, and the degree of protrusion is also reduced. If the mountain-shaped ridges and the valley-shaped ridges are alternately generated, the undulation of each ridge is also reduced. Therefore, it is preferable that the fold lines are alternately formed on the front and back surfaces of the endothelial material.

  In the present invention, since the heel is positively formed as described above, the heel is surely formed along the reinforcing body, the amount of protrusion of the heel is reduced, and any fluid generated by the heel can be obtained. Since the change in the flow direction is also reduced, the pressure loss is reduced. That is, a low pressure loss flexible duct can be obtained.

Partial perspective view of one embodiment of this invention (A)-(e) is a schematic explanatory drawing of each embodiment of this invention (A)-(e) is principal part sectional drawing of each embodiment of (a)-(e) of FIG. 2a. (A)-(e) is a schematic explanatory drawing at the time of bending of each embodiment of (a)-(e) of Drawing 2a (A), (b) is principal part fragmentary sectional drawing of each other embodiment, respectively. (A), (b) is a partially cut schematic view of each example of a flexible duct (A), (b) is each partial expanded sectional view of each example of FIG. Schematic explanatory diagram during bending of the conventional example

  The embodiment according to the present invention is also similar to the conventional one shown in FIG. 5 and FIG. 6, by winding a belt-like polyester nonwoven fabric, polyethylene terephthalate film 1 a, etc. In addition, a thread 1b such as nylon is attached to the entire length of the overlapping side edge, and the reinforcing edge 2 is formed by wrapping the overlapping side edge and the thread 1b with a steel strip 2a having a C-shaped cross section. A flexible duct D having a structure in which a heat insulating material 3 such as glass wool is provided in a cylindrical shape on the entire outer peripheral surface of 1, and a skin material 4 made of a polyethylene resin film or the like is further provided on the outer peripheral peripheral surface of the heat insulating material 3. is there.

  The difference from the conventional configuration is that when the endothelial material 1 is bent or stretched in the helical cylindrical length direction as shown in FIGS. 1, 2a and 2b (a) to (e). Further, the wrinkle promoting means 10 along the spiral direction of the reinforcing body 2 is provided for promoting the wrinkle a accompanying the bending or expansion / contraction.

In the embodiment shown in FIGS. 1, 2 a (a), and 2 b (a), reinforcements that oppose each other in the length direction (spiral cylindrical length direction) of the filament reinforcing bodies 2 and 2 wound in a spiral cylinder shape. A reinforcing tape 11 having a width smaller than the helical pitch, which is continuously along the entire length of the reinforcing body 2 in the spiral direction, is attached to the endothelial material 1 between the bodies 2 and 2 with the entire surface of the tape. The reinforcing tape 11 is appropriately selected from a material such as aluminum glass cloth (ALGC), non-woven fabric, etc., which is flexible and can exhibit the effects of the present invention. The tape width is also arbitrary.
The polyester nonwoven fabric, polyethylene terephthalate film 1a, and the like constituting the endothelial material 1 are obtained by overlapping and joining the side edges at the center between two opposing reinforcing bodies 2 (see FIG. 4 (b)). As shown in the figure, the joint portion may be the attachment position of the reinforcing body 2 or other part.

  The sticking of the reinforcing tape 11 increases the thickness of the sticking part and makes it difficult to bend, and the bending of the endothelial material 1 at that part is suppressed. Therefore, as shown in FIG. When D is bent or expanded / contracted, the generation of wrinkles a other than the part to which the reinforcing tape 11 is applied is promoted, and the number of wrinkles a along the spiral direction in the endothelial material 1 between the reinforcing bodies 2 and 2 facing each other. Will increase. If the number of the ridges a increases, the diameter difference between the inner and outer circumferences at the time of bending will be absorbed by the projections of the many ridges a, and the degree of projection will be reduced. For this reason, compared with the case where the center part which does not provide the wrinkle acceleration | stimulation means 10 shown in FIG. 7 protrudes, the protrusion amount of each wrinkle a is low, Therefore, a pressure loss reduces compared with the past.

At this time, the affixing portion of the reinforcing tape 11 is used as the portion of the endothelial material 1 in the central portion between the opposing reinforcing bodies 2 and 2, so that the central portion between the reinforcing bodies is difficult to bend, As a result, the heels a are likely to be generated on both sides, and as a result, the number of the heels a increases and the protruding amount of each heel a decreases.
The reinforcing tape 11 is not limited to a single strip, and may be a plurality of strips. For example, it can be provided adjacent to both sides of the reinforcing body 2. In any case, by forming a plurality of portions that are difficult to bend, the heel a increases and the protruding amount decreases.

2a (b), FIG. 2b (b), FIG. 2a (e), and FIG. 2b (e), the embodiment shown in FIG. A tape-like piece 14 continuously extending along the entire length in the spiral direction is welded (adhered) 12 to the outside of the endothelial material 1 to form the wrinkle promoting means 10 along the spiral direction. In (b) and (e), the white portion of the tape-like piece 14 is the welded portion 12, and (b) is a straight line in the center of the tape piece, and (e) is the tape piece. The welded portion 12 is formed by two broken lines on both sides.
Since the welded portion is hardened by the weld 12, the welded portion 12 exhibits the same action as the reinforcing tape 11, and the flexible duct D of this embodiment as shown in FIGS. 3 (b) and 3 (e). Is bent, the generation of wrinkles a other than the welded portion 12 is promoted, and the number of wrinkles a along the spiral direction in the endothelium material 1 between the opposing reinforcing bodies 2 and 2 is increased. In this case, the pressure loss is reduced.

2a (c), 2 (d), 2b (c), (d), the embodiment shown in FIG. The fold line 13 that continuously extends along the entire length of the spiral direction 2 is formed, and the fold promoting means 10 that extends along the spiral direction is formed by the fold line 13. The bending line 13 in FIG. 3C is a ruled jig, and FIG. 4D is the tip of a ballpoint pen. In the case of the illustration, the folding lines 13 are formed in total in the center between the reinforcing bodies 2 and 2 and one on each side thereof, and the number and interval of the folding lines 13 are, for example, 5 or the like, Appropriately set by experiments or the like so as to exert the effects of the present invention. The interval is preferably equal.
At this time, the polyethylene terephthalate film 1a or the like constituting the endothelial material 1 is formed by overlapping the side edges at the center between the two reinforcing bodies 2 facing each other, or the joint is formed of the reinforcing body 2. It may be an attachment position or another part.

The folding line 13 is mountain-folded so that the central line 13 between the reinforcing bodies 2 and 2 protrudes to the outside of the duct D (glass wool 3 side), and alternately turns into valley-fold and mountain-fold toward both sides. It has become. This point is the configuration regardless of the number of the folding lines 13. At this time, the folding line 13 is preferably formed on the inner side surface of the endothelial material 1 in the case of the folding side, for example, the outer mountain fold. The central fold line 13 may be protruded inside the duct D. Also in this case, the fold lines 13 on both sides of the fold line 13 in the center are alternated between the fold line 13 and the mountain fold in order from the center fold line 13 to the opposite side (outside of the duct D) and the inner side. To do.
When the flexible duct D of this embodiment is bent or expanded and contracted as shown in FIGS. 3C and 3D by the formation of the fold line 13, a crease (valley fold, mountain) is formed via each fold line 13. A large number of ridges a having a small protrusion amount are formed, and the pressure loss is reduced. The folds can be positively formed with a finger or the like simultaneously with the formation of the fold line 13.

  In the flexible duct D (total length: 5000 mm, nominal diameter: 200 mm) having the configuration shown in FIGS. 5 and 6, the arc-shaped curvature radius of the cylindrical axis of the duct is attached to each of Examples 1 to 6 below. : Table 1 below shows the pressure loss (pressure loss) result of bending 90 degrees at 200 mm and passing through the bent portion.

In each example, the endothelial material 1: non-woven fabric, the reinforcing body 2: C-type steel material, the heat insulating material 3: glass wool, the outer skin 4: a polyethylene sheet, and the configuration of each example as a comparative example 1, The thing which none of the wrinkle promotion means 10 was formed was prepared, and the same test was performed.
Moreover, the reinforcing tape 11 of Example 1 of FIG. 2A is ALGC width: 10 mm, the width of the nonwoven fabric 14 of Example 2 of FIG. 2B is 20 mm, and Example 3 of FIG. 13 is formed by a streak forming roller, and the fourth and fifth embodiments of FIG. 4 (d) are formed by forming a fold line 13 at the tip of a ballpoint pen. In the fourth embodiment, there are three fold lines 13 and an embodiment. 5 was the same two. The width of the nonwoven fabric part 14 of Example 6 in (e) was set to 15 mm.

The pressure loss measurement is performed by a conventional general method. First, a steel straight pipe spiral duct having a nominal diameter of 200 mm and a length of 12 m is connected in series before and after each bent specimen. In each of the spiral ducts, three pores having a diameter of 1 mm were formed at intervals of 1 m from both ends of the test body, and a fine differential pressure gauge (manufactured by SIBATA, model number ISP-6-50D) was connected to each pore. . Next, a sirocco fan (manufactured by HITACHI, model number NH-5127) is connected to one (front side) spiral duct via a rectifying chamber box and blown to the spiral duct (100 to 2000 m ³ / h). The static pressures P _S1 , P _S2 , P _S3 , P _S4 , P _S5 , and P _S6 at each pore position were measured with a differential pressure gauge.

The measured static pressure and the distance (1m, 2m, 3m) from the connecting part at each end of the test specimen to the pore (fine differential pressure gauge) determine the slope of the static pressure. The static pressures P _SA and P _SB immediately after the test specimen front side connection part and immediately after the test specimen (test specimen rear side connection part) are calculated, respectively, and the difference between the two calculated static pressures (P _SA −P _SB ) is the pressure loss (pressure loss) : Pa). The pressure loss by changing the air volume in the range of 100-2000 m ³ / h was measured 4 times to calculate the pressure loss at 420 m ³ / h from the regression curve of the measured value.

From this experimental result, it can be understood that if the wrinkle promoting means 10 of the present invention is formed, the pressure loss of the bent portion is reduced by about 30%. Moreover, it can be understood from the comparison between Examples 1, 2, and 6 that the tape-like adhesive piece is thin and the effect of reducing pressure loss is high if the welding area is widened. Further, it can be understood from the comparison between Examples 4 and 5 that the pressure loss can be reduced even with simple wrinkle promoting means 10 such as ruled marking of a ballpoint pen, and the reduction can be achieved depending on the number of fold lines (fold lines 13). It can be understood that the effect also changes.
The wrinkle promoting means 10 is not only when the flexible duct D is bent, but also when the helical pitch of the reinforcing body 2 is shortened (the duct length is shortened and shortened) or when it is stretched (when it is stretched). The effect of reducing the pressure loss due to the formation of 皺 a was also observed.

The material and structure of the endothelial material 1, the reinforcing body 2, the heat insulating material 3, and the outer skin materials 4 and 5 of the flexible duct D are not limited to those shown in FIG. 5 described above. For example, the reinforcing body 2 is made of a metal steel wire. Various known means such as sandwiching and adhering at both ends of the film 1a can be employed.
The wrinkle promoting means 10 is not limited to the means described in the above embodiments, but instead of the reinforcing tape 11, for example, as shown in FIG. As shown in FIG. 2B, the endothelial material 1 is hardened by application of the required width of the agent, or the endothelial material 1 at the center between the reinforcing bodies 2 and 2 is folded inward or outward to adhere to the required width. In addition, various known means can be employed, such as a method in which the side edges are overlapped and joined at the center between the two reinforcing bodies 2 facing each other, such as a nonwoven fabric constituting the endothelial material 1.
Moreover, the wrinkle promoting means 10 such as the reinforcing tape 11, the tape-shaped piece 14, and the ridges 15 can be provided inside the endothelial piece 1 as long as the protrusion amount of the wrinkles a can be suppressed and the pressure loss can be reduced. . Further, the wrinkle promoting means 10 can be appropriately provided on the heat insulating material 3 and the outer skin materials 4 and 5. Further, the wrinkle promoting means 10 such as the reinforcing tape 11 does not necessarily have to be continuous along the entire length of the reinforcing body 2 in the spiral direction, and may be intermittent (intermittent) as long as the pressure loss can be reduced. Moreover, the wrinkle promotion means 10 should just be formed at least in the part bent or expanded / contracted.
Thus, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Endothelial material 1a Film or nonwoven fabric which comprises endothelial material 2 Reinforcing body such as steel wire 3 Glass wool (heat insulating material)
4, 5 Outer material 10 Wrinkle promoting means 11 Reinforcement tape 12 constituting wrinkle promoting means Same welded portion 13 Folding line 14 Tape-like piece 15 Convex strip D with same adhesive material Flexible duct a

Claims (4)

A filament reinforcing body (2) wound in a spiral cylindrical shape, a tubular endothelial material (1) provided on the entire cylindrical peripheral surface of the reinforcing body (2), and an outer peripheral surface of the endothelial material (1) A flexible duct (D) having a cylindrical heat insulating material (3) provided on the outer peripheral surface of the outer peripheral surface of the heat insulating material (3) (4, 5),
When the endothelium material (1) is bent or stretched in the helical cylindrical length direction, it follows the spiral direction of the reinforcing body (2) for promoting wrinkles (a) accompanying the bending or stretching. A flexible duct provided with heel promoting means (10).   The wrinkle promoting means (10) is applied to the endothelial material (1) between the reinforcing bodies (2, 2) facing each other in the helical cylindrical length direction, and the reinforcing tape (11) along the spiral direction of the reinforcing body (2). ), The bending of the endothelial material (1) is suppressed by the reinforcing tape (11), and the generation of wrinkles (a) other than the bonded portion of the reinforcing tape (11) is promoted. The flexible duct according to claim 1, wherein the flexible duct is formed.   The flexible duct according to claim 2, characterized in that the affixing portion of the reinforcing tape (11) is an endothelium material (1) at the center between the opposing reinforcing bodies (2, 2).   The wrinkle promoting means (10) is provided with the reinforcing body (1) between the reinforcing bodies (2, 2) facing each other in the longitudinal direction of the linear reinforcing body (2) wound in the spiral tube shape. 2. The structure according to claim 1, wherein a plurality of folding lines (13) are formed along the spiral direction of 2), and the generation of wrinkles (a) is promoted by the folding lines (13). Flexible duct.

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