JP7249135B2 - Duct member - Google Patents

Description

The present invention relates to a duct member obtained by blow molding.

An automobile air conditioning system is provided with a duct member. The duct member includes a duct body having a channel space that is a fluid passage. In addition, the duct member is provided with an attachment portion for attaching the duct member to the automobile.

A duct member, which is a hollow molded product, is produced by blow molding as described in Patent Document 1, for example. Blow molding is a molding method in which a pipe-shaped raw material member (parison) is sandwiched between a plurality of molds in which only the outer shape of the duct member is formed, and air is blown into the parison. The air-inflated parison is formed into a shape that conforms to the inner peripheral surface of the mold. In blow molding, since the parison is sandwiched between a plurality of molds, the end of the duct body having the flow passage space is closed. Therefore, the opening end of the duct body is formed by cutting the portion that will be the end of the duct body.

JP-A-57-89930

When manufacturing a blow-molded article having a curved shape, such as a duct member, the parison material tends to be excessive on the inside of the curve compared to the outside of the curve. The surplus material (hereinafter referred to as surplus material) tends to gather near the ends of the duct body, where the parison is crimped between the molds. Excess material gathered in one place tends to protrude into the channel space. If the surplus wall protrudes into the flow path space, the blowing resistance of the duct body is deteriorated, and noise is generated when blowing air.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and one of its objects is to provide a duct member capable of suppressing excess thickness from protruding into a channel space.

A duct according to an aspect of the present invention includes
A blow-molded duct member comprising a duct body having a flow channel space serving as a fluid passage,
A hollow portion is integrally formed on the outer circumference of the duct body near the opening end and has an internal space independent of the flow passage space.

In the duct member having the above configuration, excess thickness is less likely to be formed in the channel space of the duct body. This is because the hollow portion is formed in the outer circumference of the duct body near the opening end, so that when excess thickness is generated by blow molding, the excess thickness can be released into the inner space of the hollow portion. Since the internal space of the hollow portion is independent of the flow path space and is not used as a path for the fluid, even if the excess wall protrudes into the internal space of the hollow portion, there will be no deterioration in airflow resistance and no noise.

1 is a schematic perspective view of a duct member of an air conditioning system shown in Embodiment 1. FIG. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a cross-sectional view taken along line III-III of FIG.

An embodiment of a duct member 1 according to the present invention will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same names. The arrows in the figure indicate "FR" for the front of the vehicle, "RR" for the rear of the vehicle, "UP" for the top of the vehicle, "DW" for the bottom of the vehicle, "LH" for the left of the vehicle, and "RH". indicates the right side of the vehicle. It should be noted that the present invention is not limited to the exemplification of the embodiments, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

<Embodiment 1>
≪Overall composition≫
A duct member 1 shown in FIG. 1 is a blow-molded body made from a single parison. The duct member 1 is attached to a module component (HVAC: heating, ventilating and air-conditioning unit) that integrates air conditioning functions. The HVAC of this example has an outlet for conditioned air directed upwards of the vehicle, and the duct member 1 of this example is attached above the outlet.

The duct member 1 of this example comprises a base 4 and two duct bodies 2 and 3 extending from the base 4 . The base 4 is a plate-like member constructed by press-fitting a parison, and is attached to the air outlet of the HVAC (not shown). The duct body 2 (3) is a curved tube made by inflating a parison, and extends from the base 4 toward the left (right) of the vehicle. The open end 20 (30) of the duct body 2 (3) on the center side of the vehicle opens to the lower surface of the base 4 and serves as an air-conditioning air inlet that communicates with the air outlet of the HVAC. On the other hand, the opening end 21 (31) on the side of the vehicle of the duct body 2 (3) is an outlet (side vent) for conditioned air that opens to the left (right) of the passenger compartment. According to the duct member 1 having such a configuration, the conditioned air from the HVAC can be introduced into the vehicle compartment through the duct bodies 2 and 3 .

Here, the blow-molded article immediately after being removed from the mold is a tubular member having no opening. For example, as indicated by a two-dot chain line in FIG. 2, the ends 2e, 3e of the duct bodies 2, 3 on the side of the base 4 are closed immediately after blow molding. One of the open ends 20, 30 is formed by cutting the ends 2e, 3e. The other open ends 21 and 31 in FIG. 1 are similarly formed by cutting the ends (not shown) of the duct bodies 2 and 3 .

The duct member 1 of this example further comprises a hollow portion 5 in the upper surface of the base portion 4 . Reinforcement portions 60 , 61 and 62 are provided at various locations of the duct member 1 . Further, although not shown in FIG. 1, a reinforcing portion 6 (see FIG. 3) connected to the duct main body 2 and the duct main body 3 across the hollow portion 5 is provided.

≪Hollow part≫
A hollow portion 5 is formed between the open ends 20 and 30 of the base portion 4 . That is, as shown in FIG. 2, the hollow portion 5 is formed integrally with the outer periphery of the duct bodies 2 and 3 near the opening ends 20 and 30, and is structurally continuous with the outer peripheral surfaces of the duct bodies 2 and 3. . The internal space 5 s of the hollow portion 5 is independent of the channel space 2 s formed inside the duct body 2 and the channel space 3 s formed inside the duct body 3 . Here, since the duct member 1 is a blow-molded body made from one parison, the internal space 5s and the channel spaces 2s and 3s are formed by partitioning the one parison inner space. More specifically, during blow molding, the parison is sandwiched between dies in the middle in the longitudinal direction and crimped to define the inner space of the parison. As a result, a constricted portion 42 (43) is formed by crimping the parison between the hollow portion 5 and the duct body 2 (3), and the internal space 5s and the passage spaces 2s and 3s are independent. space.

The hollow portion 5 is further provided with blow holes 5h. The blow hole 5h is a through hole penetrating inside and outside the internal space 5s, and is provided on the lower surface of the base 4 in this example. The blow hole 5h is a trace of a blow tube arranged in a portion that becomes the hollow portion 5 during blow molding. A hollow portion 5 having an internal space 5s is formed by blowing air through a blow pipe into a portion that will become the hollow portion 5 .

An excess thickness 5p is formed in the internal space 5s of the hollow portion 5. As shown in FIG. The excess thickness 5p protrudes from the positions of the constricted portions 42 and 43 toward the internal space 5s. The extra thickness 5p is the parison material left over when the parison is blow-molded. The total length of the vehicle upper side in the cross section shown in FIG. 2 is longer than the total length of the vehicle lower side. That is, when the parison is sandwiched between the molds and closed together to form the constricted portions 42 and 43, the material on the lower side of the vehicle remains. Since the outer periphery of the parison is pressed by the mold, if the hollow portion 5 were not provided, the destination of the excess thickness 5p would be the passage spaces 2s and 3s. On the other hand, in this example, since the hollow portion 5 is located adjacent to the constricted portions 42 and 43, the excess thickness 5p can be guided into the internal space 5s.

≪Reinforcement part≫
Reinforcing portions 60, 61, and 62 shown in FIG. 1 reinforce various portions of the duct member 1 and function as attachment portions when the duct member 1 is attached to a vehicle. Further, the duct member 1 of this example includes a reinforcing portion 6 (FIG. 3) that suppresses bending of the duct member 1 at the positions of the constricted portions 42 and 43 of FIG. The reinforcing portion 6 connects the outer peripheral surface of the duct body 2 on the vehicle rear side and the outer peripheral surface of the duct body 3 on the vehicle rear side in FIG. Even if stress acts on the duct bodies 2 and 3, the duct bodies 2 and 3 are less likely to bend due to the reinforcing part 6 provided across the duct bodies 2 and 3. - 特許庁As a result, it is possible to prevent the duct member 1 from bending at the constricted portions 42 and 43 (FIG. 2).

The reinforcing portion 6 can also be used as a mounting portion. A screw hole 6h for screwing the duct member 1 to a structural member of the vehicle body is formed in the reinforcing portion 6 of this example.

<<Manufacturing method of duct member>>
The duct member 1 is manufactured by sandwiching a parison between a pair of molds that open and close in the vertical direction of the vehicle in FIG. More specifically, when the parison is sandwiched between the pair of molds, air is blown into the parison from positions corresponding to the open ends 21 and 31 in FIG. . At this time, the blow pressure at the part to be the hollow portion 5 is made lower than the blow pressure at the parts to be the duct main bodies 2 and 3 . The left and right positions of the hollow portion 5 are sandwiched by a mold and crimped to form constricted portions 42 and 43 in FIG. As a result, the internal space 5s of the hollow portion 5 and the passage spaces 2s and 3s of the duct bodies 2 and 3 become independent spaces partitioned by the constricted portions 42 and 43 . The excess thickness 5p of the parison gathered at the constricted portions 42 and 43 sandwiched between the molds during molding protrudes into the hollow portion 5 where the blow pressure is low. Finally, the ends 2e and 3e (see the two-dot chain line in FIG. 2) of the duct bodies 2 and 3 on the vehicle center side are cut to form one open ends 20 and 30, and the duct bodies 2 and 3 are cut. The other open ends 21 and 31 are formed by cutting the ends (not shown) on the side of the vehicle.

≪Effect≫
In the duct member 1 of this example, since the hollow portion 5 is formed in the outer periphery near the opening ends 20 and 30 of the duct bodies 2 and 3, when the excess thickness 5p is generated by blow molding, the excess thickness 5p is removed. It can escape to the internal space 5 s of the hollow portion 5 . An internal space 5s of the hollow portion 5 is independent of the channel spaces 2s and 3s and is not used as a fluid passage. Therefore, the excess thickness 5p does not interfere with the flow of air-conditioning air and does not become a source of noise. In addition, the inner peripheral surfaces of the duct bodies 2 and 3 are smoothed by forming the excess thickness 5p in the inner space 5s. Therefore, according to the duct member 1 of the present embodiment, the conditioned air from the HVAC can be smoothly introduced into the vehicle, and the noise accompanying the passage of the conditioned air can be reduced.

<Other embodiments>
Although the duct member including two duct bodies has been described in the first embodiment, the number of duct bodies is not particularly limited. For example, the number of duct bodies may be one, or three or more. In that case, a hollow portion is formed in the vicinity of the portion where the parison is closed at the end of the duct body. The number of hollow portions is also not particularly limited, and the number and positions of the hollow portions should be determined so as to effectively accommodate the excess material.

Reference Signs List 1 duct members 2, 3 duct body 2e, 3e ends 2s, 3s channel space 20, 21, 30, 31 opening end 4 base 42, 43 constricted portion 5 hollow portion 5h blow hole 5p excess wall 5s internal space 6, 60 , 61, 62 Reinforcing portion 6h Screw hole

Claims (1)

A blow-molded duct member comprising a duct body having a flow channel space serving as a fluid passage,
a hollow portion having an internal space independent of the channel space;
a plate-like constricted portion that connects the hollow portion and an outer periphery near the open end of the duct body,
Furthermore, the surplus material of the duct body that constitutes the flow passage space has surplus material protruding toward the internal space through the constricted portion.
duct member.

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