JP2010144560A - Duct made of resin and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a duct and resonator made of resins and a manufacturing method therefor capable of easily forming a water drain hole by eliminating the need for a slide core and post-processing. <P>SOLUTION: Recessed portions 35, 42 are formed in advance on welded rib surfaces of a pair of divided members 3, 4 made of resins forming a duct 1 and a resonator 2, and the water drain hole 5 that makes the internal communicate with the external is formed from the recessed portions 35, 42 when they are welded. The recessed portions 35, 42 eliminate the need for a slide core during molding of the divided members 3, 4 so that they can easily be formed, thus bringing mold die costs in line. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin duct such as an air intake duct of an automobile and a manufacturing method thereof, and more particularly to a resin duct formed by welding a plurality of divided bodies to each other and a manufacturing method thereof.

  The intake duct of an automobile is a cylindrical part that connects an intake port and an air filter device. If this intake duct has a simple shape, it is generally manufactured by blow molding from a thermoplastic resin. However, since a resonator and a side branch for reducing intake noise are attached, and the space in the engine room is restricted by various devices in recent years, the shape of the intake duct is complicated. Therefore, a mainstream is a manufacturing method in which a plurality of divided bodies are formed by injection molding or the like and welded together to form a cylindrical intake duct. With this method, a box-shaped halved body is formed integrally with the divided body that forms part of the duct, and the resonator and side branch that are integrated with the duct body can be easily formed by welding the halved bodies together. Can be formed.

By the way, since outside air directly enters the intake duct, moisture in the air may enter, and water may accumulate at the lowermost part during use. When this water flows into the air filter, various problems occur such as the filter function of the filter being impaired. Therefore, a water drain hole is generally formed at the lowermost portion of the intake duct. For example, Japanese Utility Model Laid-Open No. 02-001460 discloses a vehicle intake pipe having an upper end of a hermetic housing arranged in a vertical posture on the pipe wall of a downward bent portion of the intake pipe and a drain hole provided at the lower end of the hermetic housing. Are listed.
Japanese Utility Model No.02-001460 microfilm

  However, when the drain hole as described in the above-mentioned patent document is formed by molding, there is a problem that the mold cost is high because a slide core is often required. Further, there is a method of forming a drain hole by post-processing after molding, but there is a problem that the number of post-processing steps increases.

  This invention is made | formed in view of such a situation, and makes it the subject which should be solved to set it as the structure which can form a drain hole easily without requiring a slide core and post-processing.

  A feature of the resin duct of the present invention that solves the above problems is a resin duct in which a plurality of divided bodies are welded to each other. It has a closed portion formed by welding the weld surfaces, and the closed portion has a drain hole that is formed by a recess formed in advance in the weld surface and communicates the inside and the outside.

  Further, the resin duct manufacturing method of the present invention is characterized in that a plurality of divided bodies are respectively formed, weld ribs are formed in at least one of the divided bodies, and the weld ribs are melted and welded to other divided bodies. A method of manufacturing a resin duct, in which a recess is formed in a part of the welding rib at a position which is a lower position when the resin duct is used, so that the welding rib is divided, and the inside and outside are communicated from the recess remaining after the welding. The purpose is to form a drain hole.

  According to the resin duct of the present invention, the portion that is in the lower position when the resin duct is used has a closed portion formed by welding the welding surfaces of the pair of divided bodies to the closed portion. Is formed with a recess formed in advance on the welding surface, and is formed with a drain hole that communicates the inside and the outside. The welding surface is formed by the mold surface of the mold when each divided body is molded, and the concave portion can also be formed by the mold surface of the mold, so that the concave portion can be formed without using the slide core.

  And since a drain hole can be formed from a recessed part simultaneously with welding a pair of division body, a drain hole can be formed without a slide core and post-processing, and it can manufacture cheaply. Moreover, since the metal mold | die which shape | molds a division body can form a recessed part only by building up a part of concave mold surface which forms the welding surface of the conventionally used metal mold | die, the increase in mold cost can also be suppressed.

  It is desirable that the divided body has a welding flange on the outer periphery, a welding rib is formed on the welding flange, the closing portion is formed by welding the welding rib, and the welding rib has a recess in the closing portion. In this way, it is not necessary to change the outer shape of the divided body, and the drainage hole is hardly visible from the outside.

  And according to the manufacturing method of the resin-made duct of this invention, a drain core can be formed without a slide core and post-processing, and it can manufacture cheaply, suppressing the increase in metal mold | die cost.

  The resin duct of the present invention is formed by welding a plurality of divided bodies to each other. The number of divided bodies is required at least two, and there is no restriction on the upper limit of the number. In general, two is sufficient. The resin species is not particularly limited as long as it is a thermoplastic resin that can be welded.

  The resin duct of the present invention has a closed portion formed by welding the welding surfaces of a pair of divided bodies at a position which is a lower position during use. Here, the part that is the lower position when in use is a resin duct in which a resonator and a side branch are integrally formed, such as a lower part of a bent part of a resin duct that extends vertically downward and then bends to the right or left. If there is, it is the part where the internal water accumulates, such as the resonator and the lower end of the side branch.

  The closing part has a drain hole made of a concave portion formed in advance on the welding surface and communicating inside and outside. Since the welding surface is formed by the mold surface of the mold, the concave portion is also formed simultaneously with the formation of the divided body. In order to form the recess, it is only necessary to build up the concave mold surface that molds the welding surface of the mold. Can do.

  The welding surface can be, for example, a parting surface of a divided body. That is, the resin duct of the present invention can be manufactured by welding the split surfaces of the pair of divided bodies using a hot plate welding method or a vibration welding method. In this case, the concave portion can be formed by recessing the surface of the parting surface into a concave shape, or by cutting out a part of the parting surface.

  For example, recesses having a semicircular cross section are formed on the mold dividing surfaces of the pair of divided bodies, and the drain holes are formed by welding the periphery of the recesses. Moreover, the half cylinder part (recessed part) connected with the inside of a duct may be formed in the parting surface of a pair of division body, and a half cylinder part can be welded and it can also be set as a drain hole.

  However, in these methods, a drain hole is conspicuous from the outside, and a design problem occurs. Further, when the semi-cylinder part is formed, the cylindrical part protrudes from the duct body, so that the outer shape is increased by that amount, and the arrangement space in the engine room may be restricted.

  Therefore, it is desirable that the divided body has a welding flange on the outer periphery, a welding rib is formed on the welding flange, the closing portion is formed by welding the welding rib, and the concave portion is formed on the welding rib. That is, it is desirable to form a recess in a part of the welding rib to divide the welding rib at a position that is a lower position when the resin duct is used, and to form a drain hole that communicates the inside and the outside from the recess remaining after welding. . If the recess is formed in the welding rib, the drainage hole is formed between the pair of welding flanges in the resin duct obtained, and is not conspicuous because it is hidden by the welding flange. Further, since the outer shape of the resin duct is the same as the conventional one, design problems are also avoided.

  Hereinafter, the present invention will be described specifically by way of examples.

Example 1
FIG. 1 shows a side view of the intake duct of this embodiment. The intake duct includes a tubular duct body 1 having an intake port 10 and a connection port 11 connected to an air filter device, and two resonators 2 communicating with the duct body 1 through a neck portion 20. The intake duct is formed by welding a first divided body 3 made of PP and a second divided body 4 also made of PP. As shown in FIG. 1, this intake duct is assembled to a vehicle in a vertically placed state in the vertical direction, and a closed portion 12 is formed at the lowermost part of the duct body 1 and the lowermost part of the resonator 2. In the blocking part 12, drain holes 5 are formed to communicate between the inside and the outside.

  FIG. 2 shows a plan view of the first divided body 3. The first divided body 3 includes a duct body portion 30 and a resonator portion 31, and the resonator portion 31 communicates with the duct body portion 30 by a divided neck portion 32. As shown in an enlarged view in FIG. 3, a plate-shaped welding flange 33 is formed on the entire periphery of the periphery of the duct main body 30, the resonator unit 31, and the divided neck portion 32. A plate-like welding rib 34 is formed on the plate. A welding surface indicated by hatching in FIG. 2 is formed on the tip surface of the welding rib 34. As shown in FIG. 4, a welding flange 40 having the same welding rib 41 is also formed in the second divided body 4.

  As shown in an enlarged view in FIG. 3, recesses 35 in which the welding ribs 34 are divided are formed at three portions corresponding to the blocking portion 12. As shown in FIG. 4, concave portions 42 are also formed at corresponding positions of the second divided body 4.

  In order to manufacture the intake duct of the present embodiment, first, the first divided body 3 and the second divided body 4 are respectively formed by injection molding. The welding ribs 34 and 41 and the recesses 35 and 42 are also formed simultaneously with the formation of the first divided body 3 and the second divided body 4. At this time, since the concave portions 35 and 42 do not have undercuts in the mold opening direction, a slide core or the like is not required, the number of molding steps is small, and an increase in mold cost is prevented.

  Next, the first divided body 3 and the second divided body 4 are set in a hot plate welding machine, the tips of the welding rib 34 and the welding rib 41 are melted by a hot plate welding method, and then pressed toward each other to be welded. The ends of the rib 34 and the welding rib 41 are welded together. Thereby, the intake duct of the present embodiment is manufactured.

  In the obtained intake duct, as shown in FIG. 4, a drain hole 5 is formed by a recess 35 and a recess 42. The drain hole 5 communicates the inside and outside of the intake duct, and the water accumulated in the intake duct is discharged from the drain hole 5. Some burrs 50 are formed in the drain hole 5 at the time of welding, but the recess 35 and the recess 42 have a sufficient length in the length direction of the welding ribs 34 and 41. Does not affect sex. Further, since the drain hole 5 is formed between the pair of welding flanges 33 and 40, it is hard to be visually recognized from the outside and is excellent in design.

  Furthermore, according to the air intake duct and the manufacturing method thereof of the present embodiment, the recesses 35 and 42 can be formed only by building up a part of the concave mold surface for forming the welding ribs 34 and 41 formed on the mold surface of the mold. Since the outer shape can be the same as that of the conventional intake duct, an increase in mold cost can be suppressed. .

(Example 2)
The intake duct of the present embodiment is the same as the embodiment except that the shape of the welding ribs 34 and 41 formed in the first divided body 3 and the second divided body 4 is different. Therefore, only different parts will be described with reference to the drawings. Further, parts having the same functions as those in the first embodiment are given the same reference numerals as those in the first embodiment.

  As shown in FIG. 5, the welding ribs 34 and 41 have a rib shape that is narrower and higher in height than the first embodiment. On the inner and outer peripheries of the welding ribs 34 and 41, inner peripheral ribs 37 and 43 and outer peripheral ribs 38 and 44 having a height lower than that of the welding ribs 34 and 41, the welding ribs 34 and 41 are spaced apart from the welding ribs 34 and 41, respectively. Are formed in parallel. Further, at the lowermost part of the portion corresponding to the blocking part 12 and the lowermost part of each resonator part 31, there are recessed parts 35, 42 in which welding ribs 34, 41, inner peripheral ribs 37, 43 and outer peripheral ribs 38, 44 are divided. Is formed.

  In order to manufacture the intake duct of the present embodiment, first, the first divided body 3 and the second divided body 4 are first formed. The welding ribs 34 and 41, the inner peripheral ribs 37 and 43, the outer peripheral ribs 38 and 44, and the recesses 35 and 42 are also formed simultaneously with the formation of the first divided body 3 and the second divided body 4. At this time, since the concave portions 35 and 42 do not have undercuts in the mold opening direction, a slide core or the like is not required, the number of molding steps is small, and an increase in mold cost is prevented.

  Next, the 1st division body 3 and the 2nd division body 4 are set to a hot plate welding machine, and the front-end | tip (welding surface) of the welding rib 34 and the welding rib 41 is welded by the hot plate welding method. Thereby, the intake duct of the present embodiment is manufactured. As shown in FIG. 6, the amount of crushing of the welding rib 34 and the welding rib 41 is regulated by the inner circumferential rib 37 and the inner circumferential rib 43 coming into contact with each other and the outer circumferential rib 38 and the outer circumferential rib 44 coming into contact with each other. Stable welding is performed. Further, the recess 35 and the recess 42 form a drain hole 5.

  According to the intake duct of the present embodiment, in addition to the same effects as those of the first embodiment, the burrs generated in the welded portion are hidden by the outer peripheral ribs 38 and 44, so that the appearance quality is further improved. Moreover, by adjusting the height of the inner peripheral ribs 37 and 43 and the outer peripheral ribs 38 and 44, the cross-sectional area of the recess 5 can be adjusted with high dimensional accuracy, the water drainage can be adjusted, and the sound absorption characteristics of the resonator 2 can be adjusted. It is also possible to do.

(Example 3)
In the above embodiment, the concave portion is formed by dividing the welding rib. However, as shown in FIGS. 7 and 8, the shape of the welding flanges 33 and 40 located at the lowermost portion is curved or semi-cylindrical. The recesses 35 and 42 can also be formed.

  In the above embodiment, the present invention is applied to the intake duct. However, the resin duct of the present invention is not limited to the intake duct, and any duct that requires drainage can be applied.

It is a side view of the air intake duct which concerns on one Example of this invention. It is a top view of the 1st division object used for the air intake duct concerning one example of the present invention. It is a principal part expansion perspective view of the 1st division body used for the air intake duct which concerns on one Example of this invention. It is explanatory sectional drawing which shows the manufacturing method of the air intake duct which concerns on one Example of this invention. It is a principal part expansion perspective view of the 1st division body used for the air intake duct which concerns on the 2nd Example of this invention. It is a principal part expansion perspective view of the intake duct which concerns on 2nd Example of this invention. It is a principal part expansion perspective view of the 1st division body used for the air intake duct which concerns on the 3rd Example of this invention. It is a principal part expansion perspective view of the 1st division body used for the air intake duct which concerns on the 3rd Example of this invention.

Explanation of symbols

1: Duct body 2: Resonator 3: First divided body 4: Second divided body 5: Drain hole 12: Blocking portion
30: Duct body 31: Resonator 32: Split neck
33: Weld flange 34: Weld rib 35: Recess

Claims (4)

  A resin duct in which a plurality of divided bodies are welded to each other, and a closed portion formed by welding a pair of welded surfaces of the divided bodies to a lower position when the resin duct is used The resin duct is characterized in that the closed portion has a drain hole formed of a recess formed in advance on the welding surface and communicating between the inside and the outside.   The divided body has a welding flange on an outer periphery, a welding rib is formed on the welding flange, the closing portion is formed by welding the welding rib, and the concave portion is formed on the welding rib. Item 2. A resin duct according to Item 1.   The resin-made duct according to claim 1, wherein the blocking portion is formed in a resonator. A method of manufacturing a resin duct by forming a plurality of divided bodies, forming weld ribs in at least one divided body, and melting the weld ribs and welding them to other divided bodies,
A concave portion is formed in a part of the welding rib to divide the welding rib at a portion that is in a lower position when the resin duct is used, and a water drain hole that communicates the inside and outside from the concave portion remaining after welding is formed. A method for manufacturing a resin duct, which is characterized.

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