JP2020056329A - Manufacturing method of composite duct, and composite duct - Google Patents

Abstract

To provide a technique for integrating a pipe body to an air intake duct and saving a space for the integrated component.SOLUTION: The present invention relates to a manufacturing method of a composite duct comprising an air intake duct 3 which is constituted of a first duct split body 1 and a second duct split body 2 that are joined and integrated, and in which an air flow passage 35 is defined inside. The manufacturing method of the composite duct includes: a first molding step of injection-molding the first duct split body 1; a second molding step of injection-molding the second duct split body 2; and a junction step of joining and integrating the first duct split body 1 and the second duct split body 2. In the first molding step, a hollow first pipe body 50 which is integrated on an outer peripheral surface of the first duct split body 1 is injection-molded integrally with the first duct split body 1 by a fluid-assist molding method.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a composite duct having an intake duct for a vehicle, and to the composite duct.

  The air intake duct for a vehicle has an air flow path defined inside and is disposed in a limited space of the vehicle. Since various in-vehicle members are disposed near the intake duct, attempts have been made to integrate a part of the in-vehicle members into the intake duct in order to save space in the intake duct and the in-vehicle members.

As part of this kind of attempt, a technique has been proposed in which a pipe disposed near the intake duct is fixed to the intake duct.
For example, in Patent Document 1, a fuel pipe holding section (35) is formed integrally with an intake passage member (30), and a fuel pipe (50) connected to an internal combustion engine (12) is connected to the fuel pipe holding section (35). ) Has been proposed.
Further, Patent Literature 2 proposes a technique in which a resonator clamp portion 3h is formed integrally with an upper cylindrical portion 3a of an air cleaner outlet hose 3, and an intermediate portion 6c of the resonator 6 is fixed by the resonator clamp portion 3h. .

  According to the techniques introduced in Patent Documents 1 and 2, in order to integrate a pipe, that is, a fuel pipe (50) and a resonator 6 into an intake duct, that is, an intake passage member (30) and an air cleaner outlet hose 3. In addition, a fastening part such as the fuel pipe holding part (35) and the resonator clamp part 3h is required. Therefore, these techniques have room for improvement from the viewpoint of saving space and reducing the number of parts.

JP 2016-44668 A JP-A-11-132122

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a technique for integrating a pipe into an intake duct and saving space for the integrated product.

The method for producing a composite duct of the present invention that solves the above-mentioned problems,
A method of manufacturing a composite duct having an intake duct, which is constituted by a first duct divided body and a second duct divided body that are joined and integrated, and has an air duct defined inside,
A first molding step of injection molding the first duct split, a second molding step of injection molding the second duct split, and joining and integrating the first duct split and the second duct split; And a bonding step of
In the first molding step, a hollow first pipe integrated with the outer peripheral surface of the first duct divided body is injection-molded integrally with the first duct divided body by a fluid assist molding method. This is a method for manufacturing a duct.

The composite duct of the present invention that solves the above problems,
An intake duct composed of a first duct divided body and a second duct divided body that are joined and integrated, and an air flow path is defined inside;
And a hollow first pipe integrally injection-molded on the outer peripheral surface of the first duct divided body.

Further, according to the method for manufacturing a composite duct of the present invention, it is possible to provide a composite duct in which a pipe is integrated with an intake duct to save space.
The composite duct of the present invention is a composite duct in which a pipe is integrated with an intake duct to save space.

FIG. 2 is a perspective view schematically illustrating the composite duct of the first embodiment. FIG. 2 is a cross-sectional view schematically illustrating a state in which the composite duct of Example 1 is cut at a position AA in FIG. 1. It is a principal part expanded sectional view which represents typically the 1st duct division body and the 2nd duct division body in the composite duct of Example 1 before a joining process. It is a principal part expanded sectional view which represents typically the 1st duct division body and the 2nd duct division body in the composite duct of Example 1 after a joining process. It is explanatory drawing explaining the 1st shaping | molding process by a water assist shaping | molding method. It is explanatory drawing explaining the 1st shaping | molding process by a water assist shaping | molding method. It is a principal part expanded sectional view which shows typically the 1st duct division body and the 2nd duct division body in the composite duct of Example 2 before a joining process. It is a principal part expanded sectional view which represents typically the 1st duct division body and the 2nd duct division body in the composite duct of Example 2 after a joining process. It is sectional drawing which represents typically the mode which cut | disconnected the composite duct of the modification in the same position as the AA position in FIG.

  In the composite duct manufactured by the method for manufacturing a composite duct of the present invention, the intake duct includes a first duct divided body and a second duct divided body, and the first duct divided body includes a hollow first pipe body. It is integrally injection molded. By doing so, the hollow first pipe body can be integrated with the intake duct without requiring a structure such as a fastening portion. That is, the composite duct manufactured by the method for manufacturing a composite duct of the present invention is space-saving because it has no fastening portion.

The method for manufacturing a composite duct according to the present invention includes a step of injection-molding each of the one-duct divided body and the second duct-divided body (that is, a first molding step and a second molding step). Then, the first tubular body is injection-molded integrally with the first duct divided body.
By doing so, the above-described composite duct can be manufactured.

  Further, according to the method for manufacturing a composite duct of the present invention, there is also an advantage that a composite duct having an excellent degree of freedom in shape can be manufactured by injection molding the intake duct and the first pipe.

That is, as a method of integrating the intake duct and the first pipe, a method of forming the intake duct and the first pipe by a blow molding method and integrating them into a composite duct is generally used.
However, since the blow molding method is a molding method having a relatively low degree of freedom in molding, according to the molding method, only a molded article having a relatively low degree of freedom in shape can be obtained. Therefore, it is difficult to say that the molding method is suitable as a method for manufacturing a composite duct for a vehicle mounted in a limited space.

  As described above, in the method for manufacturing a composite duct of the present invention, the first duct divided body, the first pipe body, and the second duct divided body are molded by an injection molding method having a high degree of freedom in molding. According to such a method of manufacturing a composite duct of the present invention, it is possible to manufacture the composite duct of the present invention having a high degree of freedom in shape, and to further reduce the space of the composite duct of the present invention. .

  Further, by forming the first duct divided body, the first pipe body, and the second duct divided body by the injection molding method, for example, it is possible to control the thickness of the intake duct with high accuracy, or to integrate a reinforcing rib or the like into the intake duct. There is also an advantage that it can be molded.

  Further, in the method of manufacturing a composite duct of the present invention, the first duct divided body and the first pipe are integrally formed by using the fluid assist molding method among the injection molding methods. According to the fluid assist molding method, there is an advantage that a tube having a three-dimensional shape, for example, a complicated curved shape can be relatively easily molded. Details of the fluid assist molding method will be described later.

  Since the composite duct of the present invention is obtained by integrally molding the first duct divided body and the first pipe body by the injection molding method, the degree of freedom of the shape is high and the space is further reduced. Since the first duct divided body and the first pipe body are injection-molded, as described above, the advantage is that the thickness of the intake duct can be controlled with high accuracy, and the reinforcing ribs and the like can be integrally formed with the intake duct. There is also.

Hereinafter, the method for manufacturing a composite duct and the composite duct of the present invention will be described in detail.
First, a composite duct manufactured by the method for manufacturing a composite duct of the present invention is integrated with an intake duct composed of a first duct divided body and a second duct divided body, and on an outer peripheral surface of the intake duct. And a hollow first tube. The composite duct is not limited to one having only one first tube, and may have another tube such as a second tube or a third tube. The other pipes may be integrated with the outer peripheral surface of the first duct split like the first pipe, or may be integrated with the outer peripheral face of the second duct split.

  In any case, since the first duct divided body and the first pipe body are integrally formed by a fluid assist molding method, which is a kind of injection molding method, the first duct divided body and the first pipe body are firmly integrated, and the fastening portion is formed. It is space-saving because it is unnecessary.

  In the method for manufacturing a composite duct of the present invention, the first duct divided body and the first pipe are injection-molded in a first molding step, and the second duct divided body is injection-molded in a second molding step. When the composite duct of the present invention includes a pipe other than the first pipe, that is, another pipe, the other pipe is provided on the outer peripheral surface of the first duct divided body in the first forming step with the first duct. What is necessary is just to carry out injection molding integrally with a division body. Alternatively, the other pipe may be injection-molded integrally with the second duct divided body on the outer peripheral surface of the second duct divided body in the second molding step.

  The method for manufacturing a composite duct of the present invention includes a joining step of joining and integrating the first duct divided body and the second duct divided body. The joining step can be performed after the first molding step and the second molding step for the purpose of joining the first duct divided body obtained in the first molding step and the second duct divided body obtained in the second molding step. .

  In the joining step, the first duct divided body and the second duct divided body may be joined by any method. As a joining method of the first duct divided body and the second duct divided body, a method such as welding, adhesion, engagement, fitting and the like can be exemplified.

  Among these, when the first duct divided body and the second duct divided body are joined by welding or bonding, it is only necessary to join the joint surfaces of both directly or via an adhesive, so that the composite duct is more space-saving. Can be

  In the case where the first duct divided body and the second duct divided body are joined by engagement or fitting, an engaging portion and a fitting portion are required in addition to the joint surface of the two. For this reason, considering the space saving of the composite duct, in the joining step, it is preferable to join the first duct divided body and the second duct divided body by welding or bonding.

  Considering the workability of the joining step, it is preferable to employ welding as the joining method. Specific methods of welding include vibration welding, ultrasonic welding, hot plate welding, and the like.

  The material of the first duct divided body, the first pipe body and the second duct divided body is not particularly limited as long as it is a material that can be injection-molded, and may be appropriately selected according to the purpose of use of the composite duct. It is preferable to employ a resin. Examples of the thermoplastic resin include polyethylene resin, polypropylene resin, acrylonitrile butadiene styrene resin, acrylic resin, polyamide resin, polycarbonate resin, and polyethylene terephthalate resin.

  When the above-mentioned thermoplastic resin or elastomer is used as a material of the first duct divided body, the first pipe body, and the second duct divided body, auxiliary materials represented by various fillers may be further blended.

  As described above, in the method for manufacturing a composite duct of the present invention, an injection molding method is used in the first molding step and the second molding step. The injection molding method according to the present invention means that a molten or softened material (hereinafter, referred to as a molten material as necessary) is injected into a cavity of a molding die, cured, and formed into a shape corresponding to the mold surface of the cavity. That is, it means a method of applying to the first duct divided body and the first pipe or the second duct divided body. The injection molding method is a concept including a fluid-assisted molding method in which a fluid such as gas or water is further injected into a cavity into which a molten material is injected to obtain a hollow-shaped molded body, an extrusion molding method, and the like.

  According to the fluid assist molding method, the first duct divided body and the hollow tubular body can be molded simultaneously, and there is an advantage that a curved three-dimensional tubular body can be easily formed.

  In the method for manufacturing a composite duct of the present invention, at least the first molding step may use the fluid-assisted molding method, and the second molding step may use the fluid-assisted molding method or injection molding other than the fluid-assisted molding method. Method may be used. When a hollow tube such as the second tube is integrally molded with the second duct divided body as described above, it is preferable that the second molding step also uses the fluid assist molding method.

  By the way, in the method for manufacturing a composite duct of the present invention, the first forming step is performed by a fluid-assisted forming method. Therefore, the materials of the first duct divided body and the first pipe body are the same. Hereinafter, as necessary, the materials of the first duct divided body and the first pipe body are referred to as a first material, and the material of the second duct divided body is referred to as a second material.

  The first material and the second material may be appropriately selected according to the use of the composite duct. However, when the joining step by welding is performed, materials that can be welded to each other as the first material and the second material, that is, It is necessary to select a soluble material. Further, it is preferable to select a material suitable for the fluid used for the fluid assist molding at least for the first material. For example, when performing water-assist molding using water as a fluid as the first molding step, it is preferable to use a resin material that is not easily hydrolyzed as the first material, and it is preferable to use a polyamide resin.

By the way, the polyamide resin is basically hardly hydrolyzed, but may be hydrolyzed when exposed to water at a high temperature for a long time. For this reason, depending on the use of the composite duct, a general polyamide resin such as PA6 may not satisfy the durability. The use of the composite duct is specifically when the first pipe is used as a pipe for a relatively high-temperature aqueous medium such as a cooling hose for a vehicle.
When the composite duct is used for such a purpose, it is preferable to use PA66 (also referred to as nylon 66 or nylon 6/6) and PA612 (also referred to as nylon 612 or nylon 6/12) as the first material. PA66 and PA612 are both types of polyamide resins. Since PA66 is excellent in strength and PA612 is excellent in water resistance, by using them together, it is possible to impart to the first duct divided body and the first tube body characteristics that are hardly hydrolyzed at the time of production and use, and water assist molding Excellent durability can be imparted to the first duct divided body and the first pipe obtained by the above.

  The first material used in the first molding step may be composed of only PA66 and PA612, but may include other materials. The other materials are auxiliary materials represented by the above-mentioned various fillers. For example, by mixing glass fiber or carbon fiber with the first material, the strength of the first duct divided body and the first pipe body can be further improved.

  The second material may be selected according to the first material. For example, when welding the first duct divided body and the second duct divided body, and when the first material includes a polyamide resin, a polyamide resin is also selected as the second material in consideration of mutual compatibility. Is preferred.

As the second material, the same material as the first material may be used, or a different material may be used. For example, when the first material includes PA66 and PA612, as the second material, the same material including PA66 and PA612 as the first material may be selected, or PA66 or PA612 used as the first material may be used alone. Alternatively, a polyamide resin different from the first material such as PA6 may be used.
Also in this case, the compatibility between the first material and the second material is sufficiently high, and the first duct divided body and the second duct divided body can be sufficiently firmly integrated. If a second material that is cheaper than the first material is used, there is also an advantage that the manufacturing cost of the composite duct can be reduced.

  When the second pipe or the like is integrally provided on the outer peripheral surface of the second duct divided body, it is preferable that the second duct divided body and the second pipe be integrally injection-molded. As the injection molding method, it is preferable to select the above-mentioned fluid assist molding method, and as the second material, select a material containing PA66 and PA612, which is the same as the first material, or use the first material. It is preferable to use PA66 or PA612 alone.

  Further, for example, when bonding the first duct divided body and the second duct divided body, an adhesive is selected that can firmly bond both according to the material of the first duct divided body and the material of the second duct divided body. Just do it. In this case, not only polyamide resin but also various other materials can be selected as the second material constituting the second duct divided body.

  By the way, when the first duct divided body and the second duct divided body are welded, especially when they are welded by vibration welding or ultrasonic welding, the shape of the joint surface of the two is optimized, and thus the first duct divided body and the second duct divided body are optimized. The duct divided body and the second duct divided body can be more firmly integrated.

  Specifically, a joint surface between the first duct divided body and the second duct divided body (hereinafter, referred to as a first joint surface as necessary) and a joint between the second duct divided body and the first duct divided body. One (hereinafter, referred to as a second bonding surface as necessary) is narrower than the other. As the resin material included in one of the narrow widths, a resin material having a higher melting point than the resin material included in the other is used.

  By doing so, the timing at which the first bonding surface melts or softens can be matched with the timing at which the second bonding surface melts or softens, and the bonding portion where the first bonding surface and the second bonding surface are sufficiently melted Can be formed. In such a joint portion, the first duct divided body and the second duct divided body can be welded and integrated with high strength. In this case, the first duct divided body and the second duct divided body are further combined. It can be said that it can be firmly integrated.

  Hereinafter, assuming that the second bonding surface is a narrow bonding surface, the reason why the timing of melting or softening the first bonding surface and the second bonding surface matches will be described. In the present specification, the width of the bonding surface means a length in a direction orthogonal to the longitudinal direction of the bonding surface. The longitudinal direction of the joining surface may be referred to as the direction in which the joining surface extends.

First, the first joint surface, which is a part of the first duct split, is made of the material of the first duct split, that is, the first material. Similarly, the second joint surface that is a part of the second duct split is made of the material of the second duct split, that is, the second material.
If the melting point of the resin material included in the first material is the same as the melting point of the resin material included in the second material, the first bonding surface and the second bonding surface are considered to melt or soften at substantially the same temperature. . Therefore, when the first duct divided body and the second duct divided body can be made of the same material, if the first joint surface and the second joint surface have the same shape, there is no particular problem and the first joint surface and the second joint surface can be formed. It is considered that the joint surface can be melted or softened at the same timing, and the first duct divided body and the second duct divided body can be welded and integrated with high strength.

  However, when the first duct divided body and the second duct divided body are made of different materials for some reason, it is difficult to melt or soften the first joint surface and the second joint surface having the same shape at the same timing. Become. For example, when a resin material having a high melting point is used as the second material of the second duct divided body, the second joint surface melts or softens later than the first joint surface.

When the first duct divided body and the second duct divided body are made of different materials as described above, and a high melting point resin material is used as the second material, the second joint surface is narrower than the first joint surface. By doing so, the melting or softening timing of the second bonding surface can be advanced, and the melting or softening timing of the first bonding surface and the second bonding surface can be matched.
Alternatively, by making the second joint surface narrower than the first joint surface, the specific surface area of a portion near the second joint surface in the second duct divided body is increased, and the volume and mass of the portion are substantially reduced. It may be said that the size is reduced and heat is applied to the second duct divided body efficiently to accelerate the melting or softening timing of the second joint surface.
Alternatively, by reducing the amount of the portion near the second joining surface in the second duct divided body with respect to the amount of the portion near the first joining surface in the first duct divided body, the portion is melted or softened. It can be said that the total amount of heat energy required for the second bonding surface is reduced, and the timing of melting or softening the second bonding surface is advanced. Here, the “amount” refers to the volume or mass of the portion.

  The width of the second bonding surface is not particularly limited as long as it is smaller than the width of the first bonding surface. For example, the width of the second bonding surface is 70% or more of the width of the first bonding surface. It is preferably at most 80%. If the width of the first joint surface and the second joint surface is within the above range, sufficient welding strength can be obtained.

  The composite duct of the present invention has an intake duct in which a first duct divided body and a second duct divided body are joined and integrated, and a hollow first tubular body. The first pipe body is integrated with the outer peripheral surface of the first duct divided body in the intake duct by being injection-molded integrally with the first duct divided body. The outline of the composite duct of the present invention is as described in the above-described method of manufacturing the composite duct of the present invention.

  In the composite duct manufacturing method of the present invention, both the first duct divided body and the second duct divided body are injection-molded, but the second divided body in the composite duct of the present invention is formed by injection molding. However, the present invention is not limited to this, and may be formed by an extrusion molding method or the like.

  Hereinafter, the composite duct of the present invention will be described with reference to specific examples.

(Example 1)
The composite duct of the first embodiment has an intake duct, a first pipe, and a second pipe. Among them, the intake duct is an air duct connecting the turbocharger of the vehicle and the intercooler, and the first pipe and the second pipe are cooling water ducts for the intercooler. Therefore, air flows through the intake duct, and a long life coolant mainly composed of water flows through the first pipe and the second pipe.

  FIG. 1 is a perspective view schematically illustrating the composite duct of the first embodiment, and FIG. 2 is a cross-sectional view schematically illustrating a state where the composite duct of the first embodiment is cut along a line AA in FIG. . In addition, FIGS. 3 and 4 are enlarged cross-sectional views of main parts schematically showing the first duct divided body and the second duct divided body in the composite duct of the first embodiment. 3 shows the first and second duct divisions before the joining step, and FIG. 4 shows the first and second duct divisions after the joining step. FIG. 5 and FIG. 6 are explanatory views illustrating a first molding step by the water assist molding method.

  In each of the following embodiments and modifications, the “longitudinal direction of the intake duct” and “upper and lower” mean the longitudinal direction of the intake duct shown in FIG. 1 and upper and lower portions.

  As shown in FIG. 1, the composite duct of the first embodiment includes an intake duct 3, a first pipe 50, and a second pipe 55. The intake duct 3 is formed by welding and integrating the first duct split 1 and the second duct split 2, and the first pipe 50 and the second pipe 55 are integrated with the outer peripheral surface of the first duct split 1. Has been Hereinafter, the integral part of the first duct divided body 1, the first tubular body 50, and the second tubular body 55 will be referred to as a first divided body 17 as necessary.

  The intake duct 3 has a curved cylindrical shape having two duct openings 30 and 31. An air passage 35 (see FIG. 2) is defined inside the intake duct 3, one duct opening 30 serves as an air inlet for air from the outside to the air passage 35, and the other duct opening 31 serves as an air inlet. It serves as an outlet for air from the flow path 35 to the outside.

  The intake duct 3 is divided into two divided bodies. The first duct divided body 1, which is one of the divided bodies, has a first tubular body 50 and a second tubular body 55 integrally. A second duct divided body 2 as the other divided body constitutes a portion of the intake duct 3 other than the first duct divided body 1. Each of the two duct openings 30 and 31 of the intake duct 3 is included in the second duct divided body 2. The shape of the first duct divided body 1 can also be said to be a shape in which a part of the upper part of the intake duct 3 is cut off in a part of the intake duct 3 in the longitudinal direction.

  The first duct divided body 1 has a first flange portion 10 which is a portion to be joined to the second duct divided body 2. The first flange portion 10 is provided over the entire periphery of a joint portion between the first duct divided body 1 and the second duct divided body 2. As shown in FIG. 2, the first flange portion 10 has a first joint portion 11 that joins with the second duct divided body 2. The first joint portion 11 has a rib shape protruding downward. The lower surface of the first joint portion 11 forms a first joint surface 15.

  The first tubular body 50 and the second tubular body 55 have substantially the same shape and have a cylindrical shape smaller than the intake duct 3. The first tubular body 50 has two first tubular body openings 51 and 52 that open further upward than the first duct divided body 1. The second pipe 55 also has two second pipe openings 56, 57 that open further above the first duct split 1. The first tube 50 and the second tube 55 have refrigerant channels 53 and 58 inside, respectively. One of the first tube openings 51 of the first tube 50 and one of the second tube openings 57 of the second tube 55 serve as an inlet for the refrigerant from the outside to the refrigerant flow paths 53 and 58. . The other first tube opening 52 of the first tube 50 and the other second tube opening 56 of the second tube 55 serve as an outlet for the refrigerant from the refrigerant channels 53 and 58 to the outside.

  In addition, as shown in FIG. 2, the refrigerant flow path 53 of the first pipe 50, the refrigerant flow path 58 of the second pipe 55, and the air flow path 35 are independent of each other.

  The first duct divided body 1 has a sub pipe 18 connecting the inside and outside of the intake duct 3, in addition to the first pipe 50 and the second pipe 55. The sub-pipe 18 has one sub-opening 19 that opens further above the first duct divided body 1 and one sub-opening (not shown) that opens into the air flow path 35 inside the intake duct 3. Have. In the composite duct of the first embodiment, the sub pipe 18 is a PCV pipe for reusing unburned gas.

  The second duct divided body 2 has a second flange portion 20 which is a portion to be joined to the first duct divided body 1. The second flange portion 20 faces the first flange portion 10 and is provided over the entire circumference of a joint portion of the second duct divided body 2 with the first duct divided body 1. The second flange portion 20 has a second joint portion 21 that joins with the first joint portion 11. The second joint 21 has a rib shape protruding upward. The upper surface of the second bonding portion 21 forms a second bonding surface 25 that bonds to the first bonding surface 15.

  The second duct divided body 2 is also provided with a second sub pipe 28 connecting the inside and outside of the intake duct 3. The second sub-pipe 28 has one second sub-opening 29 that opens radially outward of the second duct divided body 2 and one second sub-opening that opens into the air passage 35 inside the intake duct 3. (Not shown).

  As shown in FIGS. 2 and 3, the second flange portion 20 further has two wall portions 23. Each wall portion 23 is provided on each of both ends in the width direction of the second joint surface 25 distant from the second joint surface 25, and extends along the longitudinal direction of the second joint surface 25. In the composite duct of the first embodiment, the height of each wall 23 is higher than the height of the second joint surface 25 before the joining step. In other words, in the composite duct of the first embodiment, the top surface of each wall 23 is above the second joint surface 25, that is, on the side of the first duct divided body 1.

Hereinafter, a method of manufacturing the composite duct of the first embodiment will be described.
The manufacturing method of the composite duct of the first embodiment includes a first forming step, a second forming step, and a joining step.

(First molding step)
The first forming step is a step of integrally forming the first duct divided body 1, the first tube 50, and the second tube 55 by a water assist molding method. In the manufacturing method of the composite duct of the first embodiment, as the first material for the first duct divided body 1, the first pipe 50, and the second pipe 55, PA66, PA612, and glass fiber have a mass ratio of 1: 1. : 1 mixed resin material was used. Among them, PA66 and PA612 are referred to as a first polyamide resin.

First, the first material was put into a molding machine for water-assist molding, and the first material was heated and softened. As the first polyamide resin contained in the first material was heated and melted, the first material was softened as a whole. The softened first material was injected (injected) from the molding machine into the cavity of the injection mold. The cavity has a mold surface corresponding to the outer shape of the first divided body 17, that is, a mold surface corresponding to the outer shape of the first duct split 1, the first tube 50, and the second tube 55. .
Next, press-in liquid (water in Example 1) was press-injected into two places of the cavity into which the softened first material was injected. The first material existing in the cavity was extruded by the press-in liquid, and a hollow portion was formed in the cavity. Thereafter, the first material in the cavity was cooled and solidified to obtain a molded body having two hollow portions, that is, a first separated body 17. Note that one of the two hollow portions formed here is the coolant channel 53 of the first tube 50, and the other of the two hollow portions is the coolant channel 58 of the second tube 55.

The water assist molding method described above will be described in more detail. FIG. 5 and FIG. 6 show how to manufacture an X region surrounded by a two-dot chain line in FIG.
First, as shown in FIG. 5, the softened first material M was injected from the fluid gate 60 into the cavity 62 of the mold 61. The cavity 62 has a main chamber 64 and a sub chamber 65 which communicate with each other via an opening / closing valve 63. At this time, the opening / closing valve 63 was in the closed state, and the first material M was filled only in the main chamber 64.

  After injecting the first material M and maintaining the pressure for a predetermined time, water W was injected into the main chamber 64 from the fluid gate 60 as shown in FIG. Then, a part of the first material M in the main chamber 64 was extruded by the water W, and a hollow portion 66 serving as the refrigerant flow path 53 of the first tube 50 was formed. When injecting the water W, it is preferable to inject the air A into the main chamber 64 before the water W in order to prevent the first material M from being rapidly cooled and solidified by the water W.

When water W was injected, the open / close valve 63 was opened, and the main chamber 64 and the sub chamber 65 were connected. Therefore, the first material M extruded by the water W flows into the sub chamber 65.
After the water W was injected, the pressure was maintained for a predetermined time, and then the injected water W was discharged from the fluid gate 60 to the outside of the cavity 62. The opening and closing of the fluid gate 60 was controlled by a gate valve (not shown).
By cooling and solidifying the first material M, an integrated product of the first duct divided body 1 and the first pipe 50 was obtained.

  In FIG. 6, the first material M located at the periphery of the hollow portion 66 has become the first tube 50 in the integrated product. In addition, the first material M located below the hollow portion 66 in FIG. 6 became the first duct divided body 1 in the integrated product.

(Second molding step)
The second molding step is a step of injection molding the second divided duct body 2. In the method of manufacturing the composite duct of Example 1, PA66, which is a second polyamide resin, was used as the second material for the second duct divided body 2. The melting point of the second polyamide resin used for the second material is higher than the melting point of the first polyamide resin used for the first material.
The second material was charged into a molding machine, and the second material was heated and melted. The molten second material was injected (injected) from the molding machine into the cavity of the injection mold. The cavity has a mold surface corresponding to the outer shape of the second duct divided body 2. Thereafter, the second material in the cavity was cooled and solidified to obtain a molded body, that is, a second duct divided body 2.

(Joining process)
The first divided body 17 obtained in the first forming step and the second duct divided body 2 obtained in the second forming step were welded.
Specifically, as shown in FIG. 3, the first split body 17 and the second duct split body 2 were positioned such that the first flange section 10 and the second flange section 20 faced each other. At this time, the first split body 17 was disposed above the second duct split body 2.

  Here, before the joining step, the second joint surface 25 of the second duct divided body 2 is narrower than the first joint surface 15 of the first duct divided body 1, and the width W2 of the second joint surface 25 is smaller than the width W2. Was about 75% of the width W1 of the first bonding surface 15. As described above, the first duct segment 1 having the first joint surface 15 is made of the first material, and the second duct segment 2 having the second joint surface 25 is made of the second material. The melting point of the second polyamide resin used for the second material is higher than the melting point of the first polyamide resin used for the first material.

  For this reason, the first flange portion 10 and the second flange portion 20 are brought into contact with each other, and a welding jig (not shown) is applied to the upper surface of the first flange portion 10 and the lower surface of the second flange portion 20, respectively. When the joint surface 15 and the second joint surface 25 are vibrated while being pressed against each other, the first joint surface 15 and the second joint surface 25 are melted almost simultaneously. Therefore, the first joint surface 15 and the second joint surface 25 are homogeneously and well melted, and as shown in FIG. 4, the joint portion 33 between the first joint surface 15 and the second joint surface 25 is firmly joined. Integrate.

  Further, as shown in FIG. 3, in the method for manufacturing the composite duct of Example 1, the second joint surface 25 before the joining step was made uneven so that the second joint surface 25 was easily melted. This is also considered to contribute to the fact that the first joint surface 15 and the second joint surface 25 are almost simultaneously melted.

By the way, the hardly hydrolyzable resin material suitably used in the water assist molding method is expensive on the other hand. For this reason, it is not preferable in terms of cost to constitute the entire composite duct with the material that is not easily hydrolyzed.
However, according to the joining process of the first embodiment, materials having melting points can be strongly joined and integrated. For this reason, a part of the composite duct including the hollow tubular body is formed by the water-assist molding method using the above-mentioned hardly hydrolyzable material, and the other part is formed by a normal injection using a relatively inexpensive normal material. What is necessary is just to shape | mold with a shaping | molding method. By doing so, according to the method for manufacturing a composite duct of Example 1, there is also an advantage that the material cost of the composite duct can be reduced.

  Further, the second flange portion 20 has two wall portions 23, and a joint portion 33 between the first joint surface 15 and the second joint surface 25 is substantially isolated from the outside by the two wall portions 23. . For this reason, the joint portion 33 between the first joint surface 15 and the second joint surface 25 is hardly affected by the outside world, and a stable joint state is maintained.

  In the first embodiment, the first pipe 53 and the second pipe 55 are used as refrigerant pipes. However, the first pipe in the method for manufacturing a composite duct of the present invention is used not only for refrigerant pipes but also for air pipes and the like. May be.

(Example 2)
The method of manufacturing the composite duct of the second embodiment and the composite duct of the second embodiment are substantially the same as the composite duct of the first embodiment except for the shapes of the first flange portion and the second flange portion.
FIGS. 7 and 8 are enlarged cross-sectional views of main parts schematically showing a first duct divided body and a second duct divided body in the composite duct of the second embodiment. FIG. 7 shows the first duct divided body and the second duct divided body of the embodiment 2 before the joining step, and FIG. 8 shows the first duct divided body and the second duct divided body of the embodiment 2 after the joining step. Represents

  As shown in FIG. 7, the lower portion of the first flange portion 10 in the composite duct of the second embodiment before the joining step has a flat shape without ribs. In the composite duct of the second embodiment, the entire lower surface of the first flange portion 10 becomes the first joint surface 15.

On the other hand, the second flange portion 20 in the composite duct of the second embodiment before the joining step does not have the wall portion 23 but has the rib-shaped second joining portion 21. The upper surface of the second joint 21 is the second joint surface 25 in the composite duct of the second embodiment. The width W2 of the second bonding surface 25 is smaller than the width W1 of the first bonding surface 15, and is about 75% of the width W1 of the first bonding surface 15.
In the method of manufacturing the composite duct of Example 2, the melting point of the second polyamide resin used as the second material is higher than the melting point of the first polyamide resin used as the first material.

  In the method for manufacturing a composite duct according to the second embodiment, the first duct divided body 1 does not have the rib-like first joint portion 11 and the first joint surface 15 is simply a flat surface, but as shown in FIG. The first split body 17 and the second duct split body 2 are positioned so that the first flange portion 10 and the second flange portion 20 face each other, and the first joint surface 15 and the second joint surface 25 are pressed against each other. When vibrating while the first joint surface 15 and the second joint surface 25 are melted almost simultaneously. Therefore, the first joint surface 15 and the second joint surface 25 are homogeneously and well fused, and as shown in FIG. 8, the joint portion 33 between the first joint surface 15 and the second joint surface 25 is firmly joined. Integrate.

  In the method of manufacturing the composite duct according to the first and second embodiments, the first segment 17 having the first duct segment 1 and the first pipe 50 is subjected to water-assist molding, and the material of the first segment 17 is used. As the first material, a resin material having a lower melting point than the second material, which is the material of the second duct split 2, is used, and the second joining surface 25 of the second duct split 2 is connected to the first duct split. 1 is smaller than the first bonding surface 15. However, in the method for manufacturing a composite duct of the present invention, the first segment 17 is subjected to water assist molding, a resin material having a higher melting point than the second material is used as the first material, and The first joint surface 15 may be narrower than the second joint surface 25 of the second divided duct body. Also in this case, the first joint surface 15 and the second joint surface 25 are substantially simultaneously melted and the first joint surface 15 and the second joint surface are melted similarly to the composite duct manufacturing method of the first and second embodiments. The composite duct in which the joint portion 33 with the 25 is firmly joined and integrated can be manufactured.

(Modification)
Hereinafter, a modified example of the composite duct of the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view schematically showing a state where the composite duct of the modified example is cut at the same position as the position AA in FIG. 1.

The modified duct shown in FIG. 9 is an example in which the first tubular body 50 and the second tubular body 55 are configured by the rectangular tubular flat portion 15 and the cylindrical general portion. The cross section of the general portion is substantially the same as the cross section of the first tube 50 and the second tube 55 shown in FIG. As shown in FIG. 9, the cross section of the flat part 15 has a flat rectangular shape whose height is lower than that of the general part.
According to the composite duct of the modified example, the first tubular body 50 and the second tubular body 55 are integrally formed with the first duct divided body 1 by a water assist molding method, so that the flat portion 15 and the cylindrical portion having a flat rectangular tubular shape are formed. And the first tubular body 50 having the flat portion 15 and the general portion can be integrally formed simultaneously with the first duct divided body 1. For this reason, the composite duct of the modified example has a high degree of freedom in shape and is suitable as a composite duct for a vehicle mounted in a limited space. The diameter and the axial length of the flat portion 15 may be appropriately set according to the requirements for mounting the composite duct on a vehicle.

  By the way, as described above, in the composite duct of the first and second embodiments, the shape of the first duct divided body 1 is such that the upper part of the intake duct 3 is partially formed in the longitudinal direction of the intake duct 3. Make a shape that has been removed. Further, the shape of the second duct divided body 2 is a substantially cylindrical shape in which a part of an upper portion is cut off and constitutes a cylindrical intake duct 3 together with the first duct divided body 1.

  However, the shapes of the first duct split and the second duct split in the composite duct of the present invention are not limited thereto. As an example, a shape in which the intake duct is divided into two in the axial direction is illustrated. In such a composite duct, the joint portion between the first duct split and the second duct split extends linearly along the axial direction of the intake duct, in other words, along the longitudinal direction of the intake duct. The first flange portion and the second flange portion also respectively extend along the longitudinal direction of the intake duct, and the first joint surface and the second joint surface similarly extend along the longitudinal direction of the intake duct.

  Even in such a composite duct, the first duct divided body can be injection-molded integrally with the first and second pipes by the water assist molding method, and the second duct divided body can be formed by the usual injection molding method. Can be molded.

Alternatively, the first duct divided body can be injection-molded integrally with the first pipe by a water-assist molding method, and the second duct divided body can be injection-molded integrally with the second pipe by a water-assisted molding method. it can.
In this case, for example, PA66 and PA612 are used for the first material that is the material of the first duct split and the first pipe, and PA66 is used for the second material that is the material of the second duct split and the second pipe. For example, the second material has a higher melting point than the first material. For this reason, if the width of the second joint surface is made smaller than the width of the first joint surface, the first joint surface and the second joint surface are joined in the same manner as in the joining step in the composite duct manufacturing method of the first and second embodiments. The surfaces can be melted at the same timing, and a composite duct in which the first joint surface and the second joint surface are firmly joined can be manufactured. Further, when both the first duct divided body and the second duct divided body each have a pipe body, both divided bodies are water-assisted with the same material, and the width of the first joint surface is set. And the width of the second joint surface may be the same. Also in this case, the first joint surface and the second joint surface can be melted at the same timing, and a composite duct in which the first joint surface and the second joint surface are firmly joined can be manufactured.

  The present invention is not limited to the embodiment described above and shown in the drawings, and can be implemented with appropriate modifications without departing from the scope of the invention. Each component shown in this specification including the embodiment can be arbitrarily extracted and combined for implementation.

1: first duct divided body 2: second duct divided body 3: intake duct 15: first joint surface 25: second joint surface 35: air flow path 50: first pipe

Claims (7)

A method of manufacturing a composite duct having an intake duct, which is constituted by a first duct divided body and a second duct divided body that are joined and integrated, and has an air duct defined inside,
A first molding step of injection molding the first duct split, a second molding step of injection molding the second duct split, and joining and integrating the first duct split and the second duct split; And a bonding step of
In the first molding step, a hollow first pipe integrated with the outer peripheral surface of the first duct divided body is injection-molded integrally with the first duct divided body by a fluid assist molding method. Duct manufacturing method.   The method for manufacturing a composite duct according to claim 1, wherein in the joining step, the first duct divided body and the second duct divided body are joined and integrated by welding. The first duct segment has a first joint surface that is a joint surface with the second duct segment,
The second duct segment has a second joint surface that is a joint surface with the first duct segment,
3. The composite according to claim 2, wherein one of the first joint surface and the second joint surface is narrower than the other and includes a resin material having a higher melting point than a resin material included in the other. Duct manufacturing method. The second bonding surface is narrower than the first bonding surface,
The material of the first duct segment and the first tube body includes a first polyamide resin, and the material of the second duct segment includes a second polyamide resin having a higher melting point than the first polyamide resin,
The method for manufacturing a composite duct according to claim 3, wherein the first polyamide resin includes PA66 and / or PA612. An intake duct composed of a first duct divided body and a second duct divided body that are joined and integrated, and an air flow path is defined inside;
And a hollow first pipe integrally formed by injection molding on an outer peripheral surface of the first duct divided body.   The composite duct according to claim 5, wherein the first duct divided body and the second duct divided body are integrated by welding. The material of the first duct segment and the first tube body includes a first polyamide resin, and the material of the second duct segment includes a second polyamide resin having a higher melting point than the first polyamide resin,
The composite duct according to claim 6, wherein the first polyamide resin includes PA66 and / or PA612.

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