JPH0438956B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hollow body such as a duct, which is used as a passage for fluid such as gas or liquid, and has a joint portion provided on the wall thereof.

Prior Art As an example of this type of hollow body, FIGS. 10 and 11 show a prior art in which a joint portion is formed in an intake duct used in the engine room of an automobile.

FIG. 10 shows a process in which a pipe-shaped connecting member b, which is separate from the duct a, is simultaneously integrated with the duct a when the intake duct a is molded. The need to use a separate connection member often arises when you want to change the physical properties such as heat resistance or mechanical strength from the material of duct a, or when you want to ensure dimensional accuracy of the inner diameter of the connection member, etc. .

By the way, this separate connecting member b is connected to the duct a.
It is integrated with duct a at the same time when it is molded.
That is, the duct a is made into a hollow pipe shape by blow molding a thermoplastic resin such as polypropylene, but at the time of blow molding, a pipe-shaped connecting member b is set in the mold in advance, It is integrated by insert molding. As a result, the connecting member b is embedded and integrated in the side wall of the duct a, and the connecting portion is completely sealed. However, as it is, the buried end of the connecting member b remains covered and sealed by the covering c formed by a part of the side wall of the duct a.

Therefore, a step of removing the covering c and communicating the connecting member b with the duct a is required. FIG. 11 shows this. In other words, the drill d is inserted from the opening of the connecting member b.
Insert a tool such as, remove the covering c and duct a.
The opening communicates with the inside. At this time, some burrs f are generated around the opening e. This burr f is removed using a suitable tool inserted through the opening of the duct a when finishing the product. Also, cutting waste g of coating c
has fallen into the interior of duct a, but this is also removed when the product is finished.

Incidentally, Japanese Utility Model Publication No. 53-38344 discloses a pipe joint in which a pipe joint is fixed in advance to a frame member so as not to be able to come off, and then a sealing material is filled in the joint between the two. Furthermore, in Japanese Patent Application Laid-Open No. 51-24917, a branch pipe is welded to a hollow member in a communicating state, and
What is shown is a rib formed by injecting polyester resin to connect the two.

Problems to be Solved by the Invention By the way, if some of the burrs f and cutting waste g generated in this way remain inside the duct a, they may move inside the duct a from time to time and may damage other parts. Adhesion can adversely affect the performance of these parts. Therefore, it becomes necessary to completely remove the burrs f and cutting waste g from the inside of the duct a.

However, an extremely difficult problem arises when attempting to completely remove the burrs f and cutting waste g. That is, the work of removing the burrs f and cutting waste g while looking into the interior through the opening of the duct a is extremely troublesome, the work efficiency is poor, and it is not easy. In particular, if the duct a is complicatedly curved, the difficulty of the work increases dramatically.

In addition, in all of the above-mentioned publications, the pipe fittings and branch pipes are attached to the frame member or hollow member so that they cannot be removed before filling the connecting part with resin, etc., so the filling material is There is no risk of peeling off from the surface of the member or hollow member, or of pipe fittings or branch pipes coming out of the filling material.

However, due to structural constraints, it may not be possible to attach the connecting member to the hollow member in advance, so that the connecting member cannot be removed from the hollow member. Therefore, even if the connecting member is connected with the filling material, there is a risk that the hollow member and the connecting member may separate. Therefore, even in such a case, it is desirable to be able to reliably connect the connecting member to the hollow member in an inseparable manner.

Means for Solving the Problems The present invention solves these problems, and its means have the following configuration.

That is, in a hollow body in which a joint portion is provided by connecting a hollow connecting member that is open at both ends to a wall surface, one end of the connecting member is inserted into an opening provided in the wall surface of the hollow body in advance to correspond to the connecting member. The connecting member is inserted and the connecting member is pulled out and communicated with the inside of the hollow body in a free state, and a fluid resin is supplied to the joint between the hollow body and the connecting member and solidified to provide a sealing resin part, and the connecting member is connected to the hollow body. Each member is provided with a retaining part that is embedded in the sealing resin part and bites into the sealing resin part, and the connecting member is irremovably fixed to the wall surface of the hollow body by the sealing resin part through these retaining parts. That is.

Function The joint part of the present invention is made by inserting the previously opened end of the connecting member into the opening provided in the wall of the hollow body, and covering and fixing this with a fluid resin to integrate the joint part. Therefore, communication can be achieved without requiring any processing for making the connecting member communicate with the inside of the hollow body after integration. Further, the connecting portion is fixed to the wall surface of the hollow body by the sealing resin portion, and at the same time, the connecting portion is covered and completely sealed to prevent internal air from leaking.

At this time, since the connecting member and the hollow member are each provided with a retaining portion, the retaining portion is embedded and integrated into the sealing resin and bites into the sealing resin so that it cannot come out. Therefore, even if a force is applied to the connecting member in the direction of pulling out, the connecting member cannot be pulled out unless it is integrated with the sealing resin, and the sealing resin part is irreparably integrated with the hollow member through the retaining member. As a result, the connecting member is irremovably fixed to the hollow member.

Embodiment FIGS. 1 to 6 show an embodiment in which the present invention is applied to an air flow tube forming a part of an intake duct used in an automobile engine. Of course, this air flow tube corresponds to the hollow body in the present invention.

FIG. 2 shows the entire air flow tube. The main body 1 of the air flow tube is a rigid tube made of polypropylene, and is approximately U-shaped. Both ends 2 and 3 are open, and one end is connected to an air cleaner, and the other end is connected to the engine body or its auxiliary equipment. Also, one end 2 has an elliptical cross section due to the arrangement, and the other end 3 has a circular cross section. Furthermore, a joint portion 6 is formed on the parting line 5 on the outer peripheral side of the curved portion 4. The joint part 6 is connected to the main body 1
A bulging part 7 formed by bulging out a part of the outer periphery of the bulging part 7, a sealing resin part 8 formed integrally with the top of the bulging part 7 with a fluid resin, and a sealing resin part 8 enclosed in the sealing resin part 8 with one end protruding. It consists of pipe-shaped connecting members 9 and 10 as well as a connecting member 11 which is similarly enclosed in the sealing resin part 8 and integrated with the bulging part 7.

The detailed internal structure of the joint portion 6 is shown in FIG. The connecting members 9 and 10 are heat-resistant grade polypropylene pipes containing glass fiber, and each connecting member is provided with a flange 12 to prevent it from coming off, and both connecting members are connected to a flange-shaped connecting portion 1.
3 and are integrally molded (see Fig. 3).
The coupling member 11 is similarly made of heat-resistant grade polypropylene, is implanted by insert molding near the openings 14 and 15, and protrudes outward from the top surface of the bulge 7. Further, the top of the coupling member 11 forms an enlarged portion. The enlarged portions and flanges 12, 12 of these connecting members 11 are connected to the connecting members 9, 10.
The air flow tube extends in a direction perpendicular to the direction in which it is inserted and connected to the main body 1 of the air flow tube, and corresponds to an example of the retaining portion in the present application.

One end of the connecting members 9, 10 was inserted into the openings 14, 15 (see FIG. 3) formed on the top surface of the bulging portion 7, and the connecting portion 13 was brought into contact with the top surface of the bulging portion 7. In this state, the sealing resin portion 8 is formed by injection molding including the connecting member 11 around the connecting portion between the connecting members 9, 10 and the openings 14, 15, and solidifying it.

The sealing resin portion 8 includes the bulging portion 7, the connecting members 9, 10, and the coupling member 11, and is closely integrated with these. This seals the connecting portion and prevents air leakage, and since the bulging portion of the coupling member 11 is within the sealing resin portion 8, the bulging portion 7 and the sealing resin portion 8 are separably coupled by the coupling member 11, The joint part 6 is strengthened. Also, the flange 12,
Since the connecting portion 13 is also integrally molded and enclosed within the sealing resin portion 8, the connecting members 9, 10 will not come out from the sealing resin portion 8.

Reference numerals 16 and 17 are hook pins and bosses inserted on the parting line 5 of the main body 1, respectively, and a box-shaped damper box 18 is attached to the boss 17.

Pipe 1 is integrally attached to damper box 18.
9 and 19 are formed, and as shown by the chain line in FIG. 2, the connecting member 10 and one pipe 19 are connected to communicate the main body 1 and the damper box 18,
Furthermore, the intake noise generated when the intake air is drawn from another pipe 19 through the control valve into the intake system downstream of the throttle valve of the engine is reduced. Further, the connecting member 9 is connected to other engine control equipment.

Next, a method for forming the joint portion 6 will be explained with reference to FIGS. 3 to 6.

First, the main body 1 is blow molded as shown in FIG. At this time, as described above, the formation of the bulging portion 7 and the insertion of the coupling member 11 and other inserts are performed at the same time. Note that this molding method is arbitrary, and methods such as injection molding can be adopted as appropriate depending on the shape of the molded product. The openings 14 and 15 of the bulging portion 7 are connected to the main body 1.
Open after or at the same time as the molding. Further, the connecting members 9 and 10 and the damper box 18 are molded separately from the main body 1. Next, connecting members 9 and 10
Insert one end into the openings 14 and 15 to connect the connecting part 13.
is fixed in close contact with the top surface of the bulge 7. FIG. 4 is a sectional view of a portion corresponding to FIG. 1, showing a state in which the connecting members 9 and 10 are inserted and fixed into the openings 14 and 15.
In this state, the connecting members 9 and 10 are positioned in the insertion direction with respect to the bulge 7 and can be freely removed.

Next, a mold 20 is fixed so as to cover the connecting portion between the connecting members 9, 10 and the bulging portion 7 and the periphery of the connecting member 11, and injection molding is performed to form the sealing resin portion 8 (Figs. 5 and 6). ). The structure of this mold 20 is shown in FIG. A recess 21 corresponding to the sealing resin part 8 is provided on the side of the mold 20 facing the bulging part 7, and a peripheral wall 22 surrounds the mold 20. Furthermore, openings 23 and 24 corresponding to the connecting members 9 and 10 are provided in the center of the mold 20 so that the connecting members 9 and 10 can be inserted therein.

As shown in FIGS. 4 and 5, the openings 23, 2
The length L1 in the axial direction from the tip of the peripheral wall 22 of No. 4 is equal to the length L2 of the connecting members 9 and 10 from the bulge 7 to the tip. The mold 20 has a recess 21
A recess 25 is also formed on the opposite side, and a slider 27 guided by a peripheral wall 26 is provided within the recess 25. The slider 27 is connected to a hydraulic mechanism (not shown) via a rod 28, and has a recess 2 in the vertical direction in the figure.
It is movable within 5. Further, pins 29 and 30 are implanted in the slider 27 toward the openings 23 and 24. The pins 29, 30 have an inner diameter approximately equal to the inner diameter of the connecting members 9, 10, and are fitted into the connecting members 9, 10 to change the position of the sealing resin part 8 relative to the connecting members 9, 10 in the front, rear, left, and right directions in FIG. It acts to fix it in place.

Now, the mold 20 is placed on the top surface of the bulge 7, the peripheral wall 22 is pressed against the bulge 7, and at the same time the slider 27
If you push down in the direction of the arrow in Fig. 5, pin 29,
The tips of 30 enter the hollow portions of the connecting members 9 and 10. If you continue to lower slider 27,
The slider 27 descends until it contacts the tips of the connecting members 9 and 10 and then stops. This state is shown in FIG. At this time, the connecting members 9 and 10 are connected to the slider 2.
7, the peripheral wall 22 is tightly fixed on the bulge 7.
Since the concave portion 21 is also in close contact with the bulging portion 7, the concave portion 21 can constitute a space for injection molding. At this time, if necessary, a jig may be inserted into the main body 1 to support and fix the ends of the connecting members 9 and 10 protruding inside the bulge 7 or the inner wall of the bulge 7. good. While maintaining this state,
As shown in FIG. 6, molten polypropylene 31 is supplied as a fluid resin into the recess 21 by injection molding. If this is cooled and solidified as it is, the molten polypropylene 31 will form a sealing resin part 8 and will be integrated with the bulging part 7 while enclosing the connecting members 9 and 10, resulting in a strong joint part 6 with good sealing properties. can be formed. In this joint portion 6, the enlarged portion of the connecting member 11 and the flange 12 are embedded and integrated into the sealing resin portion 8 and are wedged into the joint portion 6, so that the sealing resin portion 8 can be pulled out from the connecting members 9 and 10 by the flange 12. At the same time, the sealing resin part 8 becomes impossible to peel off from the surface of the bulge 7 due to the bulge of the coupling member 11. Therefore, the sealing resin portion 8 is strongly bonded to both the connecting members 9, 10 and the bulging portion 7, and this bonding strength is extremely large, so that even if a force in the direction of pulling out is applied to the connecting members 9, 10, these will not swell. It is securely fixed to the protruding portion 7 in a manner that it cannot be separated. Note that the connecting members 9 and 10 are of heat-resistant grade containing glass fiber, so
It does not easily deform even if molten resin is supplied during injection molding. Moreover, by inserting the pins 29, 30 into the connecting members 9, 10 during molding, in addition to the positioning effect of the sealing resin portion 8, deformation during molding is less likely to occur. Therefore, it is suitable for molding parts that require strict air flow rate control because the accuracy of the inner diameter dimensions of the connecting members 9 and 10 can be maintained accurately. Furthermore, the strength of the joint portion 6 is extremely high due to the presence of the coupling member 11 and the like. Therefore, it is particularly advantageous for products such as automobile engine parts that have high requirements for various performances such as dimensional accuracy and anti-vibration properties. Injection molding also improves the molding cycle and is efficient.

(Other Embodiments) FIG. 7 shows an embodiment in which a joint portion 33 is provided inside the curved portion of the curved duct 32. In this case, it is impossible to perform finishing work inside the duct inside the joint while looking into the duct through the openings 34 and 35 at both ends, so the advantage of the present invention is particularly obvious.

FIG. 8 shows another embodiment regarding the formation of an opening for attaching a connecting member.

In this embodiment, the opening 37 for attaching the connecting member is simultaneously blow-molded to the hollow body 36.
A hollow protrusion 38 that protrudes outward from the main body 36 is integrally formed at a position corresponding to the main body 36 . This manufacturing method is
When blow molding the main body 36, a recess corresponding to the protrusion 38 is carved in advance on the mold surface of the main body 36, and a molten parison or the like is expanded and pressed against the mold surface. It is obtained by being formed integrally with the main body 36. To open the opening 37 from this point, the eighth
If the protrusion 38 is cut along the outer surface of the main body 36, as shown by the dotted line in the figure, this can be easily done without creating burrs inside the main body 36. Therefore, forming an opening according to this embodiment is particularly advantageous for complex-shaped objects where burrs and the like cannot be removed cleanly afterwards.

FIG. 9 shows another embodiment of the method of forming the coupling member.

That is, in this embodiment, at the same time as the main body 39 of the hollow body is formed, the opening 40 for attaching the connecting member is formed.
A hook-shaped connecting member 41 is integrally molded with the main body 39 around the periphery of the main body 39. Although various molding methods are possible, for example, in the case of blow molding, the connecting member 41 is placed on the mold surface of the main body 39 in advance, as in the previous embodiment.
A concave portion corresponding to the shape is carved, and a molten parison or the like is expanded and pressed against the mold surface to obtain the molded body integrally with the main body 39. Since this method does not require insert molding, if the connecting member 41 is made of the same material as the main body 39, it is easy to manufacture and is an advantageous method.

Furthermore, the fluid resin and its supply method are not limited to injection molding of molten resin. The fluid resin is not limited to a molten resin, and any resin that solidifies after being supplied may be used, whether it is a liquid resin or a sticky resin. Therefore, for example, a liquid unsaturated polyester resin may be cast into the connecting portion of the connecting member under normal pressure and allowed to solidify as it is. In this case, since large pressure is not required, deformation during molding can be reduced. For example, nylon powder is put into a mold, melted under pressure, and then cooled.
Even if the powder is in a normal state, as in the case of solidification, it also includes powders that exhibit a fluid state, even temporarily. Further, it may be a thermoplastic resin or a thermosetting resin.

In addition to tubular bodies such as ducts, such hollow bodies can be used in various fields such as containers such as tanks. Note that the duct is suitable for anything that requires high sealing properties such as airtightness and watertightness, regardless of whether it is gas or liquid, and has a variety of uses other than automobiles.

Furthermore, the material, cross-sectional shape, etc. of the connecting member are free.

Effects According to the present invention, when forming a joint portion that requires high sealing performance, there is no need to perform machining or the like afterwards in order to connect the connecting member to the hollow body. Therefore, no burrs or cutting chips are generated inside the hollow body, and there is no need to remove them. Therefore, no matter what shape the hollow body takes, there is no change in working efficiency, and the working efficiency is extremely high. In addition, burrs and the like will not move inside the hollow body and will not cause any adverse effects such as adhesion to connected parts, so it can be used with confidence at any time.

In addition, a sealing resin part is provided in which the connecting member is freely pulled out from the hollow body and communicated with the inside, and a fluid resin is supplied to the connecting part and solidified. A retaining portion that is embedded in the portion and bites into the connecting member so that it cannot be removed is provided, and the connecting member is irremovably fixed to the wall surface of the hollow body by means of a sealing resin portion via these retaining portions. Therefore, since the sealing resin is inseparably bonded to both the connecting member and the hollow member via each of the retaining portions, the connecting member can be firmly fixed to the wall surface of the hollow body in an inseparable manner.

[Brief explanation of drawings]

Figure 1 shows the joint part of the first embodiment.
2 is a perspective view of the same embodiment, FIG. 3 is an exploded perspective view of the same embodiment, FIG. 4 is a sectional view of the joint part of the same embodiment in the molding process, and FIG. 5 is a perspective view of the same embodiment. FIG. 6 is a cross-sectional view when the mold is set in the molding process of the joint part of the same example, and FIG.
Fig. 7 is a perspective view of the second embodiment, Fig. 8 is a sectional view of the joint part of the third embodiment, Fig. 9 is a sectional view of the joint part of the fourth embodiment, and Fig. 10 is a connection of the conventional example. FIG. 11 is a cross-sectional view of the joint part in the process of joining members, and FIG. 11 is a cross-sectional view of the joint part in the machining process in the conventional example. Explanation of symbols, 1...Duct, 2, 3...Open end, 4...Curved part, 5...Parting line,
6...Joint part, 7...Bulging part, 8...Sealing resin part, 9, 10...Connecting member, 11...Joining member, 12...Flange, 13...Connecting part, 14,
15... Opening, 16... Hook pin, 17... Boss, 18... Damper box, 19... Pipe, 20... Mold, 25... Recess, 22, 26...
... Peripheral wall, 23, 24 ... Opening, 27 ... Slider, 28 ... Rod, 29, 30 ... Pin, 31
...Melted polypropylene, 32...Main body, 33...
... joint, 34, 35 ... end, 36 ... main body, 37 ... opening, 38 ... protrusion, 39 ... main body, 40 ... opening, 41 ... coupling member.

Claims (1)

[Claims] 1. In a hollow body in which a joint portion is provided by connecting a hollow connecting member that is open at both ends to a wall surface, one end of the connecting member is inserted into an opening previously provided in the wall surface of the hollow body corresponding to the connecting member. The connecting member is inserted into the hollow body and communicated with the interior of the hollow body in a free state, and a sealing resin portion is provided by supplying and solidifying a fluid resin to the connection portion between the hollow body and the connecting member, and and the connecting member are each provided with a retaining part that is embedded in the sealing resin part and bites into the sealing resin part, and the connecting member is irremovably fixed to the wall surface of the hollow body by the sealing resin part through these retaining parts. A hollow body having a joint portion.