This application claims priority under 35 USC 119 to Japanese Patent Application No. 2007-17745 filed on Jan. 29, 2007, the entire contents of which are incorporated herein by reference.
(a) Field of the Invention
This invention relates to resin intake manifolds such as provided in intake systems of motor vehicle engines.
(b) Description of the Related Art
Surge tank-integrated intake manifolds are conventionally known as resin intake manifolds of the above kind (see, for example, Published Japanese Patent Application No. H09-177624). The surge tank-integrated intake manifold disclosed in the patent document is formed by integrating a plurality of intake pipes forming intake passages each for supplying intake air to associated one of cylinders of a multi-cylinder engine with a surge tank connected to the upstream sides of the intake pipes. The intake pipes are internally provided with individual internal pipes formed to extend to the interior of the surge tank. The provision of the internal pipes allows the intake passages in the intake pipes to be extended to the interior of the surge tank, thereby enhancing the air intake performance and the silencing effect.
The manifold body of the intake manifold is composed of two split components split along a radial direction of the intake pipes. Each split component is provided with concave parts each of which forms a half of the inner periphery of the associated intake pipe. Each internal pipe is configured to be placed between an opposed pair of concave parts of both the split components. With the internal pipes put between their associated opposed pairs of concave parts, both the split components are joined together by vibration welding. Thus, the internal pipes are held radially gripped between their associated pairs of concave parts of the split components.
Since the internal pipes must be placed in the associated intake pipes as described above, it is necessary that in producing the intake manifold, the outer peripheries of the internal pipes should be fitted onto their associated concave parts of one of the split components to combine the internal pipes with the one split component and, in this state, the other split component should be vibrated with respect to the one split component to weld them together. In this case, in order to provide a firm and reliable vibration welding, a clearance corresponding to the amplitude of vibrations during vibration welding must be kept between each concave part of the other split component and the outer periphery of the associated internal pipe to make the other split component easy to vibrate. If the clearance is kept, part of intake air in the surge tank may flow into the clearance, bypass the internal pipe and then directly reach the downstream side of the intake pipe. This reduces effects due to provision of the internal pipes, such as enhancement in air intake performance and silencing effect.
The present invention has been made in view of the foregoing points and, therefore, an object of the present invention is that when one or more internal pipes are placed in a manifold body which is to be obtained by joining a plurality of split components by vibration welding, a firm and reliable vibration welding can be implemented and, concurrently, intake air in the surge tank can be prevented from bypassing the internal pipes and flowing directly downstream thereof, thereby providing a sufficient effect of enhancing the air intake performance and a sufficient silencing effect both due to provision of the internal pipes.
A first aspect of the invention provides a resin intake manifold including: a manifold body including an intake pipe and a surge tank connected to an end of the intake pipe located upstream in the flow of intake air; and an internal pipe placed in the intake pipe and extending to the interior of the surge tank, the manifold body being composed of first and second split components joined together along a parting plane extending radially and longitudinally of the intake pipe by vibration welding, wherein the first and second split components include first and second concave parts, respectively, forming the inner periphery of the intake pipe so that a downstream part of the internal pipe is placed between the first and second concave parts, the second concave part is formed a distance away from the outer periphery of the internal pipe, the internal pipe includes a fitting part formed in a portion of the outer periphery of the downstream part thereof corresponding to the first concave part and fitted into the first concave part and a sealing part formed on a portion of the outer periphery of the downstream part thereof corresponding to the second concave part and extending radially outwardly, the second concave part has an accommodation recess accommodating the sealing part, and the inner face of the accommodation recess and the sealing part are formed along the direction of vibration of the vibration welding and are in contact with each other.
According to the first aspect of the invention, in vibrating the second split component with the fitting part of the internal pipe fitted to the first concave part to combine the internal pipe with the first split component, the internal pipe is prevented from interfering with the concave part of the second split component and the second split component is thereby easily vibrated. Thus, the first and second split components can be firmly and reliably joined together by vibration welding. Furthermore, since a sealing part is provided on a portion of the outer periphery of the internal pipe corresponding to the second concave part, an accommodation recess for accommodating the sealing part is provided in the second concave part and the inner face of the accommodation recess and the sealing part are in contact with each other, a seal can be formed between the outer periphery of the internal pipe and the second concave part of the second split component. Thus, intake air in the surge tank is prevented from bypassing the internal pipe and flowing directly downstream of the internal pipe, whereby the effect of enhancing the air intake performance and the silencing effect due to provision of the internal pipe can be well exhibited. Furthermore, since the inner face of the accommodation recess and the sealing part are formed along the direction of vibration of vibration welding, they are prevented from hampering the vibration welding.
In a second aspect of the invention, related to the first aspect of the invention, the sealing part has a sealing part-side inclined face inclined with respect to the direction of pressure application during the vibration welding, part of the inner face of the accommodation recess is an accommodation recess-side inclined face conforming to the sealing part-side inclined face, and the sealing part-side inclined face and the accommodation recess-side inclined face are in contact with each other.
According to the second aspect of the invention, since the sealing part-side inclined face inclined to the direction of pressure application during vibration welding is in contact with the accommodation recess-side inclined face, both the split components can be welded together with the sealing part-side inclined face pressed against the accommodation recess-side inclined face by a pressing force during the vibration welding. Thus, the sealing performance can be further enhanced.
In a third aspect of the invention, related to the first or second aspect of the invention, the intake pipe comprises a plurality of intake pipes, the internal pipe comprises a plurality of internal pipes, one internal pipe in each of the plurality of intake pipes, and the sealing part comprises a plurality of sealing parts, all or some of the plurality of sealing parts being integral.
According to the third aspect of the invention, a plurality of internal pipes can be joined by forming the sealing parts of the plurality of internal pipes into an integral piece. Thus, the number of parts to be assembled into both the split components can be reduced, thereby enhancing the assemblability.
In a fourth aspect of the invention, related to any one of the first to third aspects of the invention, the sealing part includes a flexible projection in contact in a bent position with the inner face of the accommodation recess.
According to the fourth aspect of the invention, since the flexible projection of the sealing part comes into contact in a bent position with the inner face of the accommodation recess, variations in the molding accuracy of the sealing part and the accommodation recess can be absorbed by the bending deformation of the flexible projection, thereby providing a reliable seal.
In a fifth aspect of the invention, related to the third aspect of the invention, the plurality of intake pipes are radially juxtaposed, each radially adjacent pair of the plurality of internal pipes are joined by a connecting part provided therebetween, one of the first and second split components includes a welding raised part welded to the other split component, the welding raised part being located between each radially adjacent pair of the plurality of internal pipes, and the connecting part has a through hole receiving the welding raised part.
According to the fifth aspect of the invention, since a through hole is formed in the connecting part joining each adjacent pair of the plurality of internal pipes and a welding raised part to be inserted into the through hole is provided on one of the first and second split components, the adjacent pair of internal pipes can be positioned, during the production of the intake manifold, with the welding raised part inserted in the through hole. In addition, since the welding raised part is welded, the welding strength of the first and second split components can be further enhanced.
Hereinafter, an embodiment of the invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the scope, applications and use of the invention.
The left pair of intake pipes 2 and 2 are provided at their downstream ends with a flange 20 which is to be fastened to the cylinder head of the engine. The flange 20 extends substantially horizontally and connects both the intake pipes 2 and 2. The flange 20 is provided with injector attachment parts 20a and 20a, one for each intake pipe 2, to each of which a fuel injector is to be attached. Furthermore, the flange 20 is provided also with a plurality of fastening holes 20b through which the flange 20 is to be bolted to the cylinder head. The right pair of intake pipes 3 and 3 are also provided at their downstream ends with a flange 21 having like injector attachment parts 21a and 21a and fastening holes 21b.
The internal pipes 12, 12, 13 and 13 are fixed to the associated intake pipes 2, 2, 3 and 3 by placing their respective parts downstream in the flow of intake air into the associated intake pipes 2, 2, 3 and 3. As also shown in
The two internal pipes 12 and 12 placed in the left pair of intake pipes 2 and 2 radially adjoin. As shown in
As shown in
As shown in
The manifold body 11 is composed of two components having a curved parting plane extending substantially along the axes of the intake pipes 2, 2, 3 and 3 (extending radially and longitudinally thereof), i.e., an upper split component 40 (a second split component) and a lower split component 50 (a first split component), and constructed so that the upper and lower split components 40 and 50 are joined together by vibration welding. The line indicated by L in
The upper split component 40 includes four upper concave parts 41, 41, . . . (second concave parts) constituting upper parts of the inner peripheries of the four intake pipes 2, 2, 3 and 3. As shown in
As shown in
As shown in
On the other hand, as shown in
The formation of the lower expanded parts 51a, 51a, . . . in the lower concave parts 51, 51, . . . is accompanied by the formation of shoulders 51b, 51b, . . . bordering on the lower expanded parts 51a, 51a, . . . . The shoulders 51b, 51b, . . . fit against the downstream ends of the internal pipes 12, 12, 13 and 13. Furthermore, as shown in
The lower split component 50 has a looped lower ridge 54 formed at a portion thereof opposed to the welding upper ridge 44 and extending upward. The lower ridge 54 and the welding upper ridge 44 are joined together at their end faces by vibration welding. Furthermore, the lower split component 50 is provided with an inner vertical wall 55 and an outer vertical wall 56. The provision of the inner vertical wall 55 and the outer vertical wall 56 prevents flash produced during vibration welding from getting in the intake passages and getting out of the manifold body 11. Furthermore, the lower split component 50 has a welding raised part 57 formed between the left pair of lower expanded parts 51a and 51a. The welding raised part 57 is formed and positioned to be inserted into the through hole 30a of the connecting part 30 provided between the adjacent internal pipes 12 and 12. A like welding raised part 57 is formed also between the right pair of lower expanded parts 51a and 51a.
Next, a description is given of production procedures of the intake manifold 1 having the above structure. First, the upper split component 40, the lower split component 50 and the left and right pairs of internal pipes 12, 12, 13 and 13 are molded with an unshown injection molding machine. Then, as shown in
Thereafter, the upper split component 40 is assembled to the lower split component 50. In this assembly, as shown in
Furthermore, the vibration welding of the upper split component 40 and the lower split component 50 provides contact of the sealing plates 12a, 12a, 13a and 13a with the inner faces of the accommodation recesses 42 and 42 and thereby forms a seal between the upper half of the outer periphery of each internal pipe 12, 13 and the associated upper concave part 41 of the upper split component 40. Thus, the intake air in the surge tank 10 can be prevented from bypassing the internal pipes 12, 12, 13 and 13 and flowing directly downstream of the internal pipes 12, 12, 13 and 13.
As described previously, in the intake manifold 1 according to this embodiment, each internal pipe 12, 13 is placed between the associated upper concave part 41 of the upper split component 40 and the associated lower concave part 51 of the lower split component 50 and the upper concave part 41 is formed a distance away from the outer periphery of the associated internal pipe 12, 13. Therefore, in vibrating the upper split component 40 with the internal pipes 12, 12, 13 and 13 combined with the lower split component 50, each internal pipe 12, 13 is prevented from interfering with the upper concave part 41 and the upper split component 40 is thereby easily vibrated. Furthermore, since the integral pieces of sealing plates 12a, 12a, 13a and 13a and the inner faces of the accommodation recesses 42 and 42 are formed along the direction of the vibration, the sealing plates 12a, 12a, 13a and 13a are prevented from hampering the vibration of the upper split component 40. For these reasons, the upper split component 40 and the lower split component 50 can be firmly and reliably joined together by vibration welding. In addition, since the sealing plates 12a, 12a, 13a and 13a of the internal pipes 12, 12, 13 and 13 come into contact with the associated inner faces of the accommodation recesses 42 and 42, the intake air in the surge tank 10 can be prevented from bypassing the internal pipes 12, 12, 13 and 13, whereby the effect of enhancing the air intake performance and the silencing effect due to provision of the internal pipes 12, 12, 13 and 13 can be well exhibited.
Furthermore, since each adjacent pair of internal pipes 12 and 12 are joined by forming the sealing plates 12a and 12a of the internal pipes 12 and 12 into an integral piece, the number of parts can be reduced. This enhances the assemblability of the internal pipes 21 and 12.
Furthermore, a through hole 30a is formed in the connecting part 30 joining each adjacent pair of internal pipes 12 and 12 and a welding raised part 57 to be inserted into the through hole 30a is provided on the lower split component 50. Therefore, during production, each adjacent pair of internal pipes 12 and 12 can be positioned with the welding raised part 57 inserted in the through hole 30a. In addition, since the welding raised part 57 is welded, the welding strength of the upper split component 40 and the lower split component 50 can be further enhanced.
Although in the above embodiment each adjacent pair of internal pipes 12 and 12 are formed integral by joining them by the connecting part 30 and the sealing plates 12a and 12a, the present invention is not limited to this. For example, each adjacent pair of internal pipes 12 and 12 may be separated from each other by eliminating the connecting part 30 and forming the sealing plates 12a and 12a separately from each other.
Alternatively, as in Modification 1 shown in
Alternatively, as in Modification 2 shown in
Although in the above embodiment each sealing plate 12a is provided at an end of the associated internal pipe 12, the present invention is not limited to this. For example, each sealing plate 12a may be provided in the axial middle of the internal pipe 12.
Alternatively, as in Modification 3 shown in
Furthermore, as shown in
During vibration welding, the lower split component 50 may be vibrated with the upper split component 40 fixed.
The present invention is applicable not only to intake manifolds for horizontally opposed engines but also to those for various types of engines including inline engines and V-engines. Furthermore, the number of intake pipes 2, 3 can be appropriately selected according to the number of engine cylinders.
As can be seen from the above, the resin intake manifold according to the present invention is suitable for placement in intake systems of motor vehicle engines.
Number | Date | Country | Kind |
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2007-017745 | Jan 2007 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
5896838 | Pontopiddan et al. | Apr 1999 | A |
6647940 | Wada et al. | Nov 2003 | B2 |
Number | Date | Country |
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9-177624 | Jul 1997 | JP |
Number | Date | Country | |
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20080178831 A1 | Jul 2008 | US |