JP2003328881A - Resin intake manifold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin intake manifold with a high degree of freedom in design of an intake passage constitution part capable of surely jointing and fixing an intermediate part to a second part. <P>SOLUTION: This resin intake manifold 11 comprises a first casing piece 12; a second casing piece 14 jointed and fixed to the first casing piece 12; and an inner piece 13 arranged between the first casing piece 12 and the second easing piece 14. The intake passage constitution part constituting a portion of the intake passage as an intake gas passage to an engine is formed between the second casing piece 14 and the inner piece 13 by jointing and fixing them. The second casing piece 14 and the inner piece 13 are fixed by laser welding. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin intake manifold used, for example, in an automobile engine.

[0002]

2. Description of the Related Art As an intake manifold of this type, for example, the one shown in FIG. 5 is disclosed in Japanese Patent Laid-Open No. 8-252864.

That is, the intake manifold 100
Is a first casing piece 101, a second casing piece 102 joined and fixed to the first casing piece 101, and an inner piece 103 arranged between the first casing piece 101 and the second casing piece 102.
It consists of First casing piece 101, second
The casing piece 102 and the inner piece 103 are each made of synthetic resin. Between the second casing piece 102 and the inner piece 103, the two 102,
An intake passage forming portion 105 that forms a part of an intake passage that is an intake gas passage to the engine by joining and fixing 103
Are formed.

Now, vibration welding is generally used for fixing the first casing piece 101 and the second casing piece 102. However, the joint portion between the second casing piece 102 and the inner piece 103 has a three-dimensionally curved shape. For this reason, it is difficult to reliably fix the inner piece 103 to the second casing piece 102 by vibrating and welding which can only apply vibration of two-dimensional amplitude to the component. Therefore, in the related art, the inner casing 103 is replaced with the second casing piece 102 by the first casing piece 101.
The structure to press down is adopted.

[0005]

However, in order to surely press the inner piece 103 against the second casing piece 102, the parts forming the both ends 105a and 105b of the intake passage forming portion 105 in the inner piece 103. The vicinity of the first casing piece 10
It is necessary to directly abut against 1. Therefore, there is a problem that there is no degree of freedom in setting the arrangement positions of both ends 105a and 105b of the intake passage forming section 105, that is, setting the length of the intake passage forming section 105.

In order to solve this problem, it is necessary to adopt the structure shown in FIGS. 6 and 7, for example. The embodiment shown in FIGS. 6 and 7 is different from the embodiment shown in FIG.
Shows the case where the length of is set short. That is, in this aspect, at the joint portion between the second casing piece 102 and the inner piece 103, the end portion 10 of the intake passage forming portion 105 where the direct pressing of the inner piece 103 by the first casing piece 101 cannot be expected.
A positioning pin 104 is interposed near 5b.

However, in the embodiment of FIGS. 6 and 7,
Thickness (space) for locating the positioning pin 104
The second casing piece 102 and the inner piece 103
Need to secure. Therefore, the intake passage forming section 105
However, the efficiency of the intake air flow in the intake manifold 100 and the funnel shape of the end portion 105b of the intake passage forming portion 105 cannot be set appropriately, and the intake resistance of the engine increases. there were.

That is, in the embodiments shown in FIGS. 5 to 7, since the inner piece 103 is securely joined and fixed to the second casing piece 102, there is a problem that the degree of freedom in designing the intake passage constituting portion is impaired. there were.

An object of the present invention is to provide a resin intake manifold in which the intermediate part can be securely joined and fixed to the second part and the degree of freedom in designing the intake passage constituent part is high.

[0010]

[Means for Solving the Problems] Means for achieving the above-mentioned objects and their effects will be described below. A resin intake manifold according to a first aspect of the present invention includes a first component, a second component joined and fixed to the first component, and a first component.
It comprises an intermediate part arranged between the part and the second part. Between the second component and the intermediate component, an intake passage constituting portion that constitutes a part of the intake passage that is an intake gas passage to the engine is formed by joining and fixing the two components.

Laser welding is used to fix the second component and the intermediate component. So, for example,
As in the embodiment of FIG. 5, the first part is used to move the intermediate part to the second part.
The intermediate component can be securely joined and fixed to the second component without adopting a structure of pressing the component. Therefore, it is not necessary to directly contact the vicinity of the parts forming both ends of the intake passage forming part with the first part in the intermediate part. Therefore, the end portion of the intake passage constituting portion can be arranged relatively freely, and the length of the intake passage constituting portion can be freely set.

Further, for example, unlike the embodiment shown in FIGS. 6 and 7, it is not necessary to use a fixing tool such as a positioning pin at the joint between the second component and the intermediate component, and the intake passage constituting portion can be routed. The space efficiency can be improved. Therefore, for example, the flow line of the intake air in the resin intake manifold and the funnel shape of the end portion of the intake passage forming portion can be appropriately set, and the intake resistance of the engine can be reduced.

As described above, according to the present invention, the intermediate component can be securely joined and fixed to the second component, and the degree of freedom in designing the intake passage constituent portion can be increased. According to a second aspect of the present invention, in the first aspect, the laser welding is continuously performed along the extending direction of the intake passage constituent portion. Therefore, for example, compared with the structure in which the intermediate component is pressed against the second component by the first component (see FIG. 5),
The adhesion between the second component and the intermediate component can be improved, and the sealing property of the intake passage constituent part is improved.

That is, the first part is replaced with the intermediate part by the second part.
In the structure of pressing down on the component, for example, when the intermediate component is warped, there is a portion where the adhesiveness is deteriorated at the joint portion between the second component and the intermediate component. Therefore,
There is a problem in that the sealing performance of the intake passage constituting portion is deteriorated at this portion, gas leakage occurs, and the intake efficiency of the engine deteriorates.

According to a third aspect of the present invention, in the first or second aspect, a plurality of intake passage constituent portions are formed between the second component and the intermediate component. Laser welding is applied to the joints between the second component and the intermediate component on both sides of each intake passage forming section. Therefore, the second component and the intermediate component can be reliably brought into close contact with each other on both sides of each intake passage constituting section. Therefore, the sealing property of each intake passage constituent portion is improved, and, for example, gas leakage between adjacent intake passage constituent portions can be prevented.

According to a fourth aspect of the present invention, in any one of the first to third aspects, at the joining portion between the second component and the intermediate component, the engaging recess and the other provided on one of the second component and the intermediate component. Is fitted with the engaging convex portion. Therefore, in cooperation with laser welding, the second component and the intermediate component can be firmly and firmly bonded and fixed to each other, and the sealing property of the intake passage constituting portion can be further improved.

Further, even before the laser welding is performed, a certain degree of positioning of the second component and the intermediate component can be achieved by fitting the engaging concave portion and the engaging convex portion. Therefore, for example, during laser welding, it is not always necessary to hold down (position) the intermediate component with respect to the second component using a jig or the like. If this jig is not used, the device for laser welding can be simplified and the resin intake manifold can be provided at low cost.

According to a fifth aspect of the present invention, in the fourth aspect, the engaging concave portion and the engaging convex portion are formed so as to extend along the intake passage forming portion. Therefore, the engagement between the engagement concave portion and the engagement convex portion becomes stronger. Therefore, the second part and the intermediate part are
Furthermore, it is strong and can be bonded and fixed with good adhesion,
Combined with the complexity of the leakage path in the fitting portion between the engagement concave portion and the engagement convex portion, the sealing property of the intake passage constituent portion can be further improved.

According to a sixth aspect of the present invention, in the fourth or fifth aspect, the laser welding is applied to a fitting portion between the engaging concave portion and the engaging convex portion. The fitting portion between the engaging concave portion and the engaging convex portion, for example, even if the intermediate component is warped, in other words, even if the fitting between the engaging concave portion and the engaging convex portion is partially shallow. It is possible to maintain a narrow gap between the inner side surface of the engaging concave portion and the side surface of the engaging convex portion in that portion. Therefore, it becomes easy to adopt the laser welding, which is important to control the clearance between the fixed components, for fixing the second component and the intermediate component.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the resin intake manifold of the present invention is embodied in an intake manifold used for an in-line four-cylinder type engine (internal combustion engine) will be described below.

As shown in FIGS. 1 and 2, the intake manifold 11 comprises a first casing piece 12 as a first part, an inner piece 13 as an intermediate part, and a second casing piece 14 as a second part. ing. These first casing piece 12 and inner piece 1
The third casing piece 14 and the third casing piece 14 are each made of synthetic resin molded by a method such as injection molding (injection molding). Although not described in detail, the first casing piece 12 is configured by joining and fixing a plurality of synthetic resin molded products.

The first casing piece 12 is in the shape of a box with a lid opening downward in the drawing. Four intake pipe portions 16 are continuously formed in the upper portion of the first casing piece 12 along the cylinder column direction (longitudinal direction) F of the engine (not shown). One end 1 of each intake pipe section 16
6a is connected to each cylinder of the corresponding engine.

The second casing piece 14 is in the shape of a box with a bottom that opens upward in the drawing. The second casing piece 14 and the first casing piece 12 are fixed to each other by vibration welding in a state where the flat open end surfaces 12a and 14a are joined to each other. A surge tank 15 in which a passage (not shown) from the outside air side is connected to the inside by joining and fixing the first casing piece 12 and the second casing piece 14.
Are sectioned.

As shown in FIGS. 1 and 3, on the bottom surface and one side wall in the second casing piece 14, four arc portions 19 having a semi-circular cross section are wavy in a row in the cylinder row direction F. Is formed in. In the inner piece 13, four arcuate portions 20 each having a semicircular cross section are formed in a wavy shape in the cylinder column direction F, corresponding to the arcuate portions 19 of the second casing piece 14. The inner piece 13 is joined and fixed to the second casing piece 14 in a state where the circular arc portion 20 and the circular arc portion 19 of the second casing piece 14 correspond to each other.

By arranging the arc portions 19 and 20 of the second casing piece 14 and the inner piece 13 so as to face each other, the space defined between the arc portions 19 and 20 constitutes the intake passage for four cylinders. It is part 21. The intake passage forming section 21 group has a three-dimensionally curved shape as a whole. Each intake passage constituting portion 21 has a funnel-shaped one end 21a opened in the surge tank 15 and the other end 21b connected to the intake pipe 16 of the first casing piece 12 at the other end 16b. Has been done. In other words, the intake passage constituent part 21 is the
5, the intake pipe portion 16 and the like form an intake passage that is an intake gas passage from the outside air to the engine.

As shown in FIGS. 1 and 4B, both sides of each arc portion 19 of the second casing piece 14, that is, the joint surface 14b with the inner piece 13 has a concave curved surface. Each arc portion 20 in the inner piece 13
On both sides, that is, the joint surface 1 with the second casing piece 14
3a has a convex curved surface shape. That is, the joint portion between the second casing piece 14 and the inner piece 13 has a three-dimensionally curved shape in accordance with the curved shape of the intake passage constituting portion 21 group, in other words, the curved shape of the inner piece 13.

As shown in FIGS. 1, 4 (a) and 4 (b), an engaging recess 22 is formed in the joint surface 14b of the second casing piece 14. The engagement recess 22 is
It extends along the intake passage forming portion 21 in a long groove shape having substantially the same length as the intake passage forming portion 21. Engagement recess 22
Has a tapered cross section in which the distance between both inner side surfaces 22a becomes narrower toward the rear side. Joining surface 13a of the inner piece 13
An engaging convex portion 23 is formed on the. Engagement protrusion 23
Along the intake passage forming part 21
1 extends in the shape of a long wall having substantially the same length. Engagement protrusion 2
No. 3 has a cross-section taper shape in which the distance between both side surfaces 23a becomes narrower toward the tip side.

The inner piece 13 is fitted into the engaging concave portion 22 of the second casing piece 14 with the engaging convex portion 23. The second casing piece 14 and the inner piece 13 are fitted to each other by the engagement recesses 22 and the engagement projections 23, specifically, the inner side surface 22a of the engagement recesses 22 and the side surface of the engagement projections 23. Since the laser welding is applied to the abutting portion with 23a, the engaging concave portion 22 and the engaging convex portion 23 are fitted together, so that they are firmly and firmly joined and fixed.

As shown in FIGS. 4 (a) and 4 (b),
In the laser welding, the second casing piece 14
Laser light L from the inner piece 13 side with respect to the fitting portion between the engaging recessed portion 22 and the engaging protruding portion 23 of the inner piece 13.
Is irradiated.

As the kind of the laser beam L, for example,
Examples include YAG: Nd3 + laser, semiconductor laser, HF chemical laser, and the like. The inner piece 13 is made of a material that is transparent to the laser light L, such as 6 nylon. The second casing piece 14 is made of a material that absorbs the laser light L without transmitting it, for example, partially aromatic nylon mixed with a coloring agent such as carbon black.

Therefore, the laser beam L emitted from the inner piece 13 side reaches the fitting portion between the engaging concave portion 22 and the engaging convex portion 23, and is in a contact state at the fitting portion (in other words, in other words). The inner side surface 22a and the side surface 23a are welded and fixed by heating and melting.

As shown by the arrow in FIG. 4 (b), the laser light L and the pieces 13, 14 are relatively moved along the extending direction of the intake passage forming portion 21 in the state where the laser light L is irradiated. It Therefore, the above-mentioned laser welding is continuously applied over almost the entire fitting portion between the engaging concave portion 22 and the engaging convex portion 23. The laser welding of the second casing piece 14 and the inner piece 13 on both sides of each intake passage constituent portion 21 is performed simultaneously by using a plurality of laser lights L (not shown, but five in this embodiment). It may be performed or may be performed separately by using one laser beam L.

After the laser welding of the second casing piece 14 and the inner piece 13 is completed, the intake manifold 11 is completed by joining and fixing the first casing piece 12 and the second casing piece 14.

The present embodiment having the above-mentioned structure has the following effects. (1) Laser welding is used to fix the second casing piece 14 and the inner piece 13. Therefore, for example, the second casing piece 14 and the inner piece 13 can be reliably joined together without employing the structure of pressing the inner piece 13 to the second casing piece 14 by the first casing piece 12 as in the embodiment of FIG. Can be fixed.
Therefore, in the inner piece 13, the intake passage forming portion 2
It is not necessary to directly abut the first casing piece 12 in the vicinity of the portions forming both end portions 21a and 21b of the first casing piece 12. Therefore, in the intake passage constituting portion 21, there is a degree of freedom in setting the arrangement position of the one end portion 21a on the surge tank 15 side, and the length of the intake passage constituting portion 21 can be freely set.

Further, as in the embodiment shown in FIGS. 6 and 7, the second
It is not necessary to use a fixing part such as a positioning pin (104) at the joint between the casing piece 14 and the inner piece 13, and the space efficiency for handling the intake passage forming part 21 can be improved. Therefore, the intake airflow line in the intake manifold 11 and the intake passage forming portion 2
The funnel shape of the one end 21a of No. 1 can be suitably set, and the intake resistance of the engine can be reduced.

As described above, according to this embodiment, the inner piece 13 can be securely joined and fixed to the second casing piece 14, and the degree of freedom in designing the intake passage constituting portion 21 can be increased. .

(2) Laser welding of the second casing piece 14 and the inner piece 13 is continuously performed along the extending direction of the intake passage forming portion 21. Therefore, for example, the inner casing 1 is made by the first casing piece 12.
3 is pressed into the second casing piece 14 (see FIG. 5).
Compared with the above (see), the adhesion between the second casing piece 14 and the inner piece 13 can be improved, and the sealing performance of the intake passage constituting portion 21 is improved. This leads to an improvement in intake efficiency of the engine.

When the second casing piece 14 and the inner piece 13 are laser-welded, the laser beam L and the pieces 13 and 14 may be moved relative to each other while the laser beam L is being irradiated. Therefore, for example, laser welding
The control of the apparatus for laser welding becomes simpler as compared with a mode in which the intake passage forming section 21 is spot-wise along the extending direction (this mode also does not depart from the gist of the present invention).

(3) A plurality of intake passage constituent parts 21 are formed between the second casing piece 14 and the inner piece 13. Laser welding is applied to the joints between the second casing piece 14 and the inner piece 13 on both sides of each intake passage forming portion 21. Therefore, the second casing piece 14 and the inner piece 13 can be surely brought into close contact with each other on both sides of each intake passage forming portion 21. Therefore, the sealing property of each intake passage constituent portion 21 is improved, and, for example, gas leakage between the adjacent intake passage constituent portions 21 can be prevented.

(4) At the joining portion between the second casing piece 14 and the inner piece 13, the engaging recess 22 provided in the second casing piece 14 and the inner piece 1
3 is fitted with the engaging convex portion 23. Therefore, in cooperation with laser welding, the second casing piece 14 and the inner piece 13 can be firmly and firmly bonded and fixed to each other, and the sealing property of the intake passage constituting portion 21 can be further improved. .

Even before the laser welding is performed, the engagement between the engaging concave portion 22 and the engaging convex portion 23 achieves a certain degree of positioning between the second casing piece 14 and the inner piece 13. it can. Therefore, for example, during laser welding, it is not always necessary to hold down (position) the inner piece 13 against the second casing piece 14 using a jig or the like. If this jig is not used, the device for laser welding can be simplified and the intake manifold 11 can be provided at low cost.

Contrary to the above, if the inner piece 13 is pressed against the second casing piece 14 using a jig or the like during the laser welding operation, both
It is possible to bond and fix the members 3 and 14 more firmly and with good adhesion. This leads to a further improvement in the sealing property of the intake passage constituent portion 21.

(5) The engaging concave portion 22 of the second casing piece 14 and the engaging convex portion 23 of the inner piece 13 are formed so as to extend along the intake passage forming portion 21. Therefore, the engagement between the engagement concave portion 22 and the engagement convex portion 23 becomes stronger. Therefore, the second casing piece 14 and the inner piece 13 can be joined and fixed more firmly and with good adhesiveness, and the complexity of the leakage path at the fitting portion between the engaging concave portion 22 and the engaging convex portion 23 can be balanced. Therefore, the sealing property of the intake passage forming portion 21 can be further improved.

(6) The second casing piece 14 and the inner piece 13 are laser-welded at the fitting portions of the engaging concave portions 22 and the engaging convex portions 23. For example, even if the inner piece 13 is warped or the like, the fitting portion between the engagement concave portion 22 and the engagement convex portion 23 is partially fitted with the engagement concave portion 22 and the engagement convex portion 23. Even if it becomes shallow, it is possible to keep the gap between the inner side surface 22a and the side surface 23a in that portion narrow. Therefore, it becomes easy to adopt the laser welding, which is important in managing the gap between the components to be fixed, for fixing the second casing piece 14 and the inner piece 13.

(7) The joint portion between the second casing piece 14 and the inner piece 13 has a three-dimensionally curved shape. Therefore, for example, by vibrating welding that can only apply vibration of two-dimensional amplitude to the component, the inner piece 1 with respect to the second casing piece 14
It is difficult to securely fix No. 3. That is, in such a configuration, the second casing piece 14 and the inner piece 1
The use of laser welding for fixing to 3 is particularly effective in achieving its effect (the degree of freedom in designing the intake passage constituent portion 21 can be increased).

It should be noted that, for example, the following embodiments can be implemented without departing from the spirit of the present invention. The above embodiment is modified so that laser welding is performed between the joining surfaces 13a and 14b of the second casing piece 14 and the inner piece 13 except the fitting portion between the engaging concave portion 22 and the engaging convex portion 23.

The modification of the above embodiment is to remove the engaging concave portion 22 and the engaging convex portion 23. In this case, the device for laser welding requires a jig for holding down the second casing piece 14 and the inner piece 13 during the irradiation of the laser light L.

The above embodiment is modified so that the laser light L is emitted from the second casing piece 14 side. In this case, a material that absorbs the laser light L without transmitting it is used for the inner piece 13, and a material that is transparent to the laser light L is used for the second casing piece 14.

The inner piece 1 is modified by modifying the above embodiment.
Laser welding only the two side edges of No. 3 to the second casing piece 14. ○ To be specified in the resin intake manifold used for single-cylinder engines.

○ 2 cylinders, 3 cylinders, 5 cylinders, 6 cylinders, etc. 4
To be embodied in a resin intake manifold used in a multi-cylinder engine other than a cylinder. The present invention is not limited to being embodied in a resin intake manifold used for an automobile engine, and may be embodied in a resin intake manifold used for a marine engine other than an automobile, for example.

The technical idea that can be understood from the above embodiment will be described. (1) The resin intake manifold according to any one of claims 1 to 6, wherein a joint portion between the second component and the intermediate component has a three-dimensionally curved shape.

(2) The first part, the second part joined and fixed to the first part, and the intermediate part arranged between the first part and the second part. In the resin intake manifold in which the intake passage constituting portion forming a part of the intake passage is formed by joining and fixing the intermediate component and the intermediate component, the fixing of the second component and the intermediate component is performed by the laser. A method for manufacturing a resin intake manifold, which is performed by welding.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an intake manifold

FIG. 2 is a perspective view of an intake manifold.

FIG. 3 is a plan view of the second casing piece with the inner piece joined thereto.

4A is an enlarged view of a main part of FIG. 3, and FIG. 4B is a view of FIG.
1-1 line sectional view.

FIG. 5 is a vertical sectional view of an intake manifold showing a conventional technique.

FIG. 6 is a vertical cross-sectional view of an intake manifold showing another conventional technique.

7 is a sectional view taken along line 2-2 of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Resin intake manifold, 12 ... 1st casing piece as a 1st part, 13 ... Inner piece as an intermediate part, 13a ... Joining surface, 14 ... 2nd casing piece as a 2nd part, 14b ... Joining surface, Reference numeral 21 ... Intake passage constituent portion, 22 ... Engagement concave portion, 22a ... Laser welded inner side surface, 23 ... Engagement convex portion, 23a ... Laser welded side surface, L ... Laser light used for laser welding.

Claims (6)

[Claims] 1. A first component, a second component joined and fixed to the first component, and an intermediate component disposed between the first component and the second component, the intermediate component being the intermediate component with the second component. An intake passage forming portion which constitutes a part of the intake passage is formed between the parts by joining and fixing the two parts together, and laser welding is used to fix the second part and the intermediate part. Characteristic resin intake manifold. 2. The resin intake manifold according to claim 1, wherein the laser welding is continuously performed along the extending direction of the intake passage forming portion. 3. A plurality of intake passage constituent portions are formed between the second component and the intermediate component, and the intake passage constituent portions are respectively formed at joint portions of the second component and the intermediate component on both sides of each intake passage constituent portion. The resin intake manifold according to claim 1 or 2, which is laser-welded. 4. The engaging concave portion provided on one side and the engaging convex portion provided on the other side are fitted to each other at a joint portion between the second component and the intermediate component. The resin intake manifold according to any one of the above. 5. The resin intake manifold according to claim 4, wherein the engagement concave portion and the engagement convex portion are formed so as to extend along the intake passage forming portion. 6. The resin intake manifold according to claim 4, wherein the laser welding is applied to a fitting portion between the engaging concave portion and the engaging convex portion.