JPH0419352A - Suction device for pneumatic multicylinder engine and manufacturing method therefor - Google Patents

Abstract

PURPOSE:To enhance the mounting operation efficiency by forming each branch pipe with use of a pipe member, the branch pipes being used for connecting a main pipe section and their corresponding air cylinders, and by mounting the end portions of the branch pipes at the main-pipe section side to the main pipe section by means of a common end metal fitting to the branch pipes. CONSTITUTION:A suction manifold 2 includes a main pipe section 3 and four branch pipes 4. Each branch pipe 4 is connected at its tip end to the suction port of its corresponding air cylinder of an engine 1. The branch pipe section 4 is formed of a branch-pipe member 14 which has been prepared as an integral unit by connecting first and second end metal fittings 12, 13 to both ends of a four branch pipe 4 arrangement respectively. The first end metal fitting 12 which concurrently serves as a side wall of the main pipe section 3 includes a plate portion 12a which has an edge portion engageable with a stepped portion 11b formed with respect to an open section 11a provided at the side face of a body 11 of the main pipe section 3. The open section 11a is closed by this plate portion 12a. The second end metal fitting 13 is secured by means of bolts or the like to the engine side after the end opening of a suction passage of each branch pipe 4 has been faced to the suction port of a corresponding air cylinder of the engine, whereby the suction manifold 2 is secured to the engine 1.

Description

[Detailed description of the invention] (Industrial application field) This invention integrally includes a main pipe portion and a plurality of branch pipes.

This invention relates to intake devices such as intake manifolds and surge tanks for multi-cylinder engines.

(Prior Art) In a multi-cylinder engine, air introduced from an air cleaner is branched at a main pipe section and supplied to each corresponding cylinder via a plurality of branch pipes. Intake devices such as intake manifolds and surge tanks are used.

In these intake systems, the branch pipes are designed to avoid the influence of intake pulsation and uniformly supply sufficient air and mixture to each cylinder, depending on factors such as the operating rotation range of the engine. The length of each branch pipe is strictly determined, and it is necessary that one end of each branch pipe be connected to the engine intake port and the other end to the main pipe portion in an airtight manner.

(Problems to be Solved by the Invention) Recently, from the viewpoint of reducing the weight of an intake device and improving intake efficiency, branch pipes have been formed using pipe materials.

In this case, since both ends of the branch pipe made of pipe material are attached to the engine's intake port and main pipe (these are collectively referred to as adherents), there are many attachment points, and these attachment points must be installed airtight. is desired, so the structure becomes complicated.

Particularly in multi-cylinder engines, many branch pipes are connected to a main pipe section that is smaller in size than the engine, so it is necessary to connect the ends of many branch pipes within a narrow space. Attaching the branch pipe to the main pipe using material is troublesome.

The invention of the present application has been made based on the above circumstances, and the invention as claimed in claim 1 of the present application is to easily install a large number of branch pipes made of pipe material in a narrow space of a main pipe portion with good workability. The purpose is to

Further, the invention as claimed in claim 3 provides a manufacturing method that can easily manufacture a branch pipe that is made of pipe material and has excellent airtightness and is easy to attach to an adherend. The purpose is to provide

(Means for Solving the Problems) For these purposes, the invention according to claim 1 of the present application provides an intake system for a multi-cylinder engine, which has a main pipe section and a plurality of branch pipes, and has a main pipe section and a plurality of branch pipes. In a pipe that connects the main pipe section and each cylinder of the engine, each of the branch pipes is formed of a pipe material, and the ends of these branch pipes on the main pipe side are connected to a common end fitting. This end fitting is attached to the main pipe.

Further, the invention according to claim 3 of the present application is such that a plurality of branch pipes of an intake system of a multi-cylinder engine are each formed from a pipe material, and a closing member for closing the inside of each branch pipe is inserted at the end of each of the branch pipes. At the same time, the ends of each of these branch pipes are placed in a mold, and then molten metal is pressurized and cast into the mold to form end fittings integrally around the shoulder circumferences of the ends of these branch pipes. The branch pipe is then attached to the adherend via this end fitting.

(Function) According to the invention recited in claim 1 of the present application, since the work of attaching the ends of the plurality of branch pipes made of pipe material on the main pipe side is performed to the end fittings, the work is performed in the surrounding open environment. This can be done with good workability under the main pipe, and the installation work is improved because it can be done by simply attaching the end fitting to the main pipe section.

According to the invention set forth in claim 3 of the present application, the end fitting is integrally formed by casting at the end of the pipe material that becomes the branch pipe, and the molten metal is pressurized when forming the end fitting, so that the pipe material and the end fitting are integrally formed. Air pockets are less likely to occur between the parts and the fittings, and a branch pipe can be easily manufactured by keeping the two in close contact.

The branch pipe manufactured by this manufacturing method has excellent airtightness even though it uses pipe material, and the branch pipe can be easily connected to the attached member such as the main pipe or engine via the end fitting as in the conventional method. It can be installed with a simple structure, and the workability of installing branch pipes is good.

(Embodiment) The present invention will be described below with reference to a first embodiment shown in FIGS. 1 to 6. First, an outline of an engine equipped with an intake system of the embodiment will be explained.

In FIG. 2, 1 is an engine, and 2 is an intake manifold as an intake device.

The engine 1 is a multi-cylinder engine having four cylinders, and fuel is supplied by an injector.

This is a so-called fuel injection engine.

The intake manifold 2 has a main pipe portion 3 and four branch pipes 4, and the tip of each branch pipe 4 is connected to an intake port (not shown) of each cylinder of the engine 1, respectively.

Also, the open end 3a of the main pipe portion 3 of this intake manifold 2
A throttle valve device 5 is attached to the throttle valve device 5, and an air cleaner 6 is supported via the throttle valve device 5.

For each cylinder of the engine 1, an injector 7 is installed near the respective intake port.

A fuel tube 8 extending from a fuel tank (not shown) is connected to these injectors 7, and fuel pressurized to a predetermined pressure is supplied from each injector 7. . The appropriate amount of fuel is injected into each cylinder at the appropriate timing.

On the other hand, the amount of air taken in from the air cleaner 6 is controlled by the throttle valve 5 by operating an accelerator pedal (not shown).
The opening is controlled by the opening degree of a, and the air sucked into the main pipe section 3 is sucked into each cylinder at an appropriate timing.

In each cylinder of the engine 1, this air and the fuel injected and supplied from the injector 7 generate an air-fuel mixture.

The intake manifold 2 of such an engine 1 is formed as shown in FIG. 1 and FIG. 3.4.

That is, the intake manifold 2 has the main pipe part 3 and four branch pipes 4 as described above, but in this embodiment, as shown in an exploded perspective view in FIG. 3, one side is open. It consists of a box-shaped main pipe body 11 and a branch pipe member 14 in which the four branch pipes 4 are connected to each other at both ends by first and second end fittings 12, 13 and integrated.

Each branch pipe 4 of this branch pipe member 14 is a pipe material made of aluminum alloy made of a wrought material, and the inside of these branch pipes 4 and the first and second end fittings 12.
An intake passage 15 is formed through each of the intake passages 13 and 13, respectively.

The first end fitting 12 is an end fitting according to the invention set forth in claim 1 of the present application, and the first end fitting 12 and the second end fitting 13 are the end fitting according to the invention set forth in claim 3 of the present application. This corresponds to the end fitting.

The first end fitting 12 is a member that also serves as a side wall of the main pipe section 3, and is a part forming part of the main pipe section 3.

That is, as shown in FIG.
By locking the edge of the plate portion 12a of the first end fitting 12 to the step portion 11b formed in the opening portion 1a, the opening portion 1
1a.

Then, in this way, the open portion 11a is connected to the first end fitting 12.
By closing the main pipe section 3, the main pipe section 3 becomes a sealed box shape with only the intake passage 15 formed in each branch pipe 4 and the open end 3a to which the throttle valve device 5 is attached open.

On the other hand, the second end fitting 13 is fixed at its four corners with bolts or the like so that the opening end of the intake passage 15 of each branch pipe 4 faces the intake port of the engine, and the intake manifold 2 is attached to the engine 1. It is fixedly supported.

In this embodiment, the first end fitting 12 includes a fifth end fitting 12.
As shown in the figure, it is cast from aluminum alloy.

That is, when forming this first end fitting 12,
A branch pipe 4 made of a pipe material processed into a predetermined shape and size is prepared in advance.

At the ends of these branch pipes 4, for example, connection ends 4a processed into a non-circular shape such as a hexagonal shape as shown in FIG. 6 are expanded to prevent rotation, and each connection of each branch pipe 4 is The end portion 4a is formed into a mold 21 (corresponding to the mold referred to in the invention of the present application).
at an appropriate position within the cavity 22 of.

In the end fitting 12 of No. 41 of this embodiment, a plate portion 12a for closing the open portion 11a of the main pipe body 11 is provided.
and a sleeve portion 12b that covers the proximal end side of the connecting end portion 4a of each branch pipe 4 from the outside.
A recess 22a for forming the sleeve portion 12b is formed at each portion of the cavity 22 to which each of the branch pipes 4 is attached.

Then, a closing member 23 is inserted from the lower side in FIG. The intake passage 15 portion is closed.

This closing member 23 holds the connecting end 4a of each branch pipe 4 in a predetermined position within the cavity 22, prevents molten metal from entering into the inside of each branch pipe 4, and furthermore, It is also made by molding, in which the opening end 15a of the intake passage 15 formed at 12 is molded into a predetermined shape.

In this embodiment, a molded part 23a is provided at the tip of the closing member 23, and a step part 23b is provided at the lower end of this molded part 23a.
A cylindrical base 23c with a constant diameter is integrally formed below the stepped portion 23b, and the molded portion 23a is formed in order to reduce the resistance of air flowing into each branch pipe 4. , the open end 15a of the intake passage 15 is filled with molten metal supplied to the cavity 22 with the outer shape of a so-called bell mouth.
It is designed to form a smooth shape (fifth
See figure.

In this embodiment, when casting the first end fitting 12, the step portion 23b is inserted into the cavity 22 by a dimension t.
Casting is performed with the metal inserted into the interior.

This is due to the casting of the first end fitting 12, which causes distortion such as overall warpage mainly in the plate part 12a of the end fitting 12, but the finish machining by cutting etc. on the lower surface of the plate part 12a is caused by This is because the opening end 15a of the intake passage 15 of the branch pipe 4 is always formed into a smooth bellmouth shape by performing the step t.

After each branch pipe 4 is set in this manner, molten aluminum alloy is supplied into the cavity 22 of the mold 21 from a sprue (not shown), and in this embodiment, casting is performed by a molten metal forging method.

That is, after a predetermined amount of molten metal is supplied to the cavity 22 in which each of the branch pipes 4 is set, at the point when the sprue system starts to solidify, the pressurizing piston 24 is moved upward to supply the molten metal in the cavity 22. Approximately 500Kg/c
Apply a pressure of m2.

In this case, since the connecting end 4a of the branch pipe 4 has an expanded shape, pressure can be introduced from the molten metal to the inner surface of the connecting end 4a, and this pressing force can be applied to the outer surface of the connecting end 4a. By opposing the pressing force applied to the side, the connection end 4
This is intended to prevent deformation of a.

As a result, the first end fitting 12 made of a cast metal is formed as a dense casting and can be formed thin.

Moreover, since the adhesion of the molten metal to the mold surface is increased by pressurization, the transferability of the cavity 22 is good, and the adhesion to the connecting end 4a of the branch pipe 4 is also good. Improves airtightness without creating air pockets.

When the lower surface of the first end fitting 12 cast in this manner is finished by cutting or the like by the dimension t as described above, the fourth end fitting 12 is finished.
It will look like the figure.

The first end fitting 12 formed in this manner has the following features.

That is, since the sleeve portion 12b is integrally formed on the first end fitting 12 and the end of the branch pipe 4 is connected thereto, the plate portion 12a of the first end fitting 12 can be made thinner. By making it lighter and at the same time ensuring a large contact area with the end of the branch pipe 4, each branch pipe 4 can be firmly held.

Since the tip of the branch pipe 4 is connected to the first end fitting 12 formed of cast metal by positioning it at a position apart from the lower surface of the first end fitting 12, the end of the branch pipe 4 is It does not interfere with the flow of molten metal.

Therefore, the opening end 15a of the intake passage 15 formed on the inner surface side of the first end fitting 12 (the side that becomes the inner surface of the main pipe section when the main pipe section is formed) is shaped like a bell mouth with a large radius of curvature. This makes it possible to improve intake efficiency.

Further, since the open end 15a of the intake passage 15 is open on the inner surface side of the first end fitting 12, it is easy to finish this part from the inner surface side, and it is possible to connect each cylinder of the engine 1. The filling efficiency of intake air can be easily increased.

Moreover, since the connecting end 4a of the branch pipe 4 has an expanded shape and is integrally cast with the first end fitting 12, the contacting surface area between the connecting end 4a and the first end fitting 12 is large. In addition, since the interface between the two is bent, pressure leakage is reduced due to the labyrinth effect, and the edge of the branch pipe 4 can be hidden from the intake passage 15, so the edge of the branch pipe 4 can reduce the intake flow. It can also eliminate clutter.

Furthermore, by forming the connecting end 4a at the tip of the branch pipe 4 into a non-circular shape, rotation between the first end fitting 12 and the branch pipe 4 can be prevented, and the contact end Since the rigidity of the branch pipe 4a is high, the end of the branch pipe 4 is prevented from becoming flattened and falling off, and the connection between the two is strengthened.

In this embodiment, the connecting end 4a of the branch pipe 4 is formed as described above, but it may also be formed as in the modification shown in FIG. 7 or 8.

In the modification shown in FIG. 7, the connecting end 4a is formed into a cylindrical shape with a substantially large diameter, and four tongues 4b and notches 4c extending in the axial direction are alternately arranged on the opening edge of the connecting end 4a. It is something that

The tongue portion 4b functions as a rotation stopper for the end fitting 12 of the branch pipe 4, and since the notches 4C are formed, the flow of molten metal during casting is performed through these notches 4c, which improves casting properties. It has the advantage of being good.

Furthermore, since the tongue portions 4b are formed as four small independent parts, the heat transferred from the molten metal during casting is difficult to diffuse, and the temperature of these tongue portions 4b becomes high. Adhesion between the tongue portion 4b and the end fitting 12 is improved.

Further, in the modification shown in FIG. 8, the connecting end 4a of the branch pipe 4
is expanded into a bellmouth shape, and a tongue portion 4b and a notch 4c are formed at the opening edge, similar to the modification shown in FIG. 7.

Therefore, in this modification as well, since the tongue portion 4b and the notch 4c are formed, the same effect as in the modification shown in FIG. In particular, since the tip of the tongue portion 4b is spaced radially outward from the axis of the branch pipe 4, it has the advantage of being able to resist large torques as a detent.

Note that a sealing material may be applied to the connection portion between the branch pipe 4 and the first end fitting 12 just in case or as necessary.

This is how it was formed. A second end fitting 13 is formed on the other end side of each branch pipe 4 of the branch pipe member 14 having the first end fitting 12 in the same manner as the first end fitting 12 described above.

Regarding the formation of the second end fitting 13, the description will be omitted since the details are generally the same.

Note that since the formation of the first and second end fittings 12 and 13 is performed by the same process, both may be formed at the same time.

The branch pipe member 14 thus formed has its shoulder edge fitted onto the step portion 11b formed along the entire circumference of the open portion 11a of the main pipe body 11, and is continuous from the outside all the way around. By welding, a box-shaped main pipe section 3 is formed, and an intake manifold 2 having four branch pipes 4 each having one end fixed to the main pipe section 3 is formed (FIG. 1).

In this way, the stepped portion 11b into which the peripheral edge of the first end fitting 12 is fitted is formed in the open portion 11a of the main pipe main body 11, and the fixing position of the first end fitting 12 with respect to the main pipe main body 11 is restricted. Therefore, the relative position between the two is constant, and the connection position of each branch pipe 4 to the main pipe portion 3 is also maintained appropriately.

According to the intake manifold 2 described above, since the pipe material made of expanded material is used as the branch pipe, the surface roughness of the inner surface of the intake passage is improved, and the intake performance of the engine can be improved.

Since the work of tightly fitting one end of the branch pipe 4 is performed on the first end fitting 12, the work can be performed with good work efficiency in an open surrounding environment.

Accordingly, since the main pipe part 3 is formed separately from the main pipe part main body 11 and the first end fitting 12, the main pipe part main body 11
It is also easy to remove ridges and the like formed on the inner surface of the first end fitting 12 and to finish the opening end 15a of the intake road 15 formed on the back surface of the first end fitting 12 into a smooth shape.

In addition, the main pipe portion 3 of the first end fitting 12 having the branch pipe 4
It is easy to install it by simply fixing it by welding, etc., and since it is not integrally formed by casting as in the past, fewer cores are used and production efficiency is improved, and the intake air If the core is clogged with the formation of the passageway, variations in wall thickness will not occur.

Moreover, since pipe material is used as the branch pipe 4,
The weight of the intake manifold 2 can be reduced.

According to the manufacturing method of this embodiment, the first end fitting 12 is integrally formed at the end of the branch pipe 4 made of pipe material, and when the first end fitting 12 is formed, the molten metal is pressurized. Therefore, the branch pipe 4 and the first end fitting 12 can be formed in close contact with each other without easily forming air pockets, thereby providing airtightness and improving the strength of the integrated structure.

Therefore, although the branch pipe 4 is made of pipe material, it has excellent airtightness, and the first and second end fittings 12
．． 13, the branch pipe 4 can be attached to the main pipe part 3, the engine 1, and other attached parts with a simple structure similar to the conventional one, and the ease of assembly and installation of the intake manifold 2 is improved. In good condition.

Next, a second embodiment shown in FIGS. 9 and 10 will be described. This embodiment differs from the previously described first embodiment only in the following points, and is similar in other points. .

In the following, only the portions related to the differences from the first embodiment described above will be explained.

Explanation of common parts will be omitted.

That is, in this second embodiment, the main pipe main body 11
Four branch pipes 4 similar to those described above are integrally formed.

Therefore, among the functions of the first end fitting 12 in the first embodiment, the function of closing the open portion 11a of the main pipe body 11 is performed by the cover body 31 made of a flat plate formed separately. That is.

In the second embodiment, the main pipe main body 32 has the function of bringing together the branch pipes 4, so it corresponds to the end fitting in the present invention.

Then, in this main pipe main body 32, an open part 11 similar to that described above is provided.
Since the opening 11a is formed, the end of the intake passage 15 and the inside of the main pipe portion 3 can be worked freely in the same manner as described above.

Furthermore, by arranging the pressurizing piston 24 as shown in FIG. 10, the main pipe body 32 is formed by the molten metal forging technique through the runner 33 in the same manner as the first end fitting 12 described above, and at the same time Each branch pipe 4 can be integrated into this main pipe body 32.

In this way, as is clear from FIG. 9, the lid 31 can be formed of a simple flat plate, so the lid
1 is cut out into a predetermined shape from a commercially available plate material and used, which has the advantage that the number of molds can be reduced.

Next, a third embodiment shown in FIGS. 11 and 12 will be described.

In the second embodiment as well, only the differences from the first embodiment described above will be explained, and the explanation of common parts will be omitted.

That is, in this third embodiment, the main pipe body 41
is formed into a substantially box shape, and does not have the open portion 11a described earlier, but has four through holes 42 corresponding to each branch pipe 4, and the formation of these through holes 42 A rectangular bulge 43 is partially formed on the outer surface of the side wall.

The first end fitting 44 is formed in the same shape as the bulged portion 43.

Since the main pipe main body 41 is formed into a substantially box shape, the first end fitting 44 does not have the function of closing the opening 11a described above, but it does not function as a lid for closing the opening 11a described above. They have the function of connecting each other, and are formed using the molten metal forging technique as described above.

The first end fitting 44 is placed over the bulge 43 and is fixed to the main pipe body 41 by continuous welding around the entire circumference at the peripheral edge.

Therefore, the first end fitting 44 having each branch pipe 4 can be attached to the main pipe main body 41 with high accuracy based on the position of the bulging part 43.
It can be installed in

In the main pipe main body 41, the intake passage 15 of each branch pipe 4 is
The opening end 15a is formed at the inner edge of the through hole 42, and finishing of these parts can be relatively easily performed from the outside through the through hole 42.

In this way, the main pipe main body 41 is integrally formed into a substantially box shape, and the first end fitting 44 is attached to the outer surface of the main pipe main body 41. However, the intake passage part, which is troublesome to form by casting, can be easily formed with pipe material made of wrought material.
An intake manifold 2 can be formed.

In other words, it is possible to reliably reduce the weight of the intake manifold 2 and the surface roughness of the inner surface of the intake passage 15 using a stable manufacturing technology.

In the embodiments described above, the first pot fitting for connecting the branch pipe 4 and the main pipe body are manufactured using molten metal forging technology, but the present application is not limited to this, and may also be manufactured by die casting or low pressure It can be similarly implemented by pressure casting technology such as casting technology.

Further, in these embodiments, the first end fitting 12
Although the description has been given of a case where the first end fitting is manufactured by casting, the invention according to claim 1 or 2 of the present application can also be implemented by manufacturing the first end fitting by plastic working such as press working.

Furthermore, although the embodiments described above have been explained using an intake manifold as an example, it goes without saying that the present invention can be implemented even with a so-called surge tank that does not support an air cleaner.

(Effects of the Invention) As explained above, according to the invention recited in claim 1 of the present application, the work of attaching the ends of the plurality of branch pipes made of pipe material on the main pipe side is performed on the end fittings. Therefore, the work can be carried out in an open environment with good work efficiency, and since the work can be done simply by attaching the end fittings to the main pipe portion, the attaching work efficiency is improved.

According to the invention set forth in claim 3 of the present application, the end fitting is integrally formed by casting at the end of the pipe material that becomes the branch pipe, and the molten metal is pressurized when forming the end fitting, so that the pipe material and the end fitting are integrally formed. Air pockets are less likely to occur between the parts and the fittings, and a branch pipe can be easily manufactured by keeping the two in close contact.

The branch pipe manufactured by this manufacturing method has excellent airtightness even though it uses pipe material, and the branch pipe can be easily connected to the attached member such as the main pipe or engine via the end fitting as in the conventional method. It can be installed with a simple structure, and the workability of installing branch pipes is good.

[Brief explanation of drawings]

1 to 6 relate to a first embodiment of the invention of the present application, in which FIG. 1 is a perspective view of an intake manifold, FIG. 2 is an overall schematic plan view of an engine equipped with an intake manifold,
Figure 3 is an exploded perspective view of the intake manifold, Figure 4 is the
5 is an explanatory diagram of the manufacturing state of the first end fitting; FIG. 6 is an explanatory diagram of the end of the branch pipe; (a) is a front view; (b) is a side view, and FIGS. 7 and 8 respectively relate to modified examples of the end of the branch pipe,
Figure 7 (a) is a front view, (b) is a sectional view taken along the line ■-■, Figure 8 (a) is a front view, (b) is a sectional view taken along the line ■-■, Figures 9 and 10 relates to the second embodiment, FIG. 9 is an exploded perspective view of the intake manifold, FIG. 10 is an explanatory perspective view of the manufacturing state of the main pipe body, and FIGS. 11 and 12.
The figures relate to the third embodiment, FIG. 11 is a perspective view explaining the assembled state of the intake manifold, and FIG. 12 is an xn-xn diagram of FIG. 11.
It is a sectional view along a line. Engine, intake manifold (intake device), main pipe section, branch pipe, 2; first end fitting, 3, second end fitting, 21; mold (mold), 23; closing member. Figure 4;, '; Te...3ushi (;, し f 13; Etc. Yu =) Trivial Figure Figure (a) (b) Figure 11

Claims (4)

[Claims] (1) In an intake system for a multi-cylinder engine, which has a main pipe section and a plurality of branch pipes, and these branch pipes connect the main pipe section and each cylinder of the engine, each of the branches: A multi-cylinder engine characterized in that the pipes are formed of pipe material, the ends of these branch pipes on the main pipe part side are connected to a common end fitting, and this end fitting is attached to the main pipe part. intake device. (2) The intake system for a multi-cylinder engine according to claim 1, wherein a part of the side wall of the main pipe portion is formed by the end fitting. (3) A plurality of branch pipes of the intake system of a multi-cylinder engine are each formed from pipe material, and a closing member is inserted into the end of each branch pipe to close the inside of each branch pipe. The end portions are placed in a mold, and then molten metal is poured into the mold under pressure to integrally form end fittings around the ends of these branch pipes, and the branch pipes are formed through the end fittings. A method for manufacturing an intake device for a multi-cylinder engine, characterized by attaching a pipe to an adherend member. (4) In the method for manufacturing an intake system for a multi-cylinder engine according to claim 3, the end fitting is formed as a partial forming part of the main pipe part, and by attaching the end fitting to the adhered member, the main pipe part 1. A method for manufacturing an intake device for a multi-cylinder engine, the method comprising: forming an intake device for a multi-cylinder engine;