JPH084609A - Intake manifold - Google Patents

Abstract

(57) [Summary] [Purpose] An object of the present invention is to provide an inexpensive intake manifold which is made of iron or an iron alloy and can reliably prevent rust. [Structure] The intake manifold 1 is composed of a surge tank 2 made of mild steel, a port portion mounting flange 3 made of mild steel, and three pipes 4a, 4b, 4c made of mild steel.
One ends 41a, 41b, 41c of the three pipes are fitted into the cylindrical portions 27a, 27b, 27c of the surge tank 2, and their joints P1a, P1b, P1c are brazed with copper. The other ends 43a, 43b, 43c of the pipes are fitted into the cylindrical portions 32a, 32b, 32c of the port portion mounting flange 3 and the joint portions P2a, P2b, P2c thereof are brazed with copper. The intake manifold 1 has a nickel phosphorus coating formed on its inner and outer surfaces by electroless nickel phosphorus plating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake manifold for supplying air from a throttle body to an engine.

[0002]

2. Description of the Related Art An automobile engine is provided with an intake manifold for evenly distributing a mixture of air and fuel to each port of the engine. Conventional intake manifolds are known that are made by die-casting an aluminum alloy and use a plurality of aluminum alloy pipes. The reason why the aluminum alloy is exclusively used as a material for the intake manifold is that it has a small specific gravity and thus can be reduced in weight and has excellent corrosion resistance.

[0003]

However, since the aluminum alloy has a high unit price, the conventional intake manifold has a problem that the material cost is high and the manufacturing cost cannot be reduced. In particular, in the case of a die-cast molded product, since the thickness increases, the amount of material used increases, and the material cost further increases.

On the other hand, when iron or mild steel is used as the material, the unit cost is lower than that of the aluminum alloy, so that it is possible to reduce the manufacturing cost, but when rust occurs on the inner surface of the intake manifold, the rust is inhaled. There is a risk that the air may be sent to the port of the engine together with the air, damaging the cylinder and damaging the engine. Therefore, how to prevent the generation of rust on the inner surface of the intake manifold has been an issue to date.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an inexpensive intake manifold which is made of iron or an iron alloy and can surely prevent the generation of rust.

[0006]

In order to solve the above-mentioned problems, an intake manifold according to claim 1 is connected to a surge tank made of iron or iron alloy connected to a throttle body and a port portion of an engine. An iron or iron alloy port portion mounting flange; and an iron or iron alloy pipe having one end brazed to the surge tank and the other end brazed to the port portion mounting flange, The surge tank, the flange for mounting the port portion, and the inner surface of each of the pipes are characterized in that a corrosion-resistant metal coating is formed including the brazed portion.

According to a second aspect of the present invention, there is provided the intake manifold according to the first aspect, wherein the outer surface of the surge tank, the flange for mounting the port portion, and the outer surface of the pipe also includes the corrosion-resistant metal film. Is formed. The invention described in claim 3 is claim 1
Alternatively, the intake manifold according to the second aspect is characterized in that the corrosion-resistant metal coating is formed by electroless plating.

The invention according to claim 4 is the intake manifold according to claim 1 or 2, characterized in that the corrosion-resistant metal coating is formed by baking.

[0009]

The intake manifold according to the first aspect is made of iron or an iron alloy, so the material cost is low, and therefore the manufacturing cost can be reduced. Here, the iron alloy is an alloy containing iron as a main component, and is meant to include soft iron, mild steel, and the like.

Further, since this intake manifold has a structure in which a surge tank, a flange for mounting a port portion and a pipe are joined, it is possible to make the plate thickness thinner than die casting, and to manufacture by reducing the amount of material used. The cost can be reduced. Further, since the corrosion-resistant metal coating is formed on the inner surface of each member including the brazed portion, the joint portion is also covered with the corrosion-resistant metal coating, and rust can be reliably prevented. Therefore, it is possible to reliably prevent damage to the engine cylinder due to rust. On the other hand, when each member is joined by arc welding as in the conventional case, a welding bead or a blow hole is generated, so that almost no corrosion resistant metal film is formed at the joint portion, and rust is generated from there. There is a problem that the rust damages the cylinder.

In the intake manifold according to the second aspect of the present invention, since the corrosion-resistant metal coating is formed on the outer surface of each member, it is possible to reliably prevent rust from being generated on the entire surface of the intake manifold. Therefore, the risk that the rust generated on the outer surface will enter the inner surface is eliminated, and the damage to the cylinder of the engine due to the rust can be prevented more reliably.

As the brazing, for example, nickel,
Silver, copper, brass or alloys thereof can be used.
Among them, nickel and silver have excellent heat resistance, but considering the operating temperature of the intake manifold, copper and brass can be used, which is advantageous in terms of cost. As the corrosion-resistant metal coating, for example, a coating containing nickel, zinc, cadmium, tin or the like as a main component can be adopted. Further, the corrosion-resistant metal coating can be formed by, for example, electroplating, hot dipping, diffusion plating, thermal spraying, vapor deposition plating, electroless plating, or baking. Considering that the corrosion-resistant metal film is uniformly formed on the inner surfaces of the surge tank, the flange for mounting the port portion, and the pipe, electroless plating or baking is employed as described in claim 3 or 4. It is preferable.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 3 are explanatory views of the intake manifold, FIG. 1 is a front view, and FIG. 2 (a) is A of FIG.
-A sectional view, FIG. 2 (b) is an end view of the pipe, FIG. 3 (a)
2 is a view from B of FIG. 2 (only the flange for mounting the throttle body is shown), and FIG. 3B is a view from C of FIG. 2 (only the flange for mounting the throttle body and the surge tank are shown).

The intake manifold 1 includes a surge tank 2, a port portion mounting flange 3 and three pipes 4a,
It is composed of 4b and 4c. In the surge tank 2, a lid member 21 and a bottom member 25 made of a mild steel plate (SPH270C of JIS standard) having a thickness of 1.6 mm are joined together, and a joint portion P4 thereof is brazed with copper. A hole 22 is provided substantially at the center of the lid member 21, and a cylindrical portion 23 is provided so as to project around the hole 22. A mounting tube 51 provided on the throttle body mounting flange 5 is fitted into the cylindrical portion 23, and a joint portion P3 thereof is brazed with copper. The flange 5 for mounting the throttle body is formed by processing a 2.8 mm thick mild steel plate (SPH270C) into a metal plate, and a fold-back portion 54 is provided on the peripheral edge thereof in the same direction as the protruding direction of the mounting pipe 51. . Due to the mounting pipe 51 and the folded portion 54, the throttle body mounting flange 5 has sufficient rigidity even if the plate thickness is thin. Further, the flange surface 52
There are a total of four bolt insertion holes 53a, 53b, 53c,
53d are provided, and bolts are inserted into each of them and fixed to a throttle body (not shown). The bottom member 25 has circular holes 26a and 26 at three locations on the bottom, left, center, and right, respectively.
b and 26c are provided, and a cylindrical portion 27 is provided around each of them.
Projections a, 27b, and 27c are provided. The throttle body refers to a device including a throttle valve that interlocks with the accelerator, a throttle position sensor that detects the opening of the throttle valve, and the like.

The port mounting flange 3 has a thickness of 2.6.
mm mild steel plate (SPH270C), elliptical holes 31a, 31b, 31c are provided on the left, middle, and right, respectively.
Cylindrical portions 32a, 32b, 32c are provided so as to project around each of them. Further, a foldback portion 33 is provided on the peripheral edge of the port portion mounting flange 3 in the same direction as the protruding direction of the tubular portions 32a, 32b, 32c. This tubular portion 32a, 32
Due to b and 32c and the folded-back portion 33, the port portion mounting flange 3 has sufficient rigidity even if the plate thickness is thin. Further, there are five bolt insertion holes 35a, 35b, 35c, 35 on the flange surface 34 of the port mounting flange 3 in total.
d and 35e are provided and fixed to an engine head (not shown) by bolts inserted through them.

The three pipes 4a, 4b and 4c are each a mild steel pipe (J) having a thickness of 1.0 mm and a diameter of 28.6 mm.
The IS standard STKM11A). In FIG. 1, the left and right pipes 4a and 4c are bent on the surge tank 2 side and are formed so as to be gradually separated from the central pipe 4b. One ends 41a, 41b, 41c of the pipes are expanded, and the cylindrical portion 2 protruding from the bottom member 25 of the surge tank 2 is provided.
7a, 27b, 27c, respectively, and their joints P1a, P1b, P1c are brazed with copper. The other ends 43a, 43b, 43c of the pipes are deformed into a substantially elliptical shape, and the tubular portion 32a protruding from the port attachment flange 3 is provided.
It is inserted into 32b and 32c. The other end 4 of this pipe
3a, 43b, 43c are arranged slightly before reaching the flange surface 34, and in this state, the joint portions P2a, P2b, P2
c is brazed with copper.

The intake manifold 1 is made of electroless nickel-phosphorus-plated joints P1a-c, P2a-c, P.
Nickel phosphorus coatings (film thickness of about 5 μm) are formed on the inner and outer surfaces including 3 and P4. The electroless nickel phosphorous plating refers to autocatalytic nickel phosphorous plating by reduction of hypophosphorous acid, and the nickel phosphorous coating formed by this contains nickel as a main component and contains 2 to 15% of phosphorus. Such electroless nickel-phosphorus plating has a nickel-phosphorus coating, especially on the inner surface side of the throttle body mounting flange 5, surge tank 2, pipes 4a, 4b, 4c, and port mounting flange 3, as compared with electroplating or the like. The feature is that it is formed reliably and reliably. Therefore, as compared with the case where the metal coating is formed by electroplating or the like, it is possible to more reliably prevent rust from being generated on the inner surface.

In the above structure, the three elliptical holes 31a, 31b, 31c of the port portion mounting flange 3 are aligned with the respective port portions of the engine (not shown), and the hole 22 in the approximate center of the surge tank 2 is for mounting the throttle body. A throttle body (not shown) is aligned through a mounting pipe 51 provided on the flange 5. Therefore, the air taken in from the air cleaner (not shown) is supplied to the surge tank 2 and the pipes 4a, 4b, 4
It is introduced into the port section of the engine via c.

Since the intake manifold 1 described above is made of an iron alloy, the manufacturing cost is reduced as compared with the conventional intake manifold using an aluminum alloy. Further, compared to an intake manifold that uses an aluminum alloy pipe, iron is superior in strength, so that the plate thickness can be reduced, the amount of material used is small, and the cost is reduced accordingly. Further, the throttle body mounting flange 5 is formed by the mounting pipe 51 and the folded portion 54, and the port portion mounting flange 3 is formed by the tubular portion 3.
Since the plates 2a, 32b, 32c and the folded-back portion 33 have sufficient rigidity even when the plate thickness is thin, the amount of material used is smaller than that of a normal plate-shaped flange, and the cost is correspondingly reduced.

Further, since the intake manifold 1 is brazed at the joint portions P1a to c, P2a to c, P3 and P4, there is no risk of beads or blowholes as in welding. Therefore, not only the inner surface and the outer surface but also the joint portions P1a to c, P2a to c, P3 and P4,
A nickel phosphorus coating is formed uniformly and reliably. Therefore, even if it is used for a long period of time, there is no risk of rusting on the inner surface of the intake manifold 1, and it is possible to reliably prevent damage to the engine cylinder due to rusting.

Further, since the intake manifold 1 has a nickel-phosphorus coating uniformly formed on the outer surface, there is no possibility of rusting on the outer surface. Therefore, as compared with the case where only the inner surface is covered, it is possible to prevent rust from entering from the outside to the inside, and thus it is possible to more reliably prevent damage to the engine cylinder due to rust.

Furthermore, since the intake manifold 1 uses a pipe rather than a die-cast molded product, the inner surface is smooth, and the performance as an intake manifold, that is, intake air is supplied to the engine by the pipes 4a, 4b, 4c. The performance of evenly and efficiently distributing to each port is improved.

Needless to say, the present invention is not limited to the above-mentioned embodiments and can be carried out in various modes without departing from the technical scope of the present invention. For example,
As another example of the corrosion-resistant metal coating, a so-called dacrotized treatment of forming a zinc chromic acid composite coating by baking may be adopted. In the dacrotizing treatment, the intake manifold before the treatment is immersed in a dacro liquid containing metallic zinc flakes, chromic anhydride, glycol, etc., and then heated to 300 to 350 ° C. in a baking furnace. As a result, hexavalent chromium is reduced with an organic substance such as glycol to produce a water-insoluble amorphous trivalent chromium polymer, which serves as a binder to bind zinc flakes laminated in several tens of layers to each other to form a corrosion-resistant metal film. Is formed.

Also by this dacrotizing treatment, a film can be formed uniformly and surely particularly on the inner surface of the intake manifold (including the joining portions P1a to c and P2a to c), as compared with electroplating. Therefore, the same effect as that of the above embodiment can be obtained. Further, in the above embodiment, the nickel phosphorus coating is formed on the outer surface as well, but the nickel phosphorus coating may be formed only on the inner surface of the intake manifold 1. In this case as well, there is no possibility of rusting on the inner surface, so that damage to the engine cylinder due to rusting can be prevented. Here, the inner surface of the intake manifold 1 will be described in the above embodiment. In the throttle body mounting flange 5, the side of the flange surface 52 that contacts the throttle body, the inner surface of the mounting pipe 51, and the surge tank 2 are the same. The inner surface of the cylindrical portion 23, the inner surfaces of the lid member 21 and the bottom member 25, the inner surfaces of the cylindrical portions 27a, 27b and 27c, the inner surfaces of the pipes 4a, 4b and 4c, and the port portion mounting flange 3. Then, the flange surface 3
4 abutting against the engine head and the tubular portions 32a, 32
The inner surfaces of b and 32c are referred to.

[Brief description of drawings]

FIG. 1 is a front view of an intake manifold.

2 is an explanatory view of the intake manifold, and FIG.
1A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is an end view of the pipe.

3 is an explanatory view of the intake manifold, and FIG.
2A is a view from B of FIG. 2, and FIG. 3B is a view from C of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Intake manifold, 2 ... Surge tank, 3 ... Port part mounting flange, 4a, 4b, 4c ... Pipe, 5 ... Throttle body mounting flange, P1a-c, P2a- c, P3, P4 ... Joined portion,

Claims (4)

[Claims] 1. An iron or iron alloy surge tank connected to a throttle body, an iron or iron alloy port mounting flange connected to an engine port, and one end brazed to the surge tank. And a pipe made of iron or an iron alloy, the other end of which is brazed to the port mounting flange, the inner surface of the surge tank, the port mounting flange, and the pipe being brazed An intake manifold characterized in that a corrosion-resistant metal coating is formed including the parts. 2. The intake manifold according to claim 1, wherein a corrosion-resistant metal coating is formed on the outer surfaces of the surge tank, the port mounting flange, and the pipe, including the brazed portion. . 3. The intake manifold according to claim 1, wherein the corrosion-resistant metal coating is formed by electroless plating. 4. The intake manifold according to claim 1, wherein the corrosion-resistant metal coating is formed by baking.