JPH0442518Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the structure of an engine intake manifold.

(Prior art) Conventionally, in engines, the intake passage of the intake manifold connected to each cylinder has been designed to have a main passage area large enough to handle the required intake air amount during high-load operation of the engine. It consists of two passages: an intake passage and an auxiliary intake passage with a small passage area commensurate with the required intake air amount during low-load operation of the engine, and a shutter valve is provided in the main intake passage to open and close it. In high-load operating ranges, the shutter valve is opened to supply a large amount of intake air to the engine from both the main intake passage and the auxiliary intake passage, while in low-load operating ranges, the shutter valve is closed and a large amount of intake air is supplied to the engine from both the main intake passage and the auxiliary intake passage. It is widely practiced to improve combustibility by supplying intake air only from the engine and maintaining the intake air flow velocity at a high speed, especially during low-load operation.

By the way, when such an intake passage configuration and intake control method are applied to an intake manifold of a multi-cylinder engine, a shutter valve is provided in each of the plurality of main intake passages of the intake manifold arranged in rows in the cylinder arrangement direction. In order to operate these in synchronization, the common valve shaft of each shutter valve is usually disposed so as to straddle the main intake passages, and
Connect the valve shaft between each main intake passage (for example, in the case of a 4-cylinder engine, between the 1st and 2nd cylinders, between the 2nd and 3rd cylinders, and between the 3rd and 4th cylinders). It must be rotatably supported by bearings formed at three locations in total.

However, when a long valve shaft is supported by a plurality of bearings in this way, the space between each main intake passage of this intake manifold (i.e., the bearing part) is smaller than that of each main intake passage. The valve shaft has low rigidity and is easily deformed by the vibrations of the intake system, so deformation of the intake manifold caused by the vibrations of the intake system causes twisting between the valve shaft and each bearing that supports it. Or, a twisting phenomenon may occur, and in some cases, the valve stem may need to be rotated.
In other words, there is a concern that it will be difficult to open and close the shutter valve.

Although it was not originally intended to increase the rigidity of the intake manifold, for example,
As shown in the above publication, as a result of providing a cooling water passage in the intake manifold for the purpose of promoting warm-up of the engine, a secondary effect of increasing the rigidity of the intake manifold has been obtained.

(Purpose of the invention) In view of the problems pointed out in the prior art section above, the present invention has a plurality of independent intake passages, and each independent intake passage is equipped with a shutter valve that is driven to open and close by the same valve shaft. In the intake manifold of a multi-cylinder engine, by effectively increasing the rigidity of the bearing part of the valve shaft without providing a dedicated reinforcing member, torsion between the valve shaft and the bearing part caused by vibrations in the intake system and The purpose of this invention is to propose an engine intake manifold structure that suppresses the occurrence of twisting as much as possible and maintains good operating characteristics of the shutter valve over a long period of time.

(Means for Achieving the Object) As a means for achieving the above object, the present invention has a plurality of independent intake passages connected independently to each cylinder of a multi-cylinder engine, which are assembled on the intake upstream side. an intake passage assembly, and is provided in each independent intake passage section of the intake passage assembly, passing through each independent intake passage section in the direction in which they are arranged, and between mutually adjacent passages of the independent intake passages. In the intake manifold of an engine, each of which is provided with shutter valves that are mounted on a common valve shaft that is rotatably supported by a bearing section that is formed astride the valve shaft and operated synchronously, the cooling water is returned to the intake manifold. Cooling water passage section for
An EGR gas passage section for EGR gas recirculation is integrally formed, and at least either the cooling water passage section or the EGR gas passage section is connected to the bearing section formed across each of the independent intake passages. One is polymerized.

(Function) In the present invention, by the above-mentioned means, the cooling water passage or the
Since the EGR gas passage section is overlapped in the radial direction with respect to the bearing section of the valve shaft formed across the adjacent independent intake passages of the intake passage section, the above-mentioned cooling water passage section or The EGR gas passage itself functions as a reinforcing member for each of the bearings,
As a result, the rigidity of each of the above-mentioned bearing parts is effectively increased without providing any special reinforcing member, and it is possible to prevent twisting and twisting phenomena between the bearing part and the valve stem caused by vibrations in the intake system. This has the effect of suppressing the

(Embodiment) A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 and FIG. 2 show 4 according to an embodiment of the present invention.
An intake manifold 1 of a cylinder motor vehicle engine is shown. This intake manifold 1 includes, in addition to an integrated intake passage section 4 formed by collecting main intake passages to be described later that communicate with each cylinder, a cooling water passage section 5 for cooling water recirculation and an EGR gas passage for EGR gas recirculation. This is a so-called composite type intake manifold in which a portion 6 is provided, and is integrally formed by casting.

The intake passage assembly 4 has four main intake passages 31, 32, 33, and 34 each independently connected to the four cylinders of the engine and having a large passage area. These main intake passages 31, 32, 33, 3
4 are configured such that their intake downstream ends are opened separately at appropriate intervals on the cylinder head mating surface 2a of the mounting flange portion 2, and their intake upstream ends are gathered at the center in the cylinder arrangement direction,
Moreover, a carburetor 8 is fastened and fixed to this gathering portion 4a (see FIG. 3).

Furthermore, each of the main intake passages 31, 32, 33,
Sub-intake passages 35, 36, 37, and 38 each have a small passage area branching from the corresponding main intake passage and extending toward the cylinder head mating surface 2a side of the mounting flange portion 2 at the lower downstream position of the intake passage 34. (Second
(see figure) are formed, and each of the main intake passages 3
The downstream ends of the intake passages 1, 32, 33, and 34 and the downstream ends of the sub-intake passages 35, 36, 37, and 38 are connected to the cylinder head mating surface 2a of the mounting flange portion 2, respectively.
Each corresponding passageway is stacked and opened at the top. These corresponding main intake passages and sub-intake passages form independent intake passages 15, 16, 17, and 18, respectively, within the scope of the utility model registration claims.

In an engine to which this intake manifold 1 is applied, two main intake manifolds are provided for each cylinder,
Both auxiliary intake passages are connected to engine operating conditions (load conditions)
The specific method is to use each independent intake passage 15, 16, 17, 18.
Each main intake passage 31, 32, 3 has a large passage area of
Shutter valve 1 is installed at the downstream end of 3 and 34, respectively.
1, 11..., and install each shutter valve 1.
1, 11... are opened and closed depending on the operating state of the engine. At this time, the shutter valves 11, 11... provided in the independent intake passages 15, 16, 17, 18, respectively, must be operated in synchronization. Connect the intake passage to the first
from the independent intake passage 15 to the fourth independent intake passage 18 at the other end (to be precise, from the first main intake passage 31 to the fourth main intake passage 34), and is arranged to penetrate in the radial direction thereof. Each of the above independent intake passages 15, 16, 17, 1 is attached to the mounting flange portion 2.
8, that is, a first bearing part 21 and a second independent intake passage 16 located between the first independent intake passage 15 and the second independent intake passage 16. Third independent intake passage 17
The valve shaft 12 is rotatably supported by a second bearing part 22 located between the third bearing part 22 and a third bearing part 23 located between the third independent intake passage 17 and the fourth independent intake passage 18. Each of the above shutter valves 11, 11
. . . are fixed, and each of the shutter valves 11, 11 . . . can be opened and closed synchronously by rotation of the valve shaft 12.

By the way, the integrated intake passage section 4 is constructed in this way, and each of the independent intake passages 15, 16, 17, 1
When the shutter valves 11, 11... are attached to the valve shaft 12 which extends through the valve shaft 12, the shutter valves 11, 11, . . . Each bearing part 21,
The rigidity of the bearing portions 22 and 23 is low, and therefore, during engine operation, the bearing portion 2 receives vibrations from the intake system.
The parts 1, 22, and 23 undergo unequal deformation, which causes twisting or twisting between the bearing parts 21, 22, 23 and the valve shaft 12, and the valve shaft 1
2 rotational operation, that is, the shutter valves 11, 11...
As mentioned above, there is a possibility that the opening/closing operation of the

Therefore, in this embodiment, the present invention is applied, and the intake manifold 1 is provided with a cooling water passage section 5 for cooling water recirculation in addition to the above-mentioned intake passage section 4.
Also equipped with an EGR gas passage section 6 for EGR gas recirculation.
The rigidity of the bearing portions 21, 22, 23 is also increased by the cross-sectional properties of the passages 5, 6 themselves. Below, these cooling water passage parts 5 and
The configuration of the EGR gas passage section 6 will be described in detail.

As shown in FIGS. 1 to 4, the cooling water passage 5 is located at a lower position of the intake passage assembly 4 and is centered at a portion corresponding to the gathering part 4a of the intake passage assembly 4. The first bearing portion 21 and the third
It extends toward the bearing portion 23 side, and its mouth ends 5a, 5a are opened on the cylinder head mating surface 2a of the mounting flange portion 2, respectively. Therefore, both ends of the cooling water passage section 5 overlap the first bearing section 21 and the third bearing section 23 in the radial direction. The rigidity of the first bearing part 21 and the second bearing part 22 is effectively increased.

Note that both ends 5a, 5a of this cooling water passage section 5
are respectively communicated with a cooling water passage on the cylinder head 52 side of the intake manifold 1.

The EGR gas passage section 6 is located below the cooling water passage section 5, as shown in FIG. 3, and further downstream of the first main intake passage 31 of the intake passage assembly 4, as shown in FIG. from a position corresponding to the first main intake passage 31 to the collecting part 4a of the intake passage assembly 4, and further extending from the collecting part 4a.
It is a substantially V-shaped passage formed so as to extend from the opening toward the second bearing portion 22 side. this
The EGR gas passage section 6 is connected to the first main intake passage 3
1 side gas inlet section 6a to the above-mentioned integrated intake passage section 4
The passage leading to the corner part 6b corresponding to the gathering part 4a is the part that becomes the original EGR gas passage, and the EGR gas introduced into the EGR gas passage part 6 from the gas inlet end 6a passes through the corner part. At 6b, as shown in FIG. 3, the air is introduced into the collective part 4a side of the intake passage assembly 4 through the EGR valve 7. On the other hand, a direct passage portion 6c extending linearly from the corner portion 6b toward the second bearing portion 22 side is formed secondarily by a core when the EGR gas passage portion 6 is cast. The mouth end portion 6d corresponding to the mounting flange portion 2 is a core support portion 4 for supporting one end of the core.
1 and is opened on the cylinder head mating surface 2a. Therefore, the direct passage section 6c of this EGR gas passage section 6 overlaps with the second bearing section 22 in its radial direction, and
The rigidity of the bearing portion 22 is increased due to the cross-sectional performance of the direct passage portion 6c itself. Note that this direct passage portion 6c is kept closed by the side end surface of the cylinder head 52.

As described above, in this embodiment, in addition to the integrated intake passage section 4, the cooling water passage section 5 and the EGR gas passage section 6 are integrally provided in the intake manifold 1, and the cooling water passage section 5 is The mouth end portion 5a.
In addition, by overlapping the direct passage section 6c of the EGR gas passage section 6 with the second bearing section 22 located at the center, these three bearing sections 21, 22,
The aim is to increase the rigidity of the 23rd part. In other words, instead of providing a dedicated reinforcing member, the cooling water passage section 5, which is essential for engine function,
By arranging the EGR gas passage section 6 together with the intake passage assembly 4 within the intake manifold 1, the rigidity of each of the bearing sections 21, 22, and 23 is increased.

Therefore, each bearing portion 21 of the intake manifold 1,
Rigidity of parts 22 and 23 and independent intake passages 31 and 3
The difference in rigidity between the bearing parts 2, 33, and 34 is small, and the bearing parts 21, 22, and 23 undergo unequal deformation due to the vibration of the intake system.
2, 23 and the valve shaft 12 is suppressed as much as possible, and smooth rotational operation of the valve shaft 12, in other words, each shutter valve 11, 11... This will ensure smooth opening and closing operations.

(Effect of the invention) The engine intake manifold structure of the invention is
An integrated intake passage is provided in which a plurality of independent intake passages each independently connected to each cylinder of a multi-cylinder engine are assembled on the intake upstream side, and
Each independent intake passage section of the above-mentioned intake passage assembly is provided with a bearing that is provided to pass through each independent intake passage section in the direction in which the individual intake passages are arranged, and that is formed to span between adjacent passages of each independent intake passage. In an engine intake manifold, each of which is provided with shutter valves that are mounted on a common valve shaft that is rotatably supported by a valve shaft and operated synchronously, the intake manifold is provided with a cooling water passage section for cooling water recirculation;
An EGR gas passage section for EGR gas recirculation is integrally formed, and at least either the cooling water passage section or the EGR gas passage section is connected to the bearing section formed across each of the independent intake passages. It is characterized in that one side is polymerized.

Therefore, according to the engine intake manifold structure of the present invention, the cooling water passage portion or the EGR gas passage portion integrally formed within the intake manifold,
Since the valve shaft bearings formed between the adjacent independent intake passages of the integrated intake passage are overlapped in the radial direction, the cooling water passage or the EGR gas passage itself is It functions as a reinforcing member for each bearing, effectively increasing the rigidity of each bearing without providing any dedicated reinforcing member, and preventing twisting between the bearing and the valve stem caused by vibrations in the intake system. The occurrence of the twisting phenomenon is suppressed as much as possible, and as a result, the practical effect of ensuring smooth rotational operation of the valve stem and maintaining good operating characteristics of the shutter valve over a long period of time can be obtained.

[Brief explanation of the drawing]

1 is a partially sectional plan view of an intake manifold of an engine according to an embodiment of the present invention, FIG. 2 is a view taken along the - arrow in FIG. 1, FIG. The figure is a -longitudinal sectional view of FIG. 1... Intake manifold, 2... Mounting flange section, 4... Intake passage assembly, 5... Cooling water passage section, 6... EGR gas passage section, 7... EGR valve, 1
0...EGR passage section, 11...Shutter valve, 1
2...Valve shaft, 15-18...Independent intake passage, 31
~34...Main intake passage, 35-38...Sub-intake passage, 50...Engine body.

Claims (1)

[Scope of utility model registration request] An integrated intake passage is provided in which a plurality of independent intake passages each independently connected to each cylinder of a multi-cylinder engine are assembled on the intake upstream side,
A bearing portion provided in each independent intake passage portion of the above-mentioned intake passage assembly, penetrating each independent intake passage portion in the direction in which the individual intake passages are lined up, and formed astride between adjacent passages of each independent intake passage. In an engine intake manifold, each of which is provided with shutter valves that are mounted on a common valve shaft that is rotatably supported by a valve shaft and operated synchronously, the intake manifold has a cooling water passage section for cooling water recirculation and an EGR valve.
An EGR gas passage section for gas recirculation is integrally formed, and at least one of the cooling water passage section or the EGR gas passage section is connected to the bearing section formed across the independent intake passages. An engine intake manifold structure characterized by polymerizing.