JP2824290B2 - Multi-cylinder engine intake system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an intake device for a multi-cylinder engine, and more particularly to a branch passage applied to an engine having a plurality of cylinder rows and connected to each cylinder. The present invention relates to an intake device for a multi-cylinder engine having a structure in which the upstream end of a multi-cylinder engine is collected in a collecting chamber.

(Prior Art) In recent years, in engines for automobiles and the like, in order to improve output performance, there is a case in which intake air charging efficiency is increased by utilizing dynamic effects of intake air in an intake system such as an inertia effect. is there. For example, in Japanese Patent Application Laid-Open No. 62-91621, in a V-type engine having two cylinder rows, a first surge tank to which an upstream passage led from an air cleaner is connected and a second surge tank are vertically stacked. The first surge tank is connected to an upstream end of a plurality of branch passages connected to each cylinder of a cylinder row located forward, and the second surge tank is connected to each cylinder of a cylinder row located rearward. Also disclosed is an intake device in which a plurality of branch passages are connected.

According to such an intake device, inertia is achieved by causing the gathering portion such as the surge tank to function as an atmosphere opening for inverting a negative pressure wave generated downstream of the branch passage into a positive pressure wave when the intake valve is opened. As a result, the effect of increasing the intake air charge can be obtained.

By the way, conventionally, as shown in the above-mentioned publication, the upstream passage is connected to the wall at one end or the center of the peripheral wall, and the branch passages are arranged side by side on the peripheral wall, as shown in the above publication. In the case of such an assembly, the distance from the connection portion of the upstream passage to the connection portion of each branch passage and the length of each branch passage differ. Therefore, the distribution of intake air to each cylinder or the effect of the inertial effect on each cylinder becomes uneven, and so on.
Further, the flow path of the intake air from the opening of the upstream passage to the opening of each branch passage is sharply bent, so that the intake resistance is increased.

On the other hand, for example, Japanese Unexamined Utility Model Publication No. 60-88062 discloses an assembly having a shape as shown in FIG. In other words, the gathering portion A has a substantially truncated cone shape,
With respect to the axis LL passing through the center of the opening B of the upstream passage opening at the end face on the small diameter side, the shape of the gathering portion itself and the opening of each branch passage C. The arrangement is substantially symmetrical.

According to this, the opening B of the upstream passage in the collecting part A
C and the lengths of the branch passages C... C are substantially equal, and the distribution of intake air to each cylinder, the effect of the inertia effect on each cylinder, and the like are made uniform. In addition, the abrupt bending of the flow path of the intake air is eliminated, and the intake resistance is reduced. As a result, the intake charging efficiency or the engine output characteristic is improved. In addition, since the upstream ends of the branch passages C... C are opened close to each other on the downstream end surface of the collecting part A, the respective branch passages C. It acts and can thus reduce the volume of the collecting part A.

(Problems to be Solved by the Invention) Incidentally, a multi-cylinder engine provided with a plurality of cylinder rows,
For example, in the intake system of a V-type engine as described in the aforementioned Japanese Utility Model Application Laid-Open No. 60-88062, branch passages connected to each cylinder row are collectively collected into corresponding collecting sections. Is performed,
In this case, in order to adopt a collective structure in which the intake charging efficiency or the engine output performance is improved as shown in FIG. 5, a plurality of substantially frustoconical collective portions A must be provided. These collecting portions must be formed individually and connected to the upstream main intake passages. For example, when the number of cylinders in each cylinder row is small, the number of branch passages of other cylinders that should serve as containers decreases. Therefore, it is necessary to increase the capacity of the collecting portion in order to increase the reversing force of the pressure liquid in the collecting portion, and the entire engine including the intake device becomes large, and the in-vehicle performance deteriorates.

In addition, since the collecting portion is formed for each cylinder row, pressure waves from other cylinders cannot be effectively used, and a high output cannot be obtained.

In view of the above, an object of the present invention is to provide a multi-cylinder engine intake device having a plurality of cylinder rows, while ensuring a high dynamic effect of intake, and by being compactly configured to improve the on-board performance of the engine. I do.

(Means for Solving the Problems) The present invention is characterized in that it is configured as follows in order to address the above problems.

First, an intake device for a multi-cylinder engine according to the invention of claim 1 of the present application (hereinafter, referred to as a first invention) is applied to an engine having a plurality of cylinder rows, and is connected to each cylinder of each cylinder row. In an intake device of a cylinder engine having a branch passage for each cylinder and the upstream ends of these branch passages being assembled on one cylinder row side, the upstream ends of the branch passages of all the cylinders are the upstream ends of the branch passages. The downstream end face of the single collective chamber forming one space volume and the above-mentioned respective branch passages are opened so as to open into the same space of the single collective chamber having the axis in the substantially same direction as the axis at the opening. It is characterized by being connected to the upstream end.

Also, the invention of claim 2 (hereinafter referred to as a second invention)
In the first invention, the engine is arranged in a V-shape.
A V-type engine having two cylinder rows is provided, and the collecting chamber is disposed above one cylinder row.

Furthermore, the invention of claim 3 (hereinafter, referred to as a third invention)
Is characterized in that, in the first invention, the branch passages for each cylinder are set to have substantially the same length.

(Operation) According to the above configuration, in any of the first to third aspects of the present invention, the upstream end of each of the branch passages of the plurality of cylinder rows is substantially the same as the axis at the upstream end of the branch passage. Is connected to the single collecting chamber having the same, the distance from the connection with the upstream passage in the collecting chamber to the upstream end of each branch passage is substantially equal, and the distribution of intake air to each cylinder and The action of the inertia effect on each cylinder is made uniform, and the intake air flow path is not sharply bent, so that the intake resistance is reduced.

With respect to the inertial effect, each branch passage acts as an open space to the other branch passages. In this case, the upstream ends of the branch passages of all the cylinders are opened in the same space of a single collective chamber. As described above, since the downstream end face of the single collecting chamber forming one space volume and the upstream end of each of the branch passages are connected, the air release space acting on the other branch passages is formed. The volume increases significantly. Therefore, even if the volume of the collecting chamber is reduced, a high inertia effect is obtained, and the amount of intake air charged into the combustion chamber is increased. In addition, due to the small volume, pressure waves of other cylinders effectively act, and a higher inertia effect is obtained. Is obtained, it is possible to make the intake device compact and, consequently, the engine compact by reducing the capacity of the collective chamber.

According to the second invention, the above-described action is obtained for a V-type engine having two cylinder rows arranged in a V-shape, and according to the third invention, the lengths of the branch passages are substantially equal. Since the setting is made, the above-mentioned action can be obtained evenly in each cylinder.

(Example) Next, an example of the present invention will be described.

FIGS. 1 and 2 show an embodiment in which the present invention is applied to a V-type engine 1 in which two banks (cylinder rows) each having three cylinders arranged in series are arranged in front and rear and arranged in a V-shape. As shown, the intake manifold 2 according to this embodiment has two flange portions 4a, 4b connected to the cylinder heads 3a, 3b of the first and second banks A, B, respectively, and one end of the flange portions 4a, 4b. branch passage 5 ₁ and for the first bank a connected three each with a second bank B (a total of six),
5 ₂ , 5 ₃ , 6 ₁ , 6 ₂ , 6 ₃ , the first bank A and the second bank
Each branch passage 5 _the bank _{B, 5 2, 5 3,} 6 1, 6 2, 6 3
And an upstream passage 9 extending upstream from the collection chamber 7, and the upstream passage 9 is connected to an air cleaner (not shown). It is connected.

In this case, the branch passages 5 ₁ , 5 ₂ , 5 ₃ , 6 ₁ , 6 ₂ , 6 ₃ are bent so that their lengths are substantially equal, and the upstream portion is integrally bundled in the collecting chamber 7. as further apparent from Figure 2, the upstream portion of the branch passage 5 _1, 5 _2, 5 ₃ in the first bank a is
Is connected in communication with the downstream end face upper of the collection chamber 7 in the state where these upstream open end 10 ... 10 are close to each other, the branch passages 6 _and 62, 6 ₃ of the upstream portion of the second bank B Is the first
Below the branch passage 5 _1, 5 _2, 5 ₃ in the bank A, is also connected in communication with the downstream end face lower collection chamber 7 in these conditions the upstream open end 11 ... 11 are close to each other. Meanwhile collecting chamber 7 These branch passage 5 _1, 5 _2, 5 _3, 6 _1, 6 _2, 6 ₃ axes at the upstream open end 10 ... 10, 11 ... 11 substantially the same direction as the axis L ₁
Cross-sectional area along with, subjected the branch passages 5 _1, 5 _2, 5 _3, 6 _1, 6 _2, 6 ₃ are connected downstream end face 7a from the upstream side end face 7b of the upstream passage 9 is connected the aforementioned having Are smoothly changed (increased).

In such an intake device, the collective chamber 7 functions as an air release section during the intake process of each cylinder of the first bank A and the second bank B by driving the engine. for that reason,
Branch passage 5 ₁ to the open time of the intake valve of each cylinder, 5 _2, 5 _3, 6 _1, 6 _2,
When a negative pressure wave generated in the downstream end of the 6 ₃ reaches the collecting chamber 7 and propagates the branch passage upstream, will be inverted to a positive pressure wave at the downstream end face 7a of the collection chamber 7 . Thus the branch passage 5 _1, 5 _2, 5 _3, 6 _1, by setting 6 _2, 6 ₃ of the length properly, the positive pressure wave branch intake valve closing shortly before passage of the 5 ₁ , 5 _2, 5 _3, 6 _1, 6 _2, 6 supercharging effect of the intake of ₃ reaches the downstream end into the combustion chamber is obtained.

In addition, according to the intake structure of FIGS. 1 and 2, the branch passage 5 ₁ of both the first bank A and a second bank B, 5 _2, 5 ₃
And 6 _1, 6 _2, 6 ₃ are connected in communication with the collection chamber 7 in a state of being close to each of the upstream open end 10 ... 10 and 11 ... 11. Moreover collecting chamber 7 branch passage 5 _1, 5 _2, 5 _3, 6 _1,
6 _2, 6 ₃ axes at the upstream open end 10 ... 10, 11 ... 11 of substantially the same direction together with the axis L _1, from the upstream side end face 7b of the upstream passage 9 is connected, the branch passages 5 _1, 5 ₂ , 5 ₃ , 6 ₁ , 6 ₂ ,
6 ₃ is connected to the downstream end face 7a having a larger cross-sectional area than the upstream end face 7b and has a shape that changes smoothly toward the downstream end face 7a.Therefore, the branch passages 5 ₁ , 5 ₂ ,
5 _3, 6 _1, 6 _2, 6 ₃ of the distance and the branch passages 5 ₁ to the upstream open end 10 ... 10, 11 ... 11, 5 _2, 5 _3, 6 _1, length of 6 _2, 6 ₃ As a result, the distribution of the intake air to each cylinder and the effect of the inertia effect on each cylinder are made uniform, and the intake air flow path is not sharply bent to reduce the intake resistance. Efficiency or engine output performance is improved.

Moreover, as described above, the branch passages 5 ₁ on the downstream side end face 7a of the collection chamber 7, 5 _2, 5 _3, 6 _1, 6 _2, 6 ₃ upstream open end 10 ... 10,
Since 11 ... 11 are open in close proximity, with respect to inertial effects, act as air release space for the branch passages 5 _1, 5 _2, 5 _3, 6 _1, 6 _2, 6 ₃ from each other other branch passages . That is, when the cylinder lead to now branch passage 5 ₁ has to be in the intake stroke, leaving 5 passages branch passage 5 _2, 5 _3, 6 _1, 6 _2, 6 air opening portion space with a collection chamber 7 in the ₃ It can be used as. In addition, as compared with the case where these branch passages are bundled in the collecting chamber corresponding to each of the banks A and B for each of the banks A and B (that is, in this case, the first bank A
Branch passage 5 ₁ Three of 5 _2, 5 ₃ are bundled by a first collection chamber corresponding thereto, three branch passages ₆₁ of the second bank B,
6 ₂ and 6 ₃ will be bundled by the corresponding second collecting chamber), and the collecting chamber 7 will have six branch passages 5 ₁ , 5 ₂ , 5 ₃ ,
Since 6 ₁ , 6 ₂ , and 6 ₃ are bundled, the volume of the open air space using these branch passages will be significantly increased,
Even if the volume of the collective chamber 7 itself is small, the open-to-atmosphere portion as a whole can be a large space. Therefore, even if the collecting chamber 7 is configured to be relatively small, the above-described supercharging effect on the combustion chamber can be suitably secured, and the intake device can be made more compact.

In this embodiment, each of the branch passages 5 ₁ , 5 ₂ ,
5 ₃ , 6 ₁ , 6 ₂ , 6 ₃ are bent so as to be equal in length and guided to the second bank B side, and the second bank B
Are gathered above. This is shown in FIG.
When the engine 1 is mounted in the engine room X of the vehicle with the axis of the crankshaft directed sideways, the space created between the second bank B located at the rear and the hood Y covering the upper part of the engine room X is effective. This is for utilizing and storing the engine.

FIGS. 3 and 4 show a modification of the above-described embodiment. In the embodiment of the intake manifold 2 shown in FIGS. 1 and 2, the first bank A is branched from the downstream end face 7a of the collecting chamber 7. passage 5 _1, 5 _2, 5 ₃ the upstream end, the branch passage ₆₁ of the second bank B,
6 _2, 6 ₃ and the upstream end is connected one on top, but in the intake manifold 12 of the modified example structure of FIG. 3 and FIG. 4, each of the branches of the first bank A and a second bank B The passages are arranged in a substantially horizontal row with respect to the single
The branch passages 15 ₁ , 15 ₂ , 15 ₃ of the bank A and the branch passages 16 ₁ , 16 ₂ , 16 _{3 of} the second bank B are connected alternately.

Also in this intake manifold 12, each branch passage 15 ₁ , 1
5 ₂ , 15 ₃ , 16 ₁ , 16 ₂ , and 16 ₃ are bent so that their lengths are substantially equal, and the upstream portion is integrally bundled with the collecting chamber 17, and the collecting chamber 17 is connected thereto. first, second bank a, which has an upstream end axially substantially same axis L ₂ of the branch passage B, the upstream side end face 17b of the upstream passage 19 is connected which is
From the branch passages 15 ₁ , 15 ₂ , 15 ₃ , 16 ₁ , 16 ₂ , and 16 ₃ , a shape that changes smoothly toward the downstream end surface 17 a having a larger cross-sectional area than the upstream end surface 17 b connected thereto. Have been.

Therefore, also in this modified example, similarly to the above-described embodiment, the branch passages 15 ₁ , 15 ₂ , 1
5 _3, 16 _1, 16 _2, 16 ₃ of the length of the distance and the branch passages to the upstream open end equal, act like the uniform inertial effects on the distribution property and the cylinders of the intake air to each cylinder In addition, the abrupt bending of the flow path of the intake air is eliminated, the intake resistance is reduced, and the intake charging efficiency or the engine output performance is improved.

Further, with regard to the inertia effect, a total of six branch passages 1 of the first and second banks A and B in the front and rear are provided in the single collective chamber 17.
5 _1, 15 _2, 15 _3, 16 _1, 16 _2, 16 ₃ from the was connected, when the branch passages acts as a open air space for other branch passages with each other, the atmosphere-release space becomes large Thus, for example, even if the collective chamber 17 is configured to have a small capacity, the open-to-atmosphere space as a whole can exert an inertia effect sufficient to secure a suitable intake action. For this reason, although there is an intake device that can increase the intake charging efficiency by utilizing the dynamic effect of intake air, the intake device can be made compact by reducing the capacity of the collecting chamber 17.

In each of the embodiments described above, the present invention is applied to a V-type 6-cylinder engine. However, the present invention is also applicable to V-type 4, 8, 10, and 12-cylinder engines, and a bank (cylinder array). Can also be applied to a W-type engine in which three are arranged.

(Effects of the Invention) As is clear from the above description, in the present invention, in a cylinder engine having a plurality of cylinder rows, all the branch passages of these cylinder rows are substantially aligned with the axis at the opening at the upstream end of the branch passage. Since it was connected to the downstream end surface of a single collecting chamber having the same direction of axis, the distance from the connection with the upstream passage in the collecting chamber to the upstream end of each branch passage became substantially equal, and the The distribution of the intake air, the effect of the inertia effect on each cylinder, and the like are made uniform, and the abrupt bending of the flow path of the intake is eliminated, thereby reducing the intake resistance. Further, the downstream end face of the single collecting chamber forming one space volume and the upstream end of each of the branch passages so that the upstream ends of the branch passages of all the cylinders open in the same space of the single collecting chamber. Since the end is connected, in the inertial effect which acts as the atmospheric release portion that reverses the negative pressure wave generated in the downstream portion of the branch passage into the positive pressure wave when the intake valve is opened, since the end chamber is connected.
When each of the branch passages serves as an open-to-atmosphere space with respect to another branch passage, the volume of the open-to-atmosphere can be increased. Therefore, even if the volume of the collecting chamber is set to a relatively small capacity, the effect of increasing the amount of intake air charged by the inertia effect is not impaired. Of the engine can be made compact, and the on-board performance of the engine can be improved.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a plan view around an intake manifold in a V-type engine, and FIG. 2 is FIG.
FIG. 3 is a sectional view taken along the line II, FIG. 3 is a plan view around the intake manifold showing a modification of FIGS. 1 and 2, and FIG. 4 is FIG.
FIG. 4 is a sectional view taken along line IV-IV. FIG. 5 is a plan view of an intake manifold showing the prior art of the present invention. 1 ...... engine, 2,12 ...... intake manifold, 5 _1, 5 _2, 5 ₃
…… Branch passage (branch passage for the first bank), 6 ₁ , 6 ₂ , 6 ₃ …
... branch passage (second bank branch passage), 7, 17 ...... collection chamber, 15 _1, 15 _2, 15 ₃ ...... branch passage (first bank branch passage), 16 _1, 16 _2, 16 ₃ ... ... branch passage (second bank branch passage), A ...... cylinder bank (first bank), B ...... cylinder bank (second bank), L _1, L ₂ ...... axis.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Mikiko Fujii 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References JP-A-62-68817 (JP, A) JP-A Sho 60-88062 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02B 27/00 F02M 35/104-35/116

Claims (3)

(57) [Claims] The invention is applied to an engine having a plurality of cylinder rows, and has a branch passage for each cylinder connected to a cylinder of each cylinder row, and an upstream end of each of the branch passages is located on one side of the cylinder row. Side of the multi-cylinder engine, wherein the upstream ends of the branch passages of all cylinders have a single collective chamber having an axis substantially in the same direction as the axis at the opening of each branch passage upstream end. An intake device for a multi-cylinder engine, wherein a downstream end face of a single collective chamber forming one space volume and an upstream end of each of the branch passages are connected so as to open in the same space. . 2. The engine according to claim 1, wherein the engine is a V-type engine having two cylinder rows arranged in a V-shape, and the collecting chamber is arranged above one of the cylinder rows. An intake device for a multi-cylinder engine according to Claim 1. 3. The intake device for a multi-cylinder engine according to claim 1, wherein the branch passages for each cylinder are set to have substantially the same length.