JP2541964B2 - V-type engine intake device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a V-type engine, and in particular, the intake passage length is made variable to enhance intake efficiency by utilizing the dynamic effect of intake in a wide operating range. The present invention relates to the intake device.

(Prior Art and Problems Thereof) Japanese Patent Application Laid-Open No. Sho 60-1985 discloses an intake system for a V-type engine of this type.
As disclosed in Japanese Patent Laid-Open No. 198323 and Japanese Patent Laid-Open No. 61-49161, a volume portion having an internal volume of a certain amount or more is disposed substantially in the center of both banks so as to extend in the cylinder row direction. From one part to one bank and an intake pipe from the volume part to the other bank are connected to the respective banks through the lower part of the volume part so that the intake pipes of both banks are below the volume part. There has been proposed a technique in which the overall height of the engine is suppressed from increasing while ensuring the intake pipe length required to obtain a predetermined dynamic effect by configuring the side to intersect.

On the other hand, the dynamic effects of intake air include the so-called inertial effect in which the negative pressure generated by the opening of the intake valve propagates in the intake pipe and is supercharged by the pressure wave reflected by the volume and returned to the positive pressure, and the multi-cylinder effect. When a steady pressure wave is generated as a result of the intake pulsation associated with the opening and closing of each intake valve interfering with each other through the volume, the vibration frequency and the opening and closing timing of the intake valve are synchronized and a positive pressure is obtained when the intake valve is closed. There are two types of so-called resonance supercharging to obtain supercharging effect.

Thus, the inertial effect and the resonance effect can be obtained by changing the intake system configuration including the intake pipe length to obtain a dynamic effect in a desired engine speed region.

In this way, change the intake passage length according to the operating state,
As a device for improving the output over a wide operating range, for example, there is one disclosed in Japanese Utility Model Laid-Open No. 61-91032.

However, in the conventional intake system of the V-type engine, when it is attempted to obtain the inertial effect or the resonance effect in a wide operating range, for example, a device that switches the intake pipe length to a plurality according to the engine speed or continuously. A device for changing is required, but if a variable means such as Japanese Utility Model Laid-Open No. 61-91032 is simply applied to the intake system of the V-type engine, a compact intake system cannot be obtained. .

In other words, in order to change the above intake characteristics,
Since a variable mechanism such as an on-off valve is installed in the intake pipe for each cylinder, the arrangement interval between the intake pipes is widened, which is an obstacle to downsizing the intake system.

(Object of the Invention) In view of the above circumstances, the present invention can obtain a dynamic effect utilizing intake pulsation in a wide range of operating regions with a compact structure by changing the intake system configuration including the intake pipe length. It is an object of the present invention to provide an intake device for a V-type engine.

(Structure of the Invention) An intake device for a V-type engine according to the present invention that achieves the above object is provided with a volume portion extending in the cylinder column direction above the first bank and the second bank on both sides, and the volume portion Downstream intake passages connecting the banks are arranged below the volume portion so as to intersect with each other, and a first downstream intake passage connected to the first bank and a second downstream intake passage connected to the second bank. Are alternately arranged in the cylinder row direction, and the intersection of the first downstream intake passage and the second downstream intake passage is set to be within the length of the volume portion in the cylinder row direction. First and second communication passages that connect the lower surface of the volume portion and the first and second downstream side intake passages that pass below the volume portion, and open and close the passages at high rotation speeds. A valve is provided, and the first communication passage and the second communication passage are connected in the crankshaft direction. It is characterized by being arranged in two rows as seen in FIG.

(Operation) In the present invention as described above, the effective intake passage length from the volume portion to each cylinder of both banks is switched according to the opening / closing operation of the opening / closing valve of the communication passage, and the opening / closing valve is opened on the high rotation side. Sometimes it is short, and when it is closed on the low rotation side, it becomes longer, and dynamic effects that match each operating range are obtained, and output can be improved.

Also, by arranging the communication passages through which intake air flows at high speed in two rows, the space between the communication passages becomes wider, and
As compared with the case of arranging in rows, it is possible to make the volume section and the like compact in the cylinder row direction. Specifically, since an opening / closing valve is arranged in the communication passage, a space for installing the opening / closing valve is required between the communication passages, and by arranging in two rows, the space between adjacent communication passages is increased. On the other hand, although the space can be widened and the installation space can be secured, the installation interval of the communication passages in the cylinder column direction and the connection interval to the volume portion can be shortened as a whole, and a compact volume structure and communication passage arrangement can be realized.

Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings. First
FIG. 2 and FIG. 2 show a V-type 6-cylinder engine to which the intake device according to the present invention is applied.

In the engine of this example, a first cylinder head 3a and a second cylinder head 3b are arranged on a cylinder block 2 in an inclined manner, and each cylinder has three cylinders at an angle to each other. And the second bank 1B on the right side are formed.

The intake passage for supplying intake air to each of the cylinders of the first and second banks 1A, 1B has a volume portion 4 (surge tank) arranged extending in the cylinder row direction above the banks 1A, 1B. I have it. The inner space of the volume part 4 is divided into the first wall on the right side by the partition wall 41 extending in the front-rear direction (crank axis direction).
It is partitioned into a volume chamber 4a and a second volume chamber 4b on the left side.

An upstream intake passage 8 for introducing fresh air into both volume chambers 4a and 4b is connected to one end of the volume portion 4. This upstream side intake passage 8 is provided near the connecting portion to the volume portion 4 thereof.
Each of the first and second volume chambers 4a, 4b having a predetermined length is independently formed by branching into a first upstream intake passage 8a and a second upstream intake passage 8b.

In addition, from the volume section 4 to the first and second banks 1A and 1B
First and second supply of intake air to each intake port 6a, 6b of
Downstream side intake passages 5a, 5b (intake pipe) are provided.
The first downstream side intake passage 5a has an upstream end on the right side surface of the volume section 4.
U is communicated with the first volume chamber 4a through a communication port opened at 42
The downstream end is connected to the intake port 6a of the first bank 1A on the left side by bending downward in a letter shape and passing below the volume portion 4. Further, the second downstream side intake passage 5b communicates with the second volume chamber 4b through a communication port whose upstream end is opened to the left side surface 43 of the volume section 4, and is bent downward in a U shape to form a volume section. The downstream end is connected to the intake port 6b of the second bank 1B on the right side through below 4.

The first downstream intake passages 5a and the second downstream air passages 5b are alternately arranged in the cylinder column direction and intersect each other below the volume portion 4. Also,
As shown in FIG. 2, this intersecting portion is arranged so as to enter below the length of the volume portion 4 in the cylinder column direction.

On the other hand, there are provided first and second communication passages 7a and 7b, respectively, which connect the lower surface of the volume portion 4 and the first and second downstream side intake passages 5a and 5b passing below the volume portion 4 to each other. There is. The lower end of the first communication passage 7a is connected to the first downstream side intake passage 5a, and the upper end is connected to the second volume chamber 4b which is not in communication with the first downstream side intake passage 5a. Further, the lower end of the second communication passage 7b is connected to the second downstream intake passage 5b,
The upper end is connected to the first volume chamber 4a which is not in communication with the second downstream intake passage 5b.

The first communication passages 7a are arranged in a line below the second volume chamber 4b along the cylinder column direction, and three of them are arranged in a line.
7b has three 1s below the first volume chamber 4a along the cylinder row direction.
In a row, when viewed in the crankshaft direction, the first and second
The communication paths 7a and 7b are arranged in two rows on the left and right.

Next, as a mechanism for switching the intake path, the main opening / closing valves 71a, 71b interposed in the first and second communication passages 7a, 7b and the opening of the partition wall 41 of the volume section 4 are provided. The sub-opening / closing valve 41a is provided.

The opening / closing operations of the main opening / closing valves 71a, 71b of the communication passages 7a, 7b are basically controlled so as to close on the low rotation side and open on the high rotation side in accordance with the engine speed. This main opening / closing valve 71a, 71b
In the closed state, the communication distance (effective intake passage length) between the volume portion 4 and the intake ports 6a, 6b becomes the length of the first and second downstream intake passages 5a, 5b, and the main opening / closing valve 71a When 71 and 71b are opened, the communication distance (effective intake passage length) between the volume 4 and the intake ports 6a and 6b is shortened by the first and second communication passages 7a and 7b.

Further, the opening / closing operation of the sub opening / closing valve 41a in the volume section 4 is basically controlled so as to close on the low rotation side and open on the high rotation side in accordance with the engine speed. When the sub opening / closing valve 41a is closed, the communication (pressure propagation) between the first volume chamber 4a and the second volume chamber 4b on both sides is such that the first upstream side intake passage 8a and the second upstream side in the upstream side intake passage 8 communicate with each other. It is performed at a position where it communicates with the side intake passage 8b, and is a position away from the intake ports 6a and 6b. On the other hand, when the sub opening / closing valve 41a is opened, the communication between the first volume chamber 4a and the second volume chamber 4b on both sides is at the opening position in the volume section 4 and is close to the intake ports 6a, 6b. Become.

In this example, the sub opening / closing valve 41a is closed on the low rotation side and switched to open on the high rotation side, and the main opening / closing valves 71a and 71b are switched on the low rotation side in the low rotation region where the sub opening / closing valve 41a is closed. While switching to close and open on the high rotation side,
In the high rotation region where the sub opening / closing valve 41a is opened, control is performed so that the sub rotation valve 41a is closed on the low rotation side and opened on the high rotation side, and four stages of intake characteristics are obtained by combining the two.

The operation of the above intake system will be described. Volume 4
In the intake system in which both the sub opening / closing valve 41a in the inside and the main opening / closing valves 71a, 71b of the communication passages 7a, 7b are closed, a dynamic transient having a characteristic curve as shown in (a) in FIG. Supply effect is intake port 6
Obtained with a and 6b. At that time, the volume section 4 and the downstream intake passage 5
The intake system such as a and 5b has characteristics for low rotation with a long intake passage length. When the main on-off valves 71a, 71b of the communication passages 7a, 7b are opened and the intake path is changed from this state, the dynamic supercharging effect having the characteristic curve as shown by (b) in FIG. 3 is obtained. Become.

That is, in the characteristic curve (a), two tuning points of the low rotation speed region and the high rotation speed region are generated, and the tuning of the low rotation speed region has the resonance supercharging effect in which the upstream intake passage 8 upstream of the volume portion 4 is used as the resonance passage. The tuning in the high rotation range is an inertia supercharging effect in the downstream side intake passages 5a and 5b with the volume portion 4 as the pressure reversal portion. On the other hand, in the characteristic curve (b), opening the main opening / closing valves 71a, 71b reduces the effective intake passage length due to the influence of the communication passages 7a, 7b, which increases the tuning point. It is shifting to the rotating side. Then, the intersection of the characteristic curves (a) and (b) in the tuning on the low rotation side becomes the first rotation speed at which the opening / closing of the main opening / closing valves 71a, 71b is switched.

On the other hand, the sub opening / closing valve 41a of the volume section 4 is opened to open the communication passage 7a,
In the intake system with the main opening / closing valves 71a and 71b of 7b closed,
The characteristic is such that the dynamic supercharging effect is obtained, which has a characteristic curve as shown in FIG. If the main opening / closing valves 71a, 71b of the communication passages 7a, 7b are opened from this state to change the intake path,
The characteristic is such that the dynamic supercharging effect is obtained, which has a characteristic curve as shown in FIG.

That is, in the characteristic curve (c), one tuning point occurs in the high rotation range, and this tuning does not change the length of the downstream side intake passages 5a and 5b, but changes in the volume of the volume section 4 and the number of communicating cylinders. Due to the change, the substantial length becomes longer, whereby the rotational range in which the inertia supercharging effect is obtained shifts to the low speed side, and the supercharging pressure rises due to the inter-cylinder interference effect. On the other hand, in the characteristic curve (d), the main opening / closing valve 71a,
By opening 71b, the communication passages 7a and 7b affect the intake passage length, which shortens the substantial intake passage length, thereby shifting the tuning point to the higher rotation side. The intersection of the characteristic curves (b) and (c) becomes the second rotational speed at which the opening / closing of the sub opening / closing valve 41a and the main opening / closing valves 71a, 71b is switched. Further, the intersection of the characteristic curves (c) and (d) becomes the third rotation speed at which the opening / closing of the main opening / closing valves 71a, 71b is switched.

The main on-off valve 71a corresponding to these engine speeds,
By controlling the opening / closing of 71b and the sub-opening / closing valve 41a, it is possible to obtain the supercharging effect by the dynamic effect of intake air in a wide operating range.

In addition, in the above-mentioned embodiment, the one having the auxiliary opening / closing valve 41a communicating with the respective volume chambers 4a, 4b has been described, but the present invention is not limited to this, and only the main opening / closing valves 71a, 71b are provided. An intake system may be provided so that it is closed on the low rotation side and opened on the high rotation side.

(Effects of the Invention) According to the intake system for the V-type engine of the present invention, the volume between V banks and each bank are connected by the downstream intake passage, and the lower surface of the volume and the downstream intake passage are short. By providing a communication path that communicates with each other through an open / close valve that opens at high rotation speed, the open / close control of this open / close valve changes the intake system configuration to utilize the dynamic effect of intake pulsation. The operating range in which the supercharging effect is generated can be expanded to contribute to the improvement of the charging efficiency and the output performance.

In addition, the volume portions provided above the V banks in the cylinder row direction and the downstream side intake passages connecting the banks are arranged alternately below the volume portions and the intersection portions are Is set so as to be within the length of the cylinder section in the cylinder row direction, and further, in the crankshaft direction, a communication passage including an on-off valve that connects the lower surface of the volume section and the downstream side intake passage that passes below the volume section is seen. By arranging them in two rows, the communication passages can be arranged by utilizing the dead space created by the intersection installation of the downstream side intake passages of the volume portion, and the space between the adjacent communication passages is widened. Can be secured, and the installation interval of the communication passages in the crankshaft direction can be shortened for the entire intake system, so that a compact volume structure and communication passage arrangement can be achieved, and compactification in the cylinder row direction can be achieved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of an intake system for a V-type engine according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. It is a graph which shows the characteristic curve of an effect. 3a, 3b …… Bank, 4 …… Volume part, 4a, 4b …… Volume chamber 5a, 5b …… Downstream intake passage, 6a, 6b …… Intake port 7a, 7b …… Communication passage, 71a, 71b …… Open / close valve

Front page continuation (72) Inventor Takenori Otsuka 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (56) Reference JP-A-61-91032 (JP, A)

Claims (1)

(57) [Claims] 1. A volume section extending in the cylinder row direction for introducing air from an upstream intake passage is provided above a first bank and a second bank on both sides, and a downstream section connecting the volume section and each bank. In a V-type engine intake device, in which the side intake passages are disposed below the volume portion and intersect each other, a first downstream side intake passage and a second downstream intake passage connected to the first bank are provided.
The second downstream side intake passages connected to the bank are alternately arranged in the cylinder row direction, and the intersection of the first downstream side intake passage and the second downstream side intake passage is formed in the cylinder row of the volume section. And a lower surface of the volume section and a lower surface of the volume section and a lower section of the volume section, the first communication path communicating the lower surface of the volume section with a first downstream side intake passage passing below the volume section. A second communication passage communicating with a second downstream side intake passage passing through, and an opening / closing valve that opens the passage at high rotation is provided in each communication passage, and the first communication passage and the second communication passage Viewed from the crankshaft direction 2
An intake system for a V-type engine, which is arranged in rows.