JP2721982B2 - V-type engine intake system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intake device for a V-type engine that performs supercharging by utilizing a dynamic effect of intake air.

(Prior Art) Conventionally, resonance supercharging,
Various intake devices have been proposed, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-91621, in which a filling effect is enhanced by utilizing a dynamic effect of intake such as inertia supercharging, that is, a pressure wave.

(Problems to be Solved by the Invention) However, in an intake device that utilizes the dynamic effects of resonance supercharging and inertial supercharging for a V-type engine, the intake passages are originally provided for the banks on both sides. The intake system becomes complicated to connect, and it is necessary to configure the intake passage to communicate with a volume chamber for obtaining a dynamic effect, which is an obstacle to downsizing the engine. I have.

Particularly, in the structure in which the tuning point is switched so that the dynamic effect of the intake can be obtained in a wide range, there is a problem that the intake device is further complicated.

In view of the above circumstances, the present invention has a structure in which a dynamic effect of intake air such as inertia supercharging is changed in accordance with an operating state, and is compactly formed in relation to the structure of a V-type engine. It is an object of the present invention to provide an intake device for a model engine.

(Means for Solving the Problems) In order to achieve the above object, an intake device for a V-type engine according to the present invention extends from the inner surface of both banks independently to each cylinder and communicates with a surge tank disposed above one bank. The independent intake passages are arranged close to each other in the space between the banks, provided with a branch passage connected to each independent intake passage and branched therefrom, and further provided with a volume chamber communicating with the branch passage. In addition, an on-off valve that opens and closes communication between each of the independent intake passages and the volume chamber according to an operation state is installed, and when the on-off valve is open, intake air flowing from the volume chamber through the branch passage is provided. The connection position between the branch passage and the independent intake passage is set so as to be directed to a portion disposed close to the independent intake passage.

In addition, a portion disposed close to the independent intake passage is provided so as to be substantially aligned on a plane including a crankshaft, while an intake manifold constituting the independent intake passage is provided in the portion disposed close to the intake passage. You may comprise so that it may divide by the formed substantially horizontal division surface.

On the other hand, in a V-type six-cylinder engine, a surge tank disposed above one bank, an independent intake passage communicating the surge tank and each cylinder independently of each other, and intake air flowing into each cylinder connected to the surge tank A throttle body having a throttle valve for controlling the amount of fuel, and arranged in such a manner that the independent intake passages are arranged substantially in a line between both banks and on a plane including the crankshaft. A branch passage that is branched and shorter in length than the independent intake passage, a volume chamber that communicates with each of the branch passages, is formed integrally with all cylinders, and is formed separately from the branch passage; Opening and closing valves for controlling the opening and closing of the communication with the volume chamber and fixed to one shaft respectively, and an upstream part and a downstream part at a dividing surface formed in a part where the independent intake passage is arranged in close proximity. part And the branch passage and the volume chamber are arranged above the division surface. When the on-off valve is open, the intake air flowing from the volume chamber via the branch passage is divided into the divided surfaces of the independent intake passage. The connection position between the branch passage and the upstream portion may be set so as to be directed toward the upstream side.

(Operation) In the intake device for a V-type engine as described above, the independent intake passages extending from the respective banks and communicating with the surge tank disposed above one of the banks are arranged close to each other between the banks, and the respective independent intake passages are provided. By providing a branch passage branching off from and communicating with the volume chamber and installing an on-off valve for opening and closing the communication, the tuning point of the inertia effect is obtained by using the volume chamber by opening and closing the on-off valve according to the operating state. The opening and closing valve is opened by providing a supercharging effect in a wide range to improve the output and improving the output, and by providing the branch passage so as to be directed to a portion arranged close to the independent intake passage. Sometimes, the passage length of the intake air flowing from the volume chamber via the branch passage becomes equal in each cylinder, so that a uniform inertia effect is obtained in each cylinder.

(Embodiments) Each embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 This embodiment is shown in FIGS. 1 and 2 and is an example of a V-type six-cylinder engine.

The engine body 1 has left and right cylinder heads 3a, 3b at predetermined angles on both sides of a cylinder block 2 at the lower center.
Are arranged, a left bank 1A and a right bank 1B are arranged, the first bank 1, 3, and 5 cylinders are arranged in the left bank 1A, and the second, 4, 6 cylinders are arranged in the right bank 1B. Have been. Intake port 4 for each cylinder
Are opened on the inner surfaces of both banks 1A and 1B so as to face each other.

An intake device that supplies intake air to each cylinder of the banks 1A and 1B on both sides includes an intake manifold 7 that forms left and right independent intake passages 6a to 6d that are respectively connected to the intake ports 4.
And a surge tank 8 which is arranged above the right bank 1B and which is connected to the upstream ends of the independent intake passages 6a to 6f.

The surge tank 8 includes a first chamber 8a and a second chamber 8b provided for the left and right banks 1A and 1B, respectively. That is, the surge tank 8 is configured as a box-shaped body that is long in the output axis direction, and is internally divided into a first chamber 8a and a second chamber 8b by a central partition wall 8c. Then, the independent intake passages 6a, 6a, 6b, 6c from the left bank 1A farthest from the surge tank 8 with respect to the rear first chamber 8a.
6c and 6e are connected and gathered, and independent intake passages 6b, 6d and 6 from the second, fourth and sixth cylinders from the right bank 1B closer to the second chamber 8b in the front.
f are connected and collected, and independent intake passages 6a to 6f are collected for each cylinder whose intake stroke is not adjacent to each other for each of the banks 1A and 1B.

A throttle body 11 is connected to the surge tank 8 on the opposite side to the independent intake passages 6a to 6f. Throttle valves 12a and 12b are interposed in the throttle body 11 for each chamber. Connected to the chambers 8a and 8b, the intake air is introduced. Further, an intake passage 13 is connected further upstream, and a first chamber 8a and a second chamber 8b on both sides are connected at a portion where the upstream intake passage 13 joins.
Is connected to an air flow meter AFM and an air cleaner AC.

The intake manifold 7 forming the independent intake passages 6a to 6f has an upstream portion 7a integrated with the surge tank 8 by using a substantially horizontal dividing surface F in the middle upper portion of the banks 1A and 1B on both sides as a dividing portion. Downstream part 7b connected to intake port 4
And two.

That is, the independent intake passages 6a, 6a connected to the left bank 1A
c and 6e extend obliquely upward toward the intermediate position between the banks 1A and 1B by the downstream portion 7b, and from the upper portion to the rear with a gentle curvature by the upstream portion 7a via the substantially horizontal division surface F. Each cylinder is extended and connected to the first chamber 8a of the surge tank 8 located above the right bank 1B with substantially the same passage length. On the other hand, the independent intake passages 6b, 6d, and 6f connected to the right bank 1B extend obliquely upward toward the intermediate position between the two banks 1A and 1B by the downstream portion 7b, and the left bank is formed by a substantially horizontal dividing surface F. The second chamber 8b of the surge tank 8, which is connected alternately with the independent intake passages 6a, 6c, 6e from 1A, extends forward from above with gentle curvature by the upstream portion 7a, and is located above the right bank 1B. Are connected with substantially the same passage length in each cylinder.

With the above structure, the independent intake passages 6a to 6
f is arranged substantially in a straight line back and forth in the order of the first to sixth cylinders so as to merge on a plane (vertical plane) including the crankshaft at the bottom of the cylinder block 2 in the V-shaped space between the banks. It is arranged close to.

A first partition 8a is provided on a central partition wall 8c of the surge tank 8.
An opening communicating with the second chamber 8b is formed, and a first switching valve 15 for resonance switching is interposed in this opening. This first
The opening / closing valve 15 is connected to a first actuator 17 and is opened / closed.

Further, the upstream side portion in each of the independent intake passages 6a to 6f.
Branch passages 9a to 9f are provided which branch from 7a and extend in the direction of the left bank 1A on the opposite side to the surge tank 8;
The tips of 9a to 9f are connected to first and second volume chambers 19a and 19b as pressure reversing parts disposed before and after in the space between the banks. Branch passages 9a to 9c of the first to third cylinders are connected to the front first volume chamber 19a, while the rear second volume chamber 19
The branch passages 9d to 9f of the fourth to sixth cylinders are connected to b, and the independent intake passages 6a to 6f of the cylinders which are gathered in the respective volume chambers 19a and 19b communicate with each other via the volume chambers 19a and 19b. It is configured. And, the volume chambers 19a, 19b of the respective branch passages 9a to 9f.
A second opening / closing valve 16 for switching inertia is provided at a portion communicating with the cylinders, and is supported by a common shaft for each of the volume chambers 19a and 19b. The second opening / closing valve 16 of each cylinder is provided at a central position. Is opened and closed by the second actuator 18.

The branch passages 9a to 9f are connected to the independent intake passages 6a to 6f (upstream portion 7a) through the branch passages 9a to 9f from the volume chambers 19a and 19b when the second on-off valve 16 is open. The inflowing intake air is connected so as to be directed to a divided surface F of a portion disposed close to each of the independent intake passages 6a to 6f. The branch passages 9a to 9f and the volume chambers 19a and 19b are shown in FIG.
As shown in FIG.

In the above-mentioned intake system, the resonance supercharging function is performed by an independent intake passage which is assembled with an assembly portion (the first chamber 8a or the first chamber 8b of the surge tank 8) which is assembled for each cylinder whose intake stroke is not continuous.
A stationary wave generated when the natural frequency of the intake system and the engine speed due to 6a to 6f are brought into a resonance state is obtained by acting on the intake port 4 at the end of the intake stroke. When the first on-off valve 15 is opened by the operation of the first actuator 17 by the resonance changing means 20 for switching the natural frequency of the intake system, the communication path of the collecting portions 8a and 8b becomes shorter than in the closed state. Natural vibration is enhanced, and a high resonance effect is obtained in a high rotation range.
In the engine according to the present embodiment, the intake stroke order (ignition order) is set in the order of 1-2-3-4-5-6 cylinders, and the independent intake passages 6a to 6f from the banks 1A and 1B are assembled. In each of the chambers 8a and 8b of the surge tank 8, the order of intake is not adjacent, and the above-described resonance supercharging can be ensured by preventing interference of intake.

In addition, the inertia supercharging function is such that the exciting force generated in the intake porter 4 is transmitted to the upstream side through the independent intake passages 6a to 6f, and the second on-off valve
When the valve 16 is closed, the entire inside of the intake pipe up to the first and second chambers 8a and 8b of the surge tank 8 is vibrated.
When the on-off valve 16 is open, the first and second volume chambers 19a,
Exciting the inside of the intake pipe up to 19b, an inertial supercharging effect is obtained when the intake port is tuned in response to the closing timing. And
The above-mentioned path, that is, the inertia changing means 21 for changing the position of the pressure oscillating portion, the length of the vibrating tube is long when the second on-off valve 16 is closed, and is tuned in the low rotation range. And tune in the high speed range,
The intake air is introduced from the independent intake passages 6a to 6f of the other cylinders through the branch passages 9a to 9f and the volume chambers 19a and 19b, so that the charging efficiency is improved by reducing the intake resistance.

Next, the first of the resonance changing means 20 and the inertia changing means 21
The operation of the second actuators 17 and 18 is controlled by control means 22 as shown in FIG. The two actuators 17 and 18 are driven by the introduction of the operating pressure through the negative pressure introducing passages 23 and 24, and the first three-way solenoid valve 25 is provided in the negative pressure introducing passage 23 for the resonance supercharging first actuator 17 with the inertial supercharging. Pressure introduction passage for the second actuator 18 for use
24 is provided with a second three-way solenoid valve 26, and the two three-way solenoid valves 25 and 26 are provided with a drive circuit 2 of the control means 22.
A drive signal is output from the first and second actuators 7 and 28, and a negative pressure is introduced into the first actuator 17 or the second actuator 18 at a predetermined time to switch the first on-off valve 15 or the second on-off valve 16.

The control means 22 includes a rotational speed signal from a rotational sensor 30 of an engine rotational speed detecting means 29 for detecting the rotational speed of the engine and a throttle opening from a throttle sensor 31 for detecting the opening of the throttle valves 12a and 12b of the engine. A signal is input. The rotation speed signal and the throttle opening signal are
The signals are input to the fourth comparison circuits 32 to 35 and compared with the set values in the respective comparison circuits. That is, for example, the rotation speed signal is
The first comparison circuit 32 has a comparison value N ₁ equivalent to 3500 rpm, the second comparison circuit 33 has a comparison value N ₂ equivalent to 5000 rpm, and the third comparison circuit 34 has a comparison value N 7.
They are respectively compared with 000rpm corresponding comparison value N ₃ of, also, the throttle opening degree signal is compared to FIG. 4 comparator circuit 35 at 73 ° corresponding comparison value T _0. The output signals of the first comparison circuit 32 and the third comparison circuit 34 are ORed through the gate circuit 36.
The OR circuit 37 receives the fourth comparison circuit
The signal from 35 is also input, and the output of the OR circuit 37 is output to the drive circuit 27 for resonance. On the other hand, the signal of the second comparison circuit 33 is output to the drive circuit 28 for inertia.

By the control of the resonance changing means 20 and the inertia changing means 21 by the control means 22 as described above, the first on-off valve 15 for resonance and the second on-off valve 16 for inertia are opened and closed with characteristics as shown in FIG. You. That is, the first on-off valve 15 is in a high load state where the throttle opening TVO is 73 ° or more and the engine speed is 3
It is closed in the low rotation range of 500 rpm or less, and in the high load state where the throttle opening is 73 ° or more and the engine rotation speed is 7000 rpm or more, while lowering the natural frequency,
In the other load and rotation regions, it is opened to increase the natural frequency. In addition, the second on-off valve 16 closes at an engine speed of 5000 rpm or less to increase the length of the vibrating tube regardless of the throttle opening, and opens at a higher engine speed to shorten the vibrating tube length. .

Based on the above control characteristics, for example, an engine output characteristic as shown in FIG. 5 can be obtained. In the drawing, four torque curves I to IV are generated corresponding to the open / close states of the first and second on-off valves 15 and 16 and are used by switching. First, a curve I shows the characteristics when the first on-off valve 15 is closed and the second on-off valve 16 is closed, and a curve II shows the characteristics when the first on-off valve 15 is closed and the second on-off valve 16 is open. curve
II indicates the characteristic when the first on-off valve 15 is open and the second on-off valve 16 is closed, and the curve IV indicates the characteristic when the first on-off valve 15 is open and the second on-off valve 16 is open. And the engine speed is 3500
In the low rotation range below rpm, the state of the curve I where both the on-off valves 15 and 16 are closed has the largest output, and in the middle rotation range of 3500 to 5000 rpm the state of the curve III where only the first on-off valve 15 is opened is the most. Large output, double open / close valve 1 in the high rotation range of 5000 to 7000 rpm
The state of the curve IV which opened 5,16 has the largest output,
In the super high speed range exceeding 7000 rpm, the state of the curve II in which only the first on-off valve 15 is closed has the largest output,
Correspondingly, in the low rotation range of 3500 rpm or less,
Close 5, 16 and open the first on-off valve 15 when it reaches 3500 rpm,
Furthermore, when reaching 5000 rpm, the second on-off valve 16 opens, and
When the rotation speed exceeds pm, the first on-off valve 15 is controlled to be closed.

Note that the above-described switching is performed in a high load state in which the throttle opening is opened by 73 ° or more.In a load state in which the throttle opening is less than 73 °, not much output is required. Open the open / close valve 15 and turn to curve III
In the region of 5000 rpm or less, switching between the two on-off valves 15 and 16 is eliminated to prevent a change in driving performance due to torque shock accompanying the switching. In addition, when the normal rotation range of the engine is set to be 7000 rpm or less, the switching operation of the first opening / closing valve 15 at 7000 rpm is unnecessary.

According to the above-described embodiment, the charging efficiency is improved by the action of resonance supercharging or inertia supercharging in which the tuning state is switched in each region from the low rotation region to the high rotation region, and the separate supercharging is performed. High output performance can be obtained with a compact configuration regardless of the type of the device.

Embodiment 2 This embodiment is a modification of Embodiment 1 and is an example of a structure in which the volume chambers of all cylinders are integrated. FIG. 6 is a plan view of the volume chamber portion, and FIG. 7 is a front view thereof. .

As in the first embodiment, the branch passages 9a to 9f are connected to the independent intake passages 6a to 6f extending from the banks 1A and 1B and extend above the left bank 1A.
Is connected to a volume chamber 45 formed separately from the upstream portion 7a of the intake manifold 7.

The volume chamber 45 is formed integrally with all cylinders, and each of the branch passages 9a to 9f communicates and opens in an internal space 45a extending before and after the cylinder, and the independent intake passages 6a to 6f of each cylinder are configured to communicate with each other. I have. Each of the branch passages 9a-
A second on-off valve 16 for switching inertia is provided at the opening of 9f, and the second on-off valve 16 of each cylinder is fixed to one width 46 by a second actuator 18 provided at the end. Opening and closing operations are linked.

In addition, the structure of a portion not shown is the same as that of the first embodiment.

In each of the above embodiments, regarding the inertia changing means 21 for switching the inertia supercharging tuning point, the volume chambers 19a, 19b, 45 serving as pressure reversing sections are integrally provided for a plurality of cylinders. However, in order to easily connect the volume chamber to the independent intake passages 6a to 6f and to simplify the installation of the second on-off valve 16 for switching the capacity, first, the two banks 1A, 1B The independent intake passages 6a to 6f are arranged close to each other, particularly in the V-shaped space between the banks, and the volume chambers 19a, 19b, 45
Is connected, the volume chambers 19a, 19b, and 45 are arranged on the space between the banks even for the integrated volume chamber, and the effective operation of the space is achieved.

At this time, the integration of the volume chambers may be performed by integrally forming all the cylinders as in the second embodiment, or may be integrally performed by grouping the banks for each bank, as in the first embodiment. Even if they are grouped and integrated, a volume chamber can be provided in the space between the banks.

In addition, when the shaft connecting the second on-off valve 16 becomes long,
Although the shaft is bent and the reliability of the opening / closing operation is lowered, in order to shorten the opening and closing operation, in the above-described embodiment, the portions where the independent intake passages 6a to 6f of both banks are close to each other and the volume chamber 19 are provided.
The branch passages 9a to 9f communicating the a, 19b and 45 are provided, and the shaft is shortened by interposing the second on-off valve 16 in a portion disposed adjacently.

On the other hand, the shaft of the second on-off valve 16 is formed in the same manner in each cylinder even when the independent intake passages 6a to 6f of both banks are mixed in a V-type engine having four or more cylinders, and can be driven by a single actuator. In the embodiment, the independent intake passages 6a to 6f of both banks are close to each other and the volume chambers 19a,
Branch passages 9a to 9f communicating with 19b and 45 are provided, and the second on-off valve 16 is arranged at the same position in each cylinder by making the independent intake passages 6a to 6f close to each other on a plane including the crankshaft. Like that. Thereby, when obtaining inertia supercharging, the length of the vibrating pipe due to the pressure reversal in the volume chambers 19a, 19b, 45 can be made uniform in each cylinder, and the tuning points can be matched to equalize the torque.

Furthermore, even in a state where the independent intake passages 6a to 6f of both banks are mixed and grouped in a V-type engine of four or more cylinders, the shape of the volume chambers 19a, 19b, and 45 is simplified and the formation thereof is facilitated. In the above embodiment, the independent intake passages 6a to 6f of both banks are brought close to each other on a plane including the crankshaft, and the volume chamber is integrally provided for a plurality of cylinders.
The second on-off valve 16 is provided.

In the above-described embodiment, the first on-off valve 15 for switching the tuning point for obtaining the resonance supercharging is provided so as to obtain the dynamic supercharging effect in a wider range. May be simply connected to the surge tank 8 and set to tune in a specific operating state.

(Effect of the Invention) According to the present invention as described above, each independent intake passage extending from each bank of the V-type engine and communicating with the surge tank disposed above one of the banks is arranged close to each other between the banks, When connecting the volume chamber as the pressure reversal part of the inertia supercharging and the branch passage branched from each independent intake passage, and installing an on-off valve to open and close the communication, the branch By providing the intake air flowing from the passage so as to be directed to the portion arranged close to the independent intake passage, the passage length from the volume chamber to each cylinder can be made uniform,
The inertia effect can be made uniform in each cylinder, and the overall mechanism can be simplified to be compact.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an intake device of a V-type six-cylinder engine according to a first embodiment of the present invention, FIG. 2 is a front view of the essential parts, FIG. 3 is a block diagram of control means, and FIG. FIG. 5 is a characteristic diagram showing the operation state of the on-off valve, FIG. 5 is a graph showing the torque characteristic by switching control of the on-off valve with respect to the engine speed, FIG. It is the same front view. 1 ... Engine body, 6a-6f ... Independent intake passage, 8 ...
Surge tank, 9a to 9f branch passage, 15 first on-off valve, 16 second on-off valve, 17 first actuator, 18
... second actuator, 19a, 19b, 45 ... volume chamber.

Claims (6)

(57) [Claims] 1. An intake system for a V-type engine, wherein an independent intake passage extending independently from each cylinder from inner surfaces of both banks is communicated with a surge tank disposed above one of the banks. Are arranged close to each other in the space between the two banks, a branch passage connected to each of the independent intake passages and branching therefrom is further provided, and a volume chamber communicating with the branch passage is provided. An on-off valve for opening and closing the communication between each of the independent intake passages and the volume chamber is provided. When the on-off valve is open, the intake air flowing from the volume chamber through the branch passage is close to the independent intake passage. A connection position between the branch passage and the independent intake passage is set so as to be directed to the portion arranged in a vertical direction. 2. The intake system for a V-type engine according to claim 1, wherein portions arranged close to each other of said independent intake passages are provided so as to be substantially aligned on a plane including a crankshaft. apparatus. 3. The V according to claim 2, wherein the intake manifold constituting the independent intake passage is divided by a substantially horizontal division surface formed in the portion arranged close to the intake manifold.
Type engine intake system. 4. The intake device for a V-type engine according to claim 1, wherein the volume chamber is formed as one. 5. The intake device for a V-type engine according to claim 4, wherein the volume chamber is formed separately from the independent intake manifold. 6. A V-type six-cylinder engine, wherein a surge tank disposed above one bank, an independent intake passage communicating the surge tank and each cylinder independently of each other, and connected to each cylinder connected to the surge tank. A throttle body provided with a throttle valve for controlling the intake flow rate of the V-type engine, wherein the independent intake passages are arranged between the banks and in a plane including the crankshaft so as to be substantially aligned in a line. In the intake device, a branch passage branched from each of the independent intake passages and having a shorter length than the independent intake passage, communicates with each of the branch passages, and is formed integrally with all cylinders and separately from the branch passage. And an opening / closing valve that controls the communication between each of the independent intake passages and the volume chamber in accordance with an operation state, and is provided with an on-off valve fixed to one shaft, and a portion where the independent intake passages are arranged close to each other. Into shape Divided into an upstream portion and a downstream portion at the divided surface, and the branch passage and the volume chamber are arranged above the divided surface, and when the on-off valve is open, the branch passage is separated from the volume chamber. A connection position between the branch passage and the upstream portion is set such that intake air flowing through the intake passage is directed to a division surface of the independent intake passage.