JP2721983B2 - 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.

2. Description of the Related Art Conventionally, in an intake system of a V-type engine, an intake device that uses a dynamic effect of intake such as resonance supercharging and inertia supercharging, that is, a pressure wave to increase a charging efficiency has been used.
Various proposals have been made as seen in JP-A-62-91621.

(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 according to the present invention is provided for each of the cylinders independently extending from each bank between both banks toward the center of both banks so that the upstream side is gathered above one bank. An independent intake passage, a branch passage branched from each of the independent intake passages and provided corresponding to each of the independent intake passages, a volume chamber communicated with the branch passage and arranged above the other bank, and An opening / closing valve for opening and closing the communication between each independent intake passage and the volume chamber is provided.

Further, it is preferable that the independent intake passage is divided by a substantially horizontal dividing surface at the center of both banks.

(Operation) In the above-described intake system for an engine, independent independent intake passages for the respective cylinders extending from the banks are assembled on one bank in the V-shaped space between the two banks. A volume chamber communicating with each branched passage is arranged on the other bank, and the communication is opened and closed according to the operation state by an on-off valve, and a tuning point for obtaining a dynamic effect of intake by inertia supercharging is changed. A mechanism that improves the engine output over a wide range by effectively utilizing the space is arranged.

(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 of the independent intake passages 6a to 6f. The throttle body 11 is provided with throttle valves 12a and 12b 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 communicate with each other at a portion where the upstream intake passage 13 joins.
Is connected to an air flow meter AFM and an air cleaner AC.

Further, the intake manifold 7 constituting the independent intake passages 6a to 6f has an upstream surge tank side integral with the surge tank 8 by using a substantially water dividing surface F in the middle upper portion of the banks 1A and 1B on both sides as a divided portion. A portion 7a and a downstream intake port-side portion 7b connected to the intake port 4 are divided into two parts, and the entire layout is obtained while securing the assemblability.

That is, the independent intake passages 6a, 6a connected to the left bank 1A
c, 6e extend obliquely upward toward the intermediate position between the banks 1A, 1B by the intake port side portion 7b, and from the upper side to the rear with a gentle curvature by the surge tank side portion 7a via the substantially horizontal dividing surface F. Each cylinder is 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, 6f connected to the right bank 1B extend obliquely upward toward the intermediate position between the two banks 1A, 1B by the intake port side portion 7b, and form the left intake passage at a substantially horizontal dividing surface F. Independently connected to the independent intake passages 6a, 6c, 6e from the bank 1A, the surge tank side portion 7a
As a result, each of the cylinders is connected to the second chamber 8b of the surge tank 8 located above the right bank 1B with substantially the same passage length.

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

In the above-described intake system, the resonance supercharging function is performed by an independent intake passage that is integrated with a collecting portion (the first chamber 8a or the second chamber 8b of the surge tank 8) that is collected for each cylinder whose intake stroke is not continuous.
The stationary wave generated when the natural frequency of the intake system and the engine speed due to 6a to 6f resonate 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. The natural frequency increases, 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.
In each of the chambers 8a and 8b of the surge tank 8 in which the independent intake passages 6a to 6f from the banks 1A and 1B are assembled, the intake order is not adjacent to each other, and the above-described resonance supercharging can be ensured because the intake interference does not occur.

In addition, the inertia supercharging function is such that the exciting force generated in the intake port 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 rotation speed signal from a rotation sensor 39 of an engine rotation speed detection means 29 for detecting the rotation speed of the engine and a throttle opening from a throttle sensor 31 for detecting the opening degrees of the throttle valves 12a and 12b of the engine. A signal is input. The rotation speed signal and the throttle opening signal are
To the fourth comparison circuits 32 to 35 and are compared with the set values by the respective comparison circuits. That is, for example rotational speed signal, a comparison value N ₁ equivalent 3500rpm first comparator circuit 32, a second
A comparison value N ₂ of 5000rpm corresponding comparison circuit 33, the third comparator circuit 3
4 is compared with the comparison value N ₃ equivalent to 7000 rpm, respectively.
The throttle opening signal is compared by a fourth comparison circuit 35 with a comparison value T ₀ corresponding to 73 °. Then, the output signals of the first comparison circuit 32 and the third comparison circuit 34 are output via the gate circuit 36.
The signal is input to the OR circuit 37, and the signal from the fourth comparison circuit 35 is also input to the OR circuit 37, and the output of the OR circuit 37 is output to the resonance driving circuit 27. On the other hand, the second comparison circuit 33
Is output to the inertial drive circuit 28.

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
III shows the characteristics when the first on-off valve 15 is open and the second on-off valve 16 is closed, and the curve IV shows the characteristics when the first on-off valve 15 is open and the second on-off valve 16 is open. And the engine speed is 35
In the low rotation region of 00 rpm or less, the state of the curve I in which both the on-off valves 15 and 16 are closed has the largest output, and in the middle rotation region of 3500 to 5000 rpm, the state of the curve III in which only the first on-off valve 15 is opened is the most. The output is large, and in the high rotation range of 5000 to 7000 rpm, the state of the curve IV where both the on-off valves 15 and 16 are opened has the largest output, and in the ultra-high rotation range exceeding 7000 rpm, only the first on-off valve 15 is closed. In the state of the curve II, the output is the largest, and in the low rotation region corresponding to 3500 rpm or less, both the on-off valves 15 and 16 are closed, and when the speed reaches 3500 rpm, the first on-off valve 15 is opened, and further, at 5,000 rpm. When it reaches, the second on-off valve 16 also opens,
The first on-off valve 15 is controlled to be closed when the rotation speed exceeds 000 rpm.

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 regardless of the machine.

Embodiment 2 This embodiment is also an intake device for a V-type six-cylinder engine similar to the previous embodiment, and a schematic configuration is shown in FIGS. 6 and 7.

The independent intake passages 6a to 6f from the respective cylinders of the banks 1A and 1B on both sides arranged in the same manner as in the previous example are assembled in the first chamber 8a and the second chamber 8b of the surge tank 8 for each of the banks 1A and 1B. The resonance changing means 40 in which the communication between the two chambers 8a and 8b is adjusted by the first on-off valve 15 to switch the natural frequency of resonance supercharging.
Is configured.

Further, branch passages 9a to 9f are respectively communicated in the middle of the independent intake passages 6a to 6f formed substantially in a line in the front-rear direction in the space between the banks 1A and 1B, and further, the branch passages 9a
9f are respectively assembled in first and second volume chambers 42a and 42b which are installed vertically for each of the banks 1A and 1B on both sides.
The second on-off valves 16 are respectively provided at the communication portions to the a and the 42b. And, the second on-off valve 16 interposed in the branch passages 9a, 9c, 9e of the odd-numbered cylinders corresponding to the cylinders of the left banks 1A, 1B is provided so as to open and close in cooperation with the first shaft 43, Similarly, the branch passage 9 of the even-numbered cylinder corresponding to the cylinder of the right bank 1B
The second on-off valve 16 is interposed between b, 9d, and 9f so as to open and close in cooperation with a second shaft 44. A second actuator (not shown) is provided for each shaft 43, 44. The inertia changing means 41 is configured so as to be linked and opened / closed.

The opening / closing control of the first opening / closing valve 15 and the second opening / closing valve 16 is performed in the same manner as in the previous example.

The other components are the same as in the previous example, and the same structures are denoted by the same reference numerals.

In this example, the inertia changing means 41 uses the high-speed range (50
When the second on-off valve 16 is opened such that the tuning point is on the high-speed side by shortening the length of the vibrating tube at 00 rpm), the first and second
Since the intake stroke is not continuous between the cylinders gathered in the volume chambers 42a and 42b, and when one cylinder is in the intake stroke, no intake is introduced into the other continuous ventilation cylinders, the independent intake passages 6a to From 6f, the intake air flows into the cylinder in the intake stroke, and the charging efficiency of the intake air is further improved as compared with the collective system of the previous example.

Embodiment 3 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. 8 is a plan view of the volume chamber portion, and FIG. 9 is a front view of FIG. .

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 the surge tank side part 7a of the intake manifold 7
Is connected to a volume chamber 45 formed separately.

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 through is disposed at the opening of 9f, and the second on-off valve 16 of each cylinder is fixed to one shaft 46 by a second actuator 18 disposed 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, when the second on-off valve is opened to synchronize the inertia supercharging to the high rotation side, the independent intake passages of the predetermined cylinders communicate with each other, and the intake air at the high rotation Although it is preferable to improve the charging efficiency of this cylinder, this communication preferably communicates between cylinders that do not have adjacent intake strokes as in the second embodiment, but includes adjacent cylinders as in the first embodiment, As in the third embodiment, all cylinders may communicate with each other, or may not communicate with each other if a volume chamber necessary for performing pressure reversal is formed.

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

(Effect of the Invention) According to the present invention as described above, the cylinder-independent independent intake passages extending from the respective banks are assembled on one bank, and the volumes communicate with the branch passages branched from the independent intake passages. The room is arranged on the other bank, and the on-off valve that opens and closes the communication according to the operating state is provided, so that the tuning point that obtains the dynamic effect of intake by inertia supercharging is changed and the engine A mechanism that can improve the output,
The arrangement can be made by effectively utilizing the V-shaped space between both banks.

[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 graph showing a torque characteristic of the on / off valve switching control with respect to the engine speed, and FIG. 6 is a schematic configuration of a V-type 6-cylinder engine intake device according to a second embodiment. 7, FIG. 7 is a front view of the essential part, FIG. 8 is a plan view of a volume chamber portion of the intake device of the V-type six-cylinder engine in the third embodiment, and FIG. 9 is a front view thereof. . 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, 42a, 42b, 45 ... volume chamber.

Claims (6)

(57) [Claims] An independent intake passage extending from each bank between both banks toward the center of both banks and having an upstream side gathering above one bank, independent of each cylinder, and each independent intake passage branching from each of the independent intake passages. A branch passage provided corresponding to
A volume chamber that communicates with the branch passage and is disposed above the other bank; and 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.
Type engine intake system. 2. An intake system for a V-type engine according to claim 1, wherein said intake manifold forming said independent intake passage is vertically divided by a substantially horizontal dividing plane at the center of both banks. 3. The intake device for a V-type engine according to claim 1, wherein said two chambers are formed. 4. The intake device for a V-type engine according to claim 1, wherein said volume chamber is formed as one. 5. The intake device for a V-type engine according to claim 4, wherein said volume chamber is formed separately. 6. An intake system for a V-type engine according to claim 1, wherein said on-off valve is arranged in a branch passage.