JPH02108818A - Air intake device for engine - Google Patents

Abstract

PURPOSE:To obtain a dynamic supercharging at a wide rotation sphere, by changing the tuning point of a resonance supercharging through the change of the natural frequency of a gathering air intake system, and in the meanwhile, changing the tuning point of an inertia overcharging through the change of the length of a vibration pipe, and arranging so that an inertia changing means may be made to be operated on a high rotation side by the operation of a resonance changing means. CONSTITUTION:At a V type 6 cylinder engine, branching off passages 9a-9f which branch off from the surge tank side portion 7a of right and left respective independent air intake passages 6a-6f respectively connected to the air intake ports of respective cylinders, and which extend in the left bank 1A direction, are provided, and they are connected to the 1st and 2nd volume chambers 19a, 19b. The 2nd opening/closing valves 16 are respectively provided at the connecting portions of respective branching off passages 9a-9f to volume chambers 19a, 19b, and respective opening/closing valves 16 are opened/closed by means of an inertia changing means 21 through the 2nd actuator 18. A surge tank 8 is divided into the 1st chamber 8a and the 2nd chamber 8b by means of a center partition wall 8c, and the 1st opening/closing valve 15 is interveniently furnished at an opening portion formed at the partition wall 8c, and opening/closing is made by means of a resonance changing means 20 through the 1st actuator 17.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for an engine that performs supercharging by utilizing the dynamic effect of intake air.

(Prior Art) Various intake devices have been proposed in the past for multi-cylinder engine intake systems that utilize dynamic effects of intake air, such as pressure waves, such as resonance supercharging and inertia supercharging, to increase charging efficiency. ing.

First, the above-mentioned resonant supercharging is a resonance effect that occurs when cylinders whose intake order is not adjacent are assembled, and the natural frequency of the intake system including this cluster matches the engine rotational speed, that is, the excitation frequency of the piston, and resonates. For example, a technology that obtains resonant supercharging over a wide range by changing the resonant natural frequency using a variable mechanism is, for example,
This is known as seen in Japanese Patent Application Laid-Open No. 81-226514.

In addition, the above-mentioned inertial supercharging utilizes the inertial effect of intake air, in which a negative pressure wave that occurs with the start of intake is reflected at a pressure reversal section on the upstream side of the intake passage and returns to the intake port as a positive pressure wave. A technique for obtaining inertial supercharging over a wide range using a variable mechanism that changes the length up to the pressure reversal section is known, for example, as seen in Japanese Patent Laid-Open No. 157718/1983.

(Problem to be Solved by the Invention) However, in an intake system that uses only resonance supercharging or inertia supercharging as described above, the tuning point is changed by a variable mechanism like the previous example. However, when the resonance point in a specific state is exceeded, the output improvement effect of resonance supercharging or inertial supercharging will decrease. therefore,
With these systems that utilize only the dynamic effects of resonance supercharging or inertial supercharging, the output improvement function can only be obtained within a specific and limited range, and it is important to ensure good output performance over the entire operating range. It is difficult.

Therefore, in view of the above circumstances, the present invention provides an engine intake system that combines resonance supercharging and inertial supercharging and utilizes the differences in the characteristics of the two to perform dynamic supercharging over a wide rotation speed range. The purpose is to provide

(Means for Solving the Problems) In order to achieve the above object, an intake system of the present invention is provided with an independent intake passage that independently introduces intake air into each cylinder having a different intake timing, and an independent intake passage of a predetermined cylinder. and a resonance changing means for changing the natural frequency of the intake system formed by the collecting part and the independent intake passage so that the intake air intervals are equal, and an inertia change means for changing the natural frequency of the independent intake passage. The apparatus is configured to further include a control means for receiving a signal from the engine rotation speed detection means for detecting the engine rotation speed and operating the inertia change means at a higher rotation speed than the operation of the resonance change means. . Further, the control means may further operate the resonance change means at a rotation speed higher than the switching rotation speed of the inertia change means.

Further, it is preferable that the collecting section collects only cylinders whose intake strokes are not consecutive.

On the other hand, it is preferable that the inertia changing means changes the position at which it opens into the predetermined volume chamber on the upstream side of the independent intake passage.

(Function) In the engine intake system as described above, the operating timings of the resonance changing means that changes the tuning point of resonance supercharging and the inertia changing means that changes the tuning point of inertial supercharging are shifted, and the timing of operation is adjusted to suit their respective characteristics. Correspondingly, the resonance change means is switched and operated on the low rotation side,
The inertia changing means is switched at higher rotation speeds to obtain sufficient supercharging effect due to resonance supercharging in the lower rotation range, and when the effect decreases, the resonance changing means is switched to suppress the reduction in resonance supercharging. In addition, by switching the inertia change means on the high speed side to suppress the decline in inertia supercharging and obtaining sufficient supercharging action from both, it is possible to achieve high performance over a wide range from low speeds to high speeds. It aims to improve engine output by obtaining a supercharging effect due to dynamic effects.

(Example) Hereinafter, each embodiment of the present invention will be described along with 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, 3 arranged at a predetermined angle on both sides of the cylinder block 2 at the lower center.
It has a left bank IA and a right bank IB, in which the left bank IA is provided with a 1st 3.5 cylinder, and the right bank IB is provided with a 2nd 46 cylinder. ing. The intake ports 4 of each cylinder are opened on the inner surfaces of both banks IA and 1B, facing each other.

The intake device that supplies intake air to each cylinder in banks IA and IB on both sides includes an intake manifold 7 that constitutes each left and right independent intake passage 68 to 6d connected to each intake port 4, and a cylinder in bank IB on the right side. A surge tank 8 is provided as a gathering section located above and to which the upstream ends of the independent intake passages 6a to 6f are connected.

The surge tank 8 includes a first chamber 8a and a second chamber 8b provided for the left and right banks IA and IB, respectively. That is, the surge tank 8 is configured as a box-shaped body that is long in the output shaft direction, and the interior thereof is divided into a first chamber 8a and a second chamber 8b by a central partition wall 8C. The first chamber 8a from the left bank IA, which is farther from the surge tank 8, is connected to the rear first chamber 8a. 3. The independent intake passages 6a, 6c, and 6e from the 5th cylinder are connected and collected, and the independent intake passages 6b, 6d, 6f from the 2nd, 4th, and 6th cylinders from the closer right bank IB are connected to the front second chamber 8b. are connected and aggregated, and each bank IA.

For each IB, independent intake passages 6a to 6f are grouped for each cylinder whose intake stroke is not adjacent to each other.

A throttle body 11 is connected to the surge tank 8 on the opposite side of the independent intake passages 68 to 6f, and this throttle body 11 has two throttle valves 12 for each chamber.
a, 12b are interposed, and both chambers 8a, 8 of the surge tank 8
b, and intake air is introduced. Furthermore, an intake passage 13 is connected further upstream, and this intake passage 1
The first chamber 8a and the second chamber 8 on both sides at the part where 3 joins.
b are communicated with each other, and the upstream end of the intake passage 13 is connected to an air flow meter AFM and an air cleaner AC.

In addition, the intake manifold 7 constituting the independent intake passages 6a to 6f is divided into a substantially horizontal connecting surface F at the middle upper part of the banks IA and IB on both sides, and is connected to the upstream surge tank side which is integrated with the surge tank 8. portion 7a and intake port 4
The intake port side portion 7b on the downstream side is connected to the intake port side portion 7b.

That is, the independent intake passage 6a connected to the left bank IA
, 6c, and 6e extend obliquely upward toward an intermediate position between both banks IA and IB by the intake port side portion 7b, and are extended from above to the rear with a gentle curvature by the surge tank side portion 7a via the approximately horizontal connecting surface F. The first chamber 8 of the surge tank 8 extends toward the right bank IB and is located above the right bank IB.
Each cylinder is connected to A with approximately the same passage length. On the other hand, independent intake passages 6b, 6d connected to the right bank IB,
6f is connected to both banks IA by the intake port side portion 7b.
The independent intake passages 6a, 6 from the left bank IA extend obliquely upward toward the intermediate position of IB, and are connected to the left bank IA at a substantially horizontal connecting surface F.
c and 6e, extending from above to the front with a gentle curvature by the surge tank side portion 7a, and connected to the second chamber 8b of the surge tank 8 located above the right bank IB in approximately the same manner for each cylinder. connected by a path length.

A first chamber 8 is provided in the central partition wall 8C of the surge tank 8.
An opening is formed that communicates the chamber 8b with the second chamber 8b, and a first on-off valve 15 for resonance switching is interposed in this opening. The first on-off valve 15 is connected to a first actuator 17 to be opened and closed.

Further, branch passages 98 to 9f are provided which branch 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 IA on the opposite side from the surge tank 8. The tips are connected to first and second volume chambers 19a, , ICjb, which serve as pressure inversion parts, which are arranged in front and behind in the space between the banks. The first volume chamber 19a at the front has branch passages 9a to 9 for the first to third cylinders.
C is connected, while the rear second volume chamber 19b has a fourth
~6 cylinder branch passages 9d~9f are connected, and each volume chamber 1
Independent intake passages 68 to 6f of cylinders that gather at 9a and 19b
are configured to communicate with each other via volume chambers 19a and 19b. A second on-off valve 16 for inertia switching is disposed in a communicating portion of each of the branch passages 9a to 9f with the volume chambers 19a, 19b, and each of the volume chambers 19a,
19b is supported on a common shaft, and the second on-off valve 16 of each cylinder is connected to a common second actuator 18 disposed in the center.
It is opened and closed by

In the above-mentioned intake system, the resonance supercharging function is achieved by an intake system using a collection part (the first chamber 8a or second chamber 8b of the surge tank 8) that is collected for each cylinder whose intake strokes are not consecutive, and independent intake passages 6a to 6f that are collected. This is obtained by a standing wave generated when the natural frequency of the engine resonates with the engine rotational speed acting on the intake boat 4 at the beginning of the intake stroke. Then, the first on-off valve 15 is controlled by the resonance changing means 20 that switches the natural frequency of the intake system.
When opened by the operation of the first actuator 17, the communication path between the gathering parts 8a and 8b becomes shorter than in the closed state, the natural frequency becomes higher, and a high resonance effect is obtained in the high rotation range. In the engine in this example, 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 each bank IA and 1B are grouped together. Each chamber 8a of the surge tank 8.

In 8b, the intake order is not adjacent, and the resonance supercharging described above can be ensured because intake interference does not occur.

In addition, the inertial supercharging function is such that when the excitation force generated in the intake boat 4 is transmitted upstream through the independent intake passages 6a to 6f and the second on-off valve 16 is closed, the first and second on-off valves of the surge tank 8 and The entire interior of the intake pipe up to the second chambers 8a and 8b is vibrated.ζAlso, when the second on-off valve 16 is open, the
Volume chamber 19a.

The inside of the intake pipe up to 19b is vibrated, and an inertial supercharging effect is obtained when the intake boat is synchronized with the closing timing. Then, by the inertia changing means 21 that changes the position of the above-mentioned path, that is, the pressure vibrating part, when the second on-off valve 16 is closed, the vibration pipe length is long and synchronized in the low rotation range, and when it is open, the vibration pipe length is adjusted. is shortened and synchronized in the high rotation range, and intake air is introduced from the independent intake passages 6a to 6f of other cylinders through the branch passages 98 to 9f and the volume chambers 19a and 19b, and the filling efficiency is improved by reducing the intake resistance. This is something that can be improved.

The actuation of the first and second actuators 17.18 of the resonance modification means 20 and the inertia modification means 21 then
It is controlled by a control means 22 as shown in the figure. Both actuators 17.18 are driven by the introduction of operating pressure through negative pressure introduction passages 23.24, and a first three-way solenoid valve 25 is provided in the negative pressure introduction passage 23 for the first actuator 17 for resonance supercharging. A second three-way solenoid valve 26 is interposed in the negative pressure introduction passage 24 for the second actuator 18, and a drive signal is output from the drive circuit 27.28 of the control means 22 to both three-way solenoid valves 25.26. and the first actuator 17 at a predetermined time.
Alternatively, by introducing negative pressure into the second actuator 18, the first
It performs a switching operation of the on-off valve 15 or the second on-off valve 16.

The control means 22 receives a rotation speed signal from a rotation sensor 30 of an engine rotation speed detection means 29 that detects the engine rotation speed, and a throttle opening signal from a throttle sensor 31 that detects the opening degrees of the throttle valves 12a and 12b of the engine. A signal is input.

The rotational speed signal and the throttle opening signal are input to first to fourth comparison circuits 32 to 35, and are compared with set values in each comparison circuit. That is, for example, the rotation speed signal is determined by the first comparison circuit 32 as a comparison value Nl corresponding to 350 Orpm,
The second comparison circuit 33 generates a comparison value N2 equivalent to 500 rpm, and the third comparison circuit 34 generates a comparison value N3 equivalent to 7000 rpm.
Further, the throttle opening signal is compared with a comparison value T0 corresponding to 73@ in the fourth comparison circuit 35. Then, the first comparison circuit 32 and the third comparison circuit 3
The output signal of 4 is sent to the OR circuit 37 via the gate circuit 36.
The fourth comparison circuit 3 is input to this OR circuit 37.
5 is also input, and the output of the OR circuit 37 is output to the resonance drive circuit 27. On the other hand, the signal from the second comparison circuit 33 is output to the inertia drive circuit 28.

By controlling 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 the characteristics shown in FIG. Ru. That is, the first on-off valve 15 operates in a high load state where the throttle opening TVO is 73 degrees or more and the engine rotation speed is 3500 rpm or less, and in a high load state where the throttle opening is 73 degrees or more and the engine rotation speed is 3500 rpm or less. The number is closed in a high rotation range of 700 Orpm or more, lowering the natural frequency, while it is open in other load and rotation ranges, increasing the natural frequency.

Moreover, the second on-off valve 16 is
It closes when the engine rotation speed is 5000 rpm or less to lengthen the vibrating tube length, while it opens at engine rotation speeds higher than that to shorten the vibrating tube length.

Based on the control characteristics as described above, engine output characteristics as shown in FIG. 5, for example, can be obtained. In the figure, four torque curves I to ■ are generated corresponding to the open and close states of the first and second on-off valves 15 and 16, and these are used by switching. First, curve I is the first on-off valve 15
is closed and the second on-off valve 16 is closed, the curve ■ shows the characteristics when the first on-off valve 15 is closed and the second on-off valve 16 is open, and the curve ■ is when the first on-off valve 15 is open. The curve (2) shows the characteristics when the second on-off valve 16 is in the closed state, and the curve (2) shows the characteristics when the first on-off valve 15 is open and the second on-off valve 16 is in the open state. In the low engine speed range of 3500 rpm+ or less, the state of curve I with both on-off valves 15 and 16 closed produces the highest output, and in the middle speed range of 3500 to 5000 rpm, only the first on-off valve 15 is open. In the high speed range of 5000 to 7000 rpm, the state of curve ■ with both on-off valves 15.16 open has the highest output, and in the ultra-high speed range exceeding 7000 rpm, the output is the highest.
The state of curve H where only the on-off valve 15 is closed is the state where the output is the highest, and correspondingly, in the low rotation range of 3500 rpm or less, both on-off valves 15 and 16 are closed, and the output is 3500 rpm or less.
When the rpm reaches 50 rpm, the first on-off valve 15 is opened, and
When reaching 00rpI11, the second on-off valve 16 also opens, and 70rpI11 is reached.
When the rotation speed exceeds 00 rpm, the first on-off valve 15
This is a control to close the .

Note that the above switching is performed when the throttle opening is 73''.
This is done in a high load state where the throttle opening is opened above 73 degrees, and since that much output is not required in a load state where the throttle opening is less than 73 degrees, the first on-off valve 15 is opened to set the state of curve ■, and the engine speed is 5000 rpm or less. In this region, switching of both on-off valves 15 and 16 is eliminated to prevent changes in driving performance due to torque shock caused by switching. Also, the normal rotation range of the engine is 7000rpa.
+7000 for those set to be less than or equal to
The switching operation of the first on-off valve 15 at rpm is no longer necessary.

According to the embodiment described above, charging efficiency is improved by the action of resonance supercharging or inertia supercharging in which the tuning state is switched in each region from low rotation range to high rotation range, and separate supercharging is performed. It is possible to obtain high output performance regardless of the machine.

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

Independent intake passages 6a to 6f from each cylinder of banks IA and IB on both sides arranged in the same manner as in the previous example are connected to the respective banks IA and IB.
The first chamber 8a and the second chamber of the surge tank 8 for each A and IB.
A resonance changing means 40 is assembled in the chamber 8b, and the communication between the chambers 8a and 8b is adjusted by the first on-off valve 15 to switch the natural frequency of resonance supercharging.

In addition, branch passages 9a to 9f are communicated in the middle of the independent intake passages 6a to 6f, which are formed approximately in rows in the front-rear direction in the space between the banks IA and IB, and further, the branch passages 9a to 9f are collected in first and second volume chambers 42a and 42b installed above and below for banks IA and IB on both sides, respectively, and a second on-off valve 16 is provided in a communicating portion to both volume chambers 42a and 42b, respectively. has been done. Second on-off valves 16 are interposed in the branch passages 9a, 9c, and 9e of the odd-numbered cylinders corresponding to the cylinders of the left bank LA and IB, and are provided so as to be opened and closed in conjunction with the first shaft 43. , Similarly, branch passages 9 for even-numbered cylinders corresponding to the cylinders in the right bank IB.
The second on-off valves 16 interposed in b, 9d, and 9f are provided to open and close in conjunction with a second shaft 44, and a second actuator (not shown) is connected to each shaft 43, 44. The inertia changing means 41 is configured to be opened and closed in conjunction with each other.

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

The rest of the structure is the same as in the previous example, and the same structures are given the same reference numerals.

In this example, the inertia changing means 41 controls the high speed range (5
000 rpm), the length of the vibration pipe is shortened and the second on-off valve 16 is opened so that the tuning point is on the high speed side, the intake stroke between the cylinders gathered in the first and second volume chambers 42a and 42b are not continuous, and when one cylinder is in the intake stroke, intake air is not introduced into the other communicating cylinders, so intake air flows into the cylinder in the intake stroke from the independent intake passages 6a to 6f of other cylinders. However, the intake air filling efficiency is further improved compared to the previous collection method.

Embodiment 3 This embodiment is an example of an in-line six-cylinder engine, and the schematic configuration thereof is shown in FIGS. 8 and 9.

The intake order of this 6-cylinder engine is 1-2-4-6-5.
- The independent intake passages 46a to 46f connected to each cylinder of the engine body 45 are divided into 1st, 4th and 5th cylinders and 2nd and 3.6th cylinders whose intake strokes are not adjacent to each other. are collected in a first chamber 48a and a second chamber 48b of the surge tank 48, respectively. The internal space of the surge tank 48 is divided by a partition wall 48c formed vertically in the direction of the cylinder row, and each is connected to independent intake passages 46a to 4 from below.
The upstream end of 6f is connected. This surge tank 48
A throttle body 11 equipped with throttle valves 12a, 12b corresponding to each chamber 48a, 48b is arranged at the rear end to introduce intake air, and at the front end, a partition wall 48c connects both chambers 48a, 48b. A communicating opening is formed, and a first on-off valve 50 for resonance switching is interposed to open and close this opening.

Further, a volume chamber 52 is formed adjacent to the surge tank 48 and communicates with the independent intake passages 46a to 46f of each cylinder.
A second on-off valve 51 for inertia switching is disposed on a single shaft in the communication portion with the inertial switching valve.

Switching control of the first on-off valve 50 and the second on-off valve 51 is performed in the same manner as in the first embodiment.

In this example, the independent intake passages 46a to 46f of the cylinders whose intake strokes are not continuous are collected, and this collected portion (
When obtaining a supercharging effect by the resonance action corresponding to the natural frequency in the intake system between the first chamber 48a and second chamber 48b of the surge tank 48 and the independent intake passages 46a to 46f, the communication between the gathering parts is opened and closed. Resonance changing means 53 is configured to switch the natural vibration by operating the first on-off valve 50 so that it closes at low speeds and opens at high speeds.

In addition, the negative pressure wave of the own cylinder generated at the intake port is reflected at the communication opening to the surge tank 48 as a pressure reversal section, and an inertia supercharging effect is obtained.
When the second on-off valve 51 of No. 4 is open, the opening to the volume chamber 52 is reflected as a pressure reversal section, and the vibration pipe length is switched by the operation of the second on-off valve 51, and the low-speed It closes at the same time, and opens at a higher speed than the switching timing of the first on-off valve 50. Further, the first on-off valve 50 may be closed further on the high speed side as necessary.

In this example as well, it is possible to increase charging efficiency and obtain good engine output performance by switching between resonance supercharging and inertia supercharging in an in-line six-cylinder engine from a low rotation range to a high rotation range.

Embodiment 4 This embodiment is also an example of an in-line six-cylinder engine, and the schematic configuration is shown in FIGS. 10 and 11.

The intake order of this 6-cylinder engine is 1-5-3-6-2.
- The independent intake passages 46a to 46f connected to each cylinder of the engine main body 45 are arranged in the order of 4 cylinders, and the first . 2. The first chamber 56a and the second chamber 56 of the surge tank 56 are divided into 3 cylinders and 4th, 5th, and 6th cylinders.
b and are collected respectively. The internal space of the surge tank 56 is divided into front and rear sections by a partition wall 56c formed at the center of the cylinder row, as in the first embodiment, and the upstream ends of the independent intake passages 46a to 46f are connected to each section from below. Throttle valves 12a and 12 corresponding to the respective volume chambers 56a and 56b are provided on the central side of the surge tank 56.
A throttle body 11 is provided to introduce intake air, and an opening is formed in the partition wall 56c to communicate the chambers 56a and 56b, and a first opening/closing valve 57 for resonance switching opens and closes this opening. is interposed to constitute the resonance changing means 59.

Further, a volume chamber 52 is formed adjacent to the surge tank 56 and communicates with the independent intake passages 46a to 46f of each cylinder.
A second on-off valve 58 for inertia switching is coaxially disposed in a communicating portion with the inertia changing means 60.

The resonance changing means 59 and the inertia changing means 60
The switching control of the first on-off valve 57 and the second on-off valve 58 is performed in the same manner as in the previous example, and the same supercharging effect can be obtained.

In this example, the surge tank structure is simplified by simplifying the cylinder division system.

Embodiment 5 This embodiment is an example of an in-line four-cylinder engine, and the schematic configuration thereof is shown in FIGS. 12 and 13.

The intake order of this four-cylinder engine is the order of the l-3-4-2 (or l-2-4-3) cylinder, and the engine main body 6
The independent intake passages 63a to 63d connected to each cylinder of the surge tank 64 are divided into the 1.4th cylinder and the 2.3rd cylinder whose intake strokes are not adjacent to each other. They are each collected in surge tank 64
The internal space is divided by a partition wall 64c formed vertically in the direction of the cylinder row, and an independent intake passage 6 is opened from below each of the partition walls 64c.
The upstream ends of 3a to 63d are connected.

A throttle body 11 equipped with throttle valves 12a, 12b corresponding to each chamber 64a64b is disposed at the rear end of the surge tank 64, through which intake air is introduced, and at the front end, both chambers 64a are connected to a partition wall 64c.

64b is formed, and a first on-off valve 65 for resonance switching that opens and closes this opening is interposed to constitute resonance changing means 67.

Further, a volume chamber 69 is formed adjacent to the surge tank 64 and communicates with the independent intake passages 63a to 63d of each cylinder, and an inertia switching section is formed in the communication portion between each independent intake passage 63a to 63d and the six volume chambers. The second on-off valves 66 are arranged coaxially to form an inertia changing means 68.

The resonance changing means 67 and the inertia changing means 68
The switching control of the first on-off valve 65 and the second on-off valve 16 is performed in the same manner as in the first embodiment.

In this example as well, it is possible to increase charging efficiency and obtain good engine output performance by switching between resonance supercharging and inertia supercharging in an in-line four-cylinder engine from a low rotation range to a high rotation range.

In each of the above embodiments, when the second on-off valve is opened to synchronize the inertial supercharging to the high speed side, the independent intake passages of the predetermined cylinders are communicated with each other to reduce the intake air at high speeds. Although it is preferable for this communication to communicate between cylinders whose intake strokes are not adjacent as in the second embodiment, it may also include adjacent cylinders as in the first embodiment. All the cylinders may be in communication as in Examples 3 to 5, or they may not be in communication with each other as long as a volume chamber necessary for pressure reversal is formed.

Further, in the above embodiments, examples of a type 6-cylinder engine, an in-line 6-cylinder engine, and an in-line 4-cylinder engine are shown, but the present invention is also applicable to other types of engines.

Furthermore, in each switching state between resonance supercharging and inertia supercharging, the tuning point at which the highest torque is achieved is set in accordance with the requirements of each engine, but the set rotation speed and switching timing are determined by resonance. Inertial supercharging is set higher than supercharging, and in the low rotation range, the resonance supercharging effect obtained by setting the low speed of resonance supercharging increases torque, and the resonance supercharging effect on the low speed side decreases and the resonance supercharging is set on the high speed side. When the inertia supercharging is set to a low speed, the inertia supercharging effect obtained by setting the inertia supercharging to a low speed is used to increase torque, and when the low speed inertia supercharging effect decreases, the inertia supercharging is set to a high speed to increase torque at high speeds. Furthermore, in a high-speed state, the control is performed to drive to a high-torque state as necessary.

(Effects of the Invention) According to the present invention as described above, the natural frequency of the collective intake system is changed and the tuning point of resonance supercharging is switched by the resonance changing means, while the length of the vibration pipe is changed to change the tuning point of inertial supercharging. By switching the tuning point by the inertia changing means and causing the control means to operate the inertia changing means at a higher rotational speed than the operation of the resonance changing means, the difference in characteristics between resonance supercharging and inertia supercharging is utilized. It is possible to obtain dynamic supercharging over a wide rotation range and improve engine output.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of the intake system of a V-type 6-cylinder engine according to the first embodiment of the present invention, FIG. 2 is a front view of the main parts, FIG. 3 is a block diagram of the control means, and FIG. A characteristic diagram showing the operating state of the on-off valve, Fig. 5 is a graph showing the torque characteristic due to the switching control of the on-off valve with respect to the engine speed, and Fig. 6 is a schematic configuration of the intake system of a V type 6-cylinder engine in the second embodiment. FIG. 7 is a front view of the same essential parts, FIG. 8 is a plan view showing a schematic configuration of the intake system of an in-line six-cylinder engine in the third embodiment, and FIG. 9 is a cross-sectional front view of the same essential parts. , Fig. 10 is a plan view showing a schematic configuration of the intake system of an in-line 6-cylinder engine in the fourth embodiment, Fig. 11 is a front view of the same essential parts, and Fig. 12 is an in-line 4-cylinder engine in the fifth embodiment. FIG. 13 is a plan view showing a schematic configuration of the intake device, and FIG. 13 is a front view of the main parts. 1.45.62...Engine body, 6a to 6f
. 46a to 46f, 63a to 63d...Independent intake passage, 8.48, 56.64...Surge tank, 8a, 48a, 56a, 64a---=first chamber, 8
b. 48b, 56b, 64b --- Second room, 9a to 9f
...Branch passage, 15, 50, 57.65...
...First on-off valve, 16,51,58.66...
・Second on-off valve, 17...first actuator,
18... second actuator, 19 a,
19 b, 42 a, 42 b. 52.69...Volume chamber, 20.40. 53.
59°67... Resonance changing means, 21, 41, 5
4.60°68... Inertia changing means, 22...
. . . control means, 29 . . . rotation speed detection means. Figure 4 Figure 4 Figure 4 Figure 4

Claims (4)

[Claims] (1) In an engine equipped with a plurality of cylinders with different intake timings, an independent intake passage that introduces intake air into each cylinder independently, and a collection of the above-mentioned independent intake passages of predetermined cylinders so that the intake intervals are equal a resonance changing means for changing the natural frequency of the intake system formed by the independent intake passages assembled with the gathering part; an inertia changing means for changing the natural frequency of the independent intake passages; and a resonance changing means for changing the natural frequency of the independent intake passages; An engine comprising: engine rotation speed detection means; and control means for receiving a signal from the engine rotation speed detection means and operating the inertia change means at a higher rotation speed than the operation of the resonance change means. Intake device. (2) The engine intake system according to claim 1, wherein the control means further operates the resonance changing means at a rotation speed higher than the switching rotation speed of the inertia changing means. (3) The engine intake system according to claim 1, wherein the gathering section gathers only cylinders whose intake strokes are not consecutive. (4) The engine intake system according to claim 1, wherein the inertia changing means changes the position at which the inertia changing means opens into the predetermined volume chamber on the upstream side of the independent intake passage.