JPS6357817A - Air intake device for internal combustion engine - Google Patents

Abstract

PURPOSE:To obtain an air intake passage length adjusting means with good convenience to be loaded into an engine space, by providing, within an air cleaner case, 1st air intake passage and 2nd air intake passage longer than 1st air intake passage so as to open and close 1st air intake passage depending on an engine operating condition. CONSTITUTION:An air cleaner 200 is equipped with a nearly cylindrically shaped air cleaner case 202 consisting of an upstream-side case 206 provided with an inlet port 205 and a downstream-side case 208 provided with an outlet port 207, and with a filter element 203 supported between both cases 206 and 208. In this case, a combined air intake passage 300 consisting of 1st air intake passage 310 with a larger passage sectional area and a shorter passage length, and spiral 2nd air intake passage 320 with a smaller passage sectional area and a longer passage length is provided with in the downstream-side case 208. The first air intake passage 310 is equipped with a switching valve 330, and said valve 330 is controlled by a control device 400 so as to be in the closed position when an engine rotational speed is slower than a reference value and in the open position when the engine rotational speed is faster than such reference value.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an intake system for an internal combustion engine that changes the length of the intake passage of the internal combustion engine according to the operating condition of the engine, and particularly relates to an intake system for a vehicle. It is suitable for use in engines.

[Prior Art] Due to the dynamic effects of the inertia effect and pulsation effect of the intake system in an engine, when the length of the intake passage is changed, the characteristics of intake efficiency with respect to rotational speed change significantly. In other words, in general, when the intake passage is short, the intake efficiency is high when the rotation speed is high, as shown by the broken line β in Figure 5, and conversely, when the intake passage is long, as shown by the broken line γ in Figure 5, the intake efficiency is high. , High suction efficiency at low rotation speeds.

Therefore, there is a demand for improving the intake efficiency over a wide range of rotational speeds by changing the length of the intake passage depending on the rotational speed of the engine.

In connection with the resolution of this request, Utility Model Publication No. 60-8117,
Japanese Unexamined Patent Publication No. 61-4821 is known. According to these known techniques, two intake pipes of different lengths are provided in parallel between the air cleaner and the intake boat of the engine, and an on-off valve is provided to open and close the short intake pipe. The length of the intake passage between the air cleaner and the intake boat was changed by opening and closing the valve depending on operating conditions such as the rotational speed of the engine.

[Problems to be Solved by the Invention] However, in the conventional technology, it is difficult to secure space for arranging two independent intake pipes between the air cleaner and the intake boat in a narrow engine room such as the engine room of a vehicle. It was difficult to do so. In addition, the conventional type had very poor mounting performance, making it even more difficult to install it in an existing engine room.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an intake system for an internal combustion engine that can be easily installed in an engine space and that can change the length of an intake passage.

[Means for Solving the Problems 1] In order to achieve the above object, the present invention includes an air cleaner case that houses therein a filtering element that filters air taken into a combustion chamber of an internal combustion engine; a second intake passage provided in the air cleaner and having a longer intake passage than the first intake passage; an on-off valve that opens and closes the first intake passage; The technical means includes a control device that controls opening and closing of the on-off valve according to the operating state of the internal combustion engine.

[Function] The present invention includes a first intake passage in the air cleaner case;
a second intake passage that is longer than the first intake passage;
By opening and closing the first intake passage in accordance with the operating condition of the internal combustion engine, the length of the intake passage that supplies combustion air to the combustion chamber of the internal combustion engine can be varied in accordance with the operating condition of the internal combustion engine. can.

[Effects of the Invention] According to the present invention, since the first intake passage and the second intake passage having different lengths are provided in the air cleaner case,
A device that changes the length of an intake passage depending on the operating state of an internal combustion engine can be easily installed in a narrow engine space.

[Embodiment] Next, an internal combustion air intake system of the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 shows a sectional view of the vicinity of the cylinder head of an automobile engine incorporating a first embodiment of the present invention.

In the combustion 710i of the engine 100, a piston 102
By the intake operation of the intake valve 103, combustion air is supplied via the intake boat 104, the intake manifold 105, and the air cleaner 200.

The air cleaner 200 of this embodiment is of an axial flow type, and air taken in from an inlet 201 is purified by a filtration element 203 housed in an air cleaner case 202.
04 to the intake manifold 105.

The air cleaner case 202 has a substantially cylindrical shape and includes an upstream case 206 made of resin or metal and equipped with an inlet 205 to which the inlet 201 is connected, and a connecting pipe 204.
A downstream case 208 equipped with an outlet 207 to which the
It consists of an upstream case 206 and a downstream case 208.
The filtration element 203 is supported between.

The inside of the downstream case 208 has a large passage cross-sectional area.
The first intake passage 310 and the first intake passage 310 have a short passage length.
A composite intake passage 300 consisting of a second intake passage 320 having a smaller passage cross-sectional area and a longer passage length than the intake passage 310 is provided, and the air passing through the inside of the air cleaner case 200 is It passes through either the first intake passage 310 or the second intake passage 320 of the passage 300 . The second intake passage 320 is provided in a spiral shape, as shown in FIG. The outlet 322 is provided with an outlet 322. And the first intake passage 310
is provided at the center of the second intake passage 320.

This composite intake passage 300 is made up of a plurality of assemblies for ease of assembly, and when each member is made of metal, they are connected by brazing, welding, etc., caulking, rivets, etc. In the case of resin, they are bonded together by welding, adhesive, or the like.

An on-off valve 330 that opens and closes the first intake passage 310 is provided at an intermediate position of the first intake passage 310.

This opening/closing valve 330 is pivoted at the center by a pivot 331, and has a first position where the first intake passage is blocked, as shown by the - dotted line in FIG. 1, and a first position shown by the solid line in FIG. like,
It is provided so as to be movable between a second position that ensures communication with the first intake passage.

An n-pressure actuator 340 is connected to the pivot 331 via a rod 332, and this negative pressure actuator 340
It is designed to be driven by This negative pressure actuator 340 includes a diaphragm 341, and when negative pressure is introduced into the diaphragm chamber 342, the rod 332 is pushed down against the action of a compression spring 343 to open the on-off valve 330. On the other hand, when the atmosphere is introduced into the diaphragm chamber 342, the compression coil spring 343 pushes up the rod 332 to bring the on-off valve 330 to the second position. .

The flamm chamber 342 of the negative pressure actuator 340 is connected to the first flammable chamber 342 of the electromagnetic negative pressure switching valve 350 via a conduit 344.
It is connected to boat 351. The negative pressure switching valve 350 is
In addition to the first boat 351, a second boat 352 and a third boat 353 are provided. The second boat 352 includes a conduit 354,
It is connected to the inside of the intake manifold 105 via a negative pressure restorer 355, a check valve 35G, and a conduit 357. Further, the third boat 353 is connected to an air intake port 358. Then, the solenoid 359 of the negative pressure switching valve 350
When the solenoid 359 is energized, the first boat 351 and the second boat 352 are connected, and when the solenoid 359 is de-energized, the first boat 351 and the third boat 353 are connected. The solenoid 359 is energized and controlled by the control device 400.

FIG. 3 shows a block diagram of the till device 400.

An engine rotation detection sensor 410 is connected to the input side of the control 1 device 400, and a solenoid 359 of the negative pressure switching valve 350 is connected to the output side. This engine rotation detection sensor 410 generates a pulse signal according to the rotation speed of the output shaft of the engine 100.

The control IA device U 400 receives the pulse signal generated by the engine revolution detection sensor 410 and the clock circuit 420.
A drive circuit 440 that sends a drive current to the solenoid 359 is provided with a microprocessor 430 that executes processing as described later based on a clock signal etc. generated by the microprocessor 430. controlled.

Next, the processing of the microprocessor 430 will be explained based on the chart shown in FIG.

First, when the power (not shown) is turned on, in step 431, initial values are set for the operation of the microphone setter 430 only at the start.

Next, by repeating the process from step 432 to step 435 as one block, the on-off valve 3
30 is executed for opening/closing control.

First, in step 432, the rotation speed N of the engine 100 is calculated based on the pulse signal from the engine rotation detection sensor 410 and the pulse signal generated by the clock circuit 420. Subsequently, in step 433, it is determined whether the rotational speed N calculated in step 432 is equal to or higher than the rotational speed No (see FIG. 5), which is a reference for switching the on-off valve 330. And the judgment result is YES
In the case of S, in step 434, the solenoid 35
9 is de-energized to the drive circuit 440;
Thereafter, the process returns to step 432. If the determination result in step 433 is NO, in step 435 a control signal for energizing the solenoid 359 is output to the drive circuit 440, and then the process returns to step 432.

Next, the operation of the above embodiment will be explained.

The rotational speed N, which is one element of the operating state of the engine 100, has been set in advance! 3i! If the rotation speed is lower than NO, the solenoid 359 of the negative pressure switching valve 350 is energized by the action of the control device 400, and the first boat 3
51 and a second boat 352 are connected.

As a result, negative pressure is introduced into the diaphragm chamber 342 of the negative pressure actuator 340, the diaphragm 341 pushes down the rod 332 against the action of the compression coil spring 343, and the on-off valve 330 is activated as indicated by the dashed line in FIG. brought to the first position.

As a result, the first intake passage 310 is opened, and the air taken into the combustion chamber 101 of the engine 100 has a passage cross-sectional area smaller than that of the first intake passage 310 in the air cleaner 200, and a passage with a good passage length. The air flows through the second intake passage 310 and is supplied. Therefore, at this time, since the effective passage length of the intake passage supplied to the combustion chamber 101 becomes longer, a dynamic effect appears at a rotation speed of the engine 100 that is lower than the reference rotation speed, as shown by the solid line α in FIG. , the intake efficiency of the engine 100 is improved, and the engine 100
output is improved.

When the rotational speed N of the engine 100 is faster than the preset reference rotational speed NO, the solenoid 359 of the negative pressure switching valve 350 is de-energized by touch of the control device 400, and the solenoid 359 of the negative pressure switching valve 350 is de-energized. The first boat 351 and the third port 353 are connected. As a result, the atmosphere is introduced into the diaphragm chamber 342 of the negative pressure actuator 340, the diaphragm 341 pushes up the rod 332 due to the action of the compression coil spring 343, and the on-off valve 330 moves to the second position indicated by the solid chain line in FIG. brought to you.

Then, the first intake passage 310 is opened and the engine 1
Air taken into the combustion chamber 101 of No. 00 is supplied by flowing through the first intake passage 310, which has a larger passage cross-sectional area and a shorter passage length than the second intake passage 320 in the air cleaner 200. Therefore, at this time, the combustion chamber 10
Since the effective passage length of the intake passage supplied to 1 becomes shorter,
As shown by the solid line α in FIG. 5, a dynamic effect appears at a rotational speed of the engine 100 that is faster than the reference rotational speed, the intake efficiency of the engine 100 improves, and the output of the engine 100 improves.

In other words, since the effective intake passage length changes according to the rotation I11 of the engine 100, the dynamic effect (warping) occurs in multiple rotation speed ranges of the engine 100, including the low rotation speed range and the high rotation speed range. The output of engine 100 can be increased over a range of rotational speeds.

Furthermore, since the second intake passage 320 is formed in a spiral shape, the second intake passage 320 is made smaller, and when the intake air flows through the second intake passage 320, which has a long passage length, the air The flow becomes smoother and flow resistance can be kept small.

Furthermore, an intake boat 104, an intake manifold 1
05, and air cleaner 200 from the outlet 207.
The intake noise released into the engine room is released from the inlet 201 through the inlet 205 into the engine room, but when the first intake passage 310 is opened by the on-off valve 330,
Since the outflow port 207 and the first intake passage 310 are concentric, the intake noise emitted from the inlet 201 can be suppressed to a low level because the air flows around the first intake passage 310 after being discharged to the outflow port 207. . Note that by making the first intake passage 310 and the inlet 205 eccentric,
Furthermore, intake noise can be reduced. Furthermore, when the intake passage 310 is closed, the intake noise emitted into the air cleaner 200 from the outlet 207 is muffled by passing through the second intake passage 320, so that it is further emitted from the inlet 201. It is possible to keep intake noise low. Furthermore, during deceleration, the first intake passage 310
By closing this, muffled noise during deceleration can be significantly reduced.

In addition, since the long second intake passage 320 is housed inside the air cleaner 200, the radiated sound can be significantly reduced, which is caused by internal intake noise emitted from the intake passage and the wall of the air cleaner 200. Can be done.

According to the present invention, the first intake passage 310 and the second intake passage 320 having different lengths are provided in the air cleaner case 202, so that it can be easily installed in a narrow engine space of a car.

In addition, a first intake passage 3 is provided in the air cleaner case 202.
10 and the second intake passage 320, an intake system that changes the intake passage according to the engine rotation speed can be implemented at low cost without changing the design of the existing intake manifold 105 or the like. .

(Modification) In the above embodiment, the solenoid 359 of the negative pressure switching valve 350 is energized to close the first intake passage 310 when the engine 100 rotates at low speed. The first intake passage 310 may be closed by energizing.

Further, although an example has been shown in which the on-off valve 330 is driven using a negative pressure actuator, it may be driven by other actuators such as a motor or hydraulic pressure.

Although an example has been shown in which the on-off valve 330 is switched at a predetermined rotation speed of the engine 100, hysteresis may be provided between the rotation speed at which the on-off valve 330 closes and the rotation speed at which the on-off valve 330 opens.

In addition to the first intake passage 310 and the second intake passage 320, an intake passage having different lengths and equipped with an on-off valve may be provided, and the on-off valve may be controlled by the control device 400.

Furthermore, the opening/closing valve 33 is
Although we have shown an example of controlling the opening and closing of 0, it is also possible to detect when the engine brake is being used and control the opening/closing valve 330 so that the suction efficiency deteriorates when the engine brake is being used, or to control the opening and closing according to the engine load and rotation speed. You may do so.

FIG. 6 shows a second embodiment of the invention.

In this embodiment, the second intake passage 320 is provided in a spiral shape.

7 and 8 show a third embodiment of the invention.

In this embodiment, the second intake passage 320 is provided in a zig-deg shape.

FIG. 9 shows a fourth embodiment of the invention.

In this embodiment, an outlet 322 of a second intake passage 320 is provided in the first intake passage 310, and an on-off valve 330 is provided.
, when the first intake passage 310 is closed, the outlet 3
22 is opened, and the outlet port 322 is closed when the first intake passage 310 is opened.

FIG. 10 shows a fifth embodiment of the invention.

In this embodiment, a second inlet 323 is provided upstream of the intermediate position of the second intake passage 320 of the fourth embodiment, and this inlet 323 has an intermediate opening/closing device for opening and closing the inlet 323. A valve 360 is provided.

This intermediate opening/closing valve 360 is connected to a negative pressure actuator 370 and a negative pressure switching valve (not shown), and is connected to the control device 400.
Therefore, the on-off valve 330 is provided to open at a rotation speed lower than the rotation speed at which the on-off valve 330 opens.

Thereby, the suction efficiency can be increased over a wider range than in the above embodiment.

FIG. 11 shows a sixth embodiment of the invention.

In this embodiment, the composite intake passage 300 is connected to the filter element 20.
This is provided inside the upstream case 206, which is the upstream side of No. 3.

FIG. 12 shows a seventh embodiment of the invention.

In this example, Kikuka A! A composite intake passage 300 is provided on the inner periphery of the over-element 203.

FIGS. 13 and 14 show an eighth embodiment of the present invention.

In this embodiment, a first intake passage 310 and a second intake passage 320 are provided in parallel around the outer periphery of a chrysanthemum-shaped filter element 203.

FIG. 15 shows a ninth embodiment of the present invention.

In this embodiment, the first intake passage 310 is connected to the second intake passage 3.
20, that is, an inlet 311 of the first intake passage 310 is provided in the middle of the second intake passage 320, and an on-off valve 330 for opening and closing the inlet 311 is provided in the inlet 311. It is something that

As a result, by opening the suction port 311, the effective passage length of the intake passage is shortened, and by opening the suction port 311, the effective passage length of the intake passage is lengthened.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the vicinity of the cylinder head of an automobile engine in which the first embodiment is incorporated, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a block diagram of the control 2a device. , Fig. 4 is a flowchart showing the processing of the microbrorena, Fig. 5 is a graph showing the intake efficiency of the engine in relation to the engine rotational speed and the effective passage length of the intake passage, and Fig. 6 is the second embodiment. 7 is a sectional view of the air creep showing the third embodiment, FIG. 8 is a sectional view taken along line B-B shown in FIG. 7, and FIG. 9 is a sectional view of the fourth embodiment. 10 is a sectional view of an air cleaner showing a fifth embodiment, FIG. 11 is a sectional view of an air cleaner showing a sixth embodiment, and FIG. 12 is a sectional view of an air cleaner showing a seventh embodiment. , FIG. 13 is a sectional view of the air cleaner showing the eighth embodiment, and FIG. 14 is a cross-sectional view of the air cleaner shown in FIG. 13.
FIG. 15 is a cross-sectional view of the air cleaner according to the ninth embodiment. .

Claims (1)

[Claims] 1) (a) an air cleaner case housing therein a filtration element that filters air taken into a combustion chamber of an internal combustion engine; (b) a first air cleaner case provided within the air cleaner case; (c) provided in the air cleaner case, the first air intake passage;
(d) an on-off valve that opens and closes the first intake passage; (e) opening/closing control of the on-off valve according to the operating state of the internal combustion engine; An intake system for an internal combustion engine, comprising a control device that performs the following steps. 2) The intake system for an internal combustion engine according to claim 1, wherein the first intake passage is provided in parallel with the second intake passage. 3) The first intake passage is provided in common with the downstream side of the second intake passage, and the intake port of the first intake passage is provided in the middle of the second intake passage, and the on-off valve 2. The intake system for an internal combustion engine according to claim 1, wherein the first intake passage is opened and closed by opening and closing the intake port. 4) The on-off valve is provided to open the second intake passage when closing the first intake passage, and close the second intake passage when opening the first intake passage. An intake system for an internal combustion engine according to any one of claims 1 to 3, characterized in that: 5) The second intake passage is provided with one or more inlets at an intermediate position of the second intake passage, and the inlets are controlled by the control device to open and close the inlets. An intake system for an internal combustion engine according to any one of claims 1 to 4, characterized in that an intermediate opening/closing valve is provided. 6) The intake system for an internal combustion engine according to any one of claims 1 to 5, wherein the second intake passage is formed in a spiral shape. 7) The intake system for an internal combustion engine according to any one of claims 1 to 5, wherein the second intake passage is formed in a spiral shape. 8) The intake system for an internal combustion engine according to any one of claims 1 to 5, wherein the second intake passage is formed in a zigzag shape. 9) Claims 1 to 8, wherein the operating state of the internal combustion engine is the rotational speed of the internal combustion engine.
An intake system for an internal combustion engine according to any one of paragraphs.