JPS61104120A - Intake device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve filling efficiency over the whole operating range of an engine by making two intake pipes of the engine having two intake valves for one cylinder different in length, providing a switching valve on the short pipe, and communicating both pipes downstream it via an intake control valve. CONSTITUTION:Two intake valves 6A, 6B are provided on one cylinder, and a long intake pipe 7A and a short intake pipe 7B are connected to the intake valve 6A and the intake valve 6B respectively. The first intake control valve 18 is provided on the intake pipe 7B, and both intake pipes 7A, 7B are communicated via a communicating hole 29 provided with the second intake control valve 30 downstream it. At a high rotating speed of an engine, both valves 18, 30 are opened by a control circuit 47, the inertial intake suitable for a high rotation speed particularly through the short pipe 7B is performed also to the other side via the communicating hole 29. At a medium load, only the valve 18 is closed, and the inertial intake through the long pipe 7A is performed also to the other side via the communicating hole 29. At a low load, the valve 30 is also closed, and the intake is performed only through the valve 6A side, and a reliable swirl is generated.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an intake system for an internal combustion engine.

(Conventional technology) 8! In order to achieve high engine power and acceleration response, the combustion chamber is equipped with a so-called multi-intake valve type intake passage in which the first intake passage for regular use and the second intake passage for high main power use are opened separately. The use of this is well known, and by providing the second intake passage with an output-responsive valve (III control valve) that opens at high output, the second intake passage is closed in the low-to-medium output range and the intake air in the first intake passage is closed. In addition to increasing flow velocity and improving combustion efficiency,
There is already a known device in which the second intake passage is opened in the high output range to increase the intake air filling efficiency and increase the maximum output.

One of these devices is the one shown in Figures 4(A) and 4(B) (for example, Japanese Patent Publication No. 59-5769,
Japanese Patent Publication No. 59-147867, Publication No. 47-31724
No., JP-A-58-10130, JP-A-1-57-110
(See No. 765, etc.)

To explain this, 1 in the figure is the engine body, and the shilling block 2. It has a combustion chamber 5 formed by a Schilling Rad 3 and a piston 4. The Schilling Radar 3 that forms the fR grilling chamber 5 is provided with two intake valves 6A and (iF3), and a normally used first intake valve that is used in all load ranges is provided through one first intake valve 6A. Intake x passage 7A and the other second intake valve 6B
It communicates with a second intake passage 7B for high output via. 8 is an exhaust passage led from the combustion chamber 5 via two exhaust valves 9A and 9B. 11 is a spark plug, 12 is a known valve mechanism consisting of a cam pongee 12A, a valve spring 12B, etc.
It opens and closes the intake valves GA, 6B and the exhaust valves 9A, 9B.

The first intake passage 7A and the second intake passage 7B are connected to each other from the combustion chamber 5 to the Schilling Rad 3. Although they are formed in series through the intake branch pipe 14 and the throttle chamber 15, the intake passages 7A and 7B are further branched independently from the gathering part 14A of the intake branch pipe 14, and have the length of the first intake passage 7A. are formed longer than the second intake passage 7B, and communicate with each other through a communication hole 13 inside the cylinder rad 3. The throttle chamber 15 is provided with a throttle valve 16 that is manually operated to control the engine output.

Note that the upstream end of the throttle chamber 15 communicates with the atmosphere via an air cleaner. Further, a second intake passage 7B is located near the downstream end of the branch portion 14B of the intake branch W14.
A first intake control valve 18 that closes when the engine output is low is installed in the 4° valve stem of the first intake control valve 18.
However, the 7-arm 19 is connected to a guy 7 ram device 21 via a rod 20. The Gouya 7 ram device 21 has a case 21A partitioned into an atmospheric chamber 22 and a negative pressure chamber 23 by the Gouya 7 ram 21B. The pressure is applied to the atmospheric chamber 22 side.

The atmospheric chamber 22 is always open to the atmosphere, and the negative pressure chamber 23
communicates with a vacuum tank (not shown) by a vacuum passage. Negative pressure control of the Guya 7 ram installation RR121 is achieved by, for example, interposing a three-way valve in the negative pressure passage, and in the low and medium output range, operating negative pressure is guided to the negative pressure chamber 23 through this three-way valve, and at the same time, the This negative pressure chamber 23 is opened to the atmosphere in the output range.

For example, in the low output range, the negative pressure chamber 2 is switched by switching the three-way valve.
3, the working negative pressure is introduced into the first intake control valve 18. Since the intake air flows only through the first intake passage 7A, the flow velocity of the intake air increases. Due to the effect of the air column vibration generated in the first intake passage 7A, the intake pressure near the first intake valve 6A immediately before the first intake valve 6A opens is kept relatively high. Therefore, blowback from inside the combustion chamber 5 is suppressed, and intake air flows into the combustion chamber 5 efficiently, so that a relatively high torque can be obtained.

When the intake air flow rate in the first intake passage 7A becomes higher than a predetermined value, the air flow near the opening of the first intake valve 6A increases.
WL @ causes an elephant and the inspiratory resistance increases rapidly. But n+f
A part of the intake air flows to the second intake passage 7B through the communication hole 13 and bypasses the first intake valve 6A, so that the air contraction phenomenon is avoided without reducing the intake flow rate of the first intake passage 7A. It is possible to prevent the phenomenon of the intake air flow reaching a plateau in the medium load range, which is unique to an engine having the passage 7A and the second intake passage 7B.

When the intake flow rate increases from this state, the three-way valve reaches its full capacity and atmospheric air is introduced into the negative pressure chamber 23, causing
The elasticity of the spring 24 presses the rod 20 to open the intake control valve 18 to an opening degree corresponding to the load. When the intake control valve 18 is fully opened in this way, the intake air flows into the combustion chamber 5 from both the first intake passage 7A and the second intake passage 7B, so the amount of inflow air becomes large, and the multi-intake valve type configuration is achieved. High output power is obtained.

(Problems to be Solved by the Invention) In such a device, even in the low power range where the intake control valve 18 is closed, the combustion state is inherently poor in idling or low load ranges close to it, so a strong vortex is generated in the combustion chamber. It is effective to improve the combustion state by converting this vortex into a violent turbulent flow during the subsequent compression stroke. However, when fuel is injected 1'' (supplied), most of the fuel is supplied from the first intake valve 6A to the combustion chamber 5 by the intake flow in the first intake passage 7A, but the position of the communication hole 13 is Since the two intake ports where the valves flA and 6B are open) 10A and IO[3 are close to each other, the air-fuel mixture is also drawn from the second intake passage 7B via the communication hole 13.
For this reason, the intake air from both boats 10A and 10B collides in the combustion chamber, and the formation of a vortex in the combustion chamber is not sufficient, resulting in low idling or similar low airflow compared to an intake passage formed independently without the communication hole 13. There are problems in that fuel efficiency under load and full-throttle torque during low-speed operation are inferior.

This invention was made by focusing on these conventional problems, and it not only ensures a strong vortex flow in the combustion chamber during idling or low-load operation similar to that, but also provides a system that is suitable for low- to medium-speed operation. It is an object of the present invention to provide an intake device that improves charging efficiency by providing a first intake passage with a length that exhibits an inertial supercharging effect.

(Means for Solving the Problems) The present invention branches the intake passage downstream of the intake throttle valve into an independent first intake passage and a second intake passage, which communicate with the combustion chamber, and also includes an isobar in the second intake passage. The present invention is based on an intake system for an internal combustion engine that includes a first intake control valve that opens during high-output operation. In such a device, the length of the first intake passage is longer than that of the second intake passage, and the first intake passage and the second intake passage are communicated with each other downstream of the first intake control valve. A second intake control valve is provided in the communication hole that closes when the engine is idling or at a load of 1°C near that level.

(Function) With this configuration, the second intake control valve closes during idling or similar low-load operation, so the first intake passage and the second intake passage become completely independent passages. As a result, the intake air flowing into the combustion chamber from the second intake passage through the communication hole does not collide with the intake air flowing into the combustion chamber from the first intake passage into the combustion chamber, thereby reducing the intake flow velocity. , a strong vortex is formed in the combustion chamber, resulting in stable combustion.6 Also, in the low speed range, the first intake passage has a length that suits this operating range and exerts an inertial supercharging effect. It aims to improve the filling efficiency of intake air from the intake boat (low-speed boat) that communicates with the first intake passage, and improve low-speed full-throttle torque.

In addition, in the medium speed range, the first intake passage also adapts to this operating range and exerts an inertial supercharging effect to improve the intake air filling efficiency, but in this operating range, the second intake control valve opens,
Since intake air also flows from the intake boat (high-speed boat) that communicates with the second intake passage through the communication hole, the inertial supercharging effect described in Mj also extends to the intake air flowing from this high-speed boat, which improves charging efficiency. It is possible to further increase the torque at full throttle at medium speeds.

Furthermore, in the high-speed range, the first intake control valve opens to increase the inflow area of intake air, and the second intake passage adapts to this range and exerts an inertial supercharging effect, thereby reducing the flow of air from high-speed boats. This improves the filling efficiency of the intake air, but even in this operating range, the intake air in the second intake passage enters the first intake passage through the communication hole and also flows in from the low-speed boat, so the inertial supercharging effect prevents the inflow from the low-speed boat. This also extends to the intake of air,
It is possible to further increase charging efficiency and improve high-speed full-open torque.

(Embodiment) FIG. 1(A) is a schematic configuration diagram of an embodiment of the present invention.
Figure (B) is a longitudinal section UjJ of the main part of the intake system. 1 in the diagram
is the shilling block 2 in the engine body. It has a combustion chamber 5 formed by a sill head 3 and a cylinder 4. Two intake valves 6A and 6B are provided in the cylinder throat 3 forming the combustion chamber 5, and a first intake passage 7A for regular use operates in all load ranges via the first intake valve 6A; It communicates with a second intake passage 7B for high output via the other second intake valve 6B. 8 is an exhaust passage with two exhaust valves 9A.

It is led from the combustion chamber 5 via 9B. 11 is a spark plug, 12 is a known valve train VI consisting of a cam pongee 12A, a valve spring 11B, etc. @ air valves 6 A, 6 n and an exhaust valve 9 A
, 9 B and 1111 are closed.

The first air passage 7A and the second intake passage 7B are connected from the combustion chamber 5 to the shilling head 3. Intake branch? Although the intake passages 7A and 7B are formed in series through F14 and the throttle chamber 15, the intake passages 7A and 7B are independently branched from the gathering part 14A of the intake branch pipe 14, and the length of the first intake passage 7A is the same as that of the second intake passage. 7B+ has a shape 11r in comparison with that, and communicates with each other through a communication hole 29 in the sill ring rad 3. Note that the first intake passage 7A and the second intake passage 7
The length of B is set to such a length that the inertial supercharging effect can be exerted in the low-medium speed driving range and the high-speed driving range, respectively. A throttle valve 16 is provided in the throttle chamber 15 and is manually operated to control the engine output. Note that the upstream end of the throttle chamber 15 communicates with the atmosphere via an air cleaner.

Further, 28 is a fuel injection valve arranged in the first intake passage 7A, and most of the injected fuel is supplied into the first intake passage 7A.
The arrangement is such that the remaining small amount of injected fuel is supplied into the second intake passage 7B through the communication hole 29.

A first intake control valve 18 is installed in the second intake passage 7B, which is located near the downstream end of the branch portion 14B of the intake branch pipe 14 and closes when the engine output is low. A second intake control valve 30 that blocks the communication hole 29 is installed in two communication holes located near the communication hole 29 .

Each drive means for these two @ki control valves +8.30 is constructed in the same way, and both are controlled by a control circuit 47. That is, the valve shaft of the first intake side [r, 18 has an arm 19 fixed thereto, and the arm 19 is connected via a rod 20 to a guyar 7 ram arrangement g121. The diaphragm device 21 connects the inside of the case 21A to the atmospheric chamber 22 by the diaphragm 21B.
and a negative 11 chamber 23, and the diamond 7 ram 21B
Connect the other end of the rod 20 to the spring 24
It is suppressing atmospheric chamber 22IlIIIl. Similarly, the valve shaft of the second intake control valve 30 has the arm 31 Ii! On the other hand, the 7-m 31 is connected to the diaphragm device i33 via the loft 32. The diaphragm device 33 connects the inside of the case 33A to an atmospheric chamber 34 using a diaphragm 33r3.
The other end of the rod 32 is connected to the diamond 7 ram 33B, and is urged toward the atmospheric chamber 34 by a spring 36.

Atmospheric chamber 22.34 is open to the atmosphere at all times.
d) The negative pressure chambers 23, 35 are connected to a negative pressure tank 44 by a negative pressure passage 42.43 having a three-way valve 40.41. The inside of the negative pressure tank 44 communicates with the collecting part 14A through a passage 45, and the passage 45 is provided with a check valve 46 that allows airflow only in the direction of the collecting part.

The three-way valves 40 and 41 are switched and controlled by the control circuit 47, and the three-way valve 40 is turned ON in the low-medium speed operating range (up to a predetermined engine speed N2), and is turned ON in the higher-speed operating range (up to a predetermined engine speed N2). When the rotation speed is N2 or higher), the power is turned off.

On the other hand, the three-way valve 41 is energized @ON during idling and a low-speed operating range close to it (up to the rotation speed N1, however, Nl<N2), and is energized OFF in the operating range beyond that (busy number N1 or more). be done. In addition, when the three-way valves 40 and 41 are energized, the valve 40A resists the springs 40C and 41C due to the electromagnetic force of the slides 40B and 41B.

41A to the right in the figure, the negative pressure chamber 23
．． Boat a connected to 35 is connected to boat b connected to negative pressure tank 44, and springs 40C and 41C are connected when the power is turned off.
By urging the valves 40A and 41A to the left in the figure,
Boat & is connected to boat c which emits an air filter and opens to the atmosphere. Further, 48 is a battery.

The operation and effect of the second configuration will be described based on FIG. 2. In the high-speed operation range where the engine speed exceeds the predetermined rotation speed N2, both the three-way valves 40 and 41 are energized OFF, and the negative pressure chamber 23, Since 35 is connected to the atmosphere, the spring 24.36
The intake control valves 18 and 30 are both fully open. Therefore, the intake air flows into the combustion chamber 5 from both the first intake passage 7A and the second intake passage 7B, so the amount of intake air increases, the filling efficiency is increased, and the high torque unique to a multi-intake valve type engine is achieved. However, in this embodiment, the second intake passage 7B has a length that is suitable for this operating range and exhibits an inertial supercharging effect, so that at high loads, the filling efficiency of the intake air from the high-speed boat 10B is improved and the full opening torque is increased. can be further improved. Furthermore, in this movement region, the g&air of the second intake passage 7B enters the first intake passage 7A through the two communication holes and also flows from the low-speed boat 10A, so that the inertial supercharging effect is This also applies to the intake air flowing in from the fuel tank, making it possible to obtain high-speed full-open torque (TI in the figure) that further improves charging efficiency. In addition, m3 diagram partially broken #IT4 shows the transfer torque when the first intake control valve 18 is fully open and the second intake control valve 30 is fully closed, but the inertial supercharging effect due to the second intake passage 7B is shown for comparison. It has become clear that it extends through two communicating holes.

In the medium speed operating range where the engine speed is between N1 and N2, only the three-way valve 40 is energized and the operating negative pressure is guided to the negative pressure chamber 23, which causes the first intake control valve 18 to fully open. Note that the second intake control valve 30 is open because the three-way valve 41 continues to be energized OFF'.For this reason, the flow velocity of intake air in the first intake passage 7A increases. Since the first intake passage 7A has a length suitable for this operating range and exhibits an inertial supercharging effect, the filling efficiency of the intake air from the low-speed bow 10A is improved at high loads.

Furthermore, since the intake air in the first intake passage 7A also flows from the high-speed bow 10B through the communication hole 29, the inertial supercharging effect also extends to the intake air flowing from the high-speed bow 10B, which improves the charging efficiency. Furthermore, high mid-speed full-open torque (7 in the figure)
2) is obtained, and better acceleration response can be obtained.

In addition, in this operating range, is the first intake passage? A# - When the amount of intake air flowing increases, it is restricted by the contraction phenomenon described above, but a portion of the intake air passes through the two communication holes and flows into the second intake passage 7.
Since the air flows from B to the combustion chamber 5, the phenomenon of peaking out of the intake air flow in the medium speed range, which is unique to an engine having the first intake passage 7A and the first intake passage 7B, is prevented.

When the Iffff rotation speed becomes lower than 1,
The three-way valve 41 is further turned on and the intake control valve 1 is turned on.
At 8.30, both will be fully closed. Therefore, the first intake passage 7A and the second intake passage 7B become completely independent passages. In this operating range, the first intake passage 7A has a length that is suitable for this operating range and exhibits an inertial supercharging effect, so that the filling efficiency of intake air from the low-speed coat 10A is improved during high loads. As a result, the low-speed full-open torque (73 in the figure) is higher than the conventional example in which the communication hole 29 is not closed (corresponds to when the second intake control valve 30 is fully open).
can be obtained.

In addition, during idling or a low-speed operating range close to idling, the intake air is supplied into the combustion chamber 5 only through the first intake passage 7A, and therefore from the high-speed boat 10B to the combustion chamber 5 through the communication hole 29.
This eliminates the possibility that the intake air that flows into the combustion chamber 5 in a divided manner collides with the mainstream intake air that flows into the combustion chamber 5 from the low-speed bow 10A, thereby reducing the intake flow velocity. As a result, the intake air in the first intake passage 7A becomes a high-speed airflow, and when it flows into the combustion chamber 5 when the first intake valve 6A opens, accompanied by the fuel injected from the fuel injection valve 28, the intake air flows into the combustion chamber 5.
A strong vortex is generated inside. Therefore, when the air-fuel mixture is ignited by the spark plug 11 and a flame is generated, the flame is generated in the combustion chamber 5.
The fuel propagates quickly and stably into the interior, reducing misfires and incomplete combustion. Figure 3 shows the fuel TR characteristics of this embodiment (actual #l) and the conventional example (actual #1) in idling and low-load operating ranges close to idling.
This figure shows a comparison between the two. As mentioned above, since the communication hole 29 is closed to generate a strong vortex flow in the combustion chamber 5 to improve combustion in the combustion chamber 5, fuel efficiency is further improved compared to the conventional example.

Although this embodiment shows a case where a plurality of exhaust valves are provided, the number is not limited to two and may vary.
In light of the purpose of the above, any number of intake passages may be used. (Effect of the invention) In this invention, the intake passage downstream of the intake throttle valve is branched into an independent first intake passage and a second intake passage, which communicate with the combustion chamber. Internal combustion Ff with a first intake control valve in the second intake passage that opens during high engine output operation! In the intake device of 115IT, the length of the first intake passage is much greater than that of the second intake passage, and the length of the first intake passage is greater than that of the second intake passage, and the length of the first intake passage is 11.
1f A communication hole is provided to communicate the first intake passage and the second intake passage with each other, and a second intake control valve is provided in the communication hole to close during idling or low-load operation close to idling. When loaded, the two intake passages are completely independent, and the intake air flows only from the low-speed boat, creating a strong vortex in the combustion chamber. At the same time, it is suitable for low-speed operating ranges and exhibits a +FI supercharging effect. As a result, the filling efficiency can be improved by the first intake passage, without reducing the output in high-speed operation range.
It improves fuel efficiency in idling and low-load driving ranges, and at the same time improves low-speed full-throttle torque.

[Brief explanation of drawings]

FIG. 1(A) is a schematic configuration diagram of an embodiment of the present invention.
Figure (B) is also a longitudinal cross-sectional view of the main parts of the intake system. Second
The figure is a characteristic diagram showing the relationship between engine speed and Tsumugi torque according to this invention, and Figure 3 is a comparison of fuel efficiency characteristics in idling and low-load operating ranges close to idling - characteristics shown in comparison between this embodiment and the conventional example. It is a diagram. FIG. 4(A) is a schematic configuration diagram of a conventional example, and FIG. 4(CB) is a longitudinal sectional view of the main part of the intake system. 1... Engine body, 3... Schilling head, 4...
Piston, 5... Combustion chamber, 6A... First intake valve, 6
B...Second intake valve, 7A...First intake passage, 7B...
...Second intake passage, 98+9B...Exhaust valve, +OA,
TO+3...Intake boat, 12...Valve mechanism, 14
...Intake branch pipe, 14A...Collection part, 14B...
Branch part, 16... Throttle valve, 18... First intake control valve, one... Arm, 2 ()... Rod, 21... Diamond 7 ram device, 21B... Diamond 7 ram, 22...
Atmospheric chamber, 23... Negative pressure chamber, 24... Spring, 29...
Communication hole, 30...Second intake control valve, 31...Arm, 32...Rod, 33...Diamond 7 ram device, 3
3B...Diamond 7 ram, 34...Atmospheric chamber, 35...
・Negative pressure chamber, 36... Spring, 411.41... Three-way valve, 42° 43... Negative pressure passage, 44... Negative pressure tank,
45... Passage, 46... Check valve, 47... Control circuit. Patent applicant: 11 San Jidosha Co., Ltd.
Figure 2! ! , dog advance angle figure 4 (8)

Claims (1)

[Claims] An internal combustion engine in which an intake passage downstream of an intake throttle valve is branched into an independent first intake passage and a second intake passage to communicate with a combustion chamber, and the second intake passage is provided with a first intake control valve that opens during high engine output operation. In the intake device, the length of the first intake passage is longer than that of the second intake passage, and the first intake passage and the second intake passage communicate with each other downstream of the first intake control valve. 1. An intake device for an internal combustion engine, characterized in that the communication hole is provided with a second intake control valve that closes during idling or low-load operation close to idling.