JPS5830096Y2 - Mixture stirring device for internal combustion engine combustion chamber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for stirring a mixture into a combustion chamber of an internal combustion engine, in which an exhaust turbocharger is used as a supply source of a mixture stirring fluid to be injected into the combustion chamber during the intake stroke.

Conventionally, there are engines in which pressurized air is supplied to the intake passage by an exhaust turbocharger to improve the efficiency of filling the air-fuel mixture into the combustion chamber under high load. As the engine speed increases, the amount of air supplied from the turbocharger to the intake passage also increases proportionally, which poses a problem in that abnormal combustion occurs during high loads (when the throttle valve opening is wide).

The object of the present invention is to provide a mixture stirring device for an internal combustion engine combustion chamber that solves this problem.

An embodiment of the present invention will be described below with reference to the drawings.

In the drawing, 1 is a cylinder, 2 is a piston slidably disposed within the cylinder 1, 3 is a cylinder head attached to the upper end of the cylinder 1, and 4 is a space between the cylinder 1, the piston 2, and the cylinder head 3. combustion chamber formed in
5 is an intake port formed in the cylinder head 3; 6 is an exhaust port formed in the cylinder head 3; the intake port 5 and the exhaust port 6 communicate with the combustion chamber 4.

An annular valve seat 7 is fixed to the end of the intake port 5 on the combustion chamber 4 side, and an annular valve seat 8 is fixed to the end of the exhaust port 6 on the combustion chamber side.

The cylinder head 3 is provided with a guide holding hole 9 that opens into the intake port 5 toward the valve seat 7 and a guide holding hole 10 that opens into the exhaust port 6 toward the valve seat 8 .

Cylindrical pulp guides 11 and 12 are press-fitted into both guide holding holes 9 and 10, respectively.

A shaft portion 13b of an intake valve 13 having a head 13a disposed within the combustion chamber 4 is slidably inserted into the pulp guide 11.

Inside the pulp guide 12, a shaft portion 14b of an exhaust pulp 14 having a head 14a disposed within the combustion chamber 4 is slidably held.

The intake valve 13 is always urged upward in the figure by a spring 15, and the exhaust pulp 14 is always urged upward in the figure by a spring 16.

The intake valve 13 and the exhaust valve 14 are alternately opened and closed via a camshaft 17, a rocker arm 18, etc. held by the cylinder head 3.

In the figure, 19 is a head cover that covers the upper part of the cylinder head 3.

20 is an intake pipe whose base end is connected to the intake port 5;
1 is an exhaust pipe connected to the exhaust port 6, 22 is an intake pipe 2
23 is an air cleaner connected to the air intake port of the carburetor 22, 24 is an air filter in the air cleaner 23, 20a is a main intake passage in the intake pipe 20, 25 is a carburetor 22 is the throttle valve.

Near the face 13c of the head 13a of the intake pulp 13, there is a hole that opens into the combustion chamber 4 when the intake valve 13 opens,
In addition, an ejection hole 26 is provided that opens toward the main intake passage 20a upstream from the valve seat 7 when the intake valve 13 is closed.

This jet hole 26 communicates with a lower end portion of a sub-intake passage 27 formed in the shaft portion 13b of the intake valve 13.

The auxiliary intake passage 27 extends from the head 13a of the intake valve 13 at approximately the center portion 1 of the shaft portion 13b, and is connected to the upper end of the auxiliary intake passage 27 in the shaft portion 13b, and has an opening on its outer peripheral surface. An inlet 28 facing the inner surface of the pulp guide 11 is bored.

An annular groove 29 serving as an intermediate passage is formed in the circumferential direction on the inner surface of the pulp guide 11, and this annular groove 29 is provided at a position facing the inlet 28 only when the intake valve 13 is opened.

This annular groove 29 is a passage 3 bored in the cylinder head 3.
0 to a passage 31 formed in the intake pipe 20.

A pipe 32 is connected to this passage 31, and one port of a three-port switching valve 33 is connected to this pipe 32.

One of the remaining two ports of the 3-port switching valve 33 has a
A pipe 34 connected to the air cleaner 23 is connected.

35 is an exhaust turbocharger.

The exhaust turbocharger 35 includes a turbine section 35a serving as a driving source, and a lethrower section 35b that sucks in, compresses, and then discharges fluid in conjunction with the rotation of the turbine of the turbine section 35a.

The exhaust pipe 21 is connected to the fluid inlet of the turbine section 35a, and the exhaust pipe 3 is connected to the fluid outlet of the turbine section 35a.
One end of 6 is connected.

The other end of the exhaust pipe 36 is connected to a bypass passage 37 that branches off from the middle of the exhaust pipe 21 .

The suction port of the blower part 35b is opened to the atmosphere, and the discharge port of the blower part 35b is connected to the 3-port switching valve 3 via a pipe 38.
It is connected to the remaining port (inlet side) of No.3.

This 3-port switching valve 33 connects the pipes 32 and 38 when the opening degree of the throttle valve 25 is small, and connects the pipes 34 and 3B when the opening degree of the throttle valve 25 is large.
The throttle valve 25 is connected to the throttle valve 25 so as to communicate with the throttle valve 25.

39 is a flow rate regulating valve installed in the middle of the bypass passage 37.

This flow rate adjustment valve 39 is connected to a branch portion 37 of the bypass passage 37.
a and the connection portion of the exhaust pipe 36 to the bypass passage 37.

Further, the flow rate adjustment valve 39 is linked to the throttle valve 25 so as to open and close at the same time as the throttle valve 25.

Next, the operation of the air-fuel mixture stirring device having such a configuration will be explained.

As the engine operates, when exhaust gas flows through the turbine section 5a of the exhaust turbocharger 35, the turbine within the turbine section 35 rotates, causing the impeller within the blower section 35b to rotate.

As a result, the floor part 35b sucks in and compresses air and discharges it into the pipe 38, but the discharge amount depends on the opening degree of the flow rate regulating valve 39.

That is, since the flow rate adjustment valve 39 opens and closes following the opening and closing of the throttle valve 25, the smaller the degree of closure of the throttle valve 25, the larger the ratio of the flow rate to the turbine section 35a to the total amount of exhaust gas discharged. The larger the opening degree of the valve 25, the smaller the ratio of the flow rate to the turbine section 35a to the total amount of exhaust gas discharged.

By controlling the flow rate of exhaust gas flowing to the turbine section 35a in this way, the amount of air discharged from the blower section 35b increases (increases) as the opening degree of the throttle valve 25 increases. do not have.

Note that the remaining exhaust gas that does not flow to the turbine section 35a is discharged to the outside via the bypass passage 37.

In addition, in a range where the opening degree of the throttle valve 25 is small,
The 3-port switching valve 33 connects the pipes 32 and 38,
In a range where the opening degree of the throttle valve 25 is large, the three-port switching valve 33 allows the pipes 34 and 38 to communicate with each other.

On the other hand, during the intake stroke accompanying engine operation), the intake valve 13 opens and the air-fuel mixture is sucked into the combustion chamber 4 from the intake port 5, and at the same time, the jet hole 26 opens into the combustion chamber 4.

Therefore, in a range where the opening degree of the throttle valve 25 is small, during the intake stroke, air from the exhaust turbocharger 35 flows through the pipe 38, the port switching valve 33, the pipe 32, the passages 31 and 30, and the annular groove 2a.

It is ejected into the combustion chamber 4 from the ejection hole 26 via the inlet 28 and the sub-intake passage 27 .

As a result, a strong swirl is formed in the combustion chamber 4, and the air-fuel mixture sucked into the combustion chamber 4 from the intake port 5 is rapidly stirred, creating a homogeneous lean air-fuel mixture in the combustion chamber 4. Formed in a short time.

In addition, in the range where the opening degree of the throttle valve 25 is large,
Air discharged from the exhaust turbocharger 35 is blown into the air cleaner 23 via the pipe 38, the 3-port switching valve 33, and the pipe 34, and then supplied to the carburetor 22.

As a result, the flow velocity of the air-fuel mixture taken into the combustion chamber 4 increases, so the filling efficiency of the air-fuel mixture into the combustion chamber 4 increases, but the amount of air discharged from the exhaust turbocharger 35 is It does not increase rapidly even if the opening degree increases.

In this way, by suppressing the amount of secondary air supplied from the exhaust turbocharger 35 to the combustion chamber 4, a homogeneous lean mixture is formed throughout the combustion chamber 4 in a short time, increasing the combustion rate. In addition, it is possible to prevent an abnormal combustion state from occurring in the combustion chamber 4 during high load (when the opening degree of the throttle valve 25 is in a large range).

Note that it is not necessary to provide the bypass passage 37 and the flow rate adjustment valve 39 in the embodiment described above, and if these are not provided, the capacity of the exhaust turbocharger 35 and the compression ratio of the engine can be changed to reduce the high load. It is possible to prevent abnormal combustion from occurring at times and improve engine performance.

In addition, by adjusting the 3-port switching valve 33 so that a portion of the air discharged from the exhaust turbocharger 35 flows to the jet hole 26 even under high load, the amount of air supplied to the air cleaner side can be reduced. This can also improve combustion under high loads.

As explained above, the present invention uses an exhaust turbocharger to blow out compressed air, which is secondary air, from the nozzle, so a small amount of compressed air can quickly blow up the air-fuel mixture sucked into the combustion chamber. A homogeneous air-fuel mixture can be formed throughout the combustion chamber in a short time by stirring the fuel, and since only a small amount of secondary air is needed, abnormal combustion at high loads can be prevented.

In addition, it is possible to form a stronger vortex in the combustion chamber than when secondary air is injected into the combustion chamber from the nozzle using only the intake negative pressure generated in the combustion chamber, so a homogeneous air-fuel mixture can be created throughout the combustion chamber. This has the advantage that the forming time can be significantly shortened.

Furthermore, a 3-port switching valve is installed to switch the secondary air ejection light according to the engine load condition, so ideal combustion conditions can be achieved from low load to high load. can.

[Brief explanation of drawings]

The drawing is a sectional view of an engine showing an embodiment of the present invention. 13...Intake valve, 23...Air cleaner, 26...Blowout hole, 33...3
Port switching valve, 35...exhaust turbocharger.

Claims (1)

[Scope of utility model registration request] In an engine in which an intake valve has a jet hole that opens into a combustion chamber when the intake pulp opens, an exhaust turbocharger is installed in the exhaust passage of the engine to operate by the exhaust flow to suck in and discharge secondary air. The inlet side of a 3-port switching valve is installed, and switches the discharge port of the exhaust turbocharger so that it communicates with the jet hole when the opening of the throttle valve is small, and communicates with the air cleaner when the opening of the slot pulp is large. A mixture stirring device for a combustion chamber of an internal combustion engine, characterized in that the device is connected to a combustion chamber of an internal combustion engine.