JPS5828407B2 - gasoline engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gasoline engine that has been improved so that combustion within the cylinder is almost complete and relatively clear exhaust gas can be emitted.

Engines that have been improved to suppress harmful components contained in exhaust gas as much as possible include gasoline engines that inject a lean mixture into the main combustion chamber and inject fuel into the auxiliary combustion chamber using an injector. It has been known.

This type of gasoline engine does not require two sets of intake systems (carburetor cleaner, fuel injection valve, etc.), unlike those that stratify and supply a lean mixture and a rich mixture for combustion. Injectors for fuel injection have the disadvantage of requiring high pressure pumps.

This invention was made in view of the above circumstances, and aims to provide a gasoline engine that has a relatively compact and simple structure and is improved so that fuel can be injected into a preferable sub-combustion chamber depending on the operating condition. It is something.

Hereinafter, the present invention will be specifically explained based on illustrated embodiments.

Referring to FIG. 1, reference numeral 1 denotes a cylinder in which a piston 2 is slidably fitted, and a cylinder head 3 of this cylinder 1 is shown.
A main combustion chamber 4 and a sub-combustion chamber 5 communicating with the main combustion chamber 4 are formed in the main combustion chamber 4.

An intake port 6 communicates with the main combustion chamber 4, and an intake valve 7 is disposed therein, and an exhaust valve (not shown) is provided in the main combustion chamber 4.

This intake valve 7 is biased toward the closing side by a spring 8, and the outer end of the valve rod 7a is in contact with an adjusting screw 10 provided at the tip of the rocker arm 9.

This rocker arm 9 is pivotally supported by a shaft 11, and the other end is in sliding contact with a cam 13 of a cam shaft 12 provided parallel to the shaft 11.

On the other hand, inside the auxiliary combustion chamber 5, the tip of the spark plug 14 faces and presses the button, and the fuel injection device...Using block 15
is screwed onto the cylinder head 3, with one end connected to the auxiliary combustion chamber 5.
I'm looking forward to it.

A poppet valve 16 is slidably provided on the nozzle block 15, and its valve body 16a is positioned within the sub-combustion chamber 5.

The valve rod 16b of this poppet valve 16 faces into the plunger pump chamber 17 formed in the housing block 15,
It is biased in the direction of closing the poppet valve 16 under an elastic force by the compression spring 18 .

The housing block 1 is placed around the valve rod 16b.
5 has a fuel injection port 19 formed in the shape of a vertical slit.

A fuel supply passage 20 is communicated from the side into the pump chamber 17, and a pole 2 is connected to the fuel supply passage 20.
1 Jf3 = A check valve consisting of a spring 22 is provided.

A fuel passage 23 leading to this check valve is formed in the housing block 15 together with the fuel supply passage 20, and the fuel passage 23 includes a needle opening/closing valve 25 that is linked to the choke and closes when the choke is activated, and a needle opening/closing valve 25 that operates in response to suction negative pressure. A throttle valve 24, which operates during deceleration, is provided in series to enable intermittent supply of fuel from the fuel source and adjustment of flow rate. A piston 26 is provided, and a piston rod 26 of this piston
a is made to protrude outside the housing block 15.

A compression spring 27 acts on the piston rod 26a, exerting an elastic force on the piston rod 26a to pull the piston 26 up to its upper limit.

An adjustment screw 29 provided at the tip of a rocker arm 28 is in contact with the tip of the piston rod 26a, and the rocker arm 28 is pivotally supported by a shaft 30, and the other end is attached to the camshaft 12.
It is in contact with a cam 31 provided in the.

In FIG. 1, reference numeral 32 is a lever that opens and closes the needle on-off valve 25, 33 is a spring that biases the needle on-off valve 25 in the opening direction, 34 is a lever that operates the throttle valve 24, and 35 is this button. This is a spring that biases the throttle valve 24 in the opening direction.

With such a configuration, a lean air-fuel mixture can be introduced into the main combustion chamber 4 via the intake valve 7, and fuel can be injected into the sub-combustion chamber 5 in the steps described below.

That is, with the needle opening/closing valve 25 open and the throttle valve 24 performing an appropriate throttle action, the piston 26
is raised (the rocker arm 28 is swung by the action of the cam 31), the internal pressure of the pump chamber 17 decreases, the check valve is opened, and fuel is supplied to the pump chamber 17 via the fuel passage 23.20. Supplied.

In this state, when the piston 26 descends, the internal pressure of the pump chamber 1γ increases, and this pressure opens the poppet valve 16 against the spring 18, causing fuel to flow from the fuel injection port 19 into the auxiliary combustion chamber 5. is injected.

When the piston 26 reaches the bottom dead center, the poppet valve 16 closes during the next upward stroke of the piston, and the fuel supply passage 20 closes.
is opened, the internal pressure of the pump chamber 17 decreases again, the check valve is opened, and fuel is introduced into the pump chamber 17.

In this case, the opening/closing operation of the intake valve 7 and the operation of the piston 26 are maintained in a predetermined interlocking relationship by the cams 13 and 31 provided on the same camshaft 12.

During deceleration, the lever 34 is operated by the suction negative pressure, and the throttle valve 24 is throttled to supply an appropriate amount of fuel from the fuel passage 23 to the pump chamber 17 via the check valve and the fuel supply passage 20. This prevents excessive fuel supply to the auxiliary combustion chamber 5, thereby preventing an excessively rich mixture.

Activate the choke when starting the engine in cold weather.
The air-fuel mixture supplied to the main combustion chamber 4 will be richer than when the choke is not activated, and there will be no need to supply fuel to the auxiliary combustion chamber 5, so in this case, the lever 3 that operates in conjunction with the choke
2 operates, the needle on/off valve 25 closes, and the fuel passage 23 closes.
The fuel supplied from the pump chamber 17 to the pump chamber 17 is cut to prevent the air-fuel mixture in the sub-combustion chamber 5 from becoming over-enriched.

In addition, if necessary, as shown in Fig. 2, a separate combustion chamber 5
Inside, the coiled wire 36 is connected to the fuel injection port 19.
By surrounding the spark plug 14, a so-called fried ball effect is created, which prevents the spark plug 14 from closing due to fuel when atomization is insufficient, and may also improve the combustion effect.

As explained above, the present invention includes a main combustion chamber and a sub-combustion chamber that communicates with the main combustion chamber and has a spark plug, supplies a lean air-fuel mixture to the main combustion chamber, and supplies fuel to the sub-combustion chamber. For a gasoline engine in which fuel is injected by an injector, the fuel injector communicates one end of the pump chamber with the auxiliary combustion chamber via a poppet valve that opens when the internal pressure of the plunger pump chamber increases. Since the piston, which is driven by a cam that works with the cam that opens and closes the intake valve, is fitted into the pump chamber, fuel can be injected into the auxiliary combustion chamber with a relatively simple configuration that does not require a high-pressure pump. can.

In particular, this invention provides a fuel passage communicating with the pump chamber via a check valve, including an on-off valve that works with the choke and closes when the choke is activated, and a throttle valve that operates during deceleration in response to negative suction pressure. and are installed in series, the fuel injected into the auxiliary combustion chamber can be controlled and cut when the yoke is activated during deceleration and darkening, thereby preventing the harmful effects of over-concentration of fuel in the auxiliary combustion chamber. +h can be done.

Furthermore, the present invention has a housing block screwed onto the cylinder head forming the auxiliary combustion chamber, and the main components of the fuel injection device including the poppet valve, piston, check valve, opening/closing valve, and throttle valve are attached to the housing block. Since the fuel injection device is installed, the fuel injection device can be made compact, and maintenance and inspection can be easily performed by detaching and attaching the housing block to the cylinder block.

[Brief explanation of drawings]

FIG. 1 is a longitudinal side view showing one embodiment of the present invention, and FIG. 2 is a longitudinal side view of main parts showing another embodiment.・Cylinder head, 4... Main combustion chamber, 5... Sub-combustion chamber, 6...
...Intake port, I...Intake valve, 7a...Valve ring, 8
...Spring, 9...Rocker arm, 10...Screw,
11... shaft, 12... cam shaft, 13... cam, 1
4... Spark plug, 15... Housing block,
16...Poppet valve, 16a...Valve body, 16b...
・Valve ring, 17...Pump chamber, 18...Compression spring, 1
9...Fuel injection port, 20...Fuel supply passage, 21.
...Pole, 22...Spring, 23...Fuel passage, 2
4...Comparison valve, 25...Needle opening/closing valve, 26...
Piston, 26a...Piston rod, 27...Spring,
28...Rocker arm, 29...Screw, 30...
Shaft, 31...Cam, 32...Lever, 33...Spring, 34...Lever 35...Spring, 36...Wire.

Claims (1)

[Claims] 1 Comprising a main combustion chamber and a sub-combustion chamber that communicates with the main combustion chamber and has a spark plug, the main combustion chamber is supplied with a lean air-fuel mixture, and the sub-combustion chamber is injected with fuel by a fuel injection device. In the gasoline engine, the fuel injection device communicates one end of the pump chamber with the auxiliary combustion chamber via a poppet valve that opens when the internal pressure of the plunger pump chamber increases, and connects the pump chamber with a cam for opening and closing the intake valve. At the same time, a piston driven by a cam is fitted to the fuel passage, which communicates with the pump chamber via a check valve, and an on-off valve that works with the choke and closes when the choke is activated, and a deceleration valve that responds to suction negative pressure. In addition, a housing block is screwed onto the cylinder head that forms the auxiliary combustion chamber, and a poppet valve, piston, check valve, on-off valve, and throttle valve are installed in this housing block. A Ganrin engine characterized by being equipped with main components of a fuel injection device including: