JPS5840011B2 - Direct fuel injection spark ignition engine - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in direct fuel injection spark ignition engines.

FIG. 1 is a sectional view schematically showing the main parts of a direct fuel injection type spark ignition engine.

In the figure, 1 is a cylinder, 2 is a piston having a combustion chamber 3, 4 is a cylinder head, 5G1 spark plug, 6 is a fuel injection nozzle, and the fuel injection pump is driven by a camshaft 9 etc. to supply fuel from a fuel tank 8. 7 into the combustion chamber.

10 (1 spirally formed intake port, intake valve 1
1 is provided.

Although not shown, an exhaust port and an exhaust valve are also provided.

In the internal combustion engine described above, an air vortex is created in the combustion chamber by the spiral intake port 10 during the intake stroke of the piston, and fuel is injected into this air vortex from the fuel injection nozzle 6 at an appropriate time to cause combustion. A stratified heterogeneous mixture is formed indoors and ignited by the ignition plug 5 at an appropriate time, which enables lean mixture combustion and removes harmful components such as unburned fuel and carbon monoxide from the exhaust gas. It has characteristics such as a reduction in fuel consumption, and can be operated with fuels with poor vaporization properties such as kerosene and light oil without dilution.

However, when kerosene or diesel oil is used as fuel, combustion in a high excess air ratio (combustion in a low temperature range)
That is, there is a drawback that problems such as a pungent odor in the exhaust gas and white smoke may occur immediately after startup and at low rotation speeds under no load.

In the above-mentioned internal combustion engine (1) Conventionally, the air volume was not throttled even under light load and low rotation to prevent a decrease in efficiency due to the air volume, but this resulted in the above-mentioned problems.

In order to eliminate this problem, it is necessary to raise the exhaust gas temperature, and it is known that one of the countermeasures is to raise the exhaust gas temperature by throttling the intake air.

When the intake air is throttled, the suction work of the piston increases, and part of that increased work turns into heat to raise the intake air temperature.When the intake air is throttled, combustion is delayed and combustion continues during the expansion stroke, and the exhaust gas Temperature (1) Increases significantly compared to when the intake air is not throttled.

This reduces unburned gas and reduces white smoke and irritating odors.

The purpose of the present invention is to focus on this point and provide a device that can eliminate the above-mentioned problems, and its features include an intake throttle valve that is provided in the intake port and opens and closes the intake port, The intake valve is provided with an opening/closing means for opening and closing the intake valve in conjunction with the operation of a governor device that is coupled to an injection amount adjustment rack of the fuel injection bob only in operating states other than when the engine is started or stopped due to a fuel cut operation. That's true.

This allows the governor device to start the fuel injection pump and cut fuel regardless of whether the intake throttle valve is open or closed, and the intake throttle valve automatically opens and closes in conjunction with the governor device during operation. Immediately after startup and in the no-load low speed range, the intake air is throttled to raise the exhaust temperature, which eliminates the problem of pungent odors and white smoke even when using kerosene or light oil as fuel. be able to.

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

FIG. 2 is a sectional view showing the main parts of a direct fuel injection spark ignition engine according to one embodiment of the present invention, FIG. 3 is a side view with a part of FIG. 2 omitted, and FIG. A-A cross-sectional view,
FIG. 5 is an explanatory diagram of the operation of the present invention.

In the figure, 20 is a cylinder, 21ttt is a piston having a combustion chamber 22, 23 is a cylinder head, 24 is a spark plug, and 25 is a fuel injection nozzle, which, like the conventional one, injects fuel from a fuel tank (not shown). Fuel is injected into the combustion chamber via a fuel injection pump 26 driven by a camshaft or the like that does not have a combustion engine.

27 (J Intake port formed in a spiral shape, intake valve 2
8 is provided.

Although not shown, an exhaust port and an exhaust valve are also provided.

Reference numeral 29 denotes an intake throttle valve having several holes 29a provided in the intake port 27, and its valve shaft 30ζl is rotatably supported in the intake cylinder 31.

Same valve shaft 30? A spring 32 is provided that always biases the intake throttle valve 29 in the closing direction, and a spring 32 is provided at the end of the spring 32.
A lever 33 with an i-pin 34 is fixed.

35 is a bracket fixed to the intake cylinder 31, and the cam 37
A shaft 36 is provided to rotatably support the.

As shown in FIG. 4, the cam 37 is rotatably supported at its center by a shaft 36, and has a cam surface at one end that abuts and engages with the pin 34 of the lever 33, and at the other end. A connecting rod 38 is connected to the portion.

Cam surface C1 of cam 37 Lever 33 fixed to valve shaft 30
A surface 37a that abuts and engages with the pin 34 of the intake throttle valve 29 to open and close the intake throttle valve 29, and a flank surface when the cam 37 operates in the direction of further opening the intake throttle valve 29 from the fully open position of the intake throttle valve 29. It has a circular arc surface 37b centered on the constituent shaft 36, and a stopper 37c is provided at the end of the circular arc surface 37b.

The connecting rod 38 is connected to a lever 41 which is fixedly connected to one end of an actuation lever 40 which is fixed to an actuation shaft 39 of a known governor device (not shown in detail).

The actuating lever 40 is connected to a connecting rod 42 at one end which is interlocked with the fuel injection amount adjustment rack of the C-ma fuel injection pump 26, and the other end is connected to a shaft with a spring 43 interposed therebetween. It is connected to an operating lever 45 rotatably supported by 44.

The operating lever 45 is connected to an operating device (not shown) by a cable 46.

Note that 47 is a return spring for the operating lever 45.

The operation in the case of the above configuration will be described.

In the above internal combustion engine, during the intake stroke of the piston, an air vortex is formed in the combustion chamber by the spiral intake port 27.
Fuel is injected from a fuel injection nozzle 25 into this air vortex at an appropriate time to form a layered heterogeneous mixture in the fuel chamber, which is then ignited and burned by a spark plug 24 at an appropriate time. .

First, when the starting element 46 is pulled in the direction of arrow A, the operating lever 40C1 operating shaft 3
9 is used as a support shaft in the direction of the arrow, and a force is applied to move the fuel injection amount adjustment rack of the fuel injection pump 26 to the starting amount increase position via the connecting rod 42. At this time, the fuel injection pump 26
Press the start button to enter the injection amount adjustment rack ('i start increase position).

In this case, the movement of the actuating lever 40 ("i lever 41, transmitted to the cam 37 via the connecting rod 38, cam 37C1 shaft 3
6 as a pivot in the direction of arrow C, and reaches position B shown in FIG.

This B position c1 is a position in the direction of opening further than the fully open softness of the intake throttle valve 29, but since the pin 34 of the lever 33 abuts and engages with the cam surface 37b which is the flank surface of the cam 37, cam 3 regardless of the opening/closing action of the intake throttle valve 29.
7! ``Turn i.

In such a state, the engine is started by operating a suitable engine starting device.

When the engine starts, the actuating shaft 39 is actuated by the action of the governor device (which is well known and will not be described in detail c1), and the actuating lever 40 is actuated in the two directions of the arrows.
0 to the idling position with no load and low rotation.

At this time, the injection amount adjustment rack position of the fuel injection pump 26 is also set to the no-load low rotation position by the linking rod 42 in conjunction with the operating lever 40, and an appropriate amount of fuel is injected.

Further, by operating the actuating lever 40 in two directions, the connecting rod 38 is also operated in the same manner, causing the cam 37 to rotate in the direction of the arrow H, and reaches the position C in FIG. 4 at low rotation with no load.

C position ζ1 is the fully closed position of the intake throttle valve 29, which is fully closed due to the action of the spring 32.

Therefore, the C-ma intake port 27 is closed by the intake throttle valve 29 immediately after starting and at no-load low rotation, and the intake throttle valve 29
by hole 29a provided in.

It is operated with the air volume restricted.

In addition, during normal load operation, the governor device operates according to the opening degree of the throttle, operates the injection amount adjustment rack of the fuel injection pump via the connecting rod 42, and adjusts the amount of fuel suitable for the load. At the same time, the cam 37 is operated via the connecting rod 38 from the no-load low rotation position C to the S, S, (smoke set) position in FIG.
It opens and closes between the fully closed position and the fully open position, and is operated with an appropriate amount of air.

Next, use when the engine is stopped due to a fuel cut operation will be explained.

When the operating lever 40 is actuated in the two directions of the arrow by a suitable engine stop lever, the injection amount adjustment rack of the fuel injection pump 26 is brought to the fuel injection stop position via the connecting rod 42.
Power up the heat source and stop the engine.

At this time, the operating lever 40 is further actuated in the two directions of the arrows than the no-load low rotation position, and the cam 37 is moved through the connecting rod 38 to the position E, which is further rotated from the no-load low rotation position C in the direction of the arrow H. However, the cam 37 disengages from the pin 34 and rotates regardless of whether the intake throttle valve 29 is opened or closed.
9 (1) Fully closed due to the action of spring 32.

The relationship between the injection amount adjustment rack position and the throttle opening of the fuel injection pump having the above operation is illustrated in FIG. 5.

As described above, the present invention has the following effects Lf.

Immediately after startup and in the no-load low speed range, the intake air can be throttled automatically by the intake throttle valve installed in the intake port in conjunction with the Lf and governor device. Even when using kerosene or diesel oil as the Z fuel. By increasing the exhaust temperature, problems such as pungent odors and white smoke can be resolved.

In addition, even during normal operation, the intake throttle valve is linked to the governor device to automatically open and close the intake throttle valve, allowing operation with an appropriate amount of intake air. ! The governor device can start the fuel injection pump and cut the fuel regardless of whether the intake throttle valve is open or closed.

FIG. 6 shows another embodiment of the present invention, which is a modification of the part shown in FIG.
The springs 48, 49 are inserted through the flange portion 33a of the rotating lever 33, and the springs 48, 49 are interposed on both sides with stoppers 50, 51 attached to the connecting rod 38, and the springs 48, 49?
-! When the connecting rod 38 is operated on a certain square, that is, during a starting operation or when the operation is stopped due to a fuel cut, it bends.
It is not related to the opening/closing action of the intake throttle valve 29, and is a continuous link 38 from the no-load low rotation range to S, S, (smoke set).
In operation, the valve shaft 30 is rotated via the lever 33, and the intake throttle valve 29 is opened and closed in conjunction with the governor device, and its operation and effect are the same as those shown in Fig. 4. .

[Brief explanation of drawings]

Part 1: A cross-sectional view showing the main parts of a conventional direct fuel injection spark ignition engine, Fig. 2 is a cross-sectional view showing the main parts of an embodiment of the present invention, and Fig. 3 omits a part of Fig. 2. side view, 4th
The drawings are a sectional view taken along the line A--A in FIG. 3, FIG. 5 is an explanatory diagram of the operation of the present invention, and FIG. 6 is an explanatory diagram showing the main parts of another embodiment. 20...Cylinder, 21...Piston, 23...Cylinder head, 24...
Spark plug, 25...Fuel injection nozzle, 26.
... Fuel injection pump, 27 ... Intake port, 28 ... Intake valve, 29 ... Air supply throttle valve, 29a ... Hole, 30...Valve stem,
31...Intake cylinder, 32...Spring, 33
...Lever, 34...Pin, 35...
...Bracket, 36...Shaft, 37...
...Cam, 38...Running, 39...
Operating shaft of cabana device, 40...Operating lever 4
1... Lever 42... Continuous lever, 43...
・・・Spring, 45... Operation Renoku-.

Claims (1)

[Claims] 1 In a direct fuel injection spark ignition engine that has a fuel injection nozzle and a spark plug and injects fuel directly into a fuel chamber and ignites and burns it, an intake throttle valve that is installed in an intake port and opens and closes the intake port; The intake throttle valve opening/closing means opens and closes the throttle valve in conjunction with the operation of a governor device that is linked to the injection amount adjustment rack of the fuel injection pump only in operating states other than when the engine is started or stopped due to a fuel cut operation. Direct fuel injection spark ignition engine.