JPS5950872B2 - Device for removing deposits in the combustion chamber of internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for removing deposits that accumulate within the combustion chamber of an internal combustion engine.

Increasing the compression ratio is an effective way to increase the thermal efficiency of an internal combustion engine and reduce fuel consumption.

Therefore, gasoline with a high octane number that does not cause knocking even at high compression ratios is required.

However, from the perspective of oil refining technology and the thermal efficiency of internal combustion engines, it is not advisable to pursue the development of high-octane gasoline when considering the conservation of resources and energy for society as a whole. 96RON
(Research Method Octane Number) is said to be the best.

On the other hand, as the mileage of a vehicle increases, that is, as the internal combustion engine is used, deposits that are considered to be incomplete combustion of fuel and lubricating oil accumulate on the top of the combustion chamber and on the upper surface of the piston.

These deposits reduce the anti-knock performance of the engine, and for example, when examining the reduction in anti-knock performance with respect to the required octane number of the engine, the required octane number (ONR) of the engine is determined at the time when the vehicle has traveled between 5,000 and 110,000 km. Compared to that, it increases by about 6 octane.

For this reason, the current engine compression ratio is set by taking into consideration the octane number of commercially available gasoline as well as the increase in the required octane number of the engine.

That is, the compression ratio of the engine needs to be set to a lower value by the amount of increase in the required octane number due to use.

Therefore, when the engine is first used, the engine is operated at a lower compression ratio, even though it is possible to increase thermal efficiency by operating the engine at a higher compression ratio.

The accumulation of deposits within the combustion chamber also increases the proportion of harmful components in the exhaust gas.

In view of the problems caused by deposits in the combustion chamber, the applicant advanced the ignition advance angle by a predetermined value from the normal ignition advance angle, thereby intentionally causing the cylinder to knock, and thereby eliminating the deposits. A device for removing material from a combustion chamber has previously been provided.

The process by which deposits are removed from the walls of the combustion chamber due to knocking is not well understood, but knocking generates high heat and large shock waves (vibrations), and these act synergistically to burn the deposits. It is assumed that it was peeled off from the wall of the room.

In this way, this device makes it possible to remove deposits generated within the combustion chamber from the combustion chamber, so that engines that have conventionally been set to a lower compression ratio by a predetermined amount in consideration of deposit formation can be replaced with a higher compression ratio. It is possible to reduce fuel consumption and suppress an increase in harmful component emissions due to an increase in travel distance.

However, as is well known, knocking is undesirable because it causes damage to the engine, fluctuations in engine output, and an increase in the amount of harmful components in the exhaust gas.

Furthermore, the knocking sound that occurs not only causes noise but also gives the driver a sense of anxiety.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device for causing combustion and removing deposits from a combustion chamber without damaging the engine or causing fluctuations in engine output.

Another object of the present invention is to generate knocking in such a way that the knocking sound is difficult to be perceived by a passenger when deposits are removed from the combustion chamber by knocking.

Next, the present invention will be described in detail with reference to the drawings.

A four-cylinder internal combustion engine 5 for a vehicle has a first cylinder 1 and a second cylinder 2 in this order.
, a third cylinder 3, and a fourth cylinder 4.

Spark plug 6, 7. 8. 9 is cylinder 1. 2. 3
．． 4, and is connected to the power distributor 11.

The ignition coil 12 has a primary winding 13 and a secondary winding 14 , and one end of the secondary winding 14 is connected to the power distributor 11 .

An input terminal of the ignition coil 12 is connected to an output system 15.

16 is a sensor that detects the opening degree of the carburetor throttle valve 17; 21;
22 is a sensor that detects the rotational speed of the engine 5; 23 is a sensor attached to the water jacket that detects the engine temperature; 24 25 is a sensor that detects the vehicle speed, 25 is a sensor that detects the lubricating oil temperature, 26 is a sensor that detects atmospheric temperature, and 27 is a sensor that is attached to the power distribution device 11 to know which cylinder is to be ignited next. A cylinder sensor 31 for detecting ignition is a sensor attached to the power distributor 11 to detect the crank angle of each cylinder and detects the top dead center and bottom dead center of a specific cylinder.

The outputs of the intake pipe negative pressure sensor 21, rotational speed sensor 22, and cylinder sensor 27 are sent to a cylinder-specific advance angle system 32.

Throttle sensor 16, intake pipe negative pressure sensor 21. Rotational speed sensor 22, water temperature sensor 23, vehicle speed sensor 24, lubricating oil temperature sensor 25, atmospheric temperature sensor 26, dead center sensor 31,
The output of the cylinder advance angle system 32 is sent to the advance angle control system 33.

The output of the advance angle control system 33 is sent to the output system 15.

The advance angle control system 33 controls the acceleration period (throttle sensor 16)
, engine load (intake pipe negative pressure sensor 21), engine rotation speed (
rotation speed sensor 22), engine temperature (water temperature sensor 23),
Obtaining information on vehicle speed (vehicle speed sensor 24), lubricating oil temperature (lubricating oil temperature sensor 25), and atmospheric temperature (atmospheric temperature sensor 26), determine the ignition timing required for the engine 5, and determine the ignition timing required for the engine 5. A control signal is sent to the output system 15 so that the spark plugs 6 to 9 are energized at a predetermined advance angle relative to the sensor 31).

When the advance angle control system 33 sends a control signal to the output system 15 without receiving control from the cylinder-specific advance angle system 32, knocking does not occur in the corresponding cylinder.

The individual cylinder advance angle system 32 sends a control signal to the advance angle control system 33 to advance the advance angle at the time of ignition in order to cause knocking in the cylinder and remove deposits from the combustion chamber of that cylinder.

The advance angle (additional amount) from the normal advance angle to cause knocking is related to the engine load (intake pipe negative pressure sensor 21) and the engine rotation speed (rotation speed sensor 22).
The cylinder-by-cylinder advance angle system 32 determines a value that allows engine damage, output fluctuation, and output reduction due to knocking at that time.

Details of the individual cylinder advance angle system 32 will be further explained with reference to FIG.

The advance angle system 32 for each cylinder includes an additional amount setting section 34 and a distribution section 35.
and an oscillator 36.

Signals from the intake pipe negative pressure sensor 21 and the rotational speed sensor 22 are sent to the additional amount setting section 34.

The distribution section 35 includes a cylinder sensor 27, an additional amount setting section 34,
It receives a signal from the oscillator 36 and sends its output to the advance angle control system 33.

The additional amount setting section 34 controls the engine load (intake pipe negative pressure sensor 2
1) and the engine rotation speed (rotation speed sensor 22), an additional amount (advanced from the normal ignition advance angle) to cause knocking that is difficult to detect by the driver and does not lead to engine damage. amount).

This additional amount A (unit CA: Crank angle
An example of the relationship between e) and the engine rotational speed R is shown in FIG. 3 using the intake pipe negative pressure as a parameter.

■1 is when the throttle valve 17 is fully open, and v2 is when the intake pipe negative pressure is 200
mmHg, v3 means that the intake pipe negative pressure is 400mmH
This is the relationship when g.

The distribution section 36 detects, based on the signal from the cylinder sensor 27, whether the next cylinder is to be fired.

A first example of the operation of the distribution section 36 will be explained with reference to FIG.

The elapsed time t is detected by the input from the oscillator 36, and in the first predetermined period Ta1, every time the firing order of the first cylinder 1 comes, the additional amount setting unit 34 advances the control signal corresponding to the amount set. It is sent to the control system 33.

Thus, during period Ta, knocking occurs only in the first cylinder 1, and the other cylinders are ignited at normal advance angles.

The second predetermined period Tb is a waiting time for moving to the next knocking cylinder, and all cylinders are ignited at the normal advance angle and no knocking occurs.

Knocking occurs only in the second cylinder 2 during the third predetermined period Ta2.

In this way, the period Ta1. Ta2. Ta3. Ta4 (Ta1
=Ta2=Ta3=Ta4), cylinder 1
．． 2. 3. Knocking will occur at 4.
Deposits are removed from all combustion chambers.

The period Tc following the period Ta4 is a non-knocking period, and knocking does not occur in any cylinder during this period Tc.

The values of Ta, Tb, and Tc are set to values that are difficult to detect by the driver and do not cause damage to the engine; for example, Ta - 0, 3 to 10 seconds, Tb = 0 to 3 seconds, Tc = 5～
A range of 10 seconds is preferred.

Further, in this embodiment, knocking occurs in only one cylinder during a predetermined period, but knocking may occur in two or more cylinders if there is no problem with engine damage or the like.

Another example of the operation of the distribution section 36 will be explained with reference to FIG.

Ignition order: 1st cylinder 1, 3rd cylinder 3, 4th cylinder 4, 2nd cylinder
The order is cylinder 2.

In FIG. 5, a white circle indicates ignition at a normal advance angle, and a black circle indicates a knocking state advanced from the normal advance angle by an additional amount set by the additional amount setting section 34.

In this manner, in a four-cylinder internal combustion engine, one knock occurs for every three ignitions during the period Td, so that each cylinder knocks in turn.

In an n-cylinder internal combustion engine, one knock occurs for every (n-1) ignition, and the knocking cylinder is moved.

During period Te, all cylinders stop knocking, and knocking occurs again in each cylinder during the next period Td.

It is preferable that Td is 1 second to 3 minutes, and Te is 3 seconds to 10 minutes.

In the embodiment of FIG. 5, there is no need to detect time, so
The oscillator 36 becomes unnecessary.

The degree of knocking that occurs normally varies depending on the amount of addition added to the advance angle, but according to the present invention, this amount of addition is related to the operating state of the internal combustion engine 5, for example, the engine load and engine rotation speed. Since the additional amount is set by
It is possible to prevent engine damage and output fluctuations due to knocking, and furthermore, it is possible to cause only knocking that is not noticeable to the occupants, and to suppress the amount of harmful components discharged.

Further, one cycle in which each cylinder is ignited once according to the ignition order is an ignition cycle (indicated by the symbol U in FIG. 5).

), knocking occurs discontinuously in one ignition cycle.

That is, in the present invention, all cylinders are not brought into a knocking state in one ignition cycle.

Further, in the present invention, a waiting period for shifting the knocking cylinder or a suspension period for completely stopping knocking is set, and knocking is stopped in a predetermined ignition cycle.

In this way, it is possible to prevent engine damage and output fluctuations due to knocking, and it is also possible to prevent knocking that may be felt by the occupants.

[Brief explanation of the drawing]

No. Figure 1 is a configuration diagram of an embodiment of the present invention, Figure 2 is a detailed block diagram of the advance angle system for each cylinder, and Figure 3 is an example of the relationship between the additional amount and engine rotation speed to cause appropriate knocking. 4 and 5 are diagrams for explaining the operation of the cylinder-by-cylinder advance angle system. 5...4-cylinder internal combustion engine, 6. 7. 8. 9
...Spark plug, 32...Cylinder advance system, 34...Additional amount setting section, 35...
・Distribution is by division.

Claims (1)

[Claims] 1. Each cylinder is provided with a spark plug, and the spark plug is energized at an advance angle that is advanced by a predetermined value from the normal advance angle, thereby causing knocking in the cylinder and combustion. An internal combustion engine for removing deposits in a combustion chamber of an internal combustion engine, comprising means for changing an advance angle for causing knocking in relation to an operating state of the internal combustion engine. removal device. 2. Each cylinder is provided with a spark plug, and the spark plug is energized at an advance angle that is advanced by a predetermined value from the normal advance angle, thereby causing knocking in the cylinder and removing deposits in the combustion chamber. In an internal combustion engine, 1
A device for removing deposits in a combustion chamber of an internal combustion engine, comprising means for causing knocking in all cylinders while causing knocking in only a portion of the cylinders in one ignition cycle.