JPS59115470A - Driving method with reduced cylinder for multi-cylindered engine - Google Patents

Abstract

PURPOSE:To prevent generation of water drops due to overcooling and corrosion in cylinders by intermitting the ignition of each cylinder by turns at an equal frequency at the time of partial load. CONSTITUTION:At the time of full load, cylinders are ignited in the turn of 1 3 4 2 at every cycle time. At the time of light load, one ignition cycle is prolonged double the length at the time of full load, and ignitions of cylinders are intermitted at intervals of one ignition cycle to make operation of 50% reduced cylinders. At medium load operation, a set of a double prolonged ignition cycle and the original cycle is repeated to ignite each cylinder twice in the turn of 1 4 2 3 4 1 3 2, and the ignition is intermitted once in the turn of 3 1 2 4 to make operation of 1/3 reduced cylinders.

Description

[Detailed description of the invention] The present invention relates to a method for operating a multi-cylinder engine with reduced cylinders.

2. Description of the Related Art Conventionally, it has been known to suspend ignition in some specific cylinders of the engine when the engine is under partial load, thereby reducing wasted fuel. For example, in a 4-cylinder engine that ignites cylinders 1 → 3 → 4 → 2 during full load, only two cylinders 1 and 4 will ignite during partial load, and the ignition of cylinders 3 and 2 will be stopped. There is a way to do it.

However, such a method has the following drawbacks.
That is, (i) the thermal load state is extremely different between the cylinder in which the ignition is stopped and the cylinder in which the ignition is not, and deformation of the cylinder block and gas leakage due to this deformation occur.
(11) In a cylinder in which ignition is stopped, the tension of the piston ring is weak, resulting in oil buildup, abnormal wear, and damage to the cylinder liner, piston ring, etc. (iii)
Furthermore, there are drawbacks such as water droplets that are likely to form due to proper cooling and cause corrosion of the sills.

The method of the present invention is aimed at solving the above-mentioned drawbacks, and is aimed at reducing cylinder operation of a multi-cylinder engine, which is characterized in that each cylinder is alternated in turn and stopped at the same frequency during partial load. It's a method.

The method of the present invention can also be applied to spark-ignition engines that use known carburetors to form air-fuel mixtures, but it cannot be applied to fuel-injected spark-ignition engines or diesel engines that do not pose problems such as blowing raw gas. This is even more suitable. Furthermore, the method of the present invention can be applied to both 4-stroke and 2-stroke engines.

Hereinafter, an example of the implementation procedure of the method of the present invention will be explained based on the drawings.

<First Practical Procedure Example> First, a practical procedure example applied to a cylinder reduction operation method for a 4-stroke, 4-cylinder diesel engine will be described. Prior to that, an outline of the fuel system of the engine will be described based on the drawings.

FIG. 1 is a schematic diagram of a fuel system for a four-stroke, four-cylinder diesel engine.

In each cylinder (2,) to (2,) of this engine (1),
Fuel injection nozzles (31) to (3,) are provided, respectively.

These nozzles (3□) to (34) are connected to the output chambers (51) to (5,) of the pressure increasing syringes (41) to (44), respectively. The output chambers (51) to (5,) are connected in parallel to the fuel pump (7) via check valves (61) to (6,), respectively.

The input chambers (81
) to (84) are supply/exhaust switching valves (
9, ) to (94) are connected to the pressure oil pump (10).

Each of the above-mentioned supply/discharge switching valves (9°) to (94) are constituted by electromagnetically operated valves, and are controlled by a control device (11). This control device (11) has four data input devices f.
f(12a)-(]2d), input interface (1
3), a central processing unit (14), an amplifier (15) and an output interface (16).

-1- The data input device (12a) - (12d) is
A rotation speed detector (12a) that detects the rotation speed of the engine (1) and outputs an electric signal corresponding to the rotation speed, and a rotation speed detector (12a) that detects the load of the engine (2) and outputs an electric signal corresponding to the load. load detector (121]) and engine (1
) that detects the cooling water temperature of the engine (1) and outputs an electric signal corresponding to that temperature, and an exhaust temperature detector (12c) that detects the exhaust gas temperature of the engine (1) and outputs an electric signal that corresponds to that temperature. Detector (+2d).

The central processing unit (14) first determines whether the load state of the engine (1) is full load or partial load based on the inputs from these data input devices (12a) to (12d).

As will be described later, an ignition signal is output to each of the supply/discharge switching valves (91) to (94) in accordance with the load condition.

FIGS. 2(a) and 2(b) are time charts showing the ignition schedule of the engine.

In the figure, each cylinder (2I) to (24) of the engine (1) is represented by its subscript surrounded by a solid line circle or a dotted line circle, and the position of the circle in the horizontal axis direction indicates the ignition timing of the cylinder. has been done.

The central processing unit M (14), via an amplifier (15) and an output interface (16), transmits the sign with a phase interval of 180° during one ignition cycle, i.e. 720° under full load conditions. If there are any subscripts, ignition signals are outputted to the supply switching valves (9,) to (94) in the order of cylinders 1→3→4→2.

At light load, the cycle time of one ignition cycle is extended to twice the cycle time of one ignition cycle at full load, and during the extended one ignition cycle, that is, 1440°, each wandering switching valve ( Ignition signals are outputted in the order of 1→4→2→3 to 91) to (94) if there are subscripts.
However, in this case, the distance between 1→4.2→3 is 360°, 4
→2 is 180°4-, and from the last 3 to 1 of the next ignition cycle is 5
A phase separation of 40° is provided. If the load is a medium load that is slightly heavier than the above-mentioned light load, the central processing unit (14) outputs the ignition slang in the order of 1 → 4 → 2 → 3 → 4 → 1 → 3 → 2, if there is a subscript. do.

In this case, there are 3 between 1 → 4.2 → 3.4 → 1.3 → 2.
60°, 4→2.3→4.1→3 and there is a 180° phase interval between the last 2 and the first 1 of the next ignition cycle.

The supply switching valves (9,) to (9,) with manual ignition signals are:
Switches from the oil drain position to the oil supply position as shown.

When the supply/discharge switching valves (91) to (9,) are switched to the refueling position, the input chambers of the pressure increasing sills (41) to (44) connected to the supply/discharge switching valves (9,) to (94) (81)～(
Pressure oil is introduced into the output chambers (51) to (54).
) fuel is forced out. As a result, the injection nozzles (
31) to (34) into the cylinders (21) to (2,).

Next, a first example of the procedure for carrying out the method of the present invention using the above-mentioned fuel system will be explained based on the drawings.

The ignition timing of this engine (1) is switched to three stages: full load operation, medium load operation, and light load operation, depending on the load state.

That is, in full load operation, the cycle time of one ignition cycle, that is, as shown by the symbol - in FIG.
While the phase progresses through 720°, each cylinder (2,) to (24) is ignited in the order of 1→3→4-2 each time the phase progresses through 13) 0°, and all-cylinder operation is performed.

During light load operation, each cylinder (21) to (2,) is
One ignition cycle is extended to 1440 degrees, which is twice the length of one ignition cycle at full load, and each cylinder (21) to (24)
ignition is stopped for one ignition cycle at full load in order to perform 50% reduced cylinder operation).

Immediately, as shown by → marks in FIG.
,) are fired in sequence with a phase interval of 360°, and the 3rd cylinder (23) is fired in the even numbered position at full load when the cylinder is open.
The ignition of is stopped. Then, after setting a phase interval of 180', the second and third cylinders (22) and (23), which are even-numbered to be fired at full load, are fired in sequence with a phase interval of 360°, and at full load during that time. The ignition of the first cylinder (B), which is fired at the odd numbered position, is stopped. Next, ignite cylinders 4 and 2 that have not yet stopped ignition (24)
, (22) are paused.

The ignition of the last three cylinders (23) then returns to the first ignition of the next ignition cycle with a phase interval of 540°. In this way, starting from cylinder 1, 144
Within one ignition cycle of 0°, a 50% cylinder reduction operation is performed in which the cylinders are ignited in the order of 1 → 4 → 2 → 3, and the ignition is stopped in the sequence of 3 → 1 → 4 → 2.

During medium load operation, each cylinder (2,) to (
24) is ignited twice in a row for 3 ignition cycles, then 1
Shut off the ignition. In other words, cylinder-less operation is performed with a cylinder reduction rate of ↓.

In this case, a set of an ignition cycle extended to twice one ignition cycle and an ignition cycle not extended at full load are periodically repeated. Each cylinder (2,) to (24
) is paused once during the 7-cycle of ignition, which is twice as long.

That is, first, the 1st and 4th cylinders (2,) (2,), which are fired in the odd numbered positions at full load, are fired in order with a phase interval of 36 (1'), and the even numbered cylinders are fired at the full load in between. The ignition of the third cylinder (23) that is to be ignited is stopped.

Next, two or three cylinders (22) (2,), which are even-numbered to fire at full load after a phase interval of 180', are fired in order at a phase interval of 360°, and the full load of the open The ignition of the first cylinder (21) that is fired at the odd numbered position is stopped. Then, after a phase spacing of 18 (1"), 4 and 1 cylinders (2
.

This is followed by 3 and 2 cylinders (23) (2□
) are ignited sequentially at 360° phase intervals, and during that time, the ignition of the even-numbered four cylinders (2,) at full load is stopped. In this way, 1→4→2→3
→4→1→3→2 8- Each cylinder (21) to (2,) is fired twice, and the ignition is performed three times.

<Second Embodiment> Next, an example of an implementation procedure applied to a reduced-cylinder operation method for a 4-stroke, 6-cylinder engine will be described.

FIG. 3 is a time chart showing the ignition schedule of a 4-stroke, 6-cylinder engine.

In FIG. 3, the numbers surrounded by solid circles or dotted circles represent each cylinder of the engine (not shown), and the positions of these circles in the horizontal axis direction indicate the ignition timing of the cylinder.

At full load, this engine has a cycle time of one ignition cycle, that is, 72
1 for every 12 degrees of phase progress while 0 degrees of phase advances.
- It is ignited in the order of 5 → 3 → 6-2 → 4.

At partial load, one ignition cycle for each cylinder is twice as long as one ignition cycle at full load, and JIII is also 1440 degrees.
ignition of each cylinder is stopped every other ignition cycle under full load. Then, during this extended cycle time of one ignition cycle, the ignition of each cylinder is stopped in turn to perform a 50% reduced cylinder operation.

That is, as shown by the → mark in Fig. 3, first, the odd-numbered cylinders 1 and 3.2 are fired at a phase interval of 240° at full load, and the even-numbered cylinders at full load are fired in sequence at a phase interval of 240 degrees. The ignition of the 5th and 6th cylinders, which are to be ignited first, is stopped. Next, after setting a phase interval of 12r)', the 4 and 5.6 cylinders, which are fired at even number [1] at full load, are fired in order with a phase interval of 24 + 1', and during the period of full load, The ignition of the odd-numbered cylinders 1 and 3 is stopped.

Next, the ignition of cylinders 2 and 4, which have not yet been turned off, is turned off, and the first cylinder of the next ignition cycle is turned on at a 360° phase interval from the ignition of the last cylinder of 6. Back to ignition. In this way, 1 starting from cylinder 1
Within one ignition cycle of 440°, 1 → 3 → 2 → 4 → 5 →
A 50% cylinder reduction operation will be performed in which the cylinders are ignited in the order of 6 and the ignition is stopped in the order of 5 -> 6-1-3-Toge Issan-1.

<Third Implementation Procedure Example> Next, another implementation procedure example applied to the cylinder reduction operation method of a 4-cycle 6-cylinder engine will be described.

FIG. 4 is a time chart showing the ignition schedule of a 4-stroke, 6-cylinder ennon.

In FIG. 4, the numbers surrounded by solid circles or dotted circles represent each cylinder of the engine (not shown), and the positions of these circles in the horizontal axis direction indicate the ignition timing of the cylinder.

At full load, this engine has a cycle time of one ignition cycle, as shown by the → mark in Fig. 4, that is, ? 2(
1 for every 120 degrees of phase progress while 1' phase advances.
→It is ignited in the order of 5 → 3 → 6 → 2 → 4.

At partial load, the cycle time of each cylinder is doubled for every ignition cycle at full load,
By deactivating the ignition once every two ignition cycles at full load, each cylinder's ignition is alternately deactivated twice during the cycle time of a 5-point large cycle at full load.40% Reduced cylinder operation is performed.

11- That is, as shown by the → mark in Fig. 4, first, the odd-numbered cylinders 1 and 3.2 are fired in order at a phase interval of 240° at full load, and during the full load period, The ignition of the fifth and sixth cylinders, which are sometimes even-numbered, is stopped. Next, the even-numbered cylinders 4 and 5.6, which are fired at full load with a phase interval of 120 degrees, are fired α in turn with a phase interval of 240', and the odd-numbered cylinders at full load between them are fired at a phase interval of 240'. The ignition of the 1st and 3rd cylinders, which will be ignited first, is stopped.

Subsequently, the second ignition of the 2nd and 1.3 cylinders, which are fired at the odd numbered positions at full load with a phase interval of 120°, is performed in order with a phase interval of 360°, and during the period of full load. The ignition of the 4th and 5th cylinders, which are ignited at even numbered positions, is stopped in sequence. After further setting a phase interval of 120°,
Next, the 6.4.5 cylinders that have not yet been ignited for the second time are ignited at a phase interval of 240°, and the ignition of the odd-numbered 2.1 cylinders under full load is stopped in order. let 3.2.1 with a further 120° phase interval
, are ignited in sequence with a 240° phase interval of 12 -, and at the same time, the ignition of even-numbered cylinders 6 and 4 at full load is stopped. Moreover, the ignition of each cylinder of 5.6.4 is performed in order with a phase interval of 240° at a phase interval of 120°, and the ignition of each cylinder of 3.2 is stopped during that time. Then, with a phase interval of 120° from the ignition of the last 4 cylinders, the next 5 cylinders are fired.
Return to ignition of the first cylinder of the ignition cycle. In this way, within 5 ignition cycles of 720° starting from cylinder 1, 1 → 3 → 2 → 4 → 5 → 6 → 2 → 1 → 3 → 6 → 4
→ 5 → 3 → 2 → 1 → 5 → 6 → 4 are ignited in order, 5 → 6
→1→3→4-5→2→1→6→4→3-2 A 40% reduction cylinder rolling is performed in which the ignition is stopped in the order of →1→3→4-5→2→1→6→4→3-2.

As explained above, in the method of the present invention, the cycle time of the ignition cycle of each cylinder is doubled in a predetermined order,
Since the procedure is such that the ignition of each cylinder is stopped in turn, all cylinders are repeatedly operated and stopped equally, making the heat load uniform.

As a result, thermal deformation of the cylinder block is reduced,
Gas leakage caused by this thermal deformation can be eliminated. In addition, since the piston rings of the gold cylinder are tightened (in the same way) and bulge out appropriately, there is less oil buildup, which prevents abnormal wear of the piston rings and damage to the piston rings and cylinder. Furthermore, since the cylinder in which ignition is suspended does not need to be overcooled, water droplets do not condense inside the cylinder, and corrosion due to the condensed water droplets is less likely to occur.

In addition, all cylinders are ignited in order, so the rotation is stable,
Various advantages can be obtained from the viewpoints of durability, energy saving, pollution prevention, etc., such as vibration and noise being reduced by 1 degree Celsius.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show a first implementation procedure example of the method of the present invention,
Fig. 1 is a schematic diagram of the ignition system of a 4-cycle, 4-cylinder diesel engine used to carry out the method of the present invention, and Fig. 2 (
) is a time chart showing the ignition schedule at full load and light load, Figure (11) is a time chart showing the ignition schedule at medium load, and Figure 3 is a time chart showing the ignition schedule at medium load. Time chart 15 showing the ignition schedule. FIG. 4 is a time chart showing the ignition schedule of the third example of the procedure for implementing the method of the present invention. (1)...Engine, (B)~(2,)...Cylinder. Patent applicant: Kubota Iron Works Co., Ltd. 16- JP 59-115470 (7)

Claims (1)

[Claims] 1. In a multi-cylinder engine (1) that performs all-cylinder operation in which all cylinders (2,) to (24) are ignited in sequence at a predetermined phase interval when under full load, when under partial load,
A reduced-cylinder operation method for a multi-cylinder engine, characterized by sequentially alternating the ignition of each cylinder (B) to (24) and stopping the ignition at the same frequency.