JPS5813085Y2 - cylinder number control engine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a cylinder number control engine that performs partial cylinder operation by suspending the operation of some cylinders when the engine is under light load.

In general, fuel efficiency tends to improve when an engine is operated under a high load. For this reason, in a multi-cylinder engine, when the engine load is light, the fuel supply to the partial cylinders is cut to stop operation. An engine with controlled number of cylinders was devised that relatively increases the load on the remaining active cylinders by that amount, thereby improving overall fuel efficiency in the light load range.

However, in such an engine, more stable combustion is required during partial cylinder operation in which some cylinders stop operating, compared to a normal engine in which all cylinders are always operating, and it is unclear how to actually solve this problem. This has become one issue.

By the way, in this conventional cylinder number control engine, all the cylinders are configured in the same way, and the inactive cylinder, which is inactive during partial cylinder operation, and the other active cylinder, which is always activated, are configured symmetrically with each other. Common.

For example, in a six-cylinder engine, three cylinders out of the six cylinders, which are all configured in the same way, are the inactive cylinders, and the other three cylinders that are symmetrical to these are the active cylinders.

However, the roles of the idle cylinder, which operates only under medium or high loads, and the active cylinder, which operates even under light loads, are supposed to be different, and the required characteristics are naturally different.

In other words, the characteristics of the active cylinder should be set to ensure stable engine operating performance at low speeds and light loads, and on the other hand, to ensure sufficient engine output at high speeds and high loads. The cylinder on the idle side should be set.

The present invention was developed in consideration of the above-mentioned circumstances, and the operating cylinders are set to ensure stable combustion, while the idle cylinders are set to obtain sufficient output, and the overall configuration is set so that the cylinders on the idle side can obtain sufficient output. The objective is to obtain an engine with controlled number of cylinders that can further improve stability and fuel efficiency in light load ranges without sacrificing output.

This will be explained below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention.

The intake passage 1 is located downstream of the throttle valve 2 and connects the working cylinders A, B,
The working side intake passage 3 connected to C, the idle side cylinder, E,
It branches into a closed side air road 4 that connects to F.

A cutoff valve 5 is interposed in the upstream portion of the inactive intake passage 4, and during partial cylinder operation, this shutoff valve 5 closes to cut off the supply of fresh air to the inactive cylinders E and F. do.

On the other hand, the exhaust passage 6 also branches halfway into an active exhaust passage 7 that connects to the active cylinders A, B, and C, and an idle exhaust passage 8 that connects to the idle cylinders E and F.

Of these, the idle side exhaust passage 8 is connected to the idle side intake passage 4 downstream of the cutoff valve 5 via an exhaust gas recirculation passage 9.

The exhaust gas recirculation passage 9 is provided with a three-way solenoid valve 10 and an exhaust gas recirculation valve 12 that is opened and closed by a diaphragm device 11 that responds to the valve. Exhaust gas at approximately atmospheric pressure is made to be sucked into the cylinders E and F on the idle side when the operating body is inactive.

As a result, the cylinder on the idle side becomes E. Pumping loss at F is reduced, further improving fuel efficiency.

Furthermore, an air-fuel ratio sensor 13 and a three-way catalyst 14 for purifying exhaust gas are arranged downstream of the air-fuel ratio sensor 13 in the exhaust passage 6.

Of these, the air-fuel ratio detection signal from the sensor 13 is sent to the control circuit 1.
Sent to 5.

Then, the control circuit 15 controls the fuel injection valves a-f corresponding to each cylinder A-F according to this air-fuel ratio signal, and fine-tunes the fuel injection amount so that a mixture at the stoichiometric air-fuel ratio is obtained. Pack control.

In addition, the control circuit 15 controls the fuel injection valves d, e, and f to always be closed during partial cylinder operation, and cuts the fuel supply to the idle cylinders, E, and F to prevent their operation. The engine stops and performs basic operations as a cylinder number control engine.

FIG. 2 is a sectional view showing details of the working cylinder A.

The other working cylinders B and C are constructed in exactly the same way as this cylinder A, so their explanation will be omitted.

In the figure, 16 is a combustion chamber, 17 is an intake valve, 18 is a spark plug, 19 is a piston, and 20 is an intake port that constitutes the downstream portion of the working side intake passage 4.

A feature of the present invention is that by strengthening the swirl generated within the combustion chamber 16, stable combustion in the operating cylinder A and improved fuel efficiency are achieved.

Specifically, as shown in FIG. 3, the axis of the intake port 20 is formed into a curved line, and the combustion chamber 16 is
The intake port 20 is opened eccentrically from the center of the
As shown in FIG. 2, the inclination angle of the intake port 20 is made as close as possible to a right angle to the cylinder axis, and the intake port 20 is configured to form a so-called swirl generating port to strengthen the swirl.

FIG. 4 is a sectional view showing details of the cylinder on the idle side.

The other cylinders E and F on the idle side are constructed in exactly the same way as this cylinder, so their explanation will be omitted.

In the figure, 21 is a combustion chamber, 22 is an intake valve, 23 is an ignition plug, 24 is a piston, and 25 is an intake port 1 constituting the downstream part of the intake passage 3 on the idle side.

Another feature of the present invention is that in the cylinder on the deactivation side explained in FIG. 4, as shown in FIG.
5 in a straight line, and the working cylinder A,
By making the inner diameter of the intake port 1-25 relatively larger than those in B and C, and by bringing the inclination angle of the intake port 25 closer to the cylinder axis direction to increase the filling efficiency of the air-fuel mixture, The point is to ensure a sufficiently high output at the same time.

In the present invention configured as described above, the working cylinders A and B
When the load is light when only , C is activated, the cylinders on the idle side, E, and F are activated.
In addition to the increased load and relatively better combustion, the action of the swirl-generating intake port 20 strengthens the gas flow within the cylinder and causes rapid flame propagation after ignition. Stable combustion and improved fuel efficiency can be achieved.

On the other hand, under high load conditions when the idle cylinders E and F operate simultaneously, sufficient air-fuel mixture is supplied by the action of the upper intake port 25 in the filling car, making it possible to produce high output.

Therefore, according to the present invention, it is possible to further improve combustion stability and fuel efficiency in light load ranges than in the past without losing output in high load ranges.

In the above-mentioned embodiment, the present invention was applied to an in-line 6-cylinder engine, but the present invention can be similarly applied to a ■-type engine, an 8-cylinder engine, etc.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view showing an embodiment of the present invention, Fig. 2 is a sectional view showing details of the working cylinder in the embodiment of Fig. 1, and Fig. 3 is an intake port of the working cylinder. FIG. 4 is a cross-sectional view showing details of the cylinder on the idle side in the embodiment of FIG. 1, and FIG. 5 is a schematic plan view showing the intake port of the cylinder on the idle side. 1... Intake passage, 2... Throttle valve, 3...
...Intake passage on working side, 4...Intake passage on rest side, 5...Shutoff valve, 9...Exhaust recirculation passage, 12... Exhaust recirculation valve, 15...
Control circuit, 16... Combustion chamber, 20...
Intake port, 21... Combustion chamber, 25...
・Intake port, A, B, C... Working side cylinder, D
. E, F...Cylinder on the idle side, a, l), c, d, e
, f...Fuel injection valve.

Claims (1)

[Scope of utility model registration request] In a multi-cylinder engine that has a dormant cylinder whose fuel supply is cut off and stops operating when the engine is under light load, and an active cylinder which is always in operation, the intake port of the active cylinder is offset from the center of the combustion chamber. A cylinder number control engine in which a swirl port is formed by opening at the center of the cylinder, while the axis of the intake port of the cylinder on the idle side is formed in a straight line, and its effective diameter is configured to be relatively larger than the intake port of the cylinder on the operating side. .