JPS5818533A - Cylinder number controlled engine - Google Patents

Abstract

PURPOSE:To prevent injection valves and shutoff vave from a stain and improved reliability of their action, by providing the fresh air shutoff valve in an idle side intake passage, setting the fuel injection valves in the upstream side of said fresh air shutoff valve, using injected fuel from said injection valves and cleaning said shutoff valve. CONSTITUTION:An engine, equipped with always operating cylinders A, B, C and cylinders D, E, F in idle operation in a light load range of the engine, is constituted in such a manner that in the operated cylinders A-C, fuel is injected from fuel injection valves a-c, set to each port of an operated side intake air passage 3, throughout a full operational range of load, while fresh air is supplied through a throttle valve 2. On the other hand, in the idle cylinders D-F, a fresh air shutoff valve 5, cutting off supply of fresh air to the idle cylinders D-F at partial load operation, is provided in the upstream part of an idle side intake passage 4. Further fuel injection valves d-f, feeding fuel to the idle cylinders D-F, are set to the upstream side in the vicinity of said shutoff valve 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cylinder number control engine that suspends operation of some cylinders when the engine is under light load and recirculates exhaust gas to these idle cylinders.

In general, when an engine is operated under a high load, fuel efficiency tends to improve.For this reason, multi-cylinder engines operate by cutting off the supply of fuel and fresh air to some cylinders when the engine load is low. An engine with control over the number of cylinders was devised in which the load on the remaining active cylinders was increased by that amount, thereby improving overall fuel efficiency in the light load range.

This engine previously proposed by the applicant is shown in FIG.

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 rest-side intake passage 4 connected to F.

Among these, a fresh air cutoff valve 5 is located upstream of the intake passage 4 on the pause side.
In the evening, during partial cylinder operation, this shutoff valve 5 closes to cut off the supply of fresh air to the idle cylinders E and F.

On the other hand, the exhaust passage 6 also branches halfway into the working side exhaust passage 7 that connects to the working side air 111iA, B, and C, and the rest @exhaust passage 8 that connects to the resting side cylinders E and F.

Of these, the idle-side exhaust passage 8 is connected to the idle-side intake passage 4 downstream of the fresh air cutoff valve 5 via an exhaust circulation passage 9 .

A three-way solenoid valve 10Th is provided in this exhaust circulation passage 9.
An exhaust gas recirculation valve 12 is installed, which is opened and closed by a diaphragm device 11 which is switched and controlled by a diaphragm device 11. During partial cylinder operation, this exhaust gas recirculation valve 12 opens and the cylinder on the idle side when the operating cylinder is stopped. Let DE and F inhale exhaust gas at approximately atmospheric pressure. As a result, 4 in the idle side cylinder, Fi, and F.
Since the pumping loss is reduced, further fuel efficiency can be achieved.

Further, in the exhaust passage 6, an exhaust upper sensor 13 for detecting the overall exhaust air-fuel ratio and a three-way catalyst 14 for purifying the exhaust gas are installed downstream thereof.

Of these, the air-fuel ratio detection signal from the sensor 13 is sent to the control circuit 1.
Sent to 5. Then, in the control circuit 15, in response to this air-fuel ratio signal, fuel injection valves a corresponding to the multi-cylinders A-F are installed.
-f valve opening period is controlled, and the fuel injection amount is feedback-controlled so that a mixture having a stoichiometric air-fuel ratio is obtained.

In addition, the control circuit 15 controls the engine light load, cuts the fuel supply to the cylinders on the inactive side, E, and F to stop their operation, and performs partial cylinder operation.

However, in such a conventional device, during partial cylinder operation, the exhaust gases E and F' are introduced into the idle cylinder downstream of the fresh air cutoff valve 5 through the exhaust circulation passage 9t. , car in gas? If fuel, oil, etc. deteriorate and become sticky, for example, if it adheres to the area around the fresh air cutoff valve 5, or if the injection ports of the fuel injection valves d, e, and f are blocked, the next When switching to all-cylinder operation, the opening degree of the shutoff valve 5 is worsened, and then the fuel injection valves a, e,
There was a problem in that the amount of injection from f was reduced, which could impede normal operation.

This invention was made by focusing on such conventional problems, and includes installing a fuel injection valve upstream of a fresh air cutoff valve, and shutting off fresh air using fuel injected from this injector during all-cylinder operation. The purpose is to solve the above problems by cleaning the valve.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a diagram showing a refreshing embodiment of the present invention.

In this embodiment, the positions of cylinders E and F, which cease operation (stop combustion) in the light load range of the engine, and cylinders A, B and C, which continue to operate at all times, are interchanged with those in FIG.

Of these, in the operating side cylinders A, B, and C, fuel flows into the operating side intake passage 3 during both full-cylinder operation and partial cylinder operation.
The fresh air is supplied from the fuel injection valves a, b, and c installed at each port part of the working side intake passage 3 through the throttle valve 2t.
It will be introduced from

On the other hand, fuel and fresh air are supplied to the cylinders E and F on the idle side when all cylinders are in operation, but both are shut off when one cylinder is in operation, and at the same time, the exhaust passage 8 on the idle side and the intake passage 4 on the idle side
The exhaust circulation passage 9 connecting with the exhaust II flow valve 12! 11
8!1 The exhaust gas is recirculated to the skeleton cylinder, E, and F.

In this embodiment, during this partial cylinder operation, the idle side cylinder and E
, F is provided with a fresh air cutoff valve 5 that cuts off all 3M of fresh air supply to the idle side intake passage 4, and a idle side cylinder is located close to and upstream of the fresh air cutoff valve 5, Install fuel injection valves d, e, and f that supply fuel to E and F. □ The fresh air cutoff valve 5 is specifically connected to a diaphragm device 16, and when the three-way solenoid valve 17 is switched by a command from the control circuit 15 during partial cylinder operation, the vacuum tank 1
When the negative pressure from 8 is transmitted to the diaphragm device 16, the idle side intake passage 4 is closed.

The fuel injection valves d, e, f are, for example, as shown in FIG.
The fuel is distributed around the fresh air cutoff valve 5, mainly at the outer seal portion 19.
and is arranged so as to spray toward the passage wall.

During all-cylinder operation, these injection valves d, e, and f are controlled by the controller $ like the injection valves a, b, and c of the active cylinders A, B, and C.
Each cylinder A-F is controlled by the drive signal from 1'5.
The fuel injection amount is controlled so that the stoichiometric air-fuel ratio is obtained in both cases. On the other hand, during partial cylinder operation, the cylinder is kept fully closed and fuel injection is stopped.

Note that the exhaust gas recirculation valve 12 installed in the exhaust gas circulation passage 9 is
During partial cylinder operation, the three-way solenoid valve 10 is switched by a command from the control circuit 15, and opens when negative pressure from the vacuum tank 18 is transmitted.

In such a configuration, the fuel injection valves d, e.

During partial cylinder operation in which the fuel supply from f to the idle cylinders D, B, and F is cut, the fresh air cutoff valve 5 closes and the exhaust recirculation valve 12 opens to switch to the idle cylinders, E.

Exhaust gas is refluxed to F.

Therefore, the carton, oil, etc. in the recirculated exhaust gas gradually adhere to the area around the fresh air cutoff valve 5, but the injection valves d, e, and f are provided upstream of the cutoff valve 5. Because the exhaust gas does not come into contact with the
There is no need to worry about narrowing it down.

Then, when the partial cylinder operation shifts to full cylinder operation, the exhaust recirculation valve 12 closes, the fresh air cutoff valve 5 closes, and fresh air is introduced into the idle cylinders B and F, and the injection valve d
, e, and f.

The fuel from these injection valves d, e, and f flows around the fresh air quick cutoff valve 5, mainly through its outer peripheral seal portion 9 and the passageway (the idle side intake passageway 4).
) is injected toward the wall, and enters the cylinder on the idle side along with fresh air.
, introduced in F.

For this reason, any carne or oil that has adhered to the fresh air cutoff valve 5 or its passage wall surface is immediately and thoroughly cleaned, and the outer seal portion 19 of the cutoff valve 5 and the passage wall surface are prevented from sticking and worsening the opening condition. It is prevented.

As described above, in this embodiment, the fuel injection valves d, e, and f are installed upstream of the fresh air cutoff valve 5, and the injection valves d,
Since the cutoff valve 5 is cleaned by the injected fuel of e and f, the cylinders on the idle side and e.

By ensuring that the injection valves d, e, and f are not contaminated by the exhaust gas that recirculates F, and that an appropriate injection amount is always obtained, even if sticky substances in the exhaust gas adhere to the fresh air cutoff valve 5, this will be prevented. It can be easily washed off without getting stuck,
The opening/closing operation of the shutoff valve 5 is maintained well.

FIG. 4 shows another embodiment of the present invention, in which the intake passage on the idle side is divided into three parts corresponding to the four cylinders on the idle side, E and F, and fresh air cutoff valves 20 and 21 are provided respectively.

221- is provided.

In this case, the fresh air cutoff valves 20, 21, 22 are connected to each other and opened and closed synchronously. And this shutoff valve 20.21.2
Corresponding to No. 2, fuel injection valves d, e, and f are installed on the upstream side thereof.

In this way, the shutoff valves 20, 21, 22'e are cleaned,
In this way, each cylinder on the idle side, E.

The air-fuel ratio at F can be accurately controlled.

As explained above, according to the present invention, the fuel injection valve is installed upstream of the fresh air cutoff valve, and the cutoff valve is cleaned with the injected fuel from this injection valve. This has the effect of preventing contamination, improving reliability, and providing good operating performance.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the configuration of a conventional device, Figure 2 is a cross-sectional view of the configuration of an embodiment of the present invention, Figure @3 is a layout diagram of the main parts of Figure 2, and Figure 4 is another embodiment of the present invention. FIG. 2 is a configuration cross-sectional view showing an example. 3... Working side intake passage, 4... Dormant side intake passage, 5
...Fresh air cutoff valve, 7...Working side exhaust passage, 8...
Pause side exhaust passage, 9... Exhaust circulation passage, '12...
Exhaust recirculation valve, 15... Control circuit, 16... Diaphragm device, 19... Outer seal portion, 20, 21, 22
... Fresh air cutoff valve. Patent applicant Nissan Motor Co., Ltd.

Claims (1)

[Claims] When the fuel is supplied from the fuel injection valve in the light load range of the engine.
The cylinder includes a cylinder on the idle side that is disconnected from the cylinder, and an active cylinder that is constantly supplied with fuel from a fuel injection valve, and has an intake passage corresponding to the cylinder on the idle side and the cylinder on the active side. In a multi-cylinder engine in which a fresh air cutoff valve that branches off from the middle and closes when the fuel is cut off is provided in the intake passage on the idle side, and an exhaust circulation passage that recirculates exhaust gas to the cylinder on the idle side is also provided, the fuel corresponding to the cylinder on the idle side is provided. An engine with controlled number of cylinders, characterized in that an injection valve is installed close to the upstream side of a fresh air cutoff valve.