JPH0639913B2 - Engine load detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention performs deceleration operation in which fuel supply to some cylinders is stopped at least at the time of deceleration, thereby outputting only from some cylinders. The present invention relates to an engine load detection device.

(Prior Art) Recently, in particular for automobile engines, a great improvement in fuel consumption is desired. Therefore, depending on the operating state of the engine, all cylinder operation in which all cylinders output and the above-mentioned reduction Attention has been focused on a cylinder number control engine capable of appropriately switching and selecting the cylinder operation. That is, for example, at the time of high load such as starting or running at high speed, fuel is supplied to all the cylinders and output from all the cylinders, while low load such as at constant speed, constant running or deceleration. At times, the fuel supply to some cylinders is cut off to improve the filling efficiency of other cylinders, thereby achieving fuel efficiency.

In such a reduced-cylinder operation, fuel is cut off during deceleration, and fuel is cut off only in some cylinders for a predetermined period during the initial period of deceleration in order to reduce torque shock when shifting from all-cylinder operation to all-cylinder deactivation. It is also used in the form.

By the way, when the vehicle is decelerating, the inside of the intake passage on the downstream side of the slot valve has a high negative pressure, so the residual fuel adhering to the inner wall of the intake passage is rapidly sucked into the combustion chamber and becomes a rich mixture. However, there is a problem that explosive combustion called so-called afterburn occurs in the exhaust passage, and a large amount of harmful components such as HC in the exhaust gas. As means for this problem, for example, Japanese Patent Laid-Open No. 59-229042. It is generally practiced to introduce auxiliary air to the downstream side of the throttle valve at the initial stage of deceleration as described in the publication so as to prevent the formation of the rich mixture. Problems like this
This also occurs when the reduced-cylinder operation is performed at least in the initial stage of deceleration.

Further, the intake negative pressure generated in the intake passage is used as engine load information for controlling the engine or controlling other devices. For example, it is used as information as to whether or not to perform reduced cylinder operation, as information for determining the fuel injection amount in the electronically controlled fuel injection device, and as information for unlocking the lockup in the automatic transmission. Therefore, studies are beginning to be added to improve the accuracy of detecting the intake negative pressure in the cylinder number control engine described above.

(Problems to be Solved by the Invention) In such a situation, when auxiliary air is introduced into the engine as a request from the engine side, intake air used as information for engine control or control of other devices Negative pressure, that is, increasing the detection accuracy of the load, appears as a contradictory problem.

That is, when introducing auxiliary air to the downstream side of the throttle valve in order to prevent the occurrence of the afterburn,
As a result, the intake negative pressure generated downstream of the throttle valve is weakened, and the detection of the engine load state is delayed.

The present invention has been made in view of the above circumstances, and its technical problem is to introduce an auxiliary air as a request from the engine side to the engine configured to control the number of cylinders described above. An object of the present invention is to provide an engine load detection device that satisfies both the intake negative pressure as information, that is, the load state detection.

(Means and Actions for Solving Problems) The present invention is based on the premise of an engine configured to stop fuel supply to some of the branch intake passages at least during deceleration in accordance with the operating state of the engine. The auxiliary air introduction port is opened to the branch intake passage where the fuel supply is not stopped, while the intake negative pressure intake port of the load detector that detects the load condition of the engine is connected to the branch where the fuel supply is stopped. The opening is made in the intake passage.

With such a configuration, with respect to the afterburn problem described above, since the auxiliary air introduction port is opened to the branch intake passage where the fuel supply is not stopped, the auxiliary air introduction port is not used. Air is sucked into the cylinder in which combustion continues promptly, and generation of a rich air-fuel mixture during deceleration is prevented.

On the other hand, since the intake negative pressure intake port is opened to the intake passage where the fuel supply is stopped, that is, the branch intake passage which is connected to the idle cylinder where the fuel supply is cut during the reduced cylinder operation,
The intake negative pressure can be taken out without being affected by the auxiliary air.

(Example) Hereinafter, the Example of this invention is described based on drawing.

In FIG. 1, reference numeral 1 denotes an engine body, which is an engine body 1.
In each of the cylinders 2 and 4, each of the branch pipes 8 and 1 of the intake manifold 6
0 is connected to the upstream side of the intake manifold 6, that is, the upstream side of the common pipe 12 into which the branch pipes 8 and 10 join, and a throttle valve 14 for controlling intake air in order toward the upstream side.
Throttle body 16 with built-in, surge tank 18,
The intake air purified by the air cleaner 20 is connected to the air cleaner 20, and the intake air is divided into the branch pipes 8 and 1 of the intake manifold 6.
Through 0, each cylinder 2, 4 is filled. That is, the intake port 24 and the exhaust port 26 are opened in the combustion chamber 22 of each cylinder 2, 4, and the intake valve 28 that opens and closes the intake port 24 and the exhaust valve 30 that opens and closes the exhaust port 26 are the piston 32. Of the intake manifold 6 in synchronization with the reciprocating movement of the intake manifold, that is, through a valve operating mechanism (not shown) linked to a crankshaft (not shown) at a predetermined timing. The intake air that is connected to the branch pipes 8 and 10 and is connected to the intake passages 34 and 36, respectively, and intake air passing through the intake passages 34 and 36 is disposed in the branch pipes 8 and 10. The mixture with the fuel injected from the fuel injection chamber 38 is filled in the combustion chamber 22, and the exhaust gas from the combustion chamber 22 is discharged from the exhaust port 26 to the atmosphere via the exhaust manifold 40.

Fuel injection from the fuel injection valve 38 is controlled by a pulse signal from a control unit (not shown),
As shown in FIG. 3, the reduced-cylinder operation is performed for a predetermined period at the initial stage of deceleration, the fuel supply to some cylinders is stopped, and then all cylinders are deactivated depending on the decelerated state.
That is, in the embodiment, one cylinder 2 on the left side in the drawing is a deactivated cylinder in which fuel supply is cut, and therefore, when the cylinder is reduced, fuel injection to the branch pipe 8 (left side in the drawing) connected to the cylinder 2 is stopped. Therefore, only the intake air is in the combustion chamber 2 of the idle cylinder 2.
2 is sucked. On the other hand, fuel is continuously supplied to the other cylinder 4 (on the right side in the drawing), and operation is performed only with the output of this other cylinder 4.

A bypass passage 42, one end of which is connected to the upstream side of the throttle body 16 and the other end of which is connected to the branch pipe 10, is provided to introduce auxiliary air during deceleration to such an engine. A deceleration device 44 is interposed in the bypass passage 42 to open and close the bypass passage 42. The deceleration device 44 receives a deceleration signal from the deceleration detection means 46 and bypasses during deceleration, more specifically, in the initial stage of deceleration. Control for opening the passage 42 is performed. That is, the bypass passage 42 that bypasses the throttle valve 14 is configured such that the auxiliary air introduction port 48 opens in the intake passage 36 that is connected to the cylinder 4 in which fuel supply is continued even during the reduced cylinder operation.

On the other hand, the intake negative pressure intake port 50 is opened in the deactivated cylinder 2 that is deactivated during the deceleration operation, that is, in the intake passage 34 (left side in the drawing) where the fuel supply is cut. That is, one end of the negative pressure intake pipe 51 is connected to the branch pipe 8 connected to the idle cylinder 2, and the other end of the negative pressure intake pipe 2 is, for example, a negative pressure detector 52 including a diaphragm or the like.
The load signal from the negative pressure detector 52 is used as a lockup release signal of the automatic transmission 54 in this embodiment.

In such a configuration, in the initial stage of deceleration, the auxiliary air is supplied from the auxiliary air inlet port 48 to the intake passage 36, becomes a mixture with the fuel adhering to the inner wall of the intake passage 36, and is supplied to the other cylinders 4. , It will be sucked promptly. As a result, generation of a rich mixture is prevented, and problems such as afterburn can be solved.

On the other hand, the intake negative pressure taken into the negative pressure detector 52 is
Since the negative pressure of the intake air in the intake passage 34 to which the auxiliary air is not directly supplied is used, the negative pressure detector 52 detects the load state of the engine without being affected by the auxiliary air.

FIG. 2 shows the effect of the present invention. When the intake negative pressure intake port 50 is arranged in the intake passage 36 into which the auxiliary air is introduced (two-dot chain line in the figure) and the present invention (in the figure, When compared with (solid line), the detection delay (T) due to the introduction of auxiliary air can be prevented, as shown in this figure.

(Effects of the Invention) As is apparent from the above description, according to the present invention, in an engine in which the number of cylinders is controlled, the auxiliary air is introduced to prevent generation of a rich mixture during deceleration, and intake air is introduced. It is possible to achieve compatibility with load detection accuracy due to negative pressure. That is, it is possible to prevent the load detection delay due to the introduction of the auxiliary air.

[Brief description of drawings]

 FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the effect of the present invention. FIG. 3 is a diagram showing a reduced cylinder operation region. 1: Engine Main Body 2: Inactive Cylinder 4: Fuel Supply Continued Cylinder 14: Throttle Valve 34: Intake Passage (Fuel Supply Stop) 36: Intake Passage (Fuel Supply Continue) 38: Fuel Injection Valve 42: Bypass Passage 44: Deceleration device 46: Deceleration detection means 48: Auxiliary air introduction port 50: Intake negative pressure intake port 52: Negative pressure detector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F02M 35/10 301 M 9247-3G

Claims (1)

[Claims] 1. An engine in which fuel supply is not stopped in at least some of the branch intake passages connected to each cylinder at the time of deceleration according to the operating state of the engine The load detection of the engine, characterized in that the auxiliary air introduction port during deceleration is opened in the passage, and the intake negative pressure intake port of the negative pressure detector is opened in the branch intake passage where fuel supply is stopped. apparatus.