JPH05180016A - Automobile engine - Google Patents

Abstract

PURPOSE:To reduce fuel consumption without causing a vehicle from being vibrated by an engine in which the operation of valve devices of selected those of a plurality of engine cylinders is rested, by holding an engine cylinder resting condition only in such an engine rotating condition that the vehicle body does hot vibrate during idle operation. CONSTITUTION:A valve mechanism 2 provided for intake and exhaust ports of an engine 1, is operated for opening and closing by a hydraulic drive part which may be changed over between an all engine cylinder mode in which valves of all engine cylinders are opened or closed, and a partial engine cylinder mode in which valves of only a part of the engine cylinder are opened and closed (valves of the remainder engine cylinder are rested), since the operating configuration of the mechanism 2 is set by a control part 3. The control part 3 sets the all cylinder mode or the partial cylinder mode in accordance with outputs from an engine rotational speed sensor 4 and a boost cylinder pressure sensor 5, being based upon a map. In this case, when the partial engine mode is set, an engine rotational speed which is set in accordance with a result of determination of whether an idle switch 6 is turned on or off, is compared with an actual engine rotational speed, and the rotational speed range used for setting the partial cylinder mode is set is changed over within the above- mentioned map.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile engine, and more particularly to a vehicle engine having a structure capable of suspending the operation of a valve device for intake and exhaust in a selected cylinder of a plurality of cylinders. Car engines.

[0002]

2. Description of the Related Art Generally, in an automobile engine,
The maximum opening amount of the valve corresponds to the maximum lift amount from the cam profile of the valve opening / closing cam, and since this amount is always constant, the load from the engine speed and throttle opening is changed. The current situation is that it is not possible to set the intake / exhaust efficiency according to the situation. That is, for example, in the case of an engine that requires high speed rotation, the above-described cam profile is set in consideration of increasing the intake rate of the air-fuel mixture and the exhaust efficiency. Tends to sacrifice fuel consumption rate. On the contrary to the above case, when the cam profile is set in consideration of the fuel consumption rate, there is a possibility that the output at the time of high speed rotation or high load operation may not be sufficiently obtained.

Therefore, in order to meet such operating conditions of the engine, it is necessary to satisfy both the reduction of fuel consumption at low speed and low load operation and the securing of output at high speed and high load operation. As the valve opening / closing cams, those having cam profiles set for low speed and high speed are prepared, while a rocker arm having a cam follower in contact with each of these cams and a rocking fulcrum of this arm are configured. The rocker shaft is separated from the rocker shaft, and the rocker shaft is integrally provided with a sub rocker arm that is in contact with the valve stem. And the unconnected position is selected, and rocking of the rocker arm on the connected side is controlled via the rocker shaft. Structure so as to open and close control of the valve is transmitted to Kkaamu has been proposed (e.g., Japanese Patent Application 2-1821 is a prior application filed by the present applicant
No. 31). In this structure, in addition to switching the valve opening / closing amount by the valve opening / closing cam at low speed operation and high speed operation, the plunger is not connected to each rocker arm, so-called valve operation on the cylinder side. It is also possible to stop and suspend the cylinder.

[0004]

DISCLOSURE OF THE INVENTION The above-described deactivated cylinder state is
For example, in the case of a four-cylinder engine, the fuel consumption amount is reduced by applying the first cylinder and the fourth cylinder having the same piston operation stroke to each other. And the volumetric efficiency of air in the cylinder corresponding to the load information are determined and executed by a map determined.

However, in an engine using such a cylinder deactivation system, since the number of cylinders in which the combustion stroke is executed to actually obtain the output is reduced, engine vibration caused by the explosion stroke can be suppressed. In some cases, this vibration may be transmitted to the vehicle body through the engine mount and cause noise in the room. In particular, this phenomenon becomes noticeable during low-speed rotation during cylinder deactivation.

Therefore, in order to avoid such a phenomenon, it is conceivable to switch to a state in which valves can be opened / closed in all cylinders at a low speed rotation and take balancing for damping of engine vibration modes. In particular, it is the actual situation that the cylinder deactivated state cannot be canceled because it is desired to improve fuel efficiency at low speed rotation, and the problem of vehicle body vibration described above often remains unsolved.

Therefore, an object of the present invention is to solve the above-mentioned problem in an automobile engine in which the cylinder deactivation system can be set. In particular, for a vehicle equipped with a structure capable of suppressing vehicle body vibration during low speed rotation in a cylinder deactivation state. To get the engine.

[0008]

In order to achieve this object, the present invention comprises a valve opening / closing cam having a low speed cam profile and a high speed cam profile, and switches the driven state of these cams on the rocker arm side. As a result, in an automobile engine equipped with a valve mechanism that can set the valve opening / closing amount and the valve resting state, the rotation sensor that detects the engine speed and the volumetric efficiency of air in the cylinder that corresponds to the throttle opening are set. A boost pressure sensor for indexing, an idle switch arranged on the upstream side of the intake port in the intake path of the engine, the rotation sensor, the boost pressure sensor and the idle switch are connected to the input side, and the output side is connected to the output side. A control unit to which the drive unit of the valve mechanism is connected, and the control unit controls the engine speed and It is equipped with a map that sets all cylinder states that open and close valves for all cylinders by load information based on volumetric efficiency of air, and deactivated cylinder states by stopping the opening and closing of valves in some of the cylinders. In addition to performing the determination for the cylinder state and the cylinder deactivation state, when the cylinder deactivation state is set, the on / off state of the idle switch is determined and the predetermined engine speed corresponding to this state is set. It is characterized in that the engine rotation speed at the present stage is compared and determined with the predetermined rotation speed, and the range used for setting the cylinder deactivation state in the map is switched according to the result. There is.

Further, according to the present invention, when the control section determines the on / off state of the idle switch and the idle switch is turned on, the cylinder is stopped only when the current rotational speed is equal to or higher than a predetermined rotational speed. It is characterized by maintaining the state.

Further, the present invention is characterized in that the predetermined number of revolutions set by the control unit is a limit number of revolutions that does not adversely affect the occurrence of vehicle body vibration.

[0011]

According to the present invention, when the cylinder deactivation state is set, the on / off state of the idle switch is discriminated and the predetermined rotation speed in that state is set, and the engine rotation speed at the present stage is set to the predetermined rotation speed. If the number of revolutions is equal to or higher than the number of revolutions, it is determined that the vehicle body vibration is not induced even in the cylinder deactivated state, and the cylinder deactivated state is maintained to improve fuel efficiency.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a system configuration diagram of an automobile engine according to an embodiment of the present invention. In FIG. 1, an intake / exhaust port of an engine 1 is provided with a valve mechanism 2 described in the above-mentioned specification. The hydraulic drive unit of the valve mechanism 2 has its operating position set by a control unit, which will be described later, to open / close valves in all cylinders and to open / close valves in only some of the cylinders. The operation for stopping the opening and closing of the valve in the cylinder is performed. On the other hand, the control unit (indicated by ECU in the drawing) 3 is mainly composed of a microcomputer for comprehensively performing various controls related to engine combustion such as setting of fuel injection amount. In this embodiment, a rotation speed sensor 4 for detecting the engine speed and a boost pressure sensor for detecting the boost pressure located upstream of the intake port are provided on the input side via an interface (not shown). 5 and an idle switch 6 that is turned on when the throttle is fully closed are connected, and the hydraulic drive unit of the valve mechanism 2 is connected to the output side.

The control unit 3 is adapted to set the all cylinder state and the cylinder deactivated state with respect to valve opening and closing according to the map shown in FIG. That is, FIG.
(A) is the volumetric efficiency of air indexed by boost pressure
It is a determination map of the all cylinder state and the cylinder deactivation state based on (Ev) and the engine speed (Ne), and the hatched range in FIG. 2 means the cylinder deactivation state. 2A is a determination map for the all cylinder state and the cylinder deactivated state in the entire operating range of the engine, and FIG. 2B is the map shown in FIG.
FIG. 9 is a determination map for the all cylinder state and the cylinder deactivated state based on (A), which is based on a predetermined rotation speed when the accelerator switch 6 is turned off. FIG.

In this map, the boundary between the all cylinder state and the cylinder deactivated state is set on condition that an output corresponding to the load obtained from the engine speed and the volumetric efficiency of air can be obtained. In FIG. 2 (A), the volume efficiency instantaneously increases in the low rotation range when the cylinder speed is switched from the all-cylinder state to the cylinder deactivated state when the cylinder deactivation is set. This is a measure for suppressing a sudden drop in the number of revolutions. Further, in this map, the setting condition of the cylinder deactivation state is changed depending on the on / off state of the idle switch 6. Specifically, when the cylinder deactivation state is set, whether the idle switch 6 is on or off. For this reason, the number of revolutions at which the occurrence of vehicle body vibration is remarkable is set in advance, and it is determined whether all cylinders or cylinders are deactivated based on the result of comparing and determining the engine speed at the current stage when the cylinders are deactivated. The range used for setting the cylinder deactivation state is switched on the map. 2 (A) is a map for setting the cylinder deactivation state when the idle switch 6 is turned on while being used in the entire operating range of the engine, and FIG. 2 (B) is a map for setting the idle switch. FIG. 2A is a map for setting the cylinder deactivation state when 6 is turned off, and the predetermined value of the engine speed as the selection criterion of the map used for setting the cylinder deactivation state is as shown in FIG. Is set to 600 rpm, and in the case of FIG. 2 (B),
It is set to 1600 rpm. These maps are not provided for specific types, but when the idle switch 6 is turned off in the cylinder deactivation state setting range in the map shown in FIG. Switching is performed so that only the range as shown in FIG. 2B is used on the basis of the number.

Since this embodiment has the above-mentioned configuration,
The operation of the control unit 3 will be described with reference to FIG. In FIG. 3, engine speed
When (Ne) and the volumetric efficiency (Ev) of air due to the boost pressure are input, either the full cylinder state or the non-cylinder state is determined based on the map shown in FIG. 2 to obtain this state. The drive signal is output to the valve mechanism 2. Then, when the dynamic position in the valve mechanism 2 is set in the above-described step, it is determined whether or not the cylinder is in the cylinder deactivated state. When the cylinder is in the cylinder deactivated state, the idle switch 6 is turned on / off. The engine speed according to each state is determined, that is, 60 when the idle switch 6 is on.
At 0 rpm, 1600 rpm is set when the idle switch 6 is off, and the fuel injection control is executed in response to this. On the other hand, when the engine speed at the current stage in the cylinder deactivated state is input, the engine speed is compared and determined with the above-described predetermined speed. The cylinder deactivation state is set based on the maps shown in FIGS. 2 (A) and 2 (B),
When the rotation speed is equal to or lower than the predetermined rotation speed, a drive signal is output to the valve mechanism 2 so as to switch to the all-cylinder state.
According to this embodiment, the map for setting the all cylinders / non-cylinders state according to the on / off state of the idle switch 6 can be diverted based on the rotation speed, so that the memory capacity in the control unit can be expanded. I don't have to.

Further, according to this embodiment, in the map for determining the all-cylinder / deactivated state, the all-cylinder / deactivated state can be switched only by determining the on / off state of the idle switch. Therefore, for example, when it is necessary to switch to the all-cylinder state for the purpose of accelerating when in the cylinder deactivated state, it is possible to immediately switch the cylinder to be used by ignoring the response delay that occurs when boost pressure is detected. This can improve responsiveness with respect to acceleration performance, for example.

[0018]

As described above, according to the present invention, the idle state is set in the all cylinder state in which valve opening and closing is performed in all cylinders and the cylinder inactive state in which valve opening and closing is performed in some of the cylinders. By comparing and discriminating the number of revolutions that changes depending on the on / off state of the switch with a predetermined number of revolutions that is set in advance as the limit number of revolutions in which the vehicle body vibrations occur, only when it is determined that the vehicle body vibrations do not occur Since it is possible to maintain the cylinder state, it is possible to improve the fuel efficiency at the time of cylinder deactivation and to achieve the low fuel consumption at low speed rotation without causing vibration of the vehicle body.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a system configuration of an automobile engine according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a map used for a control unit in the system configuration shown in FIG.

3 is a flowchart for explaining the operation of a control unit in the system configuration shown in FIG.

[Explanation of symbols]

 1 Engine 2 Valve Mechanism 3 Controller 4 Rotation Speed Sensor 5 Boost Pressure Sensor 6 Idle Switch

Claims (3)

[Claims] 1. A valve opening / closing cam having a cam profile for low speed and a cam profile for high speed is provided, and by switching the driven state on the rocker arm side with respect to these cams,
In an automotive engine equipped with a valve mechanism that can set the valve opening / closing amount and the valve resting state, a rotation sensor that detects the engine speed and a volumetric efficiency of air in the cylinder according to the throttle opening are calculated. A boost pressure sensor, an idle switch arranged upstream of an intake port in the intake passage of the engine, the rotation sensor, the boost pressure sensor, and the idle switch are connected to the input side, and the output side has the valve mechanism. And a control unit to which the drive unit is connected. The control unit causes all cylinders to open and close valves according to load information based on volumetric efficiency of air obtained by engine speed and boost pressure. Includes a map for setting the cylinder status and the cylinder deactivation status by stopping the opening and closing of valves in some of the cylinders. , Carries out the determination for the all-cylinder state and the cylinder deactivation state setting, when the cylinder deactivation state is set, the idle switch ON /
The off state is determined, a predetermined engine speed is set according to this state, the engine speed at the present stage is compared and determined with the predetermined speed, and depending on the result, the engine speed in the map is stopped. An automobile engine characterized in that a range used for setting a cylinder state is switched. 2. The automobile engine according to claim 1, wherein the control section determines the on / off state of the idle switch and when the idle switch is on, the rotational speed at this stage is equal to or higher than a predetermined rotational speed. The car engine that is designed to maintain the cylinder deactivated condition only in the case of. 3. The automobile engine according to claim 1 or 2, wherein the predetermined rotation speed set by the control unit is a limit rotation speed that does not adversely affect the occurrence of vehicle body vibration.