JPS6050240A - Cylinder number control engine - Google Patents

Abstract

PURPOSE:To reduce vibration of a car body and thereby improve comfortableness thereof by forcedly changing over a cylinder number control engine to a full cylinder operation when the engine and car wheels are coupled and the number of revolutions is less than a prescribed value. CONSTITUTION:A number-of-revolutions signal from an ignition coil 34 and signals from a gear switch 39, and a clutch switch 40, etc., are inputted to a control device 31 of a cylinder number control engine. The control device 31 judges the number of operating cylinders in response to engine load, etc. When the gear switch 39 and the clutch switch 40 are both turned on, the engine and car wheels are judged to be in a coupled state. When the number of engine revolutions is then less than a prescribed value and in a region large in torque variations, the engine is forcedly changed over to a full cylinder operation.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is capable of switching between an all-cylinder operation in which output is output from all cylinders and a reduced-cylinder operation in which output is output only from some cylinders, depending on the operating state of the engine. This invention relates to a cylinder number controlled engine.

(Prior art) In recent years, there has been a desire to significantly improve the fuel efficiency of automobile engines. Engines that control the number of cylinders have appeared in which it is possible to appropriately switch between an all-cylinder operation in which fuel is supplied and a reduced-cylinder operation in which the supply of fuel to some cylinders is cut off. This cylinder number control engine supplies fuel to all cylinders and outputs output from all cylinders during high loads such as when starting or driving at high speeds, and when under low loads such as when driving at a constant speed or on a steady road Sometimes, fuel efficiency is achieved by cutting the fuel supply to some cylinders and increasing charging efficiency to other cylinders. ); and a cylinder number control means that is operated in response to an output from the cylinder reduction determining means and cuts fuel supply to some cylinders. We are prepared.

The operating state of the engine can be identified by determining whether the cooling water temperature is at a set value T or below, whether the engine speed is at a predetermined value N or below, and whether the engine is in an acceleration state. , is performed based on parameters related to fuel consumption, such as whether the intake negative pressure is above a set value, and the engine speed is a predetermined value N. Reduced-cylinder operation is performed under one of the conditions: the following low speeds:

By the way, during reduced-cylinder operation, the number of cylinders decreases, so the rotation of the crankshaft is no longer smooth and torque fluctuations become large. If the engine and wheels are connected to each other, this torque fluctuation is transmitted to the wheels, causing the vehicle body to vibrate, resulting in poor ride comfort.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an engine with controlled number of cylinders that prevents vehicle body vibration and provides a good ride comfort.

(Structure of the Invention) The present invention provides a t parameter that is attributable to vehicle body vibration, and when focusing on parameters related to fuel consumption (fuel efficiency), even if the cylinder reduction operation region is in effect, the vehicle body vibration It is possible to forcibly switch from reduced-cylinder operation to full-cylinder operation depending on the returned parameters.

Specifically, as shown in FIG. 1, a cylinder reduction determination means 1 determines whether or not the engine is in a cylinder reduction operation region in which fuel supply to some cylinders is cut, depending on the operating state of the engine;
The cylinder number control means 2 is operated in response to the output from the cylinder reduction determining means 1 and cuts the fuel supply to some cylinders, so that each cylinder 3 of the engine to be reduced in cylinders is stopped. Connected state detection means 4 for detecting whether or not the engine and the wheels are connected so that engine rotation is transmitted to the wheels in order to obtain parameters contributing to vehicle body vibration in the cylinder number controlled engine. In response to the outputs of both the connection state detection means 4 and the engine rotation speed detection means 5, when the engine and the wheels are in the connection state and the engine rotation speed is below a predetermined value, cylinder reduction is performed. This configuration additionally includes forced switching determining means 6 for forcibly switching from reduced-cylinder operation to full-cylinder operation regardless of the output of the determining means.

(Example) In FIG. 2, 7 is the main body of the engine, and intake air is supplied to the combustion chamber 12 through a throttle chamber 9 provided in the middle of an intake passage 8 and an intake manifold 11 (intake bow) 11. It has become something that The intake passage 8 is provided with a fuel injection valve 13 on the upstream side of the throttle chamber 9, and the intake air flowing through the intake passage 8 is mixed with fuel from the fuel injection valve 13, and the intake air amount is controlled by the throttle. It is controlled by a valve 14. Furthermore, the exhaust gas from the combustion chamber 12 is transferred to the exhaust port 1
5, the air is discharged into the atmosphere through an exhaust manifold 16 and the like.

Intake valve 17 and exhaust port 15 that open and close intake valve 11
The exhaust valve 18 that opens and closes is opened and closed at predetermined timing by a valve operating mechanism. This valve operating mechanism includes a turn spring 19.20 that biases the intake/exhaust valves 17.18 in the closing direction, and a camshaft 21 that is rotationally driven by a crankshaft (not shown).
, a cam 22 provided on the cam shirt 21, a rocker arm 23.24, and a tappet 25.26 that constitutes a swinging fulcrum of the rocker arm 23.24. Here, the engine body 7 is for 4 cylinders,
The ignition order is 1-3-4-2, and the 1st and 4th cylinders are deactivated cylinders to be reduced.
The fuel supply to the No. 1 and No. 4 cylinders is cut off during cylinder reduction operation, and the tappets 25 and 26 for the No. 1 and No. 4 cylinders are equipped with valve drive control devices 27 and 28. has been done. The valve drive control devices 27, 28 are switched and driven by solenoids 29, 30, respectively, and when the solenoids 29, 30 are demagnetized, the swinging fulcrum of the tappet 25, 26 relative to the rocker arm 23, 24 is The rocker arms 23 and 24 are displaced in the middle and downward direction, and the rocker arms 23 and 24 are swung according to the rotation of the camshaft 21, and the intake and exhaust valves 17 are
．． 18 is opened and closed, all cylinders are operated, and solenoid 29.3
0 is excited, the swinging fulcrum can be displaced in the - direction in the figure, and the camshaft 21 and the pumping and exhaust valves 17 and 18
The interlocking relationship between cylinders 1 and 4 is cut off, and cylinder reduction operation is performed with the intake and exhaust valves 17 and 18 of cylinders 1 and 4 remaining closed.

Note that the valve drive control devices 27 and 28 themselves are already well known, as shown in, for example, Japanese Patent Laid-Open No. 52-56212, so a detailed explanation thereof will be omitted.

In Fig. 2, 31 is a control unit consisting of a microcomputer;
In order to selectively control either all-cylinder operation or reduced-cylinder operation according to the rotational state of the engine, the system is equipped with a reduced-cylinder discrimination means 1 and a forced switching discrimination means 6, and also includes a reduced-cylinder discrimination means 1 and a forced switching discrimination means 6. It has a function to control the detection (processing) of the intake negative pressure differently during cylinder reduction operation and cylinder reduction operation, and a function to control the fuel II injection amount 1 ignition timing, etc., but in the following explanation, The explanation of parts not directly related to the present invention will be omitted.

This control unit 31 includes parameters related to fuel consumption such as the opening degree of the throttle valve 14 and the engine cooling temperature I detected by the cooling water temperature sensor 32.
W, the intake negative pressure detected by the intake negative pressure sensor 33 that detects the intake negative pressure, and the engine rotation speed detected by the ignition coil 34 are respectively input, and this control unit 31 controls both solenoids 29 and 30. output to the solenoid 29.30 depending on the engine operating condition.
The solenoid 29.30, together with the valve drive control device 27.28, receives the output from the cylinder reduction determination means 1 and determines which cylinder should be operated by cutting the fuel supply to the cylinder to be reduced. This constitutes a cylinder number control means 2 that controls the number of cylinders.

In FIG. 2, 35 is a throttle valve opening detection sensor, 36 is a destroyer, 37 is a spark plug, and 38 is a battery.

Here, a gear switch 39 and a clutch switch 40 are used as the connection state detection means 4. As shown in FIG. 3, the gear switch 39 is provided on the transmission 41, and the clutch switch 40 is provided on the clutch 43 between the engine 42 and the transmission 41. In FIG. is a drive shaft, and the outputs of the gear switch 39 and the clutch switch 40 are respectively input to the forced switching determination means 6 of the control unit 31.
m/h or less, and the engine speed is 11
00 Orp or less, and when both the gear switch 39 and the clutch switch 40 are on and the engine 42 and the wheels 44 are connected, the forced switching determination means 6
All-cylinder operation is performed according to the output command from.

Next, details of the portion of the control according to the present invention of the control unit 31 will be explained with reference to the flowchart shown in FIG.

The control unit) 31 is turned on and initialized (step 46), and the cylinder flag is set to rl.
It has become known as J. Here, the number of cylinders flag rlJ means an all-cylinder operation command, and the number of cylinders flag rQJ means a reduced-cylinder operation command. Data as parameters related to fuel efficiency such as speed are input (step 47), and data as parameters contributing to vehicle body vibration such as whether the gear switch and clutch switch are on or not (step 38) is to be input. Based on each of these data, the control unit 31 performs a process of determining whether or not the cylinder reduction operation conditions are satisfied.

Here, first, it is determined whether the vehicle speed is equal to or higher than a predetermined value (step 49), and the vehicle speed value is 1.
The first condition for reduced cylinder operation is that the speed is 5 km/h or more. When the first condition for cylinder reduction operation is satisfied, step 5 determines whether the cooling water temperature is equal to or higher than a predetermined value T0.
0) is to be done. Here, the second condition for reduced-cylinder operation is that the cooling water temperature is as high as 30''C or higher. When the second condition for cylinder reduction operation is satisfied, the engine speed is a predetermined value N. A determination is made as to whether or not this is the case (step 51). Here, the third condition for reduced-cylinder operation is that the engine speed is low, 200 Or p m or less. When the third condition for cylinder reduction operation is satisfied, it is determined whether or not the engine is in an acceleration state (step 1, step 52). The determination of whether or not this is in an acceleration state is made based on the amount of change in throttle opening per unit time, and the fourth condition for reduced-cylinder operation is to be in a steady/decelerated state, not an acceleration state. It becomes. When the fourth condition for cylinder reduction operation is satisfied, it is determined whether the cylinder number flag is rOJ or rLJ (step 53). The fact that this cylinder number flag is "0" is the fifth condition for cylinder reduction operation. When the fifth condition for cylinder reduction operation is satisfied, it is determined whether the intake negative pressure in the second cylinder is greater than or equal to a predetermined value P2 (step 54). Here, the determination of the intake negative pressure of the second cylinder is made in order to update the numerical value of the cylinder number flag from "0" to rlJ, and the intake negative pressure of the second cylinder is below a predetermined value. This is considered to be the sixth condition for reduced cylinder operation.

The fact that the intake negative pressure of the second M cylinder is below the predetermined tt corresponds to low engine load, and when the sixth condition for reduced cylinder operation is satisfied, the number of cylinders is 2. 55) is performed, a cylinder reduction operation output command (step 56) is processed, a fuel injection process (step 57) is performed based on the cylinder reduction operation output command, and a series of these processes (steps 47) to ( Step 58) is repeated.

Note that the fuel injection process itself is basically the same as in the case of a conventional electronically controlled fuel injection device, so a detailed explanation thereof will be omitted.

The fact that the intake negative pressure of the second cylinder is equal to or higher than a predetermined value corresponds to a high engine load, and the control unit 31
When the intake negative pressure of the second cylinder is above a predetermined value,
The process of updating the cylinder number flag from "0" to rlJ (step 59) is performed, and the all-cylinder operation output command (step 6
0), and the fuel injection process (step 57) is performed based on this all-cylinder operation output command.

When the number of cylinders flag is determined to be 1 in the determination of the number of cylinders flag (step 53).

3. It is determined whether the intake negative pressure of the fourth cylinder is equal to or higher than a predetermined value 24 (step 61).

Here, the determination of the intake negative pressure of the No. 4 cylinder is made in order to update the numerical value of the cylinder number flag from rlJ to "0", and the intake negative pressure of the No. 4 cylinder is determined to be a predetermined value. If the number of cylinders is below, the process moves to step 55 and the numerical value of the cylinder number flag is updated from "1" to "0", and if the intake negative pressure of this No. 4 cylinder is equal to or higher than the predetermined value, step 59
In Japan, the number of cylinders flag "1" is newly processed.For example, even if the engine speed is the same, the intake negative pressure is different during reduced-cylinder operation and during full-cylinder operation. are different, and therefore, the intake negative pressure P2, which is the condition for switching to full-cylinder operation during reduced-cylinder operation, is the one used during reduced-cylinder operation, and the The intake negative pressure P4 used as the switching condition is the one used during all-cylinder operation (ie, P2>P).

When the cooling water temperature is lower than the set value TO, when the engine speed is higher than the set value N, or when accelerating, the intake negative pressure is greater than the set value P2 (during reduced-cylinder operation) or P4 (during reduced-cylinder operation). If any one of the conditions is met, the process moves to step 59, where the cylinder number flag is set to "1", and then, in step 60, an all-cylinder operation command is output. That is, by demagnetizing the solenoids 29 and 30, the intake and exhaust valves 17 of all cylinders are
, 18 are all-cylinder operation in which opening and closing are interlocked,
Steps 46 to 61 constitute a basic routine.

Returning to the determination in step 49, if the vehicle speed is 15 KM/h or less, a determination process is performed to determine whether or not to force a switch from reduced-cylinder operation to full-cylinder operation. This discrimination process is carried out by the forced switching discrimination means 6, and here two stages of discrimination are performed. First, it is determined whether the engine speed is a predetermined value (here, 101000 rpm or more (step 62)). This is because vehicle body vibration is likely to occur when the engine speed is 1100 Orp or less.
rp or higher, the process moves to step 50 and returns to the basic routine, and the engine speed is 1. When the engine speed is below OOOrpm, it is determined whether the engine 42 is connected to the wheels 44 based on whether both the gear switch 39 and the clutch switch 40 are turned on (step 63). It has become. Gear switch 39, clutch switch 4
0 is off, it is determined that there is no running condition ff, and the process moves to step 50 to return to the basic routine. When both gear switch 39 and clutch switch 40 are on, step 59 The transition process is performed, the number of cylinders flag is set to "1",
In the basic routine, a forced switch from reduced-cylinder operation to full-cylinder operation is performed even when the reduced-cylinder operation command is satisfied.

Although one embodiment has been described above, the present invention is not limited to this, and includes, for example, the following case.

■It can be applied not only to 4-cylinder engines but also to other multi-cylinder engines such as 6-cylinder engines.

(i) The control unit 31 may be an analog or digital computer.

In the above embodiment, the forced switching determining means is provided separately from the reduced cylinder determining means, but the forced switching determining means may be incorporated into the reduced cylinder determining means.

(Effects of the Invention) As explained above, the present invention makes it possible to switch to all-cylinder operation under conditions where vehicle body vibration becomes large during reduced-cylinder operation, thereby further improving ride comfort. This has the effect that it can be done.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram of all seven components of the cylinder number control engine according to the present invention. FIG. 2 is a system diagram showing one embodiment of the present invention. FIG. 3 is a schematic diagram showing a state in which the engine and wheels are connected according to the present invention. FIG. 4 shows rl of the cylinder number fli control engine according to the present invention.
j Flowchart showing control details. 1... cylinder reduction determination means 2... cylinder number control means 3... engine cylinders 4... connection 797 detection means 5 conflict φ engine speed detection means 6 fist force switching discrimination means 31 Control unit 32 Cooling water temperature sensor 33Φ Intake negative pressure sensor 34 Ignition coil 35 Slot valve opening detection sensor 39 @ fist gear switch 40 Clutch switch 41 Φ Mission 8 42nd engine 4311・Clutch 44・・Wheel patent applicant Toyo T-gyo Co., Ltd. Agent Patent attorney Mura 1) Act 9 Figure 1 Figure 3 t+→

Claims (1)

[Scope of Claims] (F) A cylinder reduction determination means for determining whether or not a cylinder reduction operation region is in which fuel supply to some cylinders is cut in accordance with the operating state of the engine; and the cylinder reduction determination means. a cylinder number control means that is operated in response to an output from the means and cuts fuel supply to some of the cylinders; and a state in which the engine and the wheels are connected so that rotation of the engine is transmitted to the wheels. a connection state detection means for detecting whether or not the engine is present; an engine rotation speed detection means for detecting the rotation speed of the engine; and the wheel is i
! (11) forced switching discrimination means for forcibly switching from reduced-cylinder operation to full-cylinder operation regardless of the output of the reduced-cylinder discrimination means when the engine is in a closed state and the rotational speed of the engine is below a predetermined value; An engine with controlled number of cylinders.