JPS6062626A - Torque shock attenuating device for engine having the number of cylinders controlled - Google Patents

Abstract

PURPOSE:To reduce torque shock in changing over the number of cylinders by providing a number-of-cylinders change-over detecting circuit in an engine having the number of cylinders controlled to increase and decrease controllably a load on an engine driving generator in synchronization with the output of a detecting circuit. CONSTITUTION:A number-of-cylinders control circuit 14a including a number-of- cylinders change-over detecting circuit is provided in a control circuit 14 for a number-of-cylinders controlling engine to control the number of operative cylinders according to the signals of an intake negative pressure sensor 10, rotational frequency sensor 11, etc. while detecting the condition of changing over the number of cylinders, so that a load on a generator is controllably increased and decreased in synchronization with the change-over by a generator load controlling circuit 14b. For example, when the number of operative cylinders is decreased, the load on the generator is increased prior to the change-over, once decreased in synchronization with the change-over and then gradually increased. Thus, torque shock in the change-over can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a torque shock mitigation device for a cylinder number controlled engine.

[Prior art]

In internal combustion engines, it is generally known that during low-load operation with a small throttle opening, the piston loss increases, leading to a decrease in fuel efficiency. As shown in , in a specific operating range such as during low-load operation, fuel supply to some cylinders is stopped and the load on the remaining operating cylinders is relatively increased, thereby lowering the intake negative pressure, i.e. A so-called engine with controlled number of cylinders has been proposed, which aims to improve fuel efficiency by bringing the pressure closer to atmospheric pressure and reducing pumping loss.

As a method of stopping fuel supply in this cylinder number control engine, as shown in Japanese Patent Application Laid-Open No. 55-78135, there are two methods: - a method of closing a shutter valve provided in the intake passage of the evil cylinder (shutter valve method); Alternatively, as shown in Japanese Patent Application Laid-Open No. 54-57009, - a method of keeping the intake and exhaust valves of the evil cylinder in a fully closed state (valve selection method); There is a method (fuel cut method) of stopping the fuel injection valve for the negative cylinder.

However, in conventional cylinder number controlled engines, there has been a problem in that when the number of operating cylinders is changed, the engine torque changes suddenly, causing an unpleasant torque shock. Conventionally, as a solution to this problem, as shown in Japanese Unexamined Patent Publication No. 53-27727,
Some systems automatically correct the opening of the throttle valve when changing the number of cylinders to prevent sudden changes in engine torque.

[Purpose of the invention]

In such a situation, the present invention aims to provide a torque shock mitigation device for a cylinder number controlled engine, which alleviates unpleasant torque shock when switching the number of cylinders by a method different from the method described in the above-mentioned conventional publication. It is something.

[Structure of the invention]

Therefore, the present invention detects the change in the number of cylinders in a cylinder number controlled engine and synchronizes the change with the change in the number of cylinders.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a torque shock mitigation device for a cylinder number controlled engine according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an engine having four cylinders 23 to 2d, first to fourth, and each cylinder 2a to 2d of the engine 1 has an intake manifold 3. and an exhaust manifold 4 constituting an exhaust passage. A throttle valve 5 is disposed at the gathering section 3a of the intake manifold 3, and a fuel injection valve 6 is disposed at the gathering section 3a of the intake manifold 3 upstream of the throttle valve 5. The end reaches the air cleaner 7. Further, a catalyst 8 is interposed on the downstream side of the collecting part of the exhaust manifold 4.

Furthermore, a pulley 1 is attached to the crankshaft 13 of the engine 1.
5, which is connected by a bell 16 to a pulley 18 of a generator 17, so that the generator 17 is driven by the engine 1.

In addition, in the figure, 9a to 9d are the second. Third cylinder 2b.

The intake and exhaust valves 2c are kept fully closed and the 2nd. An actuator for stopping the fuel supply to the third cylinders 2b and 2c, 10 a negative pressure sensor that detects the intake negative pressure downstream of the throttle valve 5, 11 a rotation sensor signal that detects the engine speed, 12 the engine 14 is a control circuit, which includes a cylinder number control circuit section 14a1, a generator load control circuit section 14b that controls increasing and decreasing the load of the generator 17, and a negative pressure and rotation speed control circuit section 14a. The fuel injection control circuit section 14c controls fuel injection by applying a fuel injection pulse corresponding to the fuel injection valve 6 to the fuel injection valve 6.

Further, FIG. 2 shows a more specific explanation of the actuators 9a to 9d (however, only the intake side actuator 9a of the second cylinder 2b is shown in the figure) and the cylinder number control circuit section 14a of the control circuit 14. Show the configuration. In the cylinder number control circuit section 14a of the control circuit 14, 19 is a comparison circuit that compares the output 10a of the negative pressure sensor 10 and the output of the set value generation circuit 20, and 21 is a comparison circuit that compares the output 11 of the rotation sensor and the set value generation circuit 22. A comparator circuit that compares the output, 23 is both comparator circuit 1
9. An AND circuit that uses the output of 24 by two people, 24 a comparison circuit that compares the output 12 of the water temperature sensor and the output of the set value generation circuit 25, and 26 an AND circuit that uses the output of the comparison circuit 24.
A gate 27 that passes or blocks the output of the D circuit 23 is an amplifier circuit that receives the output of the gate 26 and outputs a drive signal to the actuators 9a to 9d. In addition, the gate 26
The output is sent to the generator load control circuit section 14 as a cylinder switching signal.
b, and is input to the cylinder number control circuit section 14.
A also has the function of a cylinder number switching detection circuit that detects the switching of the number of cylinders.

Furthermore, in the actuator 9a, the cylinder head 29
A hydraulic chamber 30 is formed in the hydraulic chamber 30, and a pivot 3 supporting one end of a rocker arm 32 of a valve train 31 is formed in the hydraulic chamber 30.
3 is inserted in a vertically slidable manner. This hydraulic chamber 30 communicates with a hydraulic pressure supply passage 134, and one end of the hydraulic pressure supply passage 34 is connected to an oil pan 37 via a check valve 35 and a pump 36.
A solenoid valve 38 that opens the passage 34 in response to a drive signal from the cylinder number control circuit section 14a is disposed at the other end of the hydraulic pressure supply passage 34. In the figure, 39 is a camshaft, 40 is a valve spring, and 41 is an intake valve.

The other actuators 9b to 9d are also formed to have the same structure as described above.

Furthermore, FIG. 3 shows a more specific circuit configuration of the generator load control circuit section 14b and the generator 17. In the generator 17, an alternator 47 is driven by the engine and generates alternating current voltage, rectifies it, and outputs it, and this alternator is connected to the rotor coil 42. It consists of a stator coil 43 and a rectifier diode 44.

45 is a regulator for adjusting the voltage generated by the alternator 47 to a constant level, and this regulator is composed of transistors Tr 1 ,
=Tr2. Diode Di, Zener diode Dx
and resistors R1, R2, and R3. Further, in the generator load control circuit section 14b, 46 is turned ON for a predetermined time by a cylinder switching signal from 2 cylinders to 4 cylinders.
and the switch that supplies power, D2 is a diode,
R4 and R5 are resistors, C is a capacitor, and Tr3 is a transistor.

Next, the operation will be explained using FIG. 4. Here the fourth
The figure shows the change in engine torque with respect to the throttle opening. In the figure, the one-dot chain line a and the two-dot chain line indicate the change in engine torque during two-cylinder operation and four-cylinder operation, respectively, and the solid line C shows the engine torque in this device. shows the change in

When the engine is started, the generator 17 is driven by the engine and produces a more or less constant voltage.

Here, the operation of this generator 17 is conventionally known, but to explain it, first, the rG terminal of the alternator 47, that is, the generator 17, the IG terminal of the regulator 45, the resistor R2, the base terminal of the transistor Tr2, between emitters,
A current flows through the ground path, and the transistor Tr2 becomes O.
N, thereby connecting the IG terminal of the alternator 47, the rotor coil 42, and the collector-emitter of the transistor Tr2.

A current flows through the ground path and the rotor of the generator 17 is excited. At this time, a voltage is applied to the S terminal of the regulator 45 via the S terminal of the alternator 47, but since it does not reach the Zener voltage of the Zener diode Dz, no current flows to the base of the transistor Tr1. , the transistor Tr1 is OFF. In this state, when the rotor rotates due to the output of the engine, a voltage is induced in the stator coil 43, and as the engine speed increases, the voltage generated by the alternator 470 increases, the S terminal voltage of the regulator 45 also increases, and is applied to the Zener diode Dz. When the voltage reaches the Zener voltage, a current flows through the base of the transistor Tr1, turning the transistor Tr1 ON, and the base of the transistor Tr2 is grounded, turning the transistor Tr2 OFF.

Then, the power supply to the rotor coil 42 is stopped, the rotor is no longer excited, and the voltage generated by the alternator 470 decreases. Then, when the voltage of the Zener diode Dz becomes lower than the Zener voltage, no current flows through the Zener diode Dz, so the transistor Tr 1 is turned OFF, the l-transistor Tr 2 is turned ON, and the rotor coil 42 is turned off again.
A current flows through the alternator 47, and the voltage generated by the alternator 47 increases. This kind of operation is repeated while the engine is running,
Alternator 47 will generate a substantially constant voltage.

On the other hand, in the cylinder number control circuit section 14a, the comparison circuit 1
At 9.21, it is determined from the negative pressure and engine speed whether or not the engine is in a specific operating range of low rotation and low load, and if the engine is in the specific operating range, both comparison circuits i9. The output of z+ is “
1", and the output of the AND circuit 23 also becomes "1". Conversely, if it is not in the specific operating range, either one of the comparison circuits 1
Since the output of 9 or 21 is “0”, the AND circuit 23
The output of the comparison circuit 24 remains at 0''.The comparison circuit 24 compares the engine coolant temperature with the set value, and when the coolant temperature is higher, the output of the comparison circuit 24 becomes 1'' and the gate 26 is opened. Then, the output "1" from the AND circuit 23 passes through the gate 26, is amplified by the amplifier circuit 27, and is output as a drive signal. At this time, in the actuator 9a, the solenoid valve 38 closes the other end of the hydraulic pressure supply passage 34 before receiving the drive signal, the hydraulic pressure is supplied to the hydraulic chamber 30 via the hydraulic pressure supply passage 34, and the pivot 33 is moved upward. In this state, since the supporting point of the rocker arm 32 is high, the rocker arm 32 swings as the camshaft 39 rotates, and the intake valve 41 opens and closes. Further, the other actuators 9b to 9d perform the same operations as described above, and thereby all the intake and exhaust valves perform opening and closing operations, and the first to fourth all cylinders 2a to 2d
will be put into operation. Next, when the solenoid valve 38 receives a drive signal, the solenoid valve 38 moves into the hydraulic supply passage 34.
The other end is opened, the hydraulic pressure in the hydraulic chamber 30 decreases, and the pivot 3
3 slides downward.

Then, the supporting point of the rocker arm 32 becomes lower and the rocker arm 32 does not swing (so that the intake valve 41 is held in the fully closed state by the biasing force of the valve spring 40. As shown in FIG.
The supply of fuel to the third cylinders 2b, jc is stopped, and the number of cylinders is controlled in this way. The reason why it is recommended not to operate on two cylinders when the engine coolant temperature is low is because when the engine temperature is low, the vaporization of the fuel is poor.
Since the combustion state is unstable, this is to prevent further two-cylinder operation in such a state from increasing the unstable operating state of the engine.

By the way, if you control the number of cylinders like this,
When switching the number of cylinders, the engine torque during 2-cylinder operation (4th
There is a large torque difference T between the engine torque (see the dashed line a in Figure 4) and the engine torque during 4-cylinder operation (see the chain double dot line in Figure 4).
As a result, an unpleasant torque shock occurs as mentioned above, but with this device, it is possible to change from 2-cylinder operation to 4-cylinder operation.
When switching to cylinder operation, the generator load control circuit section 14b
receives the cylinder switching signal from two cylinders to four cylinders, increases the load on the random generator 17, and then gradually reduces the load, so that no unpleasant torque shock occurs. That is, for example, to explain a case where the opening degree of the throttle valve 5 is continuously increased, when the throttle opening degree increases and it is time to switch from 2-cylinder operation to 4-cylinder operation, the generator load control circuit section 14b , the switch 46 is turned on by the fall of the output of the gate 26, which is the cylinder number switching signal, and the switch 46. Diode D2. Resistors R4, R5,) Base of transistor Tr3
A current flows between the emitters and through the ground path, turning on the transistor Tr 3 and charging the capacitor C.

Then, the base of transistor Tr 1 becomes transistor T
, r3, the transistor Tr1 is turned off, and the l-transistor Tr2 is turned on, causing a current to flow through the rotor coil 42, increasing the load on the power generation fi17 and becoming the engine load. Engine output does not suddenly increase when switching to four-cylinder operation.

Then, the opening degree of the throttle valve 5 further increases, and at this time, the charge of the capacitor C is transferred to the resistor R5 and the base of the transistor Tr3.
When the emitter is discharged through the ground path, the base voltage of the transistor Tr3 gradually decreases, and as a result, the base potential of the transistor Tr1 gradually increases, and as a result, the collector of the transistor Tr1 gradually increases.
The emitter current increases, the base potential of the transistor Tr 2 decreases, and the current flowing through the transistor Tr 2 also gradually decreases, resulting in a gradual decrease in the load on the generator 17, which gradually reduces the engine load and The engine output increases smoothly as shown by the solid line C in FIG. 4, and reaches the engine output during four-cylinder operation (see the two-dot chain line in FIG. 4).

As described above, the device of this embodiment can prevent unpleasant torque shock from occurring when switching from two-cylinder operation to four-cylinder operation. Furthermore, since the load is controlled by using a generator that has been conventionally mounted on an automobile, the device does not become complicated and is advantageous in terms of cost and space.

In addition, in the above embodiment, a case was explained in which the torque shock at the time of switching from 2-cylinder operation to 4-cylinder operation is alleviated, but the present invention deals with a case where the torque shock at the time of switching from 4-cylinder operation to 2-cylinder operation is alleviated. is also valid,
In this case, the load on the generator may be increased before the switching, and in synchronization with the switching, the load may be temporarily decreased and then gradually increased. Furthermore, the present invention is not limited to changing the number of cylinders in a large throttle opening range as in the above embodiment, but also reduces torque shock when changing the number of cylinders in a small throttle opening range as shown by the broken line d in FIG. It can also be applied to cases of mitigation.

Further, in the above embodiment, the method of stopping fuel supply is by suction.

Although we have described the case where a valve select method is used to keep the exhaust valve fully closed, this may also be a shutter valve method that closes a shutter valve provided in the intake passage. It may be a cylinder engine.

〔Effect of the invention〕

As described above, according to the present invention, in a cylinder number controlled engine in which fuel supply to some cylinders is stopped in a specific operating region and fuel is supplied only to the remaining operating cylinders, a change in the number of cylinders is detected. However, in synchronization with this switching, the load on the generator driven by the engine is controlled to increase or decrease, thereby smoothing out changes in engine torque. This has the effect of preventing unpleasant torque shock from occurring.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a torque shock mitigation device for a cylinder number control engine according to an embodiment of the present invention, and FIG. 2 is an actuator 9a and a cylinder number control circuit section 1 in the above device.
4a is a specific configuration diagram, FIG. 3 is a specific configuration diagram of the generator 17 and generator load control circuit section 14b in the above device, and FIG. 4 is a diagram for explaining the operation of the above device. l...Engine, 2a-2d...Cylinder, 14a...
・Cylinder number control circuit section (cylinder number switching detection circuit), 14b・
... Generator load control circuit section, 17... Generator. Patent applicant: Toyo Kogyo Co., Ltd. Representative Patent attorney: Ken Hayase −

Claims (1)

[Claims] (11) In a cylinder number control engine in which fuel supply to some cylinders is stopped in a specific operating region and fuel is supplied only to the remaining operating cylinders, a cylinder number switching detection circuit detects a switching of the number of cylinders; and a generator load control circuit that receives the output of the cylinder number switching detection circuit and controls the load of the generator driven by the engine to increase or decrease in synchronization with the switching of the number of cylinders so that the torque shock of the engine is reduced. A torque shock mitigation device for an engine that controls the number of cylinders.