JPS63109246A - Control device for engine - Google Patents

Abstract

PURPOSE:To improve fuel consumption and prevent the lowering of an operating property by providing a supercharger control means for operating a displacement type supercharger and a means of setting a throttle valve opening characteristic. CONSTITUTION:A displacement type supercharger 11 is controlled with an electromagnetic clutch 16 being connected/disconnected in accordance with the control signal of a control unit 15. The control unit 15 stores two throttle opening characteristics, a first characteristic for setting the opening of a throttle valve 13 when the supercharger 11 is stopped and a second characteristic for setting the opening of the throttle valve 13 when the supercharger 11 is operated. And, the opening of the throttle valve 13 is set by the different characteristics depending on the on/off condition of the supercharger 11. Thereby, the fuel consumption of an engine can be improved, while preventing a torque shock and the lowering of an operating property.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an engine control device that includes a throttle valve driven by an actuator and a positive displacement supercharger driven by the driving force of the engine. It is.

(Prior Art) Conventionally, the accelerator pedal and the throttle valve are mechanically separated, and the opening degree of the throttle valve is controlled by an actuator consisting of a servo motor or the like (for example, as disclosed in Japanese Patent Application Laid-Open No. III (60-206949)). (see publication)
. In order to improve acceleration/deceleration performance during sudden acceleration and deceleration, this conventional device sets an appropriate target value for the throttle valve opening according to the operating amount and operating speed of the accelerator pedal, and adjusts the throttle valve based on this. It is configured to control opening and closing of the valve.

However, since there is usually a one-to-one correspondence between the operation amount of the accelerator pedal and the opening degree of the throttle valve, the accelerator pedal operation in an engine equipped with a positive displacement supercharger driven by the engine's driving force is It is necessary to operate the supercharger before the amount reaches a maximum, and the supercharger is configured to start operating when the throttle valve is half open when the operation amount of the accelerator pedal reaches a predetermined value. . Therefore, if the throttle valve is fully opened, the supercharger will start operating even in a region where engine output torque can be obtained without operating the positive displacement supercharger. Since the driving force of the engine is consumed for operation, there is a problem in that the effect of improving fuel efficiency in this region is insufficient. Furthermore, when the supercharger starts operating, the output torque of the engine increases rapidly, causing a problem of torque shock and deterioration of drivability.

In order to prevent the occurrence of torque shock and deterioration of drivability, a bypass passage is provided in the intake passage to bypass the positive displacement supercharger, and by adjusting the amount of intake air passing through this bypass passage, the boost pressure can be reduced. It is also possible to control The problem was that it became complicated.

(Object of the Invention) The present invention was made to solve the above problems, and includes a throttle valve driven by an actuator and a positive displacement supercharger driven by the driving force of an engine. In engines, it is possible to effectively prevent torque shock and deterioration of drivability when the above-mentioned supercharger operates with a simple configuration, and the supercharging effect of the positive displacement supercharger without reducing fuel efficiency. An object of the present invention is to provide an engine control device that can appropriately obtain the following.

(Structure of the Invention) As shown in the configuration diagram of FIG. 1, the present invention includes a throttle valve that is controlled to open and close by an actuator according to the amount of accelerator operation, and a throttle valve that is driven by the driving force of the engine according to the operating state of the engine. A control device for an engine equipped with a positive displacement supercharger, comprising: a supercharger control means for operating the positive displacement supercharger when the accelerator reaches a predetermined operation amount; an operating state determining means for determining whether or not the positive displacement turbocharger is in the stopped state; A throttle that selects a first characteristic that causes the throttle valve opening to be fully open, and selects a second characteristic that causes the throttle valve opening to be fully open in the entire operating range of the accelerator when the positive displacement supercharger is in an operating state. The valve opening characteristic setting means is provided.

According to the above configuration, the opening characteristic of the throttle valve changes depending on the on/off state of the positive displacement supercharger, and when the supercharger is in a stopped state, the throttle valve opens in a predetermined operating range of the accelerator. The opening degree of the throttle valve is controlled according to a first characteristic in which the throttle valve is fully open, and a second characteristic in which the throttle valve is fully open in the entire operating range of the accelerator when the supercharger is in operation.
The opening degree of the throttle valve will be controlled according to the characteristics.

(Embodiment) FIG. 2 shows an embodiment of the control device for the engine 1 according to the present invention. The engine 1 includes a cylinder 2, a piston 3, and an intake valve 5 for supplying air-fuel mixture to a combustion chamber 4.
, an intake passage 6 serving as a passage for the air-fuel mixture, and an exhaust valve 8 for discharging combustion gas to an exhaust passage 7.

The intake passage 6 includes an injector 9 that injects fuel, a positive displacement supercharger 11 driven by the output shaft 1o of the engine 1, and a bypass passage 12 that bypasses the supercharger 11.
A throttle valve 13 for controlling the amount of intake air, and an air flow meter 14 for detecting the amount of intake air are provided. The positive displacement supercharging 11111 operates on the electromagnetic clutch 1 according to a control signal output from the control unit 15.
6 is turned on and off, so that the on/off control is performed based on the load condition of the engine 1. Further, a bypass valve 17 is provided in the bypass passage 12 that bypasses the supercharger 11, and this bypass valve 17 is operated by an actuator 18 consisting of a servo motor or the like.
The bypass passage 12 is controlled to open and close as necessary.

The throttle valve 13 is driven by an actuator 19 such as a servo motor controlled by the control unit 15, and adjusts the amount of intake air by increasing its opening as the engine load increases.

The control unit 15 also includes a crank angle sensor 20 and an air 70-meter 14 that detect the rotational state of the output shaft 10, a throttle valve opening sensor 21 that detects the opening of the throttle valve 13, and an accelerator operation amount 22.
A predetermined calculation is performed in response to a detection signal from the accelerator position sensor 23 that detects the amount of depression (accelerator operation amount) of the injector 9, the electromagnetic clutch 16, the actuator 18 for the bypass valve 17, and the throttle valve 1.
Control signals are output to the actuators 19 for the three actuators, respectively. The control unit 15 also has a first characteristic that sets the opening degree of the throttle valve 13 when the supercharger 11 is stopped, and a second characteristic that sets the opening degree of the throttle valve 13 when the supercharger 11 is activated. The throttle valve 13 is configured to store two throttle opening characteristics, and to set the opening degree of the throttle valve 13 with different characteristics depending on whether the supercharging ta11 is on or off.

That is, as shown in FIG. 3, the positive displacement supercharging vs1
When stopped in step 1, the accelerator operation amount θ is in the predetermined operation range (pedal depression amount θ is 0%) and the throttle valve opening T is 100%.
The throttle valve opening T changes according to the first characteristic T=fa(θ), and when the supercharger 11 is activated, the throttle valve opening T changes when the accelerator operation amount θ is in the entire operation range (pedal depression amount is 100%). The second characteristic T = fb (where the opening degree T is 100%)
The throttle valve opening degree T is configured to change depending on the angle θ). Therefore, in this embodiment, the supercharger control means, the operating state determining means, and the accelerator opening characteristic setting means shown in FIG.
It is located inside.

Next, the control operation by the control unit 15 will be explained based on the flowchart shown in FIG. This flowchart starts when the ignition switch is turned on, and first, in step S1, the positive displacement supercharger 1 is turned on.
Initial setting is performed by setting parameter 1 indicating the on/off state of 1 to O (stopped state). Next, after inputting the detected values of each of the above-mentioned sensors and reading the values of the engine 1 rotational speed N, accelerator operation amount θ, and throttle valve opening T, in step S3, the display screen is used to display the previous supercharger on/off state. Replace parameter j with the current parameter i.

Next, in step S4, it is determined whether or not the engine rotation speed N is equal to or higher than the reference rotation speed No. The result of this determination is No, and it is confirmed that the engine rotation speed N is equal to or lower than the reference rotation speed NO. In this case, it is determined in step S5 whether the accelerator operation amount θ is equal to or greater than a predetermined operation amount θ0 set in advance according to the engine speed N. If the determination result is No and it is confirmed that the accelerator operation amount θ is less than or equal to the predetermined operation amount 00, the accelerator operation speed θ (dθ/dt) is set to the predetermined operation speed 60 in step S6. It is determined whether or not the value is greater than or equal to the value.

If the determination result in step S4 is YES and it is confirmed that the engine rotation speed N is equal to or higher than the reference rotation speed, or if the determination result in step S5 is YES and the accelerator operation amount θ is equal to or less than the predetermined operation amount 60. If it is confirmed that the above is the case, or the determination result in step S6 is YES, the accelerator operation speed θ is set to the predetermined operation speed 0.
If it is confirmed that the value is 0 or more, step S7
The parameter 1 is set to 1 to indicate that the supercharger 11 is in the operating state.

Next, in step S8, it is determined whether the current parameter i and the previous parameter j are equal, that is, whether they are both 1 indicating the operating range. If the determination result is NO and it is confirmed that the supercharger 11 is ready to start operating, control is executed to turn on the electromagnetic clutch 16 and close the bypass valve 12 in step $9. After outputting the signal, in step S10, the positive displacement supercharger 1
1 starts counting the elapsed time t after activation.

Then, in step S11, a target opening value T' of the throttle valve 13 is calculated in accordance with the transient characteristic T=ft(θ, 1) at the start of operation of the positive displacement supercharging 1111. The transient characteristic T=ft(θ, 1) is determined by the accelerator operation amount θ and the above-described This is a preset function based on the elapsed time t.

Further, if the determination result in step S8 is YES and it is confirmed that the positive displacement supercharger 11 is continuing to operate, the electromagnetic clutch 16 is maintained in the on state in step S12, and the bypass A control signal for maintaining the valve 12 in a closed state is output. Then step S
In Step 13, it is determined whether the elapsed time t exceeds a preset reference transient time to, and if the determination result is NO and it is confirmed that the transient state has not ended yet, the step Moving on to S11, the transient characteristics T
Control is performed according to '=ft(θ, 1). Further, if the above judgment result is YES and it is confirmed that the transition period has ended, in step S14, the above second characteristic T=fb(θ) when the positive displacement supercharger 11 is in the operating state A target opening value T' of the throttle valve 13 is calculated according to the following.

Further, the determination results in step $4, step S5, and step S6 are respectively No, and the supercharger 11
If it is confirmed that the area should be in a stopped state, the current parameter i is set to O in step S15, and
This indicates that the supercharger 11 is in a stopped state. After turning off the electromagnetic clutch 16 and outputting a control signal to open the bypass valve 12 in step S16, in step S17 the elapsed time t
stop counting. Then, in step 818, the above-mentioned first characteristic T=f when the positive displacement supercharger 11 is in a stopped state
A target opening value T' of the throttle valve 13 is calculated according to a(θ).

Next, in step S19, a throttle valve control signal corresponding to the opening degree target value T' calculated in steps S11, S14, and S18 is outputted, and then the process returns to step S2 to repeat the above flow.

In this way, it is determined whether the load is in a load range in which the positive displacement supercharger 11 should be operated based on the accelerator operation amount θ, etc., and different characteristics are determined depending on whether the supercharger 11 is on or off. Since the throttle valve opening degree T is set, the above supercharging? 111, without causing torque shock or deterioration in drivability, etc., and the above supercharging ll1.
11 can be obtained, and the fuel efficiency of the engine 1 can be effectively improved.

That is, as shown in the time chart shown in FIG. 5, when the accelerator operation amount θ is less than the predetermined operation amount θ0, the positive displacement
1 is in a stopped state, the throttle valve opening degree T changes according to the first characteristic (T=fa(θ)),
When the accelerator operation amount θ reaches the manual operation range corresponding to the predetermined operation amount θ0, the throttle valve opening T is controlled to be maximum (opening 100%). As a result, in a region where the output torque of the engine 1 can be obtained without operating the supercharger 8111, the supercharger 11
can be in a stopped state. Therefore, even within the above range, the engine output adjustment effect by the throttle valve 13 can be sufficiently exerted compared to the conventional device that operates the positive displacement supercharger, and the effect of operating the supercharger is Since a decrease in output torque can be suppressed, the fuel efficiency of the engine 1 can be improved.

Further, after the accelerator operation amount θ exceeds the predetermined operation amount θ0, the electromagnetic crank 16 is turned on and the positive displacement supercharger 11 is activated, and after the reference transient time to has elapsed, the throttle valve The opening degree T is the second characteristic (T=
, fb(θ)), and the accelerator operation amount θ is controlled so that the throttle valve opening degree T becomes maximum in the entire operation range (operation amount 100%). As a result, the supercharger 11
The output torque of the engine 1 increases in accordance with the supercharging effect, and the amount of increase in the output torque of the engine 1 is suppressed in accordance with a decrease in the throttle valve opening T. Therefore, unlike conventional devices, when the positive displacement supercharger starts operating, the engine output does not suddenly increase, and torque shock and deterioration of drivability are prevented, and the output torque of the engine 1 by the supercharger 11 is reduced. The increasing effect can be appropriately obtained.

Further, in the above embodiment, the transient characteristic T=ft(θ,
By setting the opening degree T of the throttle valve 13 according to Due to the response delay that occurs when starting -
This has the advantage that it is possible to prevent the output torque of the engine 1 from dropping at this point. Further, in the above embodiment, since the positive displacement supercharger 11 is configured to always operate when the engine speed N is equal to or higher than the predetermined speed No, the electromagnetic crank 16 is activated in the high speed region of the engine 1. It is possible to prevent wear caused by repeated turning on and off, and since the supercharger 11 is configured to operate even when the accelerator operation amount θ is a predetermined operation speed of 0 or more, the output torque is reduced. There is an advantage that the effect of increasing the output torque of the supercharger 11 can be obtained during sudden acceleration where it is desirable to increase the output torque.

(Effects of the Invention) As explained above, the present invention operates the positive displacement supercharger driven by the driving force of the engine when the accelerator operation amount reaches a predetermined operation amount, and also enables the turbocharger to operate. If it is in the stopped state, the throttle valve opening is set in accordance with a first characteristic in which the throttle valve opening is fully open in the predetermined operation range of the accelerator, and the Since the throttle valve opening is configured to be set in accordance with the second characteristic so that the throttle valve opening is fully open in the entire accelerator operation range when the turbocharger is in an operating state, the turbocharger cannot be operated. In a region where the engine output torque can be obtained without any problem, the output torque can be controlled simply by adjusting the opening degree of the throttle valve, and the fuel efficiency of the engine in this region can be improved.

Furthermore, when the accelerator operation amount falls within a predetermined operation range and the supercharger starts operating, the opening degree of the throttle valve decreases, so the engine output torque increases rapidly unlike in conventional devices. This can be prevented, and the output torque increasing effect of the positive displacement supercharger can be appropriately obtained without causing torque smudges or deterioration of drivability.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is an overall schematic diagram of an apparatus showing an embodiment of the present invention, Fig. 3 is a characteristic diagram of the throttle valve opening, and Fig. 4 is a diagram showing the configuration of the present invention. A flowchart showing the control operation of such a device, and FIG. 5 is a timing chart of the control operation. 1... Engine, 11... Positive displacement supercharger, 13...
・Throttle valve, 15...Control unit, 1
9...Actuator, 22...Accelerator.

Claims (1)

[Claims] 1. In an engine control device comprising a throttle valve that is opened and closed by an actuator according to the amount of accelerator operation, and a positive displacement supercharger that is driven by the driving force of the engine according to the operating state of the engine, the accelerator is a supercharger control means that operates the displacement supercharger when a predetermined operation amount is reached; an operating state determination means that determines whether the displacement supercharger is in an operating state; When the positive displacement supercharger is in a stopped state in response to the output signal from the determining means, a first characteristic is selected in which the throttle valve opening is fully open in the predetermined operation range of the accelerator, and the positive displacement supercharger 1. A control device for an engine, comprising: a throttle valve opening characteristic setting means for selecting a second characteristic that causes the throttle valve opening to be fully open in the entire accelerator operating range when the engine is in an operating state.