JPH02286825A - Load control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To enhance the rate of fuel consumption by installing a throttle valve upstream an air pump, wherein the throttle valve is interlocked with an accelation pedal for compensating the leakage of the air air pump under extra- low load operation, and by adjusting the revolving speed of the air pump through a variable speed mechanism. CONSTITUTION:An air pump 10 is installed on a suction pipe 8, and the drive shaft 10c of this air pump 10 is coupled with a crank shaft 1a of the engine 1 through a belt 11 and a variable speed mechanism 12 which is to vary the revolving speed of the air pump 10. A throttle valve 8a to compensate the leakage of the air pump 10 under extra-low load operation is installed upstream the air pump 10 in such a way as interlocked with an accel. pedal 15. Through a hydraulic control circuit 50 and said variable speed mechanism 12, the revolving speed of the air pump 10 is controlled by a control unit 30 so as to generate the engine output in compliance with the entered engine revolving speed sensed by sensors 16-18, degree of accel. opening, pressure in suction pipe, etc. When the load is very small, the throttle valve 8a shall be opened as specified in accordance with the degree of accelation opening. Thus the rate of fuel consumption can be enhanced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a load control device for an internal combustion engine equipped with an air pump, which controls the load of the engine by varying the rotational speed of the air pump. be.

[Conventional technology]

Conventionally, in order to increase the output of an engine, a mechanical supercharger (hereinafter referred to as a supercharger) was installed upstream or downstream of a throttle valve in the intake pipe to change the air density in the intake pipe and reduce the throttle valve. A device in which load control is performed by opening and closing a valve is already known.

The above-mentioned supercharged engine, for example, as shown in FIG.
The air pump of supercharger a is driven from the crankshaft C of engine b via belt d, etc., but since it is driven at a constant reduction ratio relative to the rotational speed of crankshaft C, the intake pipe In addition to reducing the opening degree of throttle valve f in e, a rotation sensor g is activated when the rotation speed of supercharger a becomes lower than a predetermined value. The intake air amount is controlled by opening the bypass control valve j.

However, in the conventional example described above, when the load is low, the bypass control valve j is opened and a part of the discharge air of the supercharger a is returned to the suction side of the supercharger a via the bypass passage, so that no air is supplied to the engine b. However, there is a problem in that a pumping loss as shown in the shaded area of the P-v diagram in FIG. 5 cannot be avoided. In particular, when the engine is idling, engine torque is used only for internal engine friction and the pumping action of the supercharger, so there has been a problem that fuel consumption during idling increases.

Therefore, in order to recover the intake energy loss in the engine during non-supercharging operation using an air pump, for example, Japanese Patent Application Laid-Open Nos. 60-90924 and 60-20962 disclose
A prior art as shown in Publication No. 9 has been proposed.

[Problem to be solved by the invention]

However, the former prior art has two pumps connected to the engine crankshaft, and the engine load 11111m is carried out by opening and closing the throttle valve, and during low load operation, only one air pump is connected to the pump suction side. It is configured to be rotationally driven by a pressure difference with the discharge side, transmit the generated power to the engine, and perform supercharging by driving the other air pump by the engine except during low load operation.

Therefore, one air pump is used to reduce engine pumping loss during low loads, a throttle valve is used to control engine load, and the other air pump is used to increase engine output during high engine loads. Functional components that operate in response to operating conditions are required. Therefore, there is a problem that the configuration becomes complicated.

In the latter prior art, a variable displacement air pump is connected to the engine, and the volume of the pump chamber is made variable to control the load on the engine.

Therefore, there is a problem in that it is difficult to match the pump discharge amount corresponding to the accelerator opening degree and the pump chamber volume, which in turn affects the engine output.

The present invention was proposed to address the above-mentioned problems, and in an internal combustion engine equipped with an air pump, a throttle valve is provided upstream of the air pump, and the air pump is driven by a crankshaft via a variable speed mechanism. The engine load is controlled by a simple configuration that controls the gear ratio of the transmission mechanism according to the accelerator opening.Moreover, at extremely low loads such as idling, the amount of intake air is reduced due to the amount of air pump leakage. The air pump performs load control at extremely low loads according to the accelerator opening, and at low loads, the output torque of the air pump is recovered to the engine to reduce engine pumping loss. An object of the present invention is to provide a load control device for an internal combustion engine that can improve fuel efficiency and increase the rotational speed of an air pump to perform supercharging and improve output when the load is high. It is something.

[Means to solve the problem]

In order to achieve this object, the present invention provides an internal combustion engine in which an air pump is installed in the middle of an intake pipe that supplies air taken in from an air cleaner to a combustion chamber. A throttle valve linked to the accelerator pedal is provided between the crankshaft of the engine and the drive shaft of the air pump to compensate for the amount of leakage of the air pump when The present invention is characterized in that a variable speed mechanism is provided to control the load of the engine.

[For production]

In such a configuration, a throttle valve is provided upstream of the air pump in an internal combustion engine equipped with an air pump, and the rotation speed of the air pump is variably controlled according to the accelerator opening to adjust the engine intake air amount and reduce the engine load. Since the air pump is configured to be controlled, the rotational speed of the air pump is kept at an extremely low rotational speed when the load is low. Therefore, the air pump is driven by a pressure difference between its upstream and downstream sides due to negative pressure on the engine side, so the driving torque of this air pump is transmitted to and recovered from the engine crankshaft. Ru.

On the other hand, when the load is extremely low, the throttle valve opens by a predetermined opening depending on the accelerator opening, and the load is controlled by allowing an air flow rate equal to or greater than the amount of leakage from the air pump to flow between the air pump and the throttle valve. is carried out using an air pump.

In addition, when the load is high, the rotational speed of the air pump is set to high, and the intake air is compressed and supercharged by the torque from the crankshaft, thereby obtaining high output.

In this way, the air pump rotation speed is variably controlled by the engine rotation speed according to the accelerator opening at that time, thereby adjusting the amount of intake air and controlling the engine load. The air pump also controls the load without being affected by air pump leakage, reducing engine pumping loss and fuel consumption at low loads, and supercharging and increasing output at high loads. will be done.

〔Example〕

Embodiments of the present invention will be specifically described below based on the drawings.

FIG. 1 is a schematic configuration diagram of an internal combustion engine with an air pump according to the present invention. In the figure, the symbol [ is the engine, 2 is the combustion chamber of the engine L, 3 is the intake valve, 4 is the exhaust valve, and 5 is the fuel injection nozzle. , 6 indicates a spark plug, 7 indicates an air cleaner, and 8 indicates an intake pipe.

An air pump 10 consisting of a throttle valve 8a, a rotor lOa, and a fob is disposed in the middle of an intake pipe 8 that supplies air taken in from the air cleaner 7 of the engine 1 to the combustion chamber 2.

The throttle valve 8a is connected to the accelerator pedal 15 via a link mechanism 15a, and the intake air flow rate at extremely low loads such as idling is determined to be greater than or equal to the leakage amount of the air pump [0] according to the opening degree of the accelerator pedal ■5. The throttle valve 8a is set to a predetermined opening degree, and the throttle valve 8a is configured to be fully open during low loads other than extremely low loads.

The drive shaft 10c of the rotor lOa of the air pump 10 is
Variable speed mechanism 1 rotatably driven by a crankshaft 1a of an engine 1 via a winding transmission device II such as a belt or chain
The rotational speed of the air pump IO is variably controlled by the gear ratio of the variable speed mechanism 12.

That is, the variable speed mechanism 12 is equipped with a continuously variable transmission mechanism, and the input pulley 13 attached to the input shaft 12a of the variable speed mechanism 12 is connected to the crank pulley 14 on the engine l side via the wrap transmission device ti. The input pulley 13 is rotated by the rotor L of the air pump 10 from the output shaft 12b based on the gear ratio of the variable speed mechanism 12.
It is transmitted to the drive shaft LOc that drives Oa.

The variable speed mechanism 12 has an input shaft 12a and an output shaft 12b arranged parallel to the input shaft 12a, as shown in FIG.
A is provided with a primary pulley 20 with a variable boolean interval provided with a hydraulic cylinder 20a, and a secondary pulley 22 with a hydraulic cylinder 21a is provided with the output shaft 12b. Further, a drive belt 22 is wound around both pulleys 20, 21, and both hydraulic cylinders 20a.

A circuit 21a is configured in the hydraulic control circuit 50. Then, line pressure corresponding to the transmitted torque is supplied to both cylinders 20a and 21a to apply a boolean pressing force, and the primary pressure causes the drive belt 22 to wrap around the pulley 20.21 steplessly by changing the diameter ratio. It is configured to control the speed change.

The crankshaft 1a of the engine 1 is equipped with an engine rotation speed sensor [6 sensors] that detects the engine rotation speed, the accelerator pedal 15 is equipped with an accelerator opening detection sensor 17 that detects the accelerator opening, and the intake pipe 8 is equipped with an The intake pipe pressure sensor 18 detects the pipe pressure, the primary pulley 20 of the variable speed mechanism 12 has a primary pulley rotation speed sensor 23 that detects the briquetting rotation speed, and the secondary pulley 21 detects the secondary pulley rotation speed. A secondary pulley rotation speed sensor 24 is provided.

Each of these sensors is manually operated by the control unit 30, and the control unit 30 is configured to output a speed change control signal and a line pressure control signal to the hydraulic control circuit 50.

Next, referring to FIG. 3, the gear ratio control system of the variable speed mechanism 12 will be described.
．． The primary pulley rotation speed Np and the secondary pulley rotation speed Ns of the secondary pulley rotation speed sensor 24 are input to the actual gear ratio calculation means 31, and the actual gear ratio i is calculated from the actual gear ratio 1-Np/Ns.

This actual gear ratio l and the accelerator opening degree ψ of the accelerator opening degree sensor 17 are manually input to the target secondary pulley rotation speed search means 32, and the rotor of the air pump 10 is determined using a 1-ψ map based on the accelerator opening degree ψ. Represents the rotational speed of lOa.

Search for target secondary pulley rotation speed NSD. In this case, engine speed sensor ■6 and intake pipe pressure sensor 18
is input to the load determination means 33, and when it is determined that the load is low, this signal is sent to the target secondary pulley rotation speed retrieval means 32.
is input so that the rotation speed of the secondary pulley 21 becomes an extremely low rotation speed. The target secondary boot rotation speed NSD and the primary boot rotation speed Np are input manually to the target gear ratio calculation means 34, and the target gear ratio 1s is 1s-NSD/
Calculated by Np. The target gear ratio 1s and the actual gear ratio l are then input to the duty ratio search means 35.

Here, the duty ratio DI of the manipulated variable is searched using a map of 1s-1. The value of the duty ratio DI of this operation amount is output to the speed change control solenoid valve 37 of the hydraulic control circuit 50 via the drive unit 3B.

Next, the line pressure control system will be described. It has an engine torque search means 38 which inputs the engine rotation speed sensor 1B, the engine rotation speed Ne of the accelerator opening sensor 17, and the accelerator opening φ, and calculates the engine torque T from the torque characteristic map of ψ-Ne. The engine torque T and the signal of the actual gear ratio (■) of the actual gear ratio calculating means 31 are input to the target line pressure setting means 39, and the target line pressure PLd is determined by the product of the necessary line pressure and engine torque according to the actual gear ratio l. is determined, the target line pressure PLd is input to the duty ratio search means 40, and the duty ratio DI corresponding to the line pressure PLd is determined.

The duty signal D1 is configured to be outputted to the line pressure control solenoid valve 42 via the drive section 41.

On the other hand, the engine rotation speed Ne from the engine rotation speed sensor 16 and the accelerator opening degree ψ from the accelerator opening degree sensor 17
The fuel injection control means 43 has a fuel injection control means 43 to which a signal of .

Next, the operation of the load control device for an internal combustion engine configured as described above will be explained.

First, when the load is extremely low, including the idling state when the vehicle is stopped and the accelerator pedal 15 is released, the throttle valve 8a is set to a predetermined opening degree, and the throttle valve 8a and the air pump IO
The pressure in the intake pipe 8 between the two is below atmospheric pressure, and a predetermined flow rate of air flows in. Moreover, since this predetermined air flow rate is set larger than the amount of leakage from the air pump 10, the air pump IO is not affected by the amount of leakage from the air pump 10, so the load control can be performed depending on the rotation speed of the air pump 10. When the accelerator pedal 15 is depressed from an extremely low load state, the throttle valve 8a is fully opened.

Furthermore, during low loads including extremely low loads, the variable speed mechanism 1
2 secondary boost rotation speed, i.e. air pump LO
Since the rotational speed of the air pump 10 is set to an extremely low rotational speed, the upstream pressure of the air pump 10 is atmospheric pressure, and the downstream pressure is the engine l
A negative pressure is created by the suction action of the air, and this pressure difference causes the air pump lO to rotate. Since the torque generated from the air pump IO flows to the crankshaft 1a of the engine 1 via the variable speed mechanism 12, the pumping loss shown by diagonal lines in FIG. fuel consumption is reduced.

When the accelerator pedal 15 is further depressed in a low load condition, fuel corresponding to the engine speed Ne and the accelerator opening ψ is injected from the injector 5 into the combustion chamber 2 of the engine l, and the variable speed mechanism 12 The speed of the output shaft 12b is increased at a target speed ratio Is corresponding to the accelerator opening degree ψ caused by depression of the accelerator pedal 15.

The power of the engine 1 in response to the depression of the accelerator pedal 15 is transmitted to the crankshaft 1a, the crank pulley 14. The signal is transmitted to the variable speed mechanism 12 via the input pulley 13 of the variable speed mechanism 12.

The power input to the primary pulley 20 of the variable speed mechanism 12 is transmitted to the secondary pulley 2 via the drive belt 22.
1. It is transmitted to the output shaft L2b and output to the drive shaft 10c of the air pump 10, so that the air pump IO is driven at increased speed,
The intake air is supercharged to the engine 1.

Then, when the actual gear ratio l during driving is large and the load is low, the target line pressure is set larger as the engine torque T becomes larger, and the corresponding duty signal D
L is input to the line pressure control solenoid valve 42 to generate a control pressure, and the line pressure is controlled using the averaged pressure to increase the line pressure PL. Then, as the gear ratio 1 becomes smaller and the engine torque T also becomes smaller, the line pressure PL is controlled to be reduced by the same action. acts a force.

The above line pressure PL is always applied to the secondary cylinder 21a.
The gear change is controlled by supplying and discharging oil to the primary cylinder 20a by a shift control valve (not shown) using the control pressure of the shift control solenoid valve 37. This will be explained below.

First, the primary pulley rotation speed sensor 23. Secondary boot rotation speed sensor 24 and accelerator opening sensor 17
The signals Np, Ns, and ψ are read from the control unit 30, and the actual gear ratio calculation means 31 of the control unit 30 calculates the actual gear ratio 1.

On the other hand, the engine speed sensor 16 and the intake pipe pressure sensor 1
The signals Ne and P from 8 are read, and the load determining means 33 determines whether the load is low or not. If the load determining means 33 determines that the load is not low, the target secondary pulley The rotation speed search means 32 searches the map for the target secondary pulley rotation speed NSC based on the actual speed ratio i and the accelerator opening ψ, and the target speed ratio calculation means 34 calculates the target speed ratio I corresponding to the target secondary pulley rotation speed NSD.
s is calculated. In the low load area, the target secondary pulley rotation speed search means 32 uses a map to search for the target secondary pulley rotation speed NSD, which is an extremely low rotation speed based on the actual gear ratio I and the accelerator opening ψ.

The actual speed ratio I and the target speed ratio Is are input to the duty ratio search means 35 to search for the duty ratio DI.

The duty signal Di is the solenoid valve 3 for speed change control.
7 to generate a pulse-like control pressure, which repeatedly operates a speed change control valve (not shown) in two positions: oil supply and oil drain. Here, when the duty ratio DI becomes smaller, the shift control valve operates for a longer time in the refueling position due to the off time, and the primary cylinder 20a is refueled.
This increases the gear ratio. On the other hand, when the duty ratio increases, the operating time at the oil draining position becomes longer due to the ON time, and the oil is drained from the primary cylinder 20a, thereby reducing the gear ratio. Since the change in the duty ratio is small and the flow rate change in the primary cylinder 20a is small, the shift speed becomes slow.

On the other hand, as the deviation between the target speed ratio IS and the actual speed ratio 1 increases, the change in the flow rate of the primary cylinder 20a increases due to a change in the duty ratio, and the speed change speed becomes faster.

In this way, the variable speed mechanism 12 changes the speed continuously throughout the operating range of the engine 1. Since the rotational speed of the air pump 10 is variably controlled according to the depression of the accelerator pedal 15, the rotational speed of the air pump 10 can be controlled without being affected by the amount of leakage of the air pump IO at extremely low loads. can control the engine load.

In addition, in the present invention, the control unit 3
Although the speed ratio of the variable speed mechanism 12 is variably controlled via the control unit 30, the speed ratio of the variable speed mechanism 12 can also be variably controlled directly according to the accelerator opening degree without using the control unit 30.

〔Effect of the invention〕

As explained above, the load control device for an internal combustion engine according to the present invention installs a throttle valve and an air pump in the middle of an intake pipe that supplies air taken in from an air cleaner to a combustion chamber, and Since the rotation is controlled by a variable speed mechanism driven by the crankshaft, there is no need for a bypass passage for the air pump, and the rotation speed of the air pump can be made variable, so the capacity of the air pump can be reduced. It has a simple structure that can be made small, and the entire system can be simplified.

Furthermore, a throttle valve linked to the accelerator pedal is installed upstream of the air pump to compensate for air pump leakage at extremely low loads, allowing the air pump to control the load without being affected by air pump leakage. can be done.

In addition, when the engine is under high load, the air pump's rotational speed can be increased, resulting in improved output, and when the engine is under low load, the torque generated by the air pump can be recovered to the engine crankshaft, which improves engine speed. Bumping loss can be reduced and fuel efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an internal combustion engine showing an embodiment of the present invention;
Fig. 2 is a block diagram of the control system, Fig. 3 is a block diagram of the control system, and Fig. 4 is a schematic block diagram of an internal combustion engine showing a conventional embodiment.
FIG. 5 is a PV diagram of the internal combustion engine. ■... Engine, la... Crankshaft, 2... Combustion chamber, 7... Air cleaner, 8... Intake pipe, 8a...
... Throttle valve, lO... Air pump, 10c... Drive shaft, 12... Variable speed mechanism, 15... Accelerator pedal,
16...Engine speed sensor, 17...Accelerator opening sensor, 18...Intake pipe pressure sensor. Patent applicant: Fuji Heavy Industries Co., Ltd. Agent: Patent attorney: Makoto Kobashi Ukiyo Patent attorney: Susumu Murai

Claims (1)

[Scope of Claims] In an internal combustion engine in which an air pump is installed in the middle of an intake pipe that supplies air taken in from an air cleaner to a combustion chamber, the air pump is installed upstream of the air pump when the load is extremely low. A throttle valve linked to an accelerator pedal is provided between the crankshaft of the engine and the drive shaft of the air pump to compensate for the amount of leakage, and the load on the engine is controlled by changing the rotational speed of the air pump. A load control device for an internal combustion engine, characterized in that it is equipped with a variable speed mechanism.