JPH02286824A - Load control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce the capacity of an air pump by furnishing a variable speed mechanism between a crank shaft and the drive shaft of air pump on the way of suction pipe, wherein the mechanism performs load control of engine by changing the revolving speed of the air pump. CONSTITUTION:An air pump 10 is installed on the way of a suction pipe 8, and a variable speed mechanism 12 is arranged between the drive shaft 10c of the air pump 10 and a crank shaft 1a of the engine concerned 1 with a belt 11 interposed. To a control unit 30 are fed signals from an engine revolving speed sensor 16, an accelation degree-of-opening sensor 17, a suction pipe pres sure sensor 18, and primary/secondary pulley revolving speed sensors 23, 24 for CVT, and the transmission ratio of the variable speed mechanism 12 is adjusted through a hydraulic control circuit 50 so that corresponding engine output is obtained. Thus the revolving speed of the air pump 10 is controlled. This eliminates necessity for any throttle valve, air pump bypass passage, etc. and allows making the capacity of the air pump smaller.

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 the air is not supplied to the engine b. There is a problem in that a pumping loss as shown in the shaded area of the PV 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, resulting in an increase in fuel consumption during idling.

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 engine load control is performed by opening and closing a throttle valve, and during low-load operation,
Only one air pump is rotationally driven by the pressure difference between the pump suction side and the discharge side, and the generated power is transmitted to the engine, and except during low load operation, the other air pump is driven by the engine (2) It is configured to do the following.

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, the air pump is driven by a crankshaft via a variable speed mechanism, and the gear ratio of the variable speed mechanism is adjusted according to the accelerator opening. The engine load is controlled by a simple configuration that controls the engine load according to the engine load, and at low loads, the output torque of the air pump is recovered to the engine, reducing engine pumping loss and improving fuel efficiency. It is an object of the present invention to provide a load control device for an internal combustion engine, which increases the rotational speed of an air pump to perform supercharging and improve output when the load is high.

[Means to solve the problem]

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. The present invention is characterized in that a variable speed mechanism is disposed between the drive shaft and controls the load on the engine by changing the rotational speed of the air pump.

[For production]

In such a configuration, an internal combustion engine equipped with an air pump does not have a throttle valve in the intake pipe, and the rotation speed of the air pump is variably controlled according to the accelerator opening to adjust the engine intake air amount and control the engine load. Therefore, when the load is low, the rotational speed of the air pump is kept extremely 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.

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. Bumping loss is reduced, fuel consumption is reduced, and at high loads, supercharging is performed to improve output.

〔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, reference numeral 1 is the engine, 2 is the combustion chamber of the engine 1, 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 rotors lOa and lOb without using a throttle valve is installed in the middle of the intake pipe 8 that supplies the air taken in from the air cleaner 7 of the engine l to the combustion chamber 2.
is installed.

The drive shaft 10c of the rotor lOa of the air pump lO is
Variable speed mechanism 1 rotatably driven by a crankshaft 1a of an engine 1 via a winding transmission 11 such as a belt or chain
The rotation speed of the air pump 10 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 11. The rotation speed of the input pulley 13 is determined by the rotation speed of the rotor l of the air pump 10 from the output shaft 12b based on the gear ratio of the variable speed mechanism 12.
The signal is transmitted to the drive shaft 10c 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 21 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 l has an engine rotation speed sensor 16 for detecting the engine rotation speed, the accelerator pedal 15 has an accelerator opening detection sensor 17 for detecting the accelerator opening, and the intake pipe 8 has an intake pipe pressure sensor 16 for detecting the engine rotation speed. The primary pulley 20 of the variable speed mechanism 12 has an intake pipe pressure sensor 18 that detects the rotational speed of the primary boolean, and the secondary pulley 2
1 is provided with a secondary pulley rotation speed sensor 24 that detects the secondary pulley rotation speed.

Each of these sensors is configured to input to the control unit 30, and the control unit 30 outputs a shift control signal and a line pressure control signal to the hydraulic pressure 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 manually to the actual speed ratio calculation means 31, and the actual speed ratio t is calculated from the actual speed ratio 1-Np/Ns.

The actual gear ratio l and the accelerator opening degree ψ of the accelerator opening degree sensor 17 are input to the target secondary pulley rotation speed search means 32, and the rotor of the air pump 10 is Represents the rotational speed of lOa.

Search for the target secondary 1-boot rotation speed NSD. In this case, engine speed sensor to and intake pipe pressure sensor 1
8 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 rotation speed search means 3.
2, the rotation speed of the secondary pulley 21 is set to an extremely low rotation speed. The target secondary booster rotation speed NSD and the primary booster rotation speed Np are input to the target gear ratio calculation means 34, and the target gear ratio is is 15-N5D.
/Np. The target gear ratio IS and the actual gear ratio l are input manually to the duty ratio search means 35. Here, the duty ratio DI of the manipulated variable is searched using the map 15-1. The value of the duty ratio Di of this operation amount is outputted to the speed change control solenoid valve 37 of the hydraulic control circuit 50 via the drive section 36.

Next, the line pressure control system will be described. It has an engine torque search means 38 which manually inputs the engine rotation speed Nθ and the accelerator opening ψ of the engine rotation speed sensor 1B, the accelerator opening sensor 17, and calculates the engine torque T from the torque characteristic map of ψ-Ne. The signals of the engine torque T and the actual gear ratio l from the actual gear ratio calculation 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 corresponding to the actual gear ratio 1 and the engine torque. is determined, and the target line pressure PLd is input to the duty ratio search means 40 to determine the duty ratio D L corresponding to the line pressures P1 and d.

The duty signal DL 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 No 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 48 has a fuel injection control means 48 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 low, including the idling state when the vehicle is stopped and the accelerator pedal 15 is released, the secondary boost rotation speed of the variable speed mechanism 12, that is, the rotation speed of the air pump IO, is set to an extremely low rotation speed. , air pump 1
0, the upstream pressure is atmospheric pressure, and the downstream pressure is negative pressure due to the intake action of the engine 1, and this pressure difference causes the air pump 10 to
rotates. The generated torque from the air pump lO is transmitted to the crankshaft 1a of the engine 1 via the variable speed mechanism 12.
Therefore, the pumping loss shown by diagonal lines in FIG. 5 is offset by the torque generated by the air pump 10, and fuel consumption at low loads is reduced.

When the accelerator pedal 15 is further depressed in a low load state, 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 1, and the variable speed mechanism 12 The speed of the output shaft 12b is increased at the target speed ratio is according to the accelerator opening degree ψ caused by depression of the accelerator pedal 15.

The power of the engine l 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 12b and output to the drive shaft LOc of the air pump 10, so that the air pump IO is driven at an increased speed.
Intake air is supercharged to the engine 1.

The target line pressure is set to be larger as the engine torque T becomes larger, except at low load times when the actual speed ratio I is large while driving, and the corresponding duty signal D is set.
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. As the gear ratio l becomes smaller and the engine torque T also becomes smaller, the line pressure P is controlled to decrease by acting in a similar manner. Pushing exerts force.

The line pressure PL is always supplied to the secondary cylinder 21a, and the shift control is performed by supplying and draining 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 ■7
The signals Np, Ns, 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 l. On the other hand, the engine speed sensor 16 and the intake pipe pressure sensor 18
The signals Ne and P from 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 boot is determined. The rotation speed search means 32 determines that the actual gear ratio is 1. The target secondary pulley rotation speed NSD is searched from the map based on the accelerator opening degree ψ, and the target speed change ratio calculation means 34 calculates the target speed change ratio is corresponding to this target secondary pulley rotation speed NSD.
is calculated. In the low load area, the target secondary pulley rotation speed search means 32 searches a map for the target secondary pulley rotation speed NSD, which is an extremely low rotation speed based on the actual gear ratio l and the accelerator opening ψ.

These actual gear ratios are 1. The target gear ratio is is input to the duty ratio search means 35, and the duty ratio Di is searched.

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 I 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 rotation speed of the air pump lO is variably controlled according to the depression of the accelerator pedal 15, the load on the engine is controlled by controlling the rotation speed of the air pump, instead of the conventional load control using a throttle valve. be able to.

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, in the load control device for an internal combustion engine according to the present invention, an air pump is installed in the middle of the intake pipe that supplies air taken in from the air cleaner to the combustion chamber, and the rotational speed of the air pump is controlled by the crankshaft. Since the rotation is controlled by a variable speed mechanism driven by the The structure is simple and the entire system can be simplified.

Furthermore, 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 the engine speed. Bumping loss can be reduced and fuel efficiency can be improved.

[Brief explanation of the drawing]

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 P-v diagram of the internal combustion engine. ■... Engine, la... Crankshaft, 2... Combustion chamber, 7... Air cleaner, 8... Intake pipe, 10...
...Air pump, IOC...Drive shaft, 12...Variable speed mechanism, 15...Accelerator pedal, lB...Engine speed sensor, 17...Accelerator opening sensor, 18
...Intake pipe pressure sensor.

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, between the crankshaft of the engine and the drive shaft of the air pump. A load control device for an internal combustion engine, further comprising a variable speed mechanism that controls the load on the engine by changing the rotational speed of the air pump.