JPH02291425A - Suction control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To efficiently recover pumping loss by installing an air pump linked and connected with an engine on the downstream side of a throttle valve in a suction passage, and having the air pump revolved as an air motor in the low load zone of the engine. CONSTITUTION:While an engine 1 is in its low load zone, No.1 throttle valve 9 is slightly opened in accordance with the depression of an acceleration pedal 11, and No.2 throttle valve 10 is maintained in a state of full closure. All the air sucked into a combustion chamber 2 then is passed through No.1 suction passage 8a to cause pressure differential between the top and bottom of an air pump 12. The air pump 12 is let to turn as an air motor with the pressure differential to transmit torque to the crankshaft 1a of the engine 1 through a transmission gear 13, and to recover pumping loss. On the other hand, when No.1 throttle valve 9 reaches the vicinity of full opening, No.2 throttle valve 10 is opened to have the air to be sucked into the combustion chamber 2 passed though No. and No.2 suction passages 8a, 8b, respectively, which increases the amount of suction air.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air intake control device for an internal combustion engine that improves fuel efficiency by recovering pumping loss in a low load range in an engine equipped with an air bomb. It is.

[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 increase the throttle valve. A device in which load control is performed by opening and closing a valve is already known.

However, the above-mentioned supercharged engines adjust the amount of intake air by controlling the throttle opening, and it is extremely difficult to finely control the throttle opening. It was not possible to control it.

In addition, since supercharging is not required in the low load range, torque is used only for internal friction in the engine and the pumping action of the supercharger, which makes the rotational speed unstable, especially during idling, and increases fuel consumption. There is a problem that the loss required for the pumping action becomes large.

Therefore, as a countermeasure against these problems, for example,
As shown in Publication No. 717, in a supercharged engine that has a supercharging passage and a third valve independent of the intake passage, one cylinder is used as a supercharging bomb and operates as a supercharging pump in a high load range. , a prior art has been proposed in which the suction side and the discharge side of the pump are reversed by a switching valve in a low load range, so that the pump operates as a pump that sucks in-cylinder air-fuel mixture.

[Problem to be solved by the invention]

However, in the prior art described above, one cylinder is used as a supercharging pump, which has the advantage of relatively reducing pumping loss in the low load range, but the engine body is larger than an engine with the same displacement. However, there are disadvantages such as an increase in weight, vibration, and noise.

In addition, once the mixture of fuel and air is sucked into the cylinder,
The air is returned to the intake pipe by one simple pumping action that operates as a supercharging bomb. There are problems such as unstable fuel ratio control and poor drivability.

The present invention was proposed to address the above-mentioned problems, and provides an air intake control device for an internal combustion engine that is capable of recovering pumping loss in the low engine load range and improving fuel efficiency in an engine equipped with an air bomb. The purpose is to provide

[Means to solve the problem]

In order to achieve this object, the present invention provides an engine in which an intake passage is configured with a primary intake passage and a secondary intake passage, and a primary throttle valve is branched into the primary intake passage from an upstream side of the primary throttle valve. A secondary throttle valve is disposed in each of the secondary intake passages, and downstream of the primary throttle valve in the primary intake passage,
The engine is characterized in that an air bomb is provided which is rotationally driven by the crankshaft of the engine at a predetermined reduction ratio, and the secondary throttle valve is configured to open near the fully open position of the primary throttle valve. be.

[For production]

In such a configuration, the intake passage of the engine consists of a primary intake passage having a primary throttle valve and a secondary intake passage having a secondary throttle valve, and a predetermined distance from the crankshaft is located downstream of the primary throttle valve in the primary intake passage. An air pump that is rotationally driven by the reduction ratio is installed, and the opening of the secondary throttle valve in the secondary intake passage is set to close to the fully open position of the primary throttle valve in the primary intake passage in response to the amount of depression of the accelerator pedal. In a low load range where the amount of depression of the accelerator pedal is small, all of the intake air passes through the primary intake passage, rotates the air pump, and is sucked into the combustion chamber of the engine.

At this time, pumping loss occurs in the air bomb, but since the pressure drop of the intake air occurs before and after the air bomb, the pumping loss is recovered by the air bomb and returned to the engine crankshaft. That is, the air bomb operates as an air motor.

Furthermore, when the accelerator pedal is depressed, the secondary throttle valve in the secondary intake passage gradually opens near the point where the primary throttle valve is fully open, and intake air begins to flow through the secondary intake passage, supplying the necessary amount of air to the engine.

〔Example〕

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

FIG. 1 is a schematic diagram of an engine with an air bomb showing an embodiment of the present invention, and in the figure, reference numeral 1 indicates the engine;
2 is the combustion chamber of the engine l, 3 is the intake valve, 4 is the exhaust valve, 5
is the fuel injection nozzle, B is the spark plug, 7 is the air cleaner, 8
indicate the intake pipes.

Secondary intake passage 8b of the intake pipe 8 that supplies the air taken in from the air cleaner 7 of the engine 1 to the combustion chamber 2
is the primary intake passage 8a on the downstream side of the air cleaner 7.
branched from the upstream side of the primary throttle valve 9,
They are joined together again on the upstream side of the intake boat lb of engine l.

A secondary throttle valve IO is installed in the secondary intake passage 8b. The opening degree θ of the primary throttle valve 9 and the secondary throttle valve IO changes depending on the amount of depression of the accelerator pedal 11, but the opening degree θS of the secondary throttle valve IO is different from that of the primary throttle valve IO as shown in FIG. The throttle valve 9 starts to open when the opening degree θp of the throttle valve 9 becomes fully open. Therefore, the intake air amount Qp corresponding to the opening degree θp of the primary throttle valve 9 becomes constant from the time when the accelerator pedal 11 is depressed, and the intake air amount Qs corresponding to the opening degree θS of the secondary throttle valve lO
is as shown.

On the other hand, an air bomb 2 is installed downstream of the primary throttle valve 9 provided in the primary intake passage 8a, and a crank boolean 14 provided on the crankshaft la of the engine 1 winds belts, chains, etc. A pulley 15 is rotationally driven via a hook transmission 13.

The reduction ratio between the crank pulley l4 of the crankshaft 1a and the pulley l5 of the air bomb l2 is such that at least when there is air flow in the primary intake passage 8a, the air bomb 2 is driven by the negative pressure on the engine side and generates power as an air motor. The speed reduction ratio is set to a predetermined speed reduction ratio.

In other words, in the low rotation and low load range of the engine I, the second
As shown in the figure, the secondary throttle valve [0 is the fully open state, and the primary throttle valve 9 has a small opening, so the negative pressure on the engine side is large between the upstream and downstream sides of the air bomb l2. A drop in air pressure occurs, and the air pump 12 is driven by the negative pressure on the engine side. Therefore, the air bomb l2 generates torque as an air motor, and the torque is transmitted to the crankshaft 1a via the wrap transmission device l3.

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

First, in the low speed and low load range of the engine 1, the amount of depression of the accelerator pedal ti is small, the secondary throttle valve IO is fully open, and the primary throttle valve 9 opens slightly in response to the amount of depression of the accelerator pedal 11. ing.

In this state, all of the intake air taken into the combustion chamber 2 of the engine passes through the primary intake passage 8a, causing a pressure drop in the intake air between the upstream and downstream sides of the air pump [2]. Therefore, the air bomb 12 is rotationally driven by this pressure difference and generates torque as an air motor.
Torque is transmitted to the crankshaft 1a via the wrap-around transmission l3, making it possible to effectively recover pumping losses and reduce fuel consumption in a low load range.

Furthermore, as the amount of depression of the accelerator pedal 11 is increased, the opening degree θp of the primary throttle valve 9 gradually increases, and when it approaches full opening, the secondary throttle valve 1
0 is opened, the intake air taken into the combustion chamber 2 passes through both the primary intake passage 8a and the secondary intake passage 8b, and the amount of intake air necessary for the engine is supplied, and the air pump l2 in the primary intake passage 8a is opened. The amount of intake air increases due to the supercharging effect and the intake air flowing through the secondary intake passage 8b, and the filling efficiency is improved.

Boule 14.1 is used to drive the air pump 12 according to this embodiment.
5. The wrap transmission device 13 may be replaced with a gear transmission device.

〔Effect of the invention〕

As explained above, in the intake control device for an internal combustion engine according to the present invention, the intake passage of the engine has a primary intake passage provided with a primary throttle valve and a secondary intake passage provided with a secondary throttle valve. An air pump that is rotationally driven by the crankshaft at a predetermined reduction ratio is arranged downstream of the primary throttle valve in the passage, and the opening of the secondary throttle valve in the secondary intake passage is adjusted according to the amount of depression of the accelerator pedal.
Since it is configured to open near the fully open position of the primary throttle valve in the primary intake passage, in the low load range of the engine, the amount of depression of the accelerator pedal is small and the secondary intake passage is fully opened, causing the air pump upstream and downstream of the primary intake passage to open. A pressure difference is created between the two sides due to negative pressure on the engine side, and this pressure difference drives the air pump to rotate and generates torque. This torque is returned to the crankshaft via the winding transmission, so bombing losses can be recovered. This is effectively carried out, and the fuel consumption rate in the low load range is reduced.

Additionally, when the amount of depression of the accelerator pedal is increased and the primary throttle valve approaches full open, the secondary throttle valve in the secondary intake passage opens, increasing the amount of intake air and improving output through the supercharging effect of the air bomb. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an engine with an air pump showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the accelerator pedal opening and the throttle valve opening. DESCRIPTION OF SYMBOLS 1... Engine, 2... Combustion chamber, 7... Air cleaner, 8... Intake pipe, 8a... Primary intake passage, 8b... Secondary intake passage, 9... Primary throttle valve, lO...Secondary throttle valve, 11...Accelerator pedal, l2...Air pump, 13...Wrap transmission device.

Claims (1)

[Scope of Claims] In an engine in which the intake passage is constituted by a primary intake passage and a secondary intake passage, a primary throttle valve is provided in the primary intake passage, and a primary throttle valve is provided in the secondary intake passage that branches from the upstream side of the primary throttle valve. A secondary throttle valve is respectively disposed, and an air pump rotationally driven by the crankshaft of the engine at a predetermined reduction ratio is disposed downstream of the primary throttle valve in the primary intake passage, and the secondary throttle valve is connected to the secondary throttle valve as described above. An intake control device for an internal combustion engine, characterized in that it is configured to open when a primary throttle valve is fully open.