JPS5862319A - Supercharger of internal-combustion engine - Google Patents

Abstract

PURPOSE:To miniaturize a supercharger as well as to avoid useless power loss, by installing a solenoid clutch in a power transmission mechanism driving a mechanical supercharge, while causing the supercharger to be driven only at the desired engine speed and suction air quantity ranges. CONSTITUTION:A surge tank 6 is installed in a suction air passage 10 of an internal-combustion engine while a supercharger 2 driven by the engine 1 is connected thereto. A suction air passage length l ranging from the surge tank 6 to the combustion chamber of engine is set up so as to cause the suction air quantity to be maximized at the revolution range of more than almost medium speed of the engine. A control circuit 18 is to stop the supercharger 2 upon switching off a solenoid clutch 5 when engine speed is of revolution other than low speed to medium speed as well as when the suction air quantity or fuel quantity to the engine is smaller than a certain value. Doing suchlike, an increase of fuel consumption can be obviated without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharging device for an intake system of an internal combustion engine.

It is widely said that supercharging is used as a means to improve the output and fuel efficiency of internal combustion engines, and three types of supercharging are known: exhaust turbo supercharging, mechanical supercharging, and inertial supercharging. Exhaust turbocharging uses the energy of the exhaust gas from the engine to drive the turbo supercharger, so although it is extremely effective at high speeds where the energy of the exhaust gas is large, it is effective at lower speeds. In the range, not only is there little improvement in output, but the responsiveness at the beginning of engine acceleration is poor, and there is a risk of supercharging due to the inertial rotation of the turbocharger during deceleration. On the other hand, mechanical supercharging is a system in which the supercharger is rotationally driven by the engine, so it is effective and responsive even in a lower rotation range than the exhaust turbo supercharging, and there is no supercharging during deceleration. Although it has advantages, it not only requires a supercharger to be extremely large in order to secure a specified amount of intake air in the high speed range of the engine, but also has problems with the durability of the supercharger in the high speed range.
Furthermore, since the power loss required to drive the supercharger increases approximately squarely with the number of rotations, the improvement in output in the high rotation range is small. Additionally, inertial supercharging involves installing a surge tank in the engine's intake system, and adjusting the length of the intake passage from the surge tank to the combustion chamber to maximize the amount of intake air in a specific rotation range where the engine is frequently used. Therefore, compared to the above two, the structure is simpler and the installation space is not significantly increased, but on the other hand, it achieves the effect of inertial supercharging in rotation ranges other than the above-mentioned specific rotation range. I couldn't do it.

The one party who failed to do so was the one who first filed a patent application in 1986-6
In No. 9221, the engine speed is divided into a rotation range below approximately medium speed range and a rotation range above approximately medium speed range, and in the rotation range below approximately medium speed, the engine drives the supercharger and the machine Inertial supercharging overcomes the shortcomings of mechanical supercharging in high speed ranges, by stopping the drive of the supercharger and performing inertia supercharging in the rotation range above approximately medium speed. On the other hand, the incompatibility of inertial supercharging over a wide rotation range can be compensated for mechanically and by supercharging.

Together, they proposed that the engine be able to effectively supercharge the entire rotation range.

The misfiring Fl11 follows the idea of this prior invention, but the mechanical supercharger is used in the rotation range of approximately medium speed or higher in relation to the engine rotation speed, and in the extremely low rotation range near the idle link & In addition to controlling the turbocharger so that it is driven only within a range of rotational speeds, it also controls the turbocharger to be driven when the intake air amount exceeds a certain value in relation to the actual intake air amount to the engine. This prevents the harmful effects of driving the supercharger in the engine's extremely low speed range and low load range, that is, increases in fuel consumption, making supercharging more effective. .

In other words, a certain amount of power is required to drive a mechanical supercharger, and the ratio of the power required to drive it to the engine's output increases as the engine load becomes lower. If the value is below, the increase value that can increase the engine output by driving the supercharger will balance out with the power required to drive the supercharger, and the supercharger will no longer be effective, especially if it is below this value. At a load of - The measurement is taken in the evening, and when the value exceeds a certain value and the engine output can be sufficiently increased by driving the turbocharger, the turbocharger is controlled to be driven, while the intake air amount is In the region where the above setting value is exceeded and the rotation speed is extremely low near the idle link, for example when climbing a slope or at the beginning of sudden acceleration from idling, the operation of the supercharger is slow and this condition occurs. Driving the supercharger with
Local power is required to drive the supercharger, and the power used for driving is reduced to drive the supercharger, which not only reduces driver stability but also increases fuel consumption as described above. At such extremely low rotation speeds, the drive of the supercharger is stopped in the same way as in the approximately medium speed or higher rotation range, regardless of the flow meter.

The present invention will be explained below with reference to drawings of embodiments. In the drawings, (1) indicates a multi-cylinder internal combustion engine-1 (2) a positive displacement supercharger such as an LD roots, movable blade, or reciprocating type, and the supercharger (2) has a relatively small capacity so that a constant amount of air can be secured only in the rotation range below the approximately medium speed rotation (N1) of the engine, and is connected to the engine (1) from the engine shaft (3), etc. to the belt (4), etc. The power transmission mechanism is rotatably driven via a power transmission mechanism, and the power transmission mechanism is provided with means for turning on or off power transmission to the supercharger (2), for example, an electromagnetic clutch (5).

+61 Vi This is a surge tank for inertial supercharging, and the surge tank (6) is connected to the intake port (
7) through independent intake pipes (8), and the surge tank (6) is connected to the surge tank (6) from the point where the intake port (7) in each cylinder opens into the combustion chamber of the cylinder
The length of the intake passage to the inward opening is set to such a length that the amount of intake air is maximized in a rotation range of approximately medium speed (N) or higher of the engine.

(9) is an air cleaner, and an intake passage 00 connecting the air cleaner (9) and the surge tank (6) is equipped with a carburetor (1) equipped with a throttle valve (12) for adjusting intake air. There is an air cleaner (9) upstream of the carburetor (1).
) is provided with a check valve (13) that opens only in the direction of the carburetor (I1), and the check valve 03 in the intake passage aG
) is connected to the suction passage (I4) to the M supercharger (2), and the discharge passage (15) from the supercharger (2) is connected to the downstream side of the supercharger (2).

And for the above-mentioned intake passage, the intake is directly downstream of the air cleaner [9]! i! , an air flow meter (16) for measuring air flow, and a rotation sensor (17) for the engine (1) are installed, and the drive of the supercharger (2) is turned on and off.
A control circuit (I8) for controlling the FF electromagnetic clutch (5) is connected to the control circuit (18), and signals from the air flow meter (16) and rotation sensor u7) are given as inputs to the control circuit (18).

Based on the output signal from the rotation sensor (I7), the control circuit (18) operates when the engine rotation speed is below the extremely low rotation (No) near the idle ring and when the engine rotation is at the approximately medium speed (N).
1) Turn off the electromagnetic clutch (5) when 2.
, No-N1, the electromagnetic clutch (5) is turned ON, and the air flow meter [1
Based on the output from 61, when the amount of intake air per revolution is below a certain value (Q/Ni), the electromagnetic clutch (5) is turned OFF regardless of the engine speed. 'If control [■ road (18), the engine rotation speed is N. −
within the range of N□ and the amount of intake air per revolution is (Q/
Turn on the electromagnetic clutch (5) only when the
The rotation speed is N. Below, when the intake air amount per revolution is N1 or more and less than (Q / Ni), the electromagnetic clutch (5)
They are designed to operate when the switch is turned off. However, -
No <”+<N1 and Q is a constant.

In this configuration, the amount of intake air per revolution is Q /
The rotation speed is N when it is over Ni. -N1 range, the electromagnetic clutch (5) is ON and the supercharger (2) is driven, and the intake air from the air clearer (9) is supplied to the engine via the supercharger (2). , the engine is operated with so-called mechanical supercharging. When the engine rotation exceeds N1 and becomes high speed, the electromagnetic clutch (5) is turned off and the supercharger (2) is turned off.
) is stopped, the intake air from the air cleaner (9) is introduced into the surge tank (6) without passing through the supercharger (2), and from the surge tank (6) is injected into the combustion chamber 1 of each cylinder. The length of the intake passage is set so that the amount of intake air is maximized in the engine speed range of N1 or higher.
In the rotation range of N, 1 or more, the engine is operated with so-called inertia supercharging.

Even if the amount of intake air per revolution is more than Q/M, the engine speed is N. When the number of rotations decreases below 1, the drive of the supercharger (2) stops when the electromagnetic clutch 5) is turned off, so the engine becomes non-supercharged, and the rotational speed decreases below 1.
Even if the amount of intake air per revolution becomes less than Q/Ni when the throttle valve (12) is closed, the OF of the electromagnetic ring (5)
Since the drive of the supercharger (2) is stopped at F, the engine similarly becomes non-supercharged.

In this case, the amount of intake air Q1 per revolution when the supercharger (2) is started and stopped by 1J is the amount of intake air in the suction room in a state where the engine output can be sufficiently increased by driving the supercharger. It is sufficient to set it to % amount, and in the condition below this, the rotation speed is N. Since the drive of the supercharger (2) is stopped even in the -N1 range, an increase in fuel consumption due to driving the supercharger (2) in a low load range with a small amount of intake air is reliably prevented. Even if the amount of intake air per rotation is equal to or higher than the set value Q/Ni, the engine rotation speed is N. If the rotation speed decreases further, the supercharger will stop driving, and the power load required for its drive will be released, so there will be no adverse effects when driving the supercharger in the extremely low rotation range. In other words, deterioration of the driver's grip and increase in fuel consumption can be prevented.

When stopping the drive of the supercharger (2) in a low load range, low load is detected by checking the opening degree of the intake air regulating throttle valve (as shown in the figure) installed in the intake passage (101). However, in the low load range when the throttle valve is close to fully closed, the load changes greatly due to the slight opening and closing of the throttle valve.
In other words, since the rotation angle of the crest valve in response to changes in load is extremely small, not only is it extremely difficult and inaccurate to adjust its setting position, but there is also considerable variation in control for each engine produced in large numbers. However, if an O-meter is provided in the intake passage 00 as in the present invention, and control is performed according to the intake air amount, the intake air amount will be gradually and almost completely proportional to the load. From there, turn on the supercharger.
Setting values for OFF control can be easily set, are accurate, and can reduce variation in control for each engine.

The above embodiment drawings show a case where an air flow meter (o13) is provided in the intake system of a carburetor type internal combustion engine, but in the case of a fuel injection type Kallin engine, an air flow meter is necessarily provided in the intake system. If you have a diesel engine, you can install an air flow meter in the pneumatic cabana set, which has a fuel system linked to the intake system by an intake throttle. It is not a moat to say that it can be applied in the same way by Koki. In addition, even in the case of diesel engines and January sled engines, which control the fuel amount q regardless of the intake air amount, such as the mechanical cabana one-way type, the intake pipe type, hot wire type, Gallman vortex type, intake pipe negative pressure type, etc. Instead of directly measuring the air amount, the fuel PI amount q is estimated by estimating the intake air N.
In those that control q/N:L instead of
This is also possible by using N1.

As described above, the present invention provides a dimensional gap in the intake system to an internal combustion engine, connects #rJg to a supercharger rotated by the engine, and increases the length of the intake passage from the surge tank to the combustion chamber of the engine. The engine speed is set so that the amount of intake air is maximized in the engine speed range of approximately medium speed or higher, while the power transmission mechanism from the engine to the supercharger is The supercharger is characterized by being provided with a means for stopping the drive of the supercharger when the rotation speed is other than high speed rotation and when the amount of air intake or fuel amount to the engine is smaller than a certain value, The feeder only needs to operate at approximately medium speed or lower, so it does not have a large capacity as would be the case if the supercharger operates over the entire engine speed range, and it can drive the supercharger at high speeds. On the other hand, inertia supercharging can be performed at a high efficiency only in a narrow rotation range of approximately medium speed or higher.

Moreover, with the present invention, does the rotation speed vary? The turbocharger will stop driving when the rotation becomes low around 700 degrees or when the intake air to the engine falls below a certain value. This makes it possible to reliably prevent the disadvantages of driving and increase fuel consumption.Furthermore, since the turbocharger is stopped at low loads based on the amount of intake air, This has the effect of allowing extremely accurate control without variation.

[Brief explanation of drawings]

Figure rln is a diagram showing an embodiment of the present invention. [11・@Seki, (2) -゛°supercharger, +5) l°electromagnetic'7 latch, αG...intake passage, (6)...surge tank, (1η...rotation sensor size - 06) −°°
Airf 0-meter, (18)...control circuit. 6

Claims (1)

[Claims] (1) A surge tank is provided in the intake system to the internal combustion engine, and a supercharger rotationally driven by the engine is connected,
The length of the intake passage from the surge tank to the combustion chamber of the engine is set so that the amount of intake air is maximized in a rotation range of approximately medium speed or higher, and a power transmission mechanism from the engine to the supercharger is set. The supercharger is configured to stop driving when the engine speed is other than low to medium speed and when the amount of intake air or fuel to the engine is smaller than a certain value. 1. A supercharging device for an internal combustion engine, characterized in that it is provided with a means for doing so.