JPS5974329A - Supercharging pressure controller for engine - Google Patents

Abstract

PURPOSE:To prevent an unnecessary increase in the consumption of fuel due to the operation of a supercharger under low and medium load, without deteriorating the effect of the supercharging with a throttle valve fully opened, by operating a by-pass control valve to by-pass exhaust gas unless the throttle valve is fully opened. CONSTITUTION:In ordinary working, a throttle valve 4 is not fully opened, so that a by-pass 10 is open and an exhaust turbine 13 rotates slowly. In high-load working, the throttle valve 4 is fully opened and a switch 27 is turned on by a cam 26 so that a controller 28 deenergizes a coil 25 to cause a spring 24 to close the by-pass 10 by a plunger 23 to rotate the exhaust turbine 13 rapidly. The rise in supercharging pressure after that is controlled by a valve 17.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a boost pressure regulating device for an internal combustion engine equipped with an exhaust gas-driven supercharger.

A supercharged internal combustion engine has the excellent feature of generating large output with a small, lightweight, and small-capacity engine because the air-fuel mixture is forcibly introduced into the cylinder and combusted in an overcharged state. However, on the other hand, the piston may seize due to increased heat load due to high compression combustion, or due to abnormal heat generation or vibration due to the knocking phenomenon caused by this.
The disadvantage is that the cylinder head is easily damaged. In order to improve this serious drawback, a typical supercharged internal combustion engine increases the combustion ratio in the air-fuel mixture above the required ratio, and cools the high-temperature parts using the heat of vaporization of the fuel. Therefore, in the supercharging operation range, the fuel consumption rate inevitably worsens, so it is better to save resources by ensuring that operation in this operation range is only performed when the driver truly desires it. From the point of view, υ is preferable.

(7) The invention was made in view of the above, and provides an excellent supercharging system that reduces unnecessary fuel consumption by providing a sensor that detects the fully open state of the throttle and operating the supercharger only when the throttle is fully open. The present invention aims to provide a pressure regulating device.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, (1) is an internal combustion engine, (2) is an intake duct connected to an air cleaner (not shown), (3) is an intake passage, and (4) is an intake duct connected to an air cleaner (not shown).
is a throttle valve that regulates the amount of intake air, (5) is an intake manifold, (6) is an injector that injects fuel at a constant ratio to the amount of intake air, (7) is an exhaust manifold, (8) is an exhaust passage, (9) is an exhaust pipe that releases exhaust gas to the atmosphere, QO is a bypass passage, and Q
1 is a supercharger driven by exhaust gas to supercharge intake air; an intake turbine (2) that compresses intake air flowing in from an intake duct (2) and discharges it to an intake passage (3); An exhaust turbine (2) driven by exhaust gas, and a shaft α that connects the intake turbine (2) and the exhaust turbine (to).
G] It is configured. 051 is a waste gate valve that controls the above-mentioned bypass exhaust gas flow according to the boost pressure to adjust the boost pressure) When diaphragm Q, diaphragm Q
It is composed of multiple parts, including a pulp αη directly connected to the IS, and an atmospheric chamber H1 which is divided into multiple parts by a spring OL diaphragm. Ql is a pipe communicating between the intake passage (3) and the pressure chamber, and Ql is a plunger (2) having a valve for controlling the inflow of exhaust gas into the bypass passage QO, a spring and a voltage is applied. In particular, the solenoid valve is composed of a coil that attracts the Shibranja holder and opens the valve.The holder is a cam directly connected to the throttle valve (4), and 6!
η is a switch that is closed by a cam (A) when the throttle valve (4) is fully opened, and (C) is a control unit that controls a stain solenoid valve by a switch punishment signal.

Next, the operation in the above configuration will be explained. In normal operating conditions, intake air flowing from the intake duct (2) passes through the intake turbine (2) and the intake passage (3), is regulated by the throttle valve (4), and is regulated by the intake manifold (5).
), the fuel is mixed with the fuel injected from the injector (6) and sucked into the internal combustion engine (1), where it is combusted. At this time, the cam wire is not in contact with the switch (b), so the switch (b) is open.) The control unit (c) excites the coil, causing the plunger (b) to be repulsed by the spring. It overcomes the force and attracts it. However, the combustion exhaust gas flows through the exhaust manifold (7) and the bypass passage (1).
0, the exhaust passage (8), and the exhaust turbine (to), and are discharged to the atmosphere from the exhaust pipe (9).

Under normal operating conditions, the exhaust gas flow rate from the exhaust passage (8) is low due to the small amount of exhaust gas and the fact that the bypass passage (IO) with low flow resistance is open. It rotates only at low speed.Therefore, the intake turbine υ does not have the capacity to compress and supply intake air, and the internal combustion engine (1) operates in the same way as a non-supercharged internal combustion engine.On the other hand, the null throttle valve (4) During high-load operation when the valve is almost fully opened, the cam wire closes the circuit with the switch, so the control unit demagnetizes the coil, and the plunger closes the bypass passage with the spring. When the entire amount of exhaust gas passes through the exhaust passage (8), the exhaust turbine (to) is accelerated and starts rotating at high speed.

The intake turbine (2) then forcibly sends intake air to the intake passage (3), and supercharging begins. Due to supercharging, exhaust gas increases and the exhaust turbine accelerates considerably.
In this positive feedback loop, the boost pressure rapidly increases and reaches a constant value determined by the mechanical and thermal conditions of the internal combustion engine (1). At this time, the pressure chamber - which communicates with the intake passage (3) through the pipe @0, the atmospheric chamber (due to the differential pressure between I and D), and the diaphragm (A).
moves overcoming the repulsive force of the spring, and the pulp Q opens, allowing exhaust gas to flow out to the bypass passage and stopping the increase in supercharging pressure. Therefore, the internal combustion engine (1) generates high output at a critical boost pressure determined by mechanical and thermal conditions.

In this way, supercharging operation is prevented in operating ranges where output is not required, and supercharging operation is performed only when the driver is operating the throttle fully open when output is required, so unnecessary unnecessary operation is prevented without impairing the characteristics of a supercharged internal combustion engine. Fuel consumption can be prevented.

In the embodiment of this invention, the control valve is an electromagnetically driven solenoid valve (a), but it may also be driven by a motor, pneumatic or hydraulic cylinder, and the switch may be magnetically or optically driven. Of course, the same effect can be achieved in operation.

As described above, the present invention is provided with a detector that detects the fully open state of the throttle valve, and operates the bypass control valve to bypass exhaust gas when the throttle valve is not in the fully open state, so that the supercharger is virtually inoperable. As a result, the unnecessary increase in fuel consumption caused by the operation of the supercharger in the low to medium load range can be avoided without impairing supercharging when the throttle valve is fully open when the driver requests output. It is possible to provide an excellent supercharging pressure adjustment device that can prevent such problems.

[Brief explanation of the drawing]

The figure is a configuration diagram showing an embodiment of the present invention. In the figure, (1) is the internal combustion engine, (4) is the throttle valve, (
5) is the intake manifold, (7) is the exhaust manifold, (2) is the intake turbine, 0 is the exhaust turbine, the bottom is the solenoid valve, (a) is the cam, the box is the switch, and the bottom is the control unit. Agent Makoto Kuzuno- 147

Claims (1)

[Claims] A supercharger that is driven by the exhaust gas flow of the engine to supercharge intake air, a bypass passage that bypasses and circulates exhaust gas to the supercharger, and a control that controls the exhaust gas that flows through this bypass passage. a control unit that bypasses exhaust gas in a region where the throttle of the engine is not substantially fully opened by driving the control valve in accordance with the sensor signal; An engine boost pressure adjustment device comprising: