JPH0768910B2 - Exhaust valve pause mechanism engine with supercharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an exhaust valve suspension mechanism engine with a supercharger, and in particular, to the above-mentioned structure which is configured to obtain stable torque characteristics over a wide operating range. Regarding the format engine.

<Prior Art> Conventionally, for the purpose of increasing the output of the engine, a supercharger called a turbocharger, which is composed of a compressor driven by the exhaust gas flow of the engine, has been used. These are driven by the exhaust gas flow,
In a vehicle engine in which the supercharging capacity is directly influenced by the exhaust gas pressure and the load fluctuation is relatively large, it is difficult to exert a sufficient supercharging effect in the entire operating range from low speed to high speed. is there.

That is, the turbine speed is proportional to the gas speed entering the turbine housing. Therefore, in order to improve the supercharging efficiency in the low speed region, the narrowest area of the scroll part with respect to the turbine diameter should be made small and the gas flow velocity should be small. However, on the other hand, exhaust resistance increases at high speeds, leading to output loss. On the other hand, when the capacity is increased by placing importance on the high speed range, the inertial mass of the turbine increases, and the responsiveness in the low speed range tends to be insufficient.

On the other hand, it is known that it is effective to use the inertial effect to increase the flow velocity of intake and exhaust flow in order to increase the output of the engine. A valve actuating device for increasing the flow rate of the air-fuel mixture by suspending the operation of each of the intake and exhaust valves is disclosed, for example, in JP-A-60-1312 by the same applicant as the present application. .

Such an engine is equipped with an exhaust valve that operates in the entire operating range and an exhaust valve that operates only in the high speed range. The present inventor has conceived that the supercharging efficiency can be improved in a wider engine operating range by driving the feeder.

<Problems to be Solved by the Invention> In view of the problems of the prior art and the knowledge of the present inventor, the main object of the present invention is to improve intake charging efficiency over a wider engine operating range and An object of the present invention is to provide an exhaust valve suspension mechanism engine with a supercharger capable of achieving an improvement in responsiveness in a low load and low rotation range.

<Means for Solving the Problems> According to the present invention, the object is to provide a plurality of exhaust valves in each cylinder and suspend the operation of some of the exhaust valves in the low speed operation range of the engine. An exhaust valve suspension mechanism engine with a supercharger comprising: a supercharger driven by an exhaust flow from an exhaust valve that operates in the entire operating range of the exhaust valve; and an exhaust valve that pauses in a low speed operating range. It is achieved by providing an exhaust valve deactivation mechanism engine with a supercharger, each of which is provided with a supercharger driven by an exhaust flow from the engine.

<Operation> In this way, it becomes possible to combine a plurality of exhaust valves and superchargers, which have different operating regions depending on the operating conditions of the engine, and operate them in an optimal region in a consistent manner.
It is possible to perform supercharging according to the driving situation. Further, if a plurality of superchargers are appropriately used in accordance with the operating condition, the size and weight of each supercharger can be reduced.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to the accompanying drawings with reference to specific embodiments.

FIG. 1 shows a schematic intake / exhaust system diagram of an engine according to the present invention.

The engine 1 has intake valves 3a, 3b and exhaust valves 4a, 4b for each cylinder 2.
It has a four-valve configuration with a pair of and, and one of these intake and exhaust valves operates in the entire operating range,
The other has a valve pause mechanism that operates only in the high speed range and pauses in the low speed range.

The intake ports opened and closed by the intake valves 3a and 3b are gathered by an intake manifold 5, and a fuel injection valve 6 is provided near a connection portion of the intake manifold 5 to each intake port.
However, it is provided to inject the fuel into the intake air at a predetermined timing.

A throttle body 7 with a built-in throttle valve for adjusting the intake flow rate is connected to the end portion of the intake manifold 5, and an intake chamber 8 for calming intake pulsation is connected to the intake upstream side of the throttle body 7. ing.

The inlet chamber 8 has two intake inlets 9a and 9b.
One is connected to the discharge port of the compressor of the supercharger 11a for the entire range and the other is connected to the discharge port of the compressor of the supercharger 11b for the high range via the supercharging passages 10a and 10b, respectively. , So that pressurized intake air can be introduced into the inlet chamber 8.

The intake ports of the compressors of both turbochargers 11a and 11b are installed in the intake passage.
It is connected to the air cleaner 13 via 12a and 12b so that the outside air can be sucked by operating the supercharger.

On the other hand, on the exhaust side, the exhaust valve 4a on the side that operates in the entire operating range,
Exhaust manifold on the whole area side, gathered by individual exhaust manifolds 14a, 14b connected to each exhaust port that is opened and closed by the exhaust valve 4b that operates only in the high speed range
14a is connected to the exhaust turbine section of the turbocharger 11a for the entire range, and the exhaust manifold 14b on the high speed range side is connected to the exhaust turbine section of the supercharger 11b for the high range.

The exhaust discharge ports of both the superchargers 11a and 11b are connected to the muffler 15 so that exhaust gas can be discharged into the atmosphere. Further, bypass ports 17a and 17b that are opened and closed by wastegate valves 16a and 16b, respectively, are provided immediately upstream of the exhaust turbine parts of both superchargers 11a and 11b, and allow passage through the exhaust turbine parts as necessary. Instead, the exhaust stream can be released into the atmosphere.

Next, the operating procedure of the engine having the above configuration will be described.

In the low speed and low load operation range of the engine, only the valves 3a and 4a on the side where both intake and exhaust valves are operated operate. Therefore, the exhaust gas is discharged only from the exhaust manifold 14a for the entire area. The exhaust gas discharged from the exhaust manifold 14a for the entire area drives the turbocharger 11a for the entire area, pressurizes the outside air sucked through the air cleaner 13, and the one supercharging passage
The intake air is pressure-fed into the inlet chamber 8 from the intake air inlet 9a via 10a. Further, the intake air is adjusted to a required flow rate by the throttle body 7, and is distributed from the intake manifold 5 to each cylinder 2 according to the operation of each piston. At this time,
In order to prevent the intake air from flowing out from the other intake air inlet 9b opened in the inlet chamber 8 toward the idle high-range turbocharger 11b, the inside of the high-pass side supercharging passage 10b is provided. An opening / closing valve 19 provided near the intake inlet 9b is closed so that the actuator 18 that responds to the boost pressure opens the valve.

In the high-speed, high-load operation range where all intake and exhaust valves are activated, exhaust gas is both exhaust gas for both full range and high range.
It will be discharged from 14a, 14b. Therefore, both turbochargers
Both 11a and 11b perform supercharging, the on-off valve 19 is opened due to a pressure increase in the supercharging passage 10b on the high frequency side, and a sufficient amount of supercharging intake air is supplied from both supercharging passages 10a and 10b to the inlet chamber 8
Will be sent to. Further, in the high load range, the exhaust pressure is high and there is a risk of supercharging, but the wastegate valve 16 operated by the actuator 20 that responds to the supercharging pressure is
At a and 16b, the exhaust flow is appropriately escaped to the bypass ports 17a and 17b side, whereby the rotation of the turbine is suppressed and the supercharging pressure is kept below a predetermined pressure.

<Effects of the Invention> As described above, according to the present invention, since a plurality of superchargers and the exhaust valve suspension mechanism are combined, a supercharger having a small and lightweight turbine wheel is used in a low speed range. The responsiveness can be improved, and a sufficient supercharging capacity can be secured by simultaneously operating a plurality of superchargers in parallel in a high speed range. Therefore, it is possible to exert a great effect on the improvement of the engine torque over a wider operating range and the improvement of the responsiveness in the low load region. Moreover, since the diameter of the turbine wheel can be reduced, the overall size of the engine can be reduced. Is effective.

[Brief description of drawings]

FIG. 1 is an intake / exhaust system diagram of an engine according to the present invention. 1 ... Engine, 2 ... Cylinder 3a, 3b ... Intake valve, 4a, 4b ... Exhaust valve 5 ... Intake manifold, 6 ... Fuel injection valve 7 ... Throttle body, 8 ... Inlet chamber 9a, 9b …… Intake inlet 10a, 10b …… Supercharging passage 11a …… Supercharger for all areas, 11b …… Supercharger for high range 12a, 12b …… Intake passage 13 …… Air cleaner 14a, 14b …… Exhaust manifold 15 ...... Muffler 16a, 16b ...... Wastegate valve 17a, 17b ...... Bypass port 18 ...... Actuator, 19 ...... Open / close valve 20 ...... Actuator

Claims (1)

[Claims] 1. An exhaust valve suspension mechanism engine with a supercharger, wherein each cylinder is provided with a plurality of exhaust valves, and the operation of some of the exhaust valves is suspended in a low speed operation range of the engine. A supercharger driven by the exhaust flow from the exhaust valve that operates in the entire operating range of the valve and a supercharger driven by the exhaust flow from the exhaust valve that stops in the low speed operating range are provided separately. Exhaust valve pause mechanism engine with supercharger.