JPS5865932A - Engine with supercharger - Google Patents

Abstract

PURPOSE:To simplify an opening-closing mechanism of a valve, by opening and closing the throttle valve in the side of a supercharge system line in a state of relating to intake negative pressure in an intake system line. CONSTITUTION:A supercharge system line 13 is provided independently of a normal intake system line 2, and a check valve 18, permitting only the flow of a mixture to the direction of a cylinder 1, is provided in the downstream part from the interposed part of a supercharger 11 in the supercharge system line 3, while a throttle valve 19 is provided in the upstream part from said interposed part of the supercharger 11, and a throttle valve control means 21, performing open-close control correlatively to intake negative pressure, is provided to said throttle valve 19. In this way, an opening and closing mechanism of the throttle valve in a supercharge side is simplified, further useless consumption of engine power at no-supercharge time can be substantially reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharged engine in which a normal intake system path and a supercharging system path having a supercharger are independently provided.

BACKGROUND ART Conventionally, supercharged engines generally have a supercharger disposed in a single intake system path. However, in such a system, the entire amount of intake air must be supplied by the supercharger, which results in an increase in the size of the supercharger. That is, for example, if a 4-cycle engine is used as a base, one cycle of the engine - total engine exhaust Jk V
X Ylc X supercharging ratio 1U. =Charging efficiency during natural aspiration-
A supercharger with a large air supply capacity is required.

Therefore, in recent years, in addition to the normal intake system with a carburetor, a supercharging system with a supercharger has been installed independently, and pressurized air is also supplied to the cylinder from the supercharging system during high loads. Engines have been developed that can improve charging efficiency and output by forcibly supplying fuel into the interior of the engine.

In this case, since it is not necessary to supply the entire amount of intake air into the cylinder by a supercharger, it is possible to obtain a sufficient supercharging effect using a relatively small-capacity supercharger. By the way, what has been considered in the past is to place the throttle valve in the downstream part of the supercharging system path from the supercharger insertion part. ! l
i′! The throttle valve is opened and closed in conjunction with a throttle valve or the like of a carburetor inserted in the intake system passage. That is, for example, only at high loads when the opening degree of the intake throttle valve becomes large, the turbocharging side throttle valve)/l
/The valve is opened to perform supercharging. However,
If the supercharging side throttle valve is disposed downstream of the supercharger insertion portion in this manner, it becomes difficult to dispose the throttle valve and the intake side throttle valve in close proximity to each other. Therefore, there is an inconvenience that the mechanism for interlocking both throttle valves tends to become complicated.

However, with such a configuration, when the throttle valve on the supercharging side is closed, the pressure between the throttle valve and the supercharger increases, so the pressure on the discharge port side of the supercharger increases. A large pressure difference occurs between the pressure on the suction port side and the pressure on the suction port side, and a load is applied to the supercharger. Therefore, even if it is not engine #1 with a supercharger inserted in a single intake system path, it is quite difficult to drive the supercharger when it is not doing any useful work. This has the disadvantage of requiring a large amount of force and wasting engine power.

The present invention was made with attention to such circumstances, and
A check valve is installed downstream of the supercharger insertion part of the supercharging system path, which is provided independently of the normal intake system path, to allow only the flow of air or air-fuel mixture toward the cylinder. By providing a throttle valve upstream of the feeder insertion part, and providing the throttle valve with a throttle valve control means that controls opening and closing in relation to the throttle opening or intake negative pressure provided in the intake system path. , supercharging eliminates the inconvenience of a complicated mechanism for opening and closing the supercharging side throttle valve, and also significantly reduces wasteful consumption of engine power when not supercharging. The aim is to provide a machine-equipped engine.

Hereinafter, one embodiment of the present invention will be described with reference to the first page.

A normal intake line 2 and a supercharging line 3 are provided independently for the cylinder l. The suction line 2 supplies air-fuel mixture into the cylinder l by using the negative pressure inside the cylinder l generated as the piston 4 descends, and has one end connected to each cylinder l.
- It has an intake boat 5 that communicates with the inside, and an intake passage 7 that communicates the other end of the intake boat 5 with the air cleaner 6. An intake valve 8 for opening and closing the intake port 5 is provided at one end of the intake boat 5, and a carburetor 9 is inserted in the middle of the intake passage 7. has been done. On the other hand, the supercharging system 3 is
Air pressurized by the supercharger 11 is forcibly supplied into the cylinder 1, and one end of the supercharging port 12 is opened into the cylinder 1. ... and a supercharging passage 13 whose other end communicates with the air cleaner 6. And the supercharging port 1
A supercharging pulp 14 for opening and closing the supercharging port 12 is provided at one end of the supercharging passage 13. A machine 11 is inserted. The supercharger 11 is a small air pump that is mechanically driven by the rotational force of the crankshaft, and is constantly in operation during engine operation. Further, a return passage 16 having a relief valve 15 is provided in parallel at the supercharger 11 insertion portion of the supercharging passage 13. The return passage 16 supplies pressurized air discharged from the discharge port 11a of the supercharger 11 to the suction port 1x of the supercharger 11 when the discharge pressure of the supercharger 11 becomes higher than a set value. It is meant to be returned to the air passage 17 on the 'b side.
The relief valve 15 is configured to allow only the flow of high pressure air in the direction of arrow X to pass therethrough. The intake valve 8 of the intake system path 2 is set to begin opening at the same time as a general intake valve, and to close at a point slightly beyond the bottom dead center. Further, the supercharging pulp 14 begins to open at the end of the engine intake stroke, and is set to close much later than the closing timing of the intake valve 8. The opening timing of the intake valve 8 and the supercharging pulp 14
The overlap with the opening timing is set to a value that does not cause the air-fuel mixture to blow back into the intake system path 2.

In such an engine, a back check is provided at a portion of the supercharging line 6-3 downstream of the supercharger 11 insertion portion, for example, at a joint between the supercharging port 12 and the supercharging passage 13. A valve 18 is provided, and a throttle valve 19 is provided upstream of the insertion portion of the supercharger 11, and the throttle valve 19 is opened and closed by a throttle valve control means 21. The check valve 18 has a structure called a reed valve, and has a yIJ direction, a tab, and an arrow Y.
It is designed to only allow air to pass in that direction.

Further, the throttle valve control means 21 includes, for example, a dashpot 2 that opens and closes the throttle valve 19 with the tip of an actuating rod 22b projected from one side of a diaphragm 22a.
2, and the negative pressure in the intake system passage 2 is transferred to the diaphragm 22.
A negative pressure introduction path 23 is provided on the other side of a for guiding into the diaphragm chamber 22Q.

Next, the operation of this engine will be explained. First, in a high load range where the exhaust valve lO on the intake system path 2 side is almost fully open, the intake negative pressure in the intake path 2 becomes an atmospheric pressure chamber, so the dash point supercharging system 3 side throttle valve 1
9 is in the open state. Therefore, the mixture is supplied into the cylinder 1 from the intake system path 2, and pressurized air is replenished into the cylinder 1 from the supercharging system path 3. In this case, the check valve 18 provided in the supercharging system 3 has the function of preventing the air-fuel mixture from blowing back from inside the cylinder l into the supercharging system 3, so the supercharging valve 14 is closed during the compression process. It is possible to set it to remain open until it has progressed considerably. On the other hand, in a partial load region where the throttle valve lO of the intake system passage 2 is close, the intake negative pressure in the intake system passage 2 shifts to the vacuum chamber SI, so that the actuating rod 22b of the dashpot 22 The engine moves backward, and the throttle valve 19 on the supercharging system path 3 side becomes closed. Therefore, replenishment of pressurized air from the supercharging system 3 is stopped, and only the air-fuel mixture from the intake system 2 is supplied into the cylinder 1.

As described above, in this engine, the throttle valve 19 on the side of the supercharging line 3 can be opened and closed in relation to the intake negative pressure on the side of the intake line 2, so that the engine can be supercharged according to the engine load. It has the advantage that the effect can be controlled automatically. In addition, in a partial load range where supercharging is unnecessary, the throttle valve 19 provided upstream of the supercharger 11 closes.
A portion of the supercharging passage 13 from the throttle valve 19 to the suction port 111 of the supercharger 11 is a negative pressure hand. At the same time, the portion of the supercharging passage 13 from the discharge port 11a of the supercharger 11 to the check valve 18 also becomes negative pressure due to the engine's swell effect and the backflow prevention effect of the check valve 18. Therefore, the amount of pumping work where the pressure difference between the suction port llb side and the discharge port 11a side of the supercharger 11 is small is reduced. Therefore, even if the supercharger 11 is driven all the time, there is an advantage that a large amount of engine power is not wasted in the partial load range where supercharging is not performed.

It should be noted that the sulph) μ valve control means is of course not limited to the configuration described above; for example, it opens and closes the throttle valve on the side of the supercharging system in relation to the opening degree of the throttle valve on the side of the intake system. It may also be of a link type, etc. configured as follows. Therefore, as in the present invention, the throttle valve 19 on the side of the supercharging system 17 is connected to the turbocharger 11.
If the upstream portion is also cut, the installation part of the throttle valve 19 can be adjusted to rJ! Since it is easy to configure the throttle valve control means integrally with the carburetor 9 inserted on the side of the power supply path 2, even if the throttle valve control means is of a link type, etc., the configuration will not be complicated. There are advantages.

[Brief explanation of the drawing]

The drawing is a schematic sectional view showing an embodiment of the present invention. 1...Cylinder, 2...Intake system path,
3...supercharging system path, 4 river φ...piston,
10... Sulf) A/valve, 11...
...supercharger, 19...throttle valve,
21... Throttle valve control means. Agent Patent Attorney Hiroshi Akazawa 〇 −

Claims (1)

[Claims] The intake system uses the negative pressure inside the cylinder as the piston descends to supply the air-fuel mixture into the cylinder, and the supercharger forcibly supplies pressurized air or air-fuel mixture into the cylinder. In an engine having an independent supply system path, a check valve is provided at a downstream portion of the supercharger insertion part of the supercharging system path to allow only air or air-fuel mixture to flow in the direction of the cylinder. At the same time, a throttle valve is provided in the upstream part of the turbocharger insertion part, and the opening and closing of the throttle valve provided in the intake system path is controlled in relation to the intake negative pressure. A supercharged engine characterized by being equipped with a throttle and torque valve control means.