JPS6143942Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention uses mechanical supercharging, in which the supercharger is driven by the engine, and a long intake passage from the surge tank installed in the intake system to the engine combustion chamber. The present invention relates to a supercharging device that combines the engine speed with inertial supercharging that is set so that the amount of intake air is maximized in a specific rotation range.

The inventors of the present invention have addressed the disadvantages of using a positive displacement supercharger such as Roots or movable blades even in the high rotational speed range of the engine, namely reduced durability and increased size of the supercharger, as well as increased driving power loss. In order to avoid such problems, in the patent application No. 56-125763, mechanical supercharging and inertial supercharging were combined and Mechanical supercharging is used in the rotation range, and inertia supercharging is used in the higher rotation range, while mechanical supercharging to inertia supercharging or inertia supercharging is used in the above-mentioned predetermined rotation range (for example, approximately medium speed range). We proposed using a check valve installed in the intake passage to reduce torque fluctuations in engine output caused by fluctuations in intake pressure when switching to mechanical supercharging.

However, in the invention of the earlier application, a check valve is provided in the middle of the intake passage, and the intake passage has an intake passage to the supercharger on the upstream side of the check valve, and a discharge passage from the supercharger on the downstream side. Because they were connected to each other, during mechanical supercharging by the supercharger, the pulsation of supercharging pressure caused by the rotation of the supercharger is transmitted to the check valve, which causes the check valve to open and close, causing noise. Not only was the supercharged pressure from the supercharger flowing back through the check valve, which vibrates on and off, and was sucked into the supercharger again, causing the engine's supercharging pressure to drop.

The present invention provides, in the supercharging device of the prior invention,
By connecting the discharge passage from the turbocharger to the surge tank for inertial turbocharging, the pulsations in the boost pressure from the turbocharger are absorbed by the surge tank, and the check valve is prevented from being adversely affected. This is what I did.

The drawings of the embodiment will be explained below. In the drawings, 1 indicates a multi-cylinder internal combustion engine, and 2 indicates a positive displacement supercharger such as Roots, movable blade, or reciprocating type, and the supercharger 2 is designed to operate within a predetermined rotation range of the engine. It has a relatively small capacity so that a predetermined amount of air can be secured only in the rotation range below (for example, approximately medium speed rotation), and is rotationally driven from the crankshaft 3 of the engine 1 through a power transmission mechanism such as a belt 4. The power transmission mechanism is provided with a stage, for example, an electromagnetic clutch 5, which turns on or off power transmission to the supercharger 2, and a control circuit 7 that receives a signal from a rotation sensor 6 controls the engine. When the number of rotations is less than a predetermined number of rotations (for example, approximately medium speed rotation), the supercharger 2 is driven to rotate; The rotary drive of the motor is stopped.

Reference numeral 8 denotes a surge tank for inertial supercharging, and the surge tank 8 is connected to the intake port 9 of each cylinder of the engine 1 via an independent intake pipe 10, and the intake port 9 of each cylinder is connected to the intake port 9 of each cylinder of the engine 1. The length l of the intake passage from the opening into the combustion chamber of the cylinder to the opening into the surge tank 8 is such that the amount of intake air is greater than or equal to a predetermined rotational speed of the engine (for example, approximately medium speed). The length is set to be the maximum.

11 is an air cleaner, and an intake passage 12 from the air cleaner 11 to the surge tank 8 includes:
A check valve 13 that opens only in the direction of the surge tank 8 is provided, and an intake passage 1 to the supercharger 2 is provided in the intake passage 12 on the upstream side of the check valve 13.
4, while the discharge passage 1 in the supercharger 2
5 is connected to the surge tank 8. In this case, in the carburetor type internal combustion engine, a carburetor 16 with a throttle valve is installed in the intake passage 12 at a position upstream from the connection point of the intake passage 14 of the supercharger 2 to the intake passage 12, as shown by the dashed line. In the case of a fuel injection type internal combustion engine, an air flow meter 17 and a throttle valve 18 are provided in place of the carburetor 16 as shown by the two-dot chain line, so that the amount of air measured by the air flow meter 17 can be adjusted. It is sufficient to inject and supply the corresponding fuel to each cylinder, and in the case of a diesel engine, the air flow meter 17 and throttle valve 18 are not required.

In this configuration, when the engine rotation speed does not reach a predetermined rotation speed (for example, approximately medium speed rotation), all intake air from the air cleaner 11 is pressurized through the turbocharger 2 by driving the supercharger 2. Since the check valve 13 is closed at this time, the engine is operated with so-called mechanical supercharging, and the engine rotation reaches a predetermined rotation range (for example, approximately medium speed) or higher. Then, the amount of air from the supercharger 2 becomes insufficient compared to the amount of intake air to the engine (at this time,
The supercharger 2 may remain driven in the rotation range above the medium speed of the engine, but if it is stopped when the electromagnetic clutch 5 is turned off as in the above embodiment, the durability of the supercharger 2 can be improved. (in addition to reducing the power loss of the engine), since the pressure inside the surge tank 8 becomes below atmospheric pressure and the check valve 13 opens, the intake air from the air cleaner 11 is transferred without passing through the supercharger. It is introduced into each cylinder from the check valve 13 through the surge tank 8. At this time, the length l of the intake passage from the surge tank 8 to the combustion chamber of each cylinder is set so that the amount of intake air is maximum in a rotation range above a predetermined rotation range of the engine (for example, approximately medium speed). Therefore, in a rotation range above a predetermined rotation range (for example, approximately medium speed) of the engine, the engine is operated with so-called inertial supercharging.

When the check valve 13 opens and closes during switching between mechanical supercharging and inertial supercharging, there is an equilibrium section in which the pressure in the surge tank 8 becomes approximately atmospheric pressure, and after this equilibrium section, the pressure increases to approximately atmospheric pressure. Since the pressure shifts to below the atmospheric pressure or above the atmospheric pressure, there is no sudden change in the intake pressure, and therefore the torque fluctuation at the time of the switching transition described above can be reduced.On the other hand, the supercharging pressure during the mechanical supercharging Since there is pulsation caused by the rotation of the supercharger, when the discharge passage 15 of the supercharger 2 is connected to the intake passage 12 downstream of the check valve 13 in the middle, the supercharging The pressure pulsations are transmitted to the check valve 13, causing the check valve to vibrate in opening and closing.

In contrast, in the present invention, the discharge passage 15 from the supercharger 2 is connected to the surge tank 8, so that the pulsations of supercharging pressure during mechanical supercharging enter the large capacity surge tank 8. As a result, the check valve 13 is hardly affected by the supercharging pressure from the supercharger and can maintain a closed state.

Therefore, according to the present invention, in a supercharging device that uses both mechanical supercharging and inertial supercharging, the reverse occurs during mechanical supercharging in a rotation range below a predetermined rotation range (for example, approximately medium speed rotation). Since backflow of supercharging pressure from the stop valve can be reliably prevented, mechanical supercharging can be performed accurately without causing a drop in supercharging pressure.

In addition, as described above, the discharge passage 1 from the supercharger 2
5 to the surge tank 8, when the opening of the discharge passage 15 into the surge tank 8 is coaxially opposed to the opening of one intake pipe 10 into the surge tank 8, During mechanical supercharging, supercharging from the opening of the discharge passage 15 flows toward the opening of one intake pipe 10 and is sucked into the intake pipe 10 by the pulsations within the intake pipe 10. , the supercharging cannot be distributed equally to each intake pipe, but the axis 15' at the opening of the discharge passage 15 is
As shown in FIG. 1, the axis 10' of the opening 0 may be set at a right angle or the like, or as shown in FIG. ', 10' are shifted vertically or horizontally by an appropriate distance e, or when both openings are provided facing each other, both axes 1 are shifted as shown in FIG.
By configuring the opening of the discharge passage 15 so that it does not face the opening of the intake pipe 10 on the same axis, such as by shifting the opening of the discharge passage 15 by an appropriate distance e' vertically or horizontally, mechanical overload can be prevented. The supercharging can be distributed approximately equally to each intake pipe 10 and thus to each cylinder of the engine.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an embodiment of the present invention, and FIGS. 2 and 3 are diagrams of other embodiments of the present invention. 1... Engine, 2... Supercharger, 4... Belt, 8
... surge tank, 10 ... intake pipe, 11 ... air cleaner, 12 ... intake passage, 13 ... check valve, 14 ... suction passage, 15 ... discharge passage.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A surge tank is provided in the intake passage leading from the air cleaner to the cylinder of the engine, and the length of the intake passage from the surge tank to the cylinder is limited to a rotation range exceeding a predetermined rotation of the engine. In addition, the intake passage from the air cleaner to the surge tank is equipped with a check valve that opens only in the direction from the air cleaner to the surge tank. A supercharging device for an internal combustion engine, characterized in that a supercharger is coupled to be driven and rotated by the engine, and a discharge passage from the supercharger is connected to the surge tank. (2) The opening of the discharge passage into the surge tank is configured so as not to face, on the same axis, the opening into the surge tank of the intake pipe leading from the surge tank to the cylinder. A supercharging device for an internal combustion engine according to claim 1 of the utility model registration claim.