JPS58211527A - Supercharging device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To inhibit supercharging positively, and to prevent the damage of the engine by providing a throttle control valve related to supercharging pressure to a suction system on mechanical supercharging in the specific number of revolutions or less and closing the valve when supercharging pressure exceeds a fixed value. CONSTITUTION:When the engine 1 extends over a revolution region of the specific number of revolutions (approximately intermediate-speed revolution) or less, a suction path 9 is supplied with air of the quantity of air sucked or more by the drive of a supercharger 2. Accordingly, a check valve 10 for changing over supercharging is closed, the crosscurrent of air to the air cleaner 8 side is obstructed, and the engine is operated uner a mechanical supercharging state. When supercharging pressure exceeds a fixed value on the operation of the engine, the throttle control valve 17 is closed by an actuator 21 to which supercharging pressure is introduced from a path 25, the quantity of air sucked from the air cleaner 8 is throttled, and supercharging is prevented. When the engine reaches the specific number of revolution or more, on the other hand, the quantity of air from the supercharger 2 is insufficient to some extent, the check valve 10 is opened, and the engine is operated under an inertial supercharging state.

Description

Detailed Description of the Invention The present invention provides supercharging for internal combustion engines using mechanical supercharging in which a positive displacement supercharger such as Roots or i+J rotor blades is driven by the engine, and a surge tank provided in the intake system. This invention relates to a supercharging device that combines inertial supercharging in which the length of the intake passage to the engine combustion chamber is set so that the amount of intake air reaches a maximum in a specific rotation range.

The present company aims to avoid the disadvantages of using a positive displacement turbocharger even in the high rotational speed range of the engine, such as reduced durability and increased size of the turbocharger, as well as an increase in driving power loss. Therefore, mechanical supercharging and inertial supercharging are combined, and mechanical supercharging is performed in a rotation range below a certain engine speed (for example, approximately medium speed rotation), and inertial supercharging is used in the engine rotation range beyond that. on the other hand,
When supercharging during mechanical supercharging, if the supercharging pressure exceeds a certain value, it is released into the atmosphere or into a part of the intake system near the intake air cleaner to prevent the occurrence of supercharging. , in the patent applications No. 56-125763 and No. 56-195336.

However, when overcharging during mechanical supercharging, releasing excess boost pressure to the atmosphere or to a part of the intake system near the downstream of the intake air cleaner means that the supercharger is , the amount of air required for the engine plus the above-mentioned amount of release air is compressed and blown, so the power loss of the supercharger increases during this time, and especially in the latter case, the intake system If the air is released near the downstream of the intake air cleaner, the air that escapes will repeat the cycle of being sucked into the turbocharger. This increases the engine's fuel efficiency, which causes negative thermal effects such as a reduction in engine output and frequent knocking.

The present invention uses mechanical supercharging in the rotation range below a specific rotation speed as in the previous application, and uses inertial supercharging in the rotation range below 1-, while supercharging during mechanical supercharging. Prevent 11
- a throttle control valve associated with supercharging I is provided in a portion of the intake system near the downstream of the air cleaner;
When the supercharging IE exceeds a certain value during mechanical supercharging, the throttle control valve is closed to reduce the amount of intake air from the intake air cleaner. This is to avoid the problem that we had hoped for.

The present invention will be explained below with reference to drawings of embodiments. In the drawings, CI) indicates a multi-cylinder internal combustion engine, and (2) indicates a positive displacement supercharger such as Roots, rotor blade, or reciprocating type. ), the specified supercharging is performed only in the rotation range F below the specific engine speed (approximately medium speed rotation), and the engine is relatively small in speed.
Belt (4) from the crankshaft (3) etc. of the engine (1)
It is rotationally driven via a power transmission mechanism such as the following.

(5) is a surge tank for inertial supercharging, and the surge tank (5) is an intake boat (6) for each cylinder of the engine (1).
The intake boat (6) in each cylinder opens into the combustion chamber of that cylinder [1], and the intake pipe (7) connects to the surge tank. (5) The length of the intake passage to the point where it opens [1] is less than or equal to the specified rotation speed (approximately medium speed rotation) of the engine.
The length is set so that the amount of intake air 11 is maximum in the - rotation range.

(8) is an air cleaner for intake;
) and the surge tank (5) described in 11YI, the air cleaner (8) is connected to the surge tank (5).
) A supercharging switching reverse ratio valve S o is provided which opens only in the direction of the supercharger ( 2) and connect the discharge passages o4 from each. In this case, in a carburetor type internal combustion engine 1, a carburetor a3 with a throttle valve 0 is provided as shown by the intake passage (9) f4+ + and a two-dot chain line, and in a fuel injection type internal combustion engine, a carburetor a3 is provided with a throttle valve 0. , the air flow meter αG is installed as shown by the dashed line in the middle of the intake passage (9).
It is sufficient to provide a throttle valve 0Q and an air meter in the intake passage (9) in the case of a diesel engine.

The intake passage (9) is provided with a butterfly-type throttle control valve αη for opening and closing the intake passage (9) near the downstream of the air cleaner (8), and the valve shaft of this throttle control valve 07) is provided. Connect one end of the lever C11, which is the same as 08), to the tire flam type actuator (a) via the rod (a).
It is connected to the diaphragm (2) divided into two diaphragm chambers (t), and the spring (to) in one diaphragm chamber keeps the throttle control valve 0 to fully open at all times, while the other diaphragm chamber (
The intake pressure after the switching check valve (11) is introduced into the switching check valve (c) through the passage (to), and when the intake pressure reaches a certain supercharging pressure, the throttle control valve 0 to Kabane (
2) is constructed so as to close against the

In this configuration, when the 1u rotation speed of the engine does not reach a specific rotation speed (approximately medium speed rotation), the intake passage (9) is supplied with air equivalent to 1 engine intake air by the drive of the supercharger. Then, the pressure in the intake passage (9) becomes lower than atmospheric pressure, and the supercharging switching reverse 1L valve Ql closes to block the backflow to the air IJ side, so that the pressurized air from the supercharger is All of the fuel is fed into the engine, and the engine is operated with so-called mechanical supercharging. During this operating state of mechanical supercharging, if the supercharging pressure exceeds a certain value, the throttle control valve a'? ) is closed by the actuator Qυ, and the intake air from the air cleaner (8) is throttled, so there is no more boost pressure, and the boost pressure does not exceed a certain value. It is possible to prevent damage to the engine due to overcharging, and by throttling one intake air from the air cleaner (8) by closing the throttle control valve 07) during overcharging, Since the air flowing through the supercharger (2) decreases, this supercharger (2)
) is reduced.

When the engine speed increases and reaches a certain speed, the air from the supercharger (2) becomes insufficient compared to the amount of air taken into the engine, and the pressure in the intake passage (9) increases. When the pressure approaches the atmospheric pressure and then becomes below atmospheric pressure, the check valve 00 opens, so atmospheric air from the air cleaner (8) is directly introduced into the intake passage (9) through the inverted valve QO. At this time, the length of the intake passage from the surge tank (5) to the combustion chamber of each cylinder of the engine is 1. ) is set so that the amount of intake air is maximum in the rotation range above a specific engine speed, so the engine is operated with so-called inertial supercharging in the rotation range above the specific engine speed. Additionally, when the engine speed decelerates below a certain speed, the air 1fN from the supercharger (2) becomes greater than the engine's intake air 11j, causing the pressure in the intake passage (for the intake passage) to drop to 1-1-2. Reverse 11 for Kirikiyoshi
- Valve 01 closes, so mechanical supercharging begins from this point on.

Note that the throttle control valve 07) may be provided in the intake passage (11) to the supercharger (2) instead of being provided in the intake passage (9) as in the embodiment described in +1■. Passage (9)
In place of the supercharging switching check valve tll inside, a throttle valve (14) is installed so that it closes during mechanical supercharging and opens during inertial supercharging.
Alternatively, a supercharging switching valve linked to Ot+ etc. may be used, and the supercharger (2) described in +iii is only necessary for mechanical supercharging in the rotation range of a specific engine speed, and when inertia is appropriate. Since it is unnecessary, the power transmission mechanism from the engine ( ) to the supercharger (2) is provided with a means for turning off or turning off the power transmission, such as an electromagnetic clutch (4), and the electromagnetic clutch (
4) is connected to the engine rotation sensor (a) or pressure sensor (c) via a control circuit so that the supercharger is driven only during mechanical supercharging and stopped during inertial supercharging. Good.

In summary, the present invention provides a surge tank in the intake passage from the air cooler to the cylinder of the engine, and adjusts the length of the intake passage from the surge tank to the cylinder by changing the length of the intake passage from the surge tank to the cylinder at a specific rotational speed of the engine. Set the amount of intake air to be maximum in the range tj! A supercharging switching valve is provided in the airware cleaner intake passage marked I, while +? A supercharger with a capacity suitable for the intake air in a rotation range below a specific rotation speed of the engine is connected to the engine described in il. and the discharge passages are respectively connected to the intake passages on the downstream side of the supercharging switching valve, and 1
(1) A throttle control valve is provided in a portion of the intake passage near the air cleaner or in the suction passage of the supercharger, the throttle control valve being closed when the pressure downstream of the supercharging switching valve exceeds a certain supercharging pressure. In a supercharging device that combines mechanical supercharging and inertial supercharging, supercharging during mechanical supercharging is
As mentioned above, since this is prevented by the throttle control valve provided near the air cleaner in the intake passage or in the intake passage of the supercharger, it is possible to prevent the drive power of the supercharger from increasing during boost pressure control, and 1 of intake air temperature. There is no rise,
Filling efficiency decreases as intake air temperature increases.

Also, it has the effect of preventing adverse thermal effects such as frequent occurrence of bumping.

[Brief explanation of the drawing]

The drawing is a diagram of an apparatus according to an embodiment of the present invention. (1)...engine, (2)...supercharging! , (8)...
Air cleaner, (5)...Surge tank, (9)...
・Intake passage - (1 (g) Supercharging switching check valve, (lυ
... Suction passage, o4... Discharge passage, 0η... Throttle control valve. Patent applicant Dino Hittsu Kogyo Co., Ltd.

Claims (1)

[Claims] (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 determined so that the intake air sensitivity is reduced in the engine speed range less than or equal to the specified engine speed. A supercharging switching valve is provided in the intake passage from the air cleaner, while a supercharging valve is installed in the engine with a capacity suitable for intake air in a rotation range below a specific rotation speed of the engine. The suction passages of the superchargers are connected to the intake passages on the upstream side of the supercharging switching valve, and the discharge passages of the turbocharging machines are connected to the intake passages on the downstream side of the supercharging switching valves. A throttle control valve is provided in a part near the air cleaner or in the suction passage of the supercharger, which closes when the pressure JJ of the flow from the supercharging switching valve exceeds a certain supercharging pressure. A supercharging device for internal combustion engines.