JPH0335876Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an intake system for a supercharged engine that includes an unloader valve for discharging dust and condensate into an intake passage, particularly an air cleaner.

(Prior Art) It is conventionally known to provide an unloader valve on the upstream side of a filter element of an air cleaner in an intake passage to discharge dust, drain, etc. entrained during intake to the outside of the intake passage. For example, in 1974
Publication No. 87309 discloses a structure of an unloader valve in which an opening is provided in the wall of an air cleaner installed in the intake passage, and a valve member is attached to the outer surface of the passage wall to close this opening. When the internal pressure increases and the pressure difference with the outside exceeds a predetermined value, the valve member is pushed open by the intake pressure in the passage, allowing dust, drain, etc. accumulated in the passage to be discharged. ing. The unloader valve is configured to open instantaneously when intake pressure increases mainly due to intake pulsation in a low rotational speed region.

(Problems to be Solved) However, in an intake structure equipped with a supercharger, the above-mentioned unloader valve is installed in the intake passage between the supercharger and the engine, and due to intake pulsation that occurs in a relatively low rotation range, If activated, there is a problem in that the unloader valve remains open due to the increase in supercharging pressure in a high engine speed range, which adversely affects supercharging efficiency.

(Means for solving the above problem) The present invention was constructed in order to solve the above problem, and the intake system for a supercharged engine according to the present invention includes a supercharger, a supercharger, an unloader valve that is provided in an intake passageway between the engine and communicates between the inside and outside of the intake passage when a pressure difference between the inside and outside of the intake passage is within a certain range; an outer valve member that is attached to the outer surface of the intake passage wall so as to close an opening provided in the intake passage wall and opens when the pressure difference exceeds a first operating value; and an inner valve member that closes the opening when the pressure difference exceeds a second operating value that is larger than the first operating value.

(Function) According to the present invention, in a relatively low rotation range, the pressure inside the intake passage periodically exceeds the first operating pressure due to intake pulsation, and the outer valve member opens periodically in response to this. At this time, since the inner valve member is open, the dust and drain in the intake passage are discharged to the outside by the opening operation of the outer valve member. When the operating state enters the high rotation range and the pressure in the intake passage exceeds the second operating pressure due to the operation of the supercharger, the inner member closes and blocks the opening, resulting in the unloader valve being closed. become.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the intake system of the engine E of this example has a first air cleaner 2 at the upstream end of the intake passage 1.
and a pressure wave supercharger 3 downstream thereof. Furthermore, an intercooler 4 is installed downstream of the supercharger 3 to cool the supercharged air. Further, the intake system of the engine E of this example includes a second air cleaner 5 between the intercooler 4 and the engine E, and is configured to remove dust and dehumidify the supercharged air. A relief valve 6 is provided in the intake passage 1 between the intercooler 4 and the second air cleaner 5, and a part of the supercharged air is returned into the first air cleaner 2 through the relief passage 7. Moreover, the exhaust passage 8 is
It is connected to a pressure wave supercharger 3. Intake air and exhaust air are introduced from opposite sides across the pressure wave supercharger 3 and come into direct contact within a plurality of pressure chambers formed around the rotor axis, thereby adding exhaust energy to the intake air. The structure is such that a supercharging effect can be obtained.

As shown in FIG. 2, a filter element 10 is arranged inside the second air cleaner 5 so as to block the intake passage, and an unloader valve 11 is provided in the air cleaner casing 5a. The unloader valve 11 is for appropriately discharging dust, drain, etc. captured by the filter element 10 and accumulated in the casing 5a to the outside of the air cleaner 5, and as shown in FIGS. An outer valve member 1 is attached to the outside of the casing 5a and is made of elastic rubber or the like so as to cover the recess 5b formed in the casing 5a.
2, and an inner valve member 13 that is attached from the inside of the casing 5a so as to cover the recess 5b. The outer valve member 12 penetrates through the opening 5c of the casing 5a in the center, and is connected to the casing 5a.
The inner valve member 13 is attached to the shaft portion 12a from inside the shaft portion 12a.
The inner valve member 1 is fitted over the large-diameter portion 12b formed in the inner valve member 2a so as not to be retractable.
3 and the outer valve member 12 sandwich the casing 5a and are fixed to the casing 5a. An opening 14 is formed in the recess 5b of the casing 5a, and the inner valve member 13 and the outer valve member 1
When both of 2 are in the open state, the casing 5a
Drain, dust, etc. inside the room pass through this opening 14,
Expelled from the casing. Outer valve member 12
In the normal state, the peripheral edge portion thereof is in contact with the flat portion of the peripheral edge of the recess 5b of the casing 5a, thereby blocking the interior chamber of the casing 5a from the outside. In other words, it is in a closed state. On the other hand, the inner valve member 13 is not in contact with the surface of the recess 5b in a normal state, and is therefore in an open state.

In the operating state of the engine E, pulsation of intake air occurs in a relatively low rotation range, and when the pressure inside the second air cleaner 5 exceeds a predetermined value, that is, the first working pressure due to this pulsation, the inner member 13
is maintained in the open state, but the outer valve member 12 is
It is pushed open by the intake pressure inside the air cleaner 5. As a result, the inside of the air cleaner 5 is brought into communication with the outside, and the dust and drain inside are discharged to the outside together with a portion of the intake air through the opening 14. Further, when the inside of the air cleaner 5 is brought into a low pressure state due to the pulsation, the outer member 12 returns to the closed state due to the restoring force due to the elasticity. Therefore, under such operating conditions, the unloader valve 11 is periodically opened in response to the high pressure waves of the intake pulsation, and each time the drain, dust, etc. inside the air cleaner 5 are removed.
It is discharged to the outside along with a portion of the intake air. and,
When the operating state is in a high rotation range and the pressure inside the second air cleaner 5 increases due to the operation of the supercharger 3 and exceeds the second operating pressure, the inner valve member 1
3 is in the closed state, and the internal space of the air cleaner 5 is again cut off from the outside.

(Effects of the present invention) According to the present invention, in a low rotation range where the boost pressure is relatively low, dust, condensate, etc. inside the air cleaner can be effectively discharged by using intake pulsation. , as the boost pressure increases,
Since the unloader valve is closed by the operation of the inner valve member, problems such as those caused by a drop in supercharging pressure do not occur. Moreover, the unloader valve of the present invention has an extremely simple structure and is advantageous in terms of cost.

[Brief explanation of drawings]

FIG. 1 is an overall schematic diagram of an engine according to an embodiment of the present invention, FIG. 2 is a sectional view of an air cleaner,
3 is a sectional view of an unloader valve according to an embodiment of the present invention, and FIG. 4 is a plan view of the unloader valve of FIG. 3. E...engine, 1...intake passage, 2...first
Air cleaner, 3... Pressure wave supercharger, 4... Intercooler, 5... Second air cleaner, 8... Exhaust passage, 11... Unloader valve, 12... Outer valve member, 13... Inner valve member, 14...Opening.

Claims (1)

[Scope of utility model registration request] A supercharger and an unloader that is installed in an intake passage between the supercharger and the engine and communicates between the inside and outside of the intake passage when the pressure difference between the inside and outside of the intake passage is within a certain range. an outer valve member, the unloader valve is attached to the outer surface of the intake passage wall so as to close an opening provided in the intake passage wall, and opens when the pressure difference exceeds a first actuation value; and an inner valve member mounted on the inner surface of the passage wall so as to face the opening, and closing the opening when the pressure difference exceeds a second actuation value that is larger than the first actuation value. Intake system for supercharged engines.