CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2020-0033670, filed Mar. 19, 2020, the entire contents of which are incorporated herein for all purposes by this reference.

BACKGROUND

Field of the Invention

The present disclosure relates to a variable intake system for a vehicle, and more particularly, to a variable intake system for a vehicle, which has a variable valve to vary the amount of intake air according to engine operating conditions.

Description of the Related Art

As is well known to those skilled in the art, an engine of a vehicle requires air to burn fuel, and is supplied with the required air from an outside of the vehicle. However, since the air present outside of the vehicle contains a substantial amount of foreign matter such as dust, it is necessary to remove the foreign matter contained in the air in an intake process. Accordingly, the air introduced into the engine of the vehicle passes through an air cleaner, thus removing the foreign matter from the air.

Conventionally, a separable-type air cleaner in which a body part and a cover part are separated from each other has been developed. A clamp fixing method of fixing the cover part to the body part using several clamps is applied to the separable-type air cleaner. Thus, when one desires to replace a filter with a new one, all the clamps are loosened, to separate the cover part from the body part, and then the filter is replaced. Subsequently, the cover part and the body part are coupled to each other again, and then fixed to each other via the clamps.

However, the separable-type air cleaner is problematic in that several clamps are exposed to the outside, thus reducing an aesthetic appearance, and space for manipulating each clamp is required, and the clamps are required to be loosened one by one to separate the cover part from the body part, and thus, it is complicated to replace the filter with a new one. Therefore, recently, a drawer-type air cleaner configured to simply open and close a door so as to replace the filter with a new one is widely used.

The drawer-type air cleaner is configured such that a rotatable-type door for opening or closing a filter receiving part is installed in the cover part. When replacing the filter with a new one, the door is rotated to open an entrance of the filter receiving part, to replace the filter in the filter receiving part with a new one.

Meanwhile, a variable intake system with a variable valve capable of adjusting the inflow amount of intake air according to engine operating conditions in a vehicle has been developed. In the conventional variable intake system, a sub-duct is additionally connected to the air cleaner to be installed therein, apart from a main duct connected to the air cleaner. The variable valve is installed in the sub-duct to be opened by the suction pressure of the engine (i.e. intake negative pressure).

In particular, the variable valve may be installed at an exit of the sub-duct disposed in the air cleaner. In the variable intake system, since the suction pressure of the engine is minimal in a low-speed (e.g., low RPM) operation of the engine, external air is introduced into the air cleaner only through the main duct while the variable valve is closed.

In contrast, since the suction pressure of the engine increases in a high-speed (high RPM) operation of the engine, an additional amount of air may be introduced through the sub-duct while the variable valve is opened. To be more specific, in the separable-type air cleaner, the sub-duct as well as the main duct is inserted from an outside of the body part to an inside thereof to be installed in the body part, and the variable valve is installed at the sub-duct.

The variable valve is a valve that opens or closes a passage of the sub-duct according to the engine operating conditions, and includes a rotatable flap that is opened or closed according to the suction pressure of the engine. In the separable-type air cleaner, the variable valve may be installed in the exit of the sub-duct disposed in an internal space of the body part. Conventionally, to install the variable valve, the variable valve is fixed to the exit of the sub-duct located in the body part via a rivet or a bolt, before assembling the cover part of the air cleaner, and then the cover part is assembled with the body part.

In the separable-type air cleaner, since the interior of the body part is opened before the cover part is assembled and a working space for installing the variable valve in the body part in an open state may be secured, it is possible to assemble the variable valve by disposing it into the body part. However, in the drawer-type air cleaner, it is impossible to apply a variable valve module which is applied to the existing separable-type air cleaner.

In other words, in the drawer-type air cleaner, the cover part is joined to be fixed to the body part in an ultrasonic vibration welding method. If the cover part is joined to the body part in the ultrasonic vibration welding method after the variable valve is fastened to the body part via the rivet or the bolt, cracks or damage may occur at a joint of the variable valve and the air cleaner during the ultrasonic vibration welding process.

Furthermore, when intake negative pressure increases in a high output engine, time of opening the variable valve may be undesirably delayed. If a restoring force (e.g., closing force) of the valve is substantial, hitting noise may be excessively generated due to surface contact between the flap and a valve housing. To reduce the hitting noise, the flap and the valve housing may be maintained separated by a stopper even when the variable valve is closed. However, in this case, engine noise may be discharged through a gap, so that the noise, vibration, harshness (NVH) performance of the vehicle may be deteriorated.

The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.

SUMMARY

The present disclosure provides a variable intake system for a vehicle, which improves a mounting structure of a variable valve to solve a problem of the related art in which cracks or damage may occur at a joint of the variable valve and an air cleaner, and which simultaneously solves both a hitting-noise problem at the variable valve and an engine-noise discharging problem. Furthermore, another objective of the present disclosure is to provide a variable intake system for a vehicle, which may be responsive to a problem in which time of opening a variable valve is delayed in a high output engine.

In order to achieve the objective of the present disclosure, the present disclosure provides a variable intake system for a vehicle that may include an air cleaner configured to filter air via a filter and supply the air to an engine; a main duct connected to the air cleaner to supply the air; and a variable valve having a housing coupled and mounted to a mounting aperture of a mounting part provided on a front end of the filter of the air cleaner, and an internal passage of the housing may be opened by suction pressure of the engine in the mounting part to suction external air. A projection formed on the housing of the variable valve may be inserted into a projection seat formed in the mounting part to secure the variable valve to the mounting part.

The mounting aperture may be formed in a circular shape in the mounting part, a plurality of projections may be formed on the housing of the variable valve, a plurality of projection seats may be formed in an inner surface of the mounting part around the mounting aperture to couple each of the projections to a corresponding projection seat, and a plurality of projection entry grooves may be formed in an edge of the mounting aperture in the mounting part so that each of the projections passes through an inside of the mounting part, and thus, in a state where each of the projections passes through a corresponding projection entry groove to enter the inside of the mounting part, the projection may be inserted into each of the projection seats by rotation of the variable valve including the housing.

The projection seat may be formed by two protruding steps that extend from the inner surface of the mounting part to be spaced apart from each other, and in the space between the two protruding steps may be a groove space into which the projection may be inserted. The two protruding steps may each have a protruding shape in which a surface thereof rises gradually towards the groove space, so that a height of the surface may be gradually increased from the inner surface of the mounting part towards the groove space. The mounting part may be a part on the front end of the filter in the air cleaner.

The air cleaner may include a body part having a predetermined internal volume; a cover part having a predetermined internal volume and coupled to an upper side of the body part; and a filter installed in a filter receiving part disposed in internal space defined by the body part and the cover part. Additionally, the mounting part may be the body part that is the part on the front end of the filter of the air cleaner. The air cleaner may be a drawer-type air cleaner and the filter may be inserted and received in the filter receiving part in a sliding manner. The mounting part may be the main duct. Alternatively, the mounting part may be a sub-duct connected to the part on the front end of the filter of the air cleaner, separately from the main duct.

The variable valve may include a housing that defines an internal passage in which air may be suctioned; a flap rotatably hinged to the housing and rotated to open or close the internal passage of the housing according to engine suction pressure in the mounting part; and a sealing member disposed on the flap to come into contact with the housing when the flap is closed. A hinge part may be formed on an upper end of the housing, a joint may be formed on the upper end of the flap to be hinged to the hinge part of the housing, and a stopper may protrude from the upper end of the flap to come into contact with the housing when the flap rotates downwards to close the internal passage of the housing, thus maintaining a gap between the housing and the flap.

The variable valve may further include magnets installed in a lower end of the flap and a lower end of the housing, and the magnet of the flap and the magnet of the housing may be installed to provide attractive force to maintain the flap closed. The sealing member may include a main wing part formed along an entire circumference of an edge thereof to protrude towards the housing, thus coming into close contact with the housing when the flap is closed; and a sub-wing part that extends from a lower end of the sealing member to form a ‘V’-shaped section with a lower end of the main wing part, and coming into contact with the housing when the flap is closed, thus forming an air pocket with the main wing part and a surface of the housing.

The sealing member may include a main wing part that protrudes from an edge of the flap towards the housing to come into close contact with the housing when the flap is closed. The main wing part may be formed along the entire circumference of the edge of the sealing member, and an inner portion of the main wing part in the sealing member may be fixed to the flap. The sealing member may further include a sub-wing part that defines an air pocket of a ‘V’-shaped section with the main wing part when the sealing member is in contact with the housing.

Thus, the variable intake system according to the present disclosure improves the configuration, mounting structure and position of the variable valve, thus solving the problem of the related art in which cracks or damage may occur at the joint of the variable valve. Furthermore, it may be possible to simultaneously solve the hitting-noise problem between the flap and the housing when the variable valve is closed and the engine-noise discharging problem that may occur when the flap is separated from the housing with the variable valve being closed, due to the sealing member installed on the flap. Additionally, according to the present disclosure, it may be possible to respond to the problem in which the time of opening the variable valve is delayed in the high output engine, and the opening time of the variable valve may be maintained constant by the stopper of the flap, so that the robustness and durability of the variable valve may be improved.

