JP2017040183A - Intake air quantity control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally start an engine even when valve sticking due to icing occurs.SOLUTION: A throttle valve unit 1 includes a throttle valve 2 which can open and close an intake passage 61 to a combustion chamber 130 in accordance with turning around an axial center Ax, and a driving motor 3 for turning the throttle valve 2. The throttle valve 2 is constituted of a first valve 21 which can open and close an inner peripheral portion of a cross section of the intake passage 61, and a second valve 22 which can open and close an outer peripheral portion of the cross section of the intake passage 61. The first valve 21 is connected to the driving motor 3, and the second valve 22 is energized by a second torsion spring 42 so as to integrally turn with the first valve 21 in a normal state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an intake air amount control device for an internal combustion engine, and more particularly to a technique useful for starting an engine when a valve is stuck by icing.

In a reciprocating internal combustion engine (engine) for a vehicle or the like, an intake air amount control device that controls an intake air amount into a combustion chamber is used.
Generally, in this type of intake air amount control device, the intake air amount to the downstream combustion chamber can be controlled by adjusting the opening of a throttle valve provided upstream of the intake manifold (for example, a patent) References 1 and 2).

JP-A-6-88540 JP 2010-275921 A

  By the way, in this type of intake air amount control device, a phenomenon (icing) in which the throttle valve sticks with ice may occur. In particular, icing is likely to occur in an engine in which blow-by gas is recirculated to the vicinity of a throttle valve in the intake manifold or an engine in which an intake passage closed by the throttle valve is provided substantially horizontally.

FIG. 5 is a diagram for explaining the occurrence of icing.
As shown in this figure, when the outside air is below freezing, the moisture in the blow-by gas is cooled and frozen during engine operation, and ice adheres to the inner wall of the intake manifold. The adhering ice is liquefied by dead soak heat after the engine is stopped, travels through the intake manifold and the inner wall of the throttle body as indicated by broken lines in the figure, and accumulates at the lower end of the throttle valve in the vicinity. Then, this water refreezes in an atmosphere below freezing point, and the throttle valve is fixed. If the throttle valve is stuck, intake into the combustion chamber cannot be performed and the engine cannot be started normally.
Although there is a structure that keeps the throttle valve warm by passing engine cooling water, the cooling water itself cools at the ambient temperature after the engine stops, so it is effective for fixing the throttle valve by icing. No.

  The present invention has been made to solve the above problems, and provides an intake air amount control device for an internal combustion engine that can normally start the engine even when valve sticking due to icing occurs. Objective.

In order to achieve the above object, the invention according to claim 1 is a throttle valve capable of opening and closing an intake passage to a combustion chamber in association with rotation about a rotation axis, and drive means for rotating the throttle valve. An intake air amount control device for an internal combustion engine comprising:
The throttle valve is
A first valve capable of opening and closing a portion excluding a lower end portion of the cross section of the intake passage;
A second valve capable of opening and closing other portions including a lower end portion of the cross section of the intake passage;
Consisting of
The first valve is connected to the drive means;
The second valve is biased by a biasing member so as to rotate integrally with the first valve in a normal state.

According to a second aspect of the present invention, in the intake air amount control device for an internal combustion engine according to the first aspect,
The first valve is configured to be able to open and close an inner peripheral portion of the cross section of the intake passage,
The second valve is configured to be capable of opening and closing a portion on the outer peripheral side of the inner peripheral portion in the intake passage cross section.

A third aspect of the present invention is the intake air amount control apparatus for an internal combustion engine according to the first or second aspect,
The urging member is a torsion spring having both ends fixed to a driving force transmission portion from the driving means to the first valve and a rotation shaft of the second valve.

The invention according to claim 4 is the intake air amount control device for an internal combustion engine according to any one of claims 1 to 3,
The intake passage is provided substantially horizontally.

According to the present invention, the driving force from the driving means is applied to the first valve and the second valve is biased so as to rotate integrally with the first valve at the normal time when the valve is not fixed. As a result, the first valve and the second valve are integrally opened and closed to open the intake passage.
In addition, when the valve sticking due to icing occurs, the second valve that opens and closes the portion including the lower end portion of the intake passage cross section can be fixed with ice, but the first valve that opens and closes the other portion except the lower end portion is the driving means. Is rotated in the same manner as in the normal state, and the intake passage is opened.
Therefore, not only during normal times, but also when the valve is stuck due to icing, the engine can be started with normal intake into the combustion chamber.

It is a block diagram which shows schematic structure of the intake system of the engine in embodiment. It is a figure which shows typically the structure of the throttle valve unit in embodiment. It is a figure for demonstrating the opening / closing operation | movement of the throttle valve in embodiment. It is a figure which shows typically the structure of the throttle valve unit in the modification of embodiment. It is a figure for demonstrating the occurrence condition of the icing in the conventional throttle valve.

  Embodiments of an intake air amount control apparatus for an internal combustion engine according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating a schematic configuration of an intake system of an engine (internal combustion engine) 100 according to the present embodiment, and FIG. 2 is a diagram schematically illustrating a configuration of a throttle valve unit 1 provided in the engine 100.

As shown in FIG. 1, in the intake system of the engine 100 according to the present embodiment, an intake flow path P that extends from an air duct 110 that includes an air cleaner 111 to the combustion chamber 130 through the intake manifold 120 is configured. The intake manifold 120 is provided with a gas inlet 121 for introducing blow-by gas from a crankcase (not shown).
Among the components of the intake passage P, a throttle valve unit 1 including a throttle valve 2 is provided between the air duct 110 and the intake manifold 120.

The throttle valve unit 1 is an internal combustion engine intake air amount control apparatus according to the present invention, and is a valve unit for controlling the intake air amount into the combustion chamber 130 by adjusting the opening of the throttle valve 2.
Specifically, as shown in FIG. 2, the throttle valve unit 1 includes a drive motor 3, two torsion springs 4, and two position sensors 5 in addition to the throttle valve 2.

The throttle valve 2 is a substantially disc-shaped valve body capable of opening and closing an intake passage 61 having a substantially circular cross section formed in the throttle body 6.
The intake passage 61 of the throttle body 6 communicates with the intake passages of the air duct 110 and the intake manifold 120 to form an intake passage P (see FIG. 1), and is provided substantially horizontally in the present embodiment. Yes.

Specifically, the throttle valve 2 includes a first valve 21 on the inner peripheral side and a second valve 22 on the outer peripheral side that can be rotated independently of each other.
Among these, the 1st valve | bulb 21 is formed in the substantially disc shape, and is provided integrally with the 1st rotating shaft 210 along the radial direction. The first rotation shaft 210 extends along a direction orthogonal to the intake passage 61 and extends on both sides of the first valve 21 and is pivotally supported by the throttle body 6 via a bearing (not shown). . With this configuration, the first valve 21 can open and close the inner peripheral portion of the cross section of the intake passage 61 by rotating around the axis center Ax of the first rotation shaft 210.

On the other hand, the second valve 22 is formed in an annular plate shape having an outer diameter capable of closing the cross section of the intake passage 61 and an inner diameter corresponding to the outer diameter of the first valve 21. And are provided integrally. The second rotating shaft 220 is formed in a cylindrical shape having the same axis center Ax as the first rotating shaft 210, and the first rotating shaft 210 is inserted through the inside thereof. Is pivotally supported. With such a configuration, the second valve 22 can rotate around the shaft center Ax to open and close the outer peripheral portion of the cross section of the intake passage 61 relative to the inner peripheral portion where the first valve 21 opens and closes. It has become.
Further, the second valve 22 is provided with a stopper 221 for restricting the rotation of the second valve 22 relative to the first valve 21 on the inner peripheral side (see FIG. 3). As will be described later, the stopper 221 is arranged so that the second valve 22 biased by the second torsion spring 42 does not rotate in the opening direction (the direction in which the intake passage 61 is opened) with respect to the first valve 21. The rotation is restricted.

The drive motor 3 is a drive means for rotating the throttle valve 2 and is connected to the first rotation shaft 210 of the first valve 21. More specifically, one end of the first rotation shaft 210 extends to the side of the second rotation shaft 220, and a spur gear 211 is provided at the extended portion. The drive gear 211 is connected (engaged) to the drive shaft 31 of the drive motor 3 via the speed reduction mechanism 7.
The drive motor 3 is electrically connected to an ECU (Engine Control Unit) 140 (see FIG. 1), and is driven and controlled by the ECU 140.

The two torsion springs 4 include a first torsion spring 41 and a second torsion spring 42.
Among these, the first torsion spring 41 is a return spring that urges the first valve 21 in the closing direction around the axial center Ax (the direction in which the intake passage 61 is closed), and both ends of the first torsion spring 41 and the throttle body 6 are first rotated. It is fixed to the drive gear 211 of the shaft 210.
On the other hand, the second torsion spring 42 is a biasing member according to the present invention so that the first valve 21 and the second valve 22 rotate integrally in a normal state (that is, rotate at the same rotation angle position with respect to each other). The second valve 22 is urged around the axial center Ax. More specifically, the second torsion spring 42 biases the second valve 22 in the opening direction around the axial center Ax with a biasing force smaller than the biasing force of the first torsion spring 41. The second torsion spring 42 has both ends on the inner peripheral side of the first torsion spring 41, the flange 222 provided at one end of the second rotation shaft 220 and the drive gear 211 of the first rotation shaft 210. It is fixed.

The two position sensors 5 are sensors that individually detect the opening degrees of the first valve 21 and the second valve 22, and are composed of a first position sensor 51 and a second position sensor 52.
Among these, the first position sensor 51 is provided at one end of the first rotation shaft 210 and detects the opening degree of the first valve 21 by detecting the rotation angle position of the first rotation shaft 210. It is possible.
On the other hand, the second position sensor 52 is provided at the other end of the second rotation shaft 220 and detects the opening degree of the second valve 22 by detecting the rotation angle position of the second rotation shaft 220. It is possible.
These two position sensors 5 are individually electrically connected to the ECU 140 (see FIG. 1), and output the opening information of the first valve 21 and the second valve 22 to the ECU 140.

Next, the opening / closing operation of the throttle valve 2 in the throttle valve unit 1 will be described.
FIG. 3 is a view for explaining the opening / closing operation of the throttle valve 2.

First, the opening / closing operation of the throttle valve 2 in the normal state will be described.
When the drive motor 3 is not driven (for example, when the engine is stopped, for example), as shown in FIG. 3A, the throttle valve 2 includes a first valve 21 and a second valve 22 that are integrated (that is, The air intake passage 61 is closed at a position slightly inclined with respect to the intake passage 61 (at the same rotational angle position).
More specifically, at this time, the first valve 21 is closed by the first torsion spring 41 with a larger urging force than the second torsion spring 42 that urges the second valve 22 in the opening direction (clockwise in FIG. 3). While being urged in the direction (counterclockwise direction in FIG. 3), the stopper 221 restricts the rotation of the second valve 22 relative to the first valve 21 in the opening direction. Therefore, the throttle valve 2 is in a closed state in which the first valve 21 and the second valve 22 are integrated, and the second valve 22 is in contact with the inner wall of the intake passage 61.

In this closed state, for example, when the engine 100 is started and the drive motor 3 is driven by a drive command from the ECU 140, a driving force in the opening direction that is larger than the urging force of the first torsion spring 41 is reduced. Acting on the first rotating shaft 210 via
As a result, as shown in FIG. 3 (b), the throttle valve 2 is opened by rotating in the opening direction with the first valve 21 and the second valve 22 being integrated, and the intake passage 61 is opened. Then, air is supplied to the downstream combustion chamber 130.

Next, the opening operation of the throttle valve 2 when the lower end portion of the second valve 22 is fixed by icing in the closed state of the throttle valve 2 when the engine is stopped will be described.
When the engine 100 is started in the closed state of the throttle valve 2 and the drive motor 3 is driven by a drive command from the ECU 140, the drive force in the opening direction from the drive motor 3 is applied as in the normal case described above. It acts on the first rotating shaft 210. At this time, as shown in FIG. 3C, the throttle valve 2 has the second valve 22 on the outer peripheral side fixed to the inner wall of the intake passage 61 by ice, but the first valve 21 on the inner peripheral side is opened. Rotate in the direction.
As a result, a part of the intake passage 61 is opened, and air is supplied to the downstream combustion chamber 130, so that the engine 100 can be started in the same manner as in normal times. Then, when the temperature rises by starting the engine 100 and the ice that has fixed the second valve 22 is melted, the second valve 22 is brought into contact with the first valve 21 by the urging force of the second torsion spring 42. Return to the integrated state. Further, the ECU 140 can detect whether the second valve 22 is fixed or returned from the fixed state based on the opening information from the two position sensors 5.

As described above, according to the present embodiment, the driving force from the drive motor 3 is applied to the first valve 21 and rotates integrally with the first valve 21 at the normal time when the valve is not stuck. Thus, when the second valve 22 is biased by the second torsion spring 42, the first valve 21 and the second valve 22 integrally open and close, and the intake passage 61 is opened.
When the valve sticking due to icing occurs, the second valve 22 that opens and closes the outer peripheral portion of the cross section of the intake passage 61 can be fixed with ice, but the first valve 21 that opens and closes the inner peripheral portion is usually driven by the drive motor 3. The intake passage 61 is opened in the same manner as at the time.
Therefore, not only during normal times, but also when the valve is stuck due to icing, engine 100 can be started by normally sucking air into combustion chamber 130.

  Further, since the second valve 22 only needs to be urged by the second torsion spring 42, it is simpler than the case where the first valve 21 and the second valve 22 are rotated by separate drive motors, for example. It can be configured.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

For example, in the above embodiment, the two torsion springs 4 are provided so as to directly bias the two rotation shafts (the first rotation shaft 210 and the second rotation shaft 220). The torsion spring 4 may be provided anywhere in the driving force transmission system from the driving motor 3 to the two rotating shafts 210 and 220.
For example, as shown in FIG. 4, a connecting gear 8 that can connect / disconnect the speed reduction mechanism 7 and the shaft portion is provided on the same axis, and a gear that meshes with the connecting gear 8 is formed on the outer peripheral surface of the flange 222. Then, both ends of the first torsion spring 41 are fixed to the cover 9 and the speed reduction mechanism 7 fixed to the throttle body 6, and both ends of the second torsion spring 42 are fixed to the speed reduction mechanism 7 and the connecting gear 8.
Even with such a configuration, the throttle valve 2 can be opened and closed as in the above embodiment. More specifically, in normal times, the driving force of the drive motor 3 simultaneously rotates the first valve 21 and the second valve 22 via the speed reduction mechanism 7 and the connecting gear 8. Then, when the second valve 22 is fixed, the rotation of the connecting gear 8 is restricted, but the speed reduction mechanism 7 functions to rotate the first valve 21. Further, when the second valve 22 is returned from the fixed state, the second valve 22 can be returned to an integrated state with the first valve 21 by the urging force of the second torsion spring 42. However, in this case, since various gears are interposed between the valves 21 and 22 and the torsion spring 4, it is necessary to adjust the urging force of each torsion spring 4 from that of the above embodiment.

  In addition, the throttle valve 2 is composed of the first valve 21 on the inner peripheral side and the second valve 22 on the outer peripheral side. However, the throttle valve 2 is a portion of the cross section of the intake passage 61 excluding the lower end. What is necessary is just to be comprised from the 1st valve | bulb which can be opened and closed, and the 2nd valve | bulb which can open and close the other part including a lower end part in the intake passage 61 cross section.

  Further, the intake passage 61 opened and closed by the throttle valve 2 may not be provided substantially horizontally. Even if the intake passage 61 is not substantially horizontal, if the throttle valve 2 is inclined with respect to the vertical direction in the closed state, water may accumulate at the lower end portion of the intake passage 61 and the valve may be stuck due to icing.

  Further, the stopper 221 that restricts the relative rotation between the first valve 21 and the second valve 22 may be provided in the first valve 21 instead of the second valve 22, or the second valve 22 may be provided in the second torsion. The stopper 221 may be omitted if it is configured to rotate integrally with the first valve 21 in a normal state only by the urging force of the spring 42.

1 Throttle valve unit (intake air amount control device for internal combustion engine)
2 Throttle valve 21 First valve 210 First rotation shaft 22 Second valve 220 Second rotation shaft 221 Stopper Ax Axis center 3 Drive motor (drive means)
4 Torsion spring 41 First torsion spring 42 Second torsion spring (biasing member)
5 Position Sensor 51 First Position Sensor 52 Second Position Sensor 6 Throttle Body 61 Intake Passage 7 Deceleration Mechanism 100 Engine (Internal Combustion Engine)
120 Intake manifold 130 Combustion chamber

Claims (4)

An intake air amount control device for an internal combustion engine comprising a throttle valve capable of opening and closing an intake passage to a combustion chamber in association with rotation about a rotation axis, and drive means for rotating the throttle valve,
The throttle valve is
A first valve capable of opening and closing a portion excluding a lower end portion of the cross section of the intake passage;
A second valve capable of opening and closing other portions including a lower end portion of the cross section of the intake passage;
Consisting of
The first valve is connected to the drive means;
An intake air amount control device for an internal combustion engine, wherein the second valve is biased by a biasing member so as to rotate integrally with the first valve in a normal state. The first valve is configured to be able to open and close an inner peripheral portion of the cross section of the intake passage,
2. The intake air amount control device for an internal combustion engine according to claim 1, wherein the second valve is configured to be able to open and close a portion on an outer peripheral side of the inner peripheral portion in the cross section of the intake passage.   The urging member is a torsion spring having both ends fixed to a driving force transmission portion from the driving means to the first valve and a rotation shaft of the second valve. The intake air amount control device for an internal combustion engine according to claim 2.   The intake air amount control device for an internal combustion engine according to any one of claims 1 to 3, wherein the intake passage is provided substantially horizontally.

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