JP2010106686A - Fluid control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine intake device that does not require a wide clearance between a valve body and a wall housing the valve body, and that does not cause operational failure due to deposits in the clearance. <P>SOLUTION: When an operating state of an engine is a fuel-uninjected state while a vehicle is decelerating, an electromagnetic valve 24 is opened to reciprocate a valve body 14. In response thereto, drawn air is powerfully jetted out from air outlets 21 provided on both sides of the valve body 14 to an inner wall surface of an air intake port 4. At this time, the reciprocation of the valve body 14 blows away deposits, fuel, and the like, attached to the entire clearance. This prevents operational failures in the engine intake device caused by the deposits, and enhances reliability. Further, the deposits and the like in the clearance are blown away and eliminated without requiring the wide clearance, so that a malfunction such that a tumbling flow generated in a cylinder 1 is weakened by the drawn air for eliminating the deposits is not caused. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid control apparatus that controls a fluid flow rate, a fluid pressure, or a fluid flow state. For example, a vortex (tumble flow) of intake air (combustion air) in a cylinder of an engine (internal combustion engine). The present invention relates to a technique suitable for use in an engine intake device that generates a swirl flow.

(Conventional technology)
In the fluid control device, a valve body is disposed inside a valve housing (passage forming member) that forms a fluid passage, and the valve body is displaced by a valve actuator disposed outside the fluid passage, whereby the flow rate of fluid flowing in the fluid passage , Controlling fluid pressure or fluid flow.
However, a substance (for example, an impurity) contained in the fluid flowing in the fluid passage may be deposited and deposited as a deposit in the valve body that is displaced in the fluid passage or the valve housing that accommodates the valve body. When the deposit adheres to the clearance between the valve body and the valve housing, the displacement of the valve body may be hindered by the deposit.

The above problems will be specifically described.
For example, an engine intake device that generates a vortex in intake air sucked into an engine cylinder is known (for example, Patent Document 1).
In the engine intake device disclosed in Patent Document 1, a valve body is disposed inside an intake passage, and a valve body is opened and closed by rotating a shaft that rotates integrally with the valve body from the outside of the intake manifold. Thus, a swirl flow such as a swirl flow (lateral rotation flow) or a tumble flow (vertical rotation flow) is generated in the intake air sucked into the cylinder.

In the intake passage in which the valve body is disposed, the intake air filtered by the air filter passes in a state where EGR gas and blow-by gas are included. For this reason, components (oil content and the like) contained in the exhaust gas are deposited as deposits on the clearance between the valve body and the intake passage.
Alternatively, there is a possibility that the fuel adheres to the clearance between the valve body and the intake passage by blowing back the fuel injected from the injector. The fuel adhering to the clearance between the valve body and the intake passage becomes a deposit and accumulates over time.
Deposits have the property of increasing adhesive strength when cold. As a result, the deposit attached to the clearance between the valve body and the intake passage may increase the driving torque of the valve body, which may hinder the opening and closing of the valve body. That is, there is a possibility that the engine intake device may be deteriorated in responsiveness or malfunction such as valve body sticking due to the accumulation of deposits.

Therefore, in the vicinity of the clearance where deposits are likely to accumulate, a clearance enlargement portion (a portion where the gap is widened, a secondary hole, a secondary notch, etc., which blows away the fuel adhering to the clearance or the deposit downstream): In FIG. It has been proposed to form a sub-hole J3 in the rotating valve body J2 (for example, Patent Document 2).
However, since the intake air flows through the clearance expansion portion when the vortex is generated, the vortex formed downstream of the valve body is weakened, and as a result, the fuel efficiency improvement effect due to the generation of the vortex is reduced.
JP 2002-242684 A JP 2003-293775 A

  The present invention has been made in view of the above-described problems, and an object thereof is to avoid the problem that deposits adhere to and accumulate on the clearance between the valve body and the valve housing without increasing the clearance between the valve body and the valve housing. It is in the provision of a fluid control device capable of performing the above.

[Means of claim 1]
The fluid control apparatus according to the first aspect discharges fluid toward the clearance between the valve body and the valve housing.
Thereby, the deposit adhering to the clearance between the valve body and the valve housing can be blown away by the fluid discharged from the outlet without increasing the clearance between the valve body and the valve housing. For this reason, it is possible to avoid the problem that deposits adhere and accumulate on the clearance, and the reliability of the fluid control device can be improved.

[Means of claim 2]
The air outlet of the means of claim 2 is provided in the valve body.
The formation position of the clearance changes as the rotational position of the valve body changes. And by providing a blower outlet in a valve body, the deposit of the clearance formed according to the rotation position of a valve body can be blown off and removed.

[Means of claim 3]
According to a third aspect of the present invention, the fluid control device is an engine intake device that is provided in an intake passage of an engine that generates an output for traveling of the vehicle and controls a flow state of intake air sucked into a cylinder of the engine.
As a result, it is possible to avoid the problem that deposits (including fuel) adhere to and accumulate on the clearance without weakening the vortex formed downstream of the valve body.

[Means of claim 4]
According to a fourth aspect of the present invention, there is provided a discharge fluid supply means comprising: a bypass passage that communicates an upstream of a throttle valve provided in the intake passage and a blowout outlet provided downstream of the throttle valve; and an open / close that opens and closes the bypass passage It consists of means.
As a result, a part of the intake air can be blown out from the outlet by the negative pressure generated on the downstream side of the throttle valve. That is, it is not necessary to separately provide an air pump or the like for blowing out a portion of the intake air from the air outlet, and an increase in the size and cost of the engine intake device can be avoided.

[Means of claim 5]
The control means of the means of claim 5 opens and closes the opening / closing means during the operation in which the fuel injection of the engine is stopped, such as during deceleration of the vehicle. That is, the opening / closing means is opened when the engine is in an operating state in which no fuel is burned.
During deceleration of the vehicle, the throttle valve is closed and a large negative pressure is generated on the downstream side of the throttle valve, so that the amount of intake air discharged from the outlet increases and the effect of blowing deposits adhering to the clearance is enhanced. Can do.
In addition to the intake air amount detected by the intake air amount sensor, even if the intake air amount that has passed through the bypass flow-in flows into the cylinder, fuel is not burned. The air / fuel ratio is not affected.

[Means of claim 6]
The control means of the means of claim 6 operates the valve actuator to move and displace the valve body when the opening / closing means is open.
Thereby, deposits can be removed in a clearance in a wide range (for example, the entire range of the movable range of the valve body) in the movable range of the valve body.

A fluid control device of the best mode (for example, an engine intake device) includes a valve housing (for example, a cylinder head that forms an intake port) through which fluid can pass, and a valve body that is displaceable inside the valve housing. And a valve actuator for driving the valve body, and a control means for controlling the operation of the valve actuator.
This fluid control device blows a part of the fluid flowing through a fluid passage (for example, an intake passage) and a blowout port that discharges fluid (for example, a part of the intake passage) toward a clearance between the valve body and the valve housing. Discharge fluid supply means for supplying to the outlet. And the supply operation | movement of the fluid to a blower outlet is controlled by the control means in a discharge fluid supply means.

A first embodiment in which the present invention is applied to an engine intake system will be described with reference to FIGS.
The vehicle is equipped with an engine (reciprocating engine) that generates an output for driving the vehicle by burning fuel. The engine includes an intake passage 2 (an example of a fluid passage) that guides intake air into the cylinder 1 and an exhaust passage 3 that discharges exhaust gas generated in the cylinder 1.
The intake passage 2 is provided by an intake pipe, an intake manifold, and an internal passage of the intake port 4.

The intake pipe includes an air filter 5 that removes dust and dirt contained in the intake air from the upstream side to the downstream side of the intake air, a throttle valve 6 that adjusts the intake air amount sucked into the cylinder 1, and an intake air amount. An intake air amount sensor 7 (air flow sensor) is provided for measuring.
The intake manifold is a branch pipe that distributes the intake air supplied from the intake pipe to each cylinder 1 of the engine, and in the upstream portion of the branch section, intake pulsation and intake interference that adversely affect the accuracy of the intake air amount sensor 7 are generated. A surge tank 8 is formed for prevention.

The intake port 4 is formed in the cylinder head of the engine and guides the intake air distributed by the intake manifold into the cylinder 1.
Here, in addition to the intake port 4 that guides intake air into each cylinder 1, the cylinder head is formed with an exhaust port 9 that exhausts exhaust gas generated in each cylinder 1. The cylinder head includes an intake valve 11 for opening and closing an outlet end of the intake port 4 (boundary portion with the cylinder 1) and an inlet end of the exhaust port 9 (boundary portion with the cylinder 1) for each cylinder. And an exhaust valve 12 for opening and closing. In addition, the code | symbol SP in FIG. 1 is a spark plug which ignites the compressed air-fuel | gaseous mixture.

The intake port 4 is provided with an injector 13 for spraying fuel during intake air sucked into the cylinder 1.
Further, the intake port 4 is provided with an intake flow control valve for controlling the flow state of the intake air sucked into the cylinder 1 on the upstream side of the intake air from the injector 13.
The intake flow control valve includes a valve body 14 disposed in the intake port 4 upstream of the injector 13 and valve body driving means for driving the valve body 14. In this embodiment, the valve body 14 is provided. The cylinder head (that is, the cylinder head forming the intake port 4) that accommodates the valve housing corresponds to the valve housing.

The valve body 14 switches between a closed state in which the upper part in the intake port 4 is slightly opened (hereinafter referred to as a fully closed state) and a state in which the intake port 4 is fully opened (hereinafter referred to as a fully opened state). It is a possible plate-like door, and includes a rotation shaft 15 that rotatably supports the valve body 14, and a plate door 16 that is provided integrally with the rotation shaft 15.
Specifically, the intake port 4 of this embodiment has a substantially rectangular cross section, and the plate door 16 has a substantially rectangular shape substantially coincident with the cross section of the intake port 4 so that the fully closed state can be achieved. Presents a shape.

On the lower surface of the intake port 4, a door accommodating recess 17 into which the valve body 14 is fitted when the valve body 14 fully opens the intake port 4 is formed. When the valve body 14 is fully open, the upper surface of the valve body 14 and the inner wall of the adjacent intake port 4 coincide with each other so that no irregularities are generated in the intake port 4, thereby reducing the flow resistance. ing.
As a result, the intake air flows smoothly through the intake port 4, and it is possible to avoid a decrease in engine performance at the time of high rotation and high load.
A rotating shaft 15 of the valve body 14 is disposed at the upstream end of the intake air of the door accommodating recess 17. Then, the fully closed state is set by rotating the valve body 14 in a direction that opposes the flow direction of intake air, and conversely, the fully open state is set by rotating the valve body 14 in a direction according to the flow direction of intake air. Is done.

The valve body driving means simultaneously transmits a valve actuator 18 that rotationally drives the valve body 14 and an output torque of the valve actuator 18 to the rotational shaft 15 of the valve body 14 provided for each intake port 4. It consists of means.
The valve actuator 18 includes an electric motor that generates a rotational output when energized, and a speed reducer that decelerates the rotational output of the electric motor and transmits it to the rotating shaft 15 of the valve body 14.
The valve actuator 18 is energized and controlled by an ECU 19 (abbreviation of engine control unit: corresponding to control means).

The ECU 19 is a known electronic control device equipped with a microcomputer.
The ECU 19 controls the energization of the valve actuator 18 in an operation state in which a tumble flow is required such as when the engine is cold or when the engine requires a small amount of intake air. As shown, the valve body 14 is rotated in a direction that opposes the flow direction of intake air to achieve a fully closed state. As a result, an operation state in which a drift occurs in the intake port 4 and a strong tumble flow occurs in the cylinder 1 is set.

  On the other hand, the ECU 19 controls the energization of the valve actuator 18 during an operation state in which it is not required to generate a tumble flow, such as during normal operation when the engine is warm or during operation where the engine requires a large amount of intake air. The body 14 is rotated in a direction according to the flow direction of the intake air to achieve a fully open state. As a result, the partial blockage of the intake port 4 by the valve body 14 is released, and an operation state in which the tumble flow does not occur in the cylinder 1 is set.

Here, EGR gas and blow-by gas are contained in the intake port 4 where the valve body 14 is disposed. For this reason, when no countermeasure is taken, components (oil content and the like) contained in the exhaust gas are deposited and deposited on the clearance C between the valve body 14 and the inner wall of the intake port 4.
Alternatively, there is a possibility that the fuel adheres to the clearance C between the valve body 14 and the inner wall of the intake port 4 by blowing back the fuel injected from the injector 13 and the deposited fuel deposits over time.
Then, there is a possibility that the engine intake device malfunctions, for example, the valve body 14 is fixed by deposits deposited on the clearance C.

In order to solve this problem, the engine intake device includes a blower outlet 21 that discharges intake air toward the clearance C between the valve body 14 and the inner wall of the intake port 4, and one intake air flowing through the intake passage 2. Discharge fluid supply means 22 for supplying a part to the outlet 21 is provided, and the discharge fluid supply means 22 is controlled by the ECU 19 to supply intake air to the outlet 21.
Next, the air outlet 21, the discharge fluid supply means 22, and the ECU 19 will be specifically described.

The outlet 21 is provided in the valve body 14, and discharges the intake air supplied by the discharge fluid supply means 22 into the clearance C between the valve body 14 and the inner wall of the intake port 4.
Specifically, the discharge port 21 opens to both sides of the plate door 16 (sides extending vertically when the intake port 4 is viewed from the intake upstream side), and both sides of the plate door 16. Are continuously provided in a slit shape from the rotation center toward the rotation end.

Here, the plate door 16 provided with the discharge port 21 will be specifically described.
The upstream side of the intake air in the plate thickness of the plate door 16 is provided with a wide door width in order to make the clearance C between the both sides of the valve body 14 and the inner wall of the intake port 4 as narrow as possible. Thereby, the leakage of the intake air from the both sides of the valve body 14 and the inner wall of the intake port 4 is suppressed.
On the other hand, on the downstream side of the intake air in the thickness of the plate door 16, a small amount of a gap is formed between both sides of the valve body 14 and the inner wall of the intake port 4. Is provided. Thereby, the intake air discharged from the outlet 21 is blown out toward the inner wall of the intake port 4.

The discharge fluid supply means 22 includes a bypass passage 23 that communicates the upstream of the throttle valve 6 provided in the intake passage 2 and the outlet 21 provided in the valve body 14 on the downstream side of the throttle valve 6, and this bypass passage. And an electromagnetic valve 24 that opens and closes 23 (an example of an opening / closing means).
The bypass flow path 23 sucks intake air upstream of the throttle valve 6 by negative pressure generated downstream of the throttle valve 6 and guides it to the outlet 21. It blows out toward the inner wall of 4. A part of the bypass channel 23 is provided inside the valve body 14. The bypass flow path 23 in the valve body 14 includes an in-shaft passage provided in the rotating shaft 15 and an in-door passage provided in the plate door 16.
The electromagnetic valve 24 is a normally closed type electric on-off valve that opens when energized, for example, and opens the bypass flow path 23 so that intake air is blown out from the outlet 21.

The ECU 19 is equipped with a control program for opening and closing the electromagnetic valve 24 in accordance with the driving state of the vehicle. Specifically, the ECU 19 is loaded with a control program for energizing the electromagnetic valve 24 and opening the electromagnetic valve 24 when the engine operating state is no fuel injection (deceleration of the vehicle and the accelerator is OFF).
In addition, the ECU 19 is loaded with a control program that operates the valve actuator 18 in a state where the electromagnetic valve 24 is opened, and repeatedly moves and displaces the valve body 14 from the fully open state to the fully closed state.

An example of this control will be described with reference to the flowchart of FIG.
When the control flow is entered (start), it is first determined whether or not the engine operation state is a fuel-injected state (deceleration of the vehicle and the accelerator is OFF) (step S1).
If the determination result in step S1 is NO, the process does not proceed to the deposit removal control routines S2 to S6, but proceeds to a control routine S7 for setting the opening of the intake flow control valve to an opening corresponding to the vehicle state. After execution of this control routine S7, this control flow is ended (END).

If the decision result in the step S1 is YES, the solenoid valve 24 is first opened to open the bypass passage 23 (step S2). Next, the valve actuator 18 is actuated to set the fully open state (step S3). Next, the valve actuator 18 is reversely operated to set the fully closed state (step S4).
Subsequently, it is determined whether or not the engine operating state is a fuel injection state (accelerator ON or idling) (step S5). If the decision result in the step S5 is NO, the process returns to the step S3, and the valve body 14 is moved and displaced again in the entire range from the fully open state to the fully closed state. If the decision result in the step S5 is YES, the electromagnetic valve 24 is closed and the bypass channel 23 is closed (step S6), and then the process proceeds to a step S7.

[Effect of Example 1]
The ECU 19 of the engine intake device repeats the operation of opening the electromagnetic valve 24 and reciprocating the valve element 14 in the entire rotation range when the engine operation state is the no fuel injection state (deceleration of the vehicle). During deceleration of the vehicle, the throttle valve 6 is closed and the negative pressure of the intake port 4 increases. Then, the flow of intake air toward the air outlet 21 increases in the bypass flow path 23, and the intake air is strongly discharged from the air outlets 21 provided on both sides of the valve body 14 toward the inner wall surface of the intake port 4. At this time, the valve body 14 reciprocates several times in the entire rotation range, so that deposits, fuel, and the like attached to the entire range of the clearance C are blown away by the intake air discharged from the outlet 21.

Thereby, the engine intake device of Embodiment 1 can obtain the following effects.
(1) Since deposits, fuel, etc. adhering to the inner wall surface of the intake port 4 forming the clearance C are blown away, malfunction of the engine intake device due to the deposit can be suppressed, and the reliability of the engine intake device can be improved. it can.
(2) Deposits, fuel, etc. adhering to the clearance C can be blown away and removed without increasing the clearance C between both sides of the valve element 14 and the inner wall surface of the intake port 4. In other words, the amount of intake air that passes through the clearance C can be suppressed during the operation state in which the tumble flow is generated (fully closed state). For this reason, the problem that the tumble flow generated in the cylinder 1 is weakened by the intake air for removing the deposit does not occur.

(3) Since a part of the intake air is blown out from the outlet 21 by the negative pressure generated on the downstream side of the throttle valve 6, it is not necessary to separately provide an air pump or the like for blowing out a part of the intake air from the outlet 21. For this reason, the enlargement and cost increase of the engine intake device can be suppressed.
(4) When the engine operating state is a no fuel injection state (during deceleration of the vehicle), a portion of the intake air is blown out from the outlet 21 to remove deposits. For this reason, the amount of intake air discharged from the outlet 21 can be increased by using a large negative pressure generated on the downstream side of the throttle valve 6, and the effect of blowing off the deposit can be enhanced.

(5) When the engine operation state is a fuel non-injection state (deceleration of the vehicle), a portion of the intake air is blown out from the outlet 21 to remove deposits. For this reason, apart from the intake air amount detected by the intake air amount sensor 7, the intake air amount that has passed through the bypass flow path 23 flows into the cylinder 1, but since no fuel is burned in the cylinder 1, the engine This does not affect the torque generated and the air-fuel ratio in the cylinder 1.
(6) Since the valve body 14 reciprocates in the entire rotation range, deposits, fuel, and the like attached to the entire range of the clearance C can be blown off and removed. Thereby, generation | occurrence | production of a malfunction can be prevented in any rotation position of the valve body 14. FIG.

[Modification]
In the above embodiment, the example in which the valve body 14 of the intake flow control valve is disposed in the intake port 4 is shown, but the valve body 14 may be disposed in the downstream end of the intake manifold. Alternatively, a valve housing may be disposed between the cylinder head and the intake manifold, and the valve body 14 may be disposed therein.

  In the above embodiment, the example in which the air outlet 21 is provided in the valve body 14 has been shown. However, the air outlet 21 is provided in the valve housing (cylinder head in the embodiment) that accommodates the valve body 14 and the intake air is blown out from the valve housing. Then, the deposit at the clearance C may be removed.

  In the above embodiment, an example in which the present invention is applied to an intake flow control valve that generates a vortex flow has been described. However, the present invention is not limited to the intake flow control valve, and other fluid controls such as a throttle valve 6, an EGR valve, a blow-by gas valve, and the like. Deposits also occur in the clearance C in the valve. Therefore, the present invention may be applied to another fluid control valve different from the intake flow control valve.

1 is a schematic view of an engine intake device (Example 1). FIG. (Example 1) which is the side view and top view of the valve body which were set to the fully closed state. It is a flowchart which shows the example of control (Example 1). It is explanatory drawing of the intake flow control valve in which the subhole was formed in the valve body (conventional example).

Explanation of symbols

2 Intake passage 6 Throttle valve 14 Valve body 18 Valve actuator 19 ECU (control means)
21 Outlet 22 Discharge fluid supply means 23 Bypass flow path 24 Solenoid valve (opening / closing means)
C Clearance

Claims (6)

A valve housing through which fluid can pass;
A valve body provided to be displaceable inside the valve housing;
A valve actuator for driving the valve body;
Control means for controlling the operation of the valve actuator;
A fluid control device comprising:
This fluid control device
An outlet for discharging fluid toward the clearance between the valve body and the valve housing;
A discharge fluid supply means for supplying a part of the fluid to the outlet,
The discharge fluid supply means is a fluid control apparatus, wherein the control means controls the supply operation of the fluid to the outlet. The fluid control device according to claim 1,
The fluid control device according to claim 1, wherein the air outlet is provided in the valve body. In the fluid control device according to claim 1 or 2,
The fluid control device is an engine intake device in which the valve body is provided in an intake passage of an engine that generates an output for running a vehicle, and controls a flow state of intake air sucked into a cylinder of the engine. Fluid control device. The fluid control device according to claim 3,
The discharge fluid supply means includes
A bypass flow path that connects an upstream of a throttle valve provided in the intake passage and the outlet provided on the downstream side of the throttle valve;
Opening and closing means for opening and closing the bypass flow path;
A fluid control device comprising: The fluid control device according to claim 4, wherein
The fluid control apparatus, wherein the control means opens the opening / closing means during engine operation in which fuel injection of the engine is stopped, such as during deceleration of the vehicle. The fluid control device according to claim 5, wherein
The fluid control apparatus according to claim 1, wherein the control means operates the valve actuator to move and displace the valve body when the opening / closing means is open.

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