JP2010174704A - Suction control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suction control device for an internal combustion engine fitted with a suction flow control valve having a valve element made of a resin material, capable of sensing a breakage of the valve element properly. <P>SOLUTION: The valve element 21a of the suction flow control valve is to be accommodated in an accommodation part 23, which is formed at the wall surface of an intake manifold 20, and is furnished with a communication hole 25 having communication with inside the intake manifold 20 in the position confronting the valve element 21a. A pressure sensor 26 is connected with this communication hole 25. A breakage of the valve element 21a is detected on the basis of the pressure sensed by the pressure sensor 26 when the valve element 21a is in the valve opening position. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is provided in an intake passage of an internal combustion engine, and is displaced between a valve opening position for increasing a flow passage sectional area of the intake passage and a valve closing position for reducing a flow passage sectional area of the intake passage. The present invention relates to an intake air control device for an internal combustion engine including an intake air flow control valve having a valve body made of a resin material that controls the degree of deflection of the intake air flow.

  Many internal combustion engines including the in-cylinder injection type are equipped with an intake air control device for controlling an intake air flow in the cylinder such as a swirl flow or a tumble flow. For example, an intake control device for an internal combustion engine described in Patent Document 1 includes an intake flow control valve installed in an intake passage of the internal combustion engine, and a flow passage cross-sectional area in the intake passage through opening and closing of the valve body of the intake flow control valve. Is changed to change the degree of deflection of the intake air flow in the intake passage, thereby making the flow of the intake air flow in the cylinder variable.

JP 2008-240706 A

  However, in such an intake control device for an internal combustion engine, if the valve body of the intake flow control valve is made of a resin material, part of the valve body may be damaged and chipped. It becomes difficult to appropriately control the intake flow by the flow control valve.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to control intake air of an internal combustion engine that can appropriately detect breakage of the valve body of an intake flow control valve having a valve body made of a resin material. To provide an apparatus.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is provided in the intake passage of the internal combustion engine, and includes a valve opening position for increasing the flow passage cross-sectional area of the intake passage and a valve closing position for reducing the flow passage cross-sectional area of the intake passage. An intake control device for an internal combustion engine having an intake flow control valve having a valve body made of a resin material that controls the degree of deflection of the intake flow by displacing the intake flow, wherein the valve body is disposed on a wall surface of the intake passage. A storage portion for storing the valve body when the valve body is in the valve open position is formed, and the portion facing the valve body when the valve body is in the valve opening position in the storage portion is A communication hole communicating with the intake passage is formed, and a pressure sensor is connected to the communication hole, and detection is performed by the pressure sensor when the valve body is in the valve open position. The gist is to detect the breakage of the valve body based on the pressure.

  Normally, the intake pressure in the intake passage varies according to the opening / closing operation of the intake valve. Here, according to the above configuration, when the valve body of the intake flow control valve is in the open position without being damaged, the communication hole is closed by the valve body, so that it is detected by the pressure sensor. The detected pressure is higher than the intake pressure in the intake passage, and the fluctuation range of the detected pressure is thereby reduced compared to the fluctuation range of the intake pressure in the intake passage. On the other hand, when the valve body of the intake flow control valve is in the damaged position, the communication hole is exposed in the intake passage, so that the detected pressure detected by the pressure sensor is This is equivalent to the intake pressure in the intake passage, whereby the fluctuation range of the detected pressure is also equivalent to the fluctuation range of the intake pressure in the intake passage. As described above, according to the above configuration, the value or fluctuation of the detected pressure detected by the pressure sensor when the valve body is in the valve open position between the state where the valve body is not damaged and the state where the valve body is damaged. Since the widths are different, the breakage of the valve body made of the resin material can be detected based on the detected pressure.

  In the same configuration, when the value of the detected pressure (for example, the lowest value) when the valve body is in the valve open position is lower than a predetermined value, or the fluctuation range of the detected pressure is lower than the predetermined value. When it is larger, it is possible to determine that the valve body is damaged.

  Also, if there is a gap between the valve body at the valve opening position and the opening of the communication hole, the change in the detection pressure when the valve body is damaged and when it is not damaged becomes small, and when detecting damage to the valve body There is a risk that the accuracy of the lowering. Therefore, in a state where the valve body is in the valve opening position in at least one of a part surrounding the position facing the communication hole in the valve body or a part surrounding the communication hole in the storage part. In this case, a sealing member for sealing between the valve body and the periphery of the opening of the communication hole may be disposed. In this case, since the sealing member enhances the airtightness between the valve body at the valve opening position and the periphery of the opening of the communication hole, the change in the detected pressure when the valve body is damaged and when it is not damaged is clarified. As a result, the accuracy in detecting the breakage of the valve body can be improved.

The longitudinal cross-sectional view which shows a part of engine body in 1st Embodiment. The expanded sectional view which shows the structure of the intake flow control valve arrange | positioned in an intake manifold, and its periphery. The expanded sectional view which shows the state which the intake flow control valve damaged. The graph which shows the relationship between the detection pressure detected by a pressure sensor, and time. (A) is an expanded sectional view which shows the structure of the intake flow control valve arrange | positioned in an intake manifold and its periphery in 2nd Embodiment, (b) is a plane sectional view of a sealing member. The expanded sectional view which shows the structure of the intake flow control valve and its periphery in the modification of 1st Embodiment.

(First embodiment)
Hereinafter, a first embodiment of an internal combustion engine intake control device according to the present invention will be described with reference to FIGS.

  First, the engine body E in the internal combustion engine will be described. As shown in FIG. 1, the cylinder head 11 is formed with a plurality of intake ports 12 and exhaust ports 13 (only one is shown in FIG. 1) spaced apart from each other. A cylinder block 14 is attached to the lower part of the cylinder head 11. A plurality of cylinders 15 (only one is shown in FIG. 1) are formed in the cylinder block 14. A piston 16 is accommodated in each cylinder 15 so as to be able to reciprocate, and a combustion chamber 17 is defined by a top surface of the piston 16 and an inner wall surface of the cylinder 15. Corresponding intake ports 12 and exhaust ports 13 are connected to the respective intake ports 12 and the respective combustion chambers 17. The portion of the intake port 12 that opens to the combustion chamber 17 is opened and closed by the intake valve 12b, and the portion of the exhaust port 13 that opens to the combustion chamber 17 is opened and closed by the exhaust valve 13b.

Next, the intake system of the internal combustion engine including the intake port 12 will be described.
An intake manifold 20 is connected to an opening portion of the intake port 12 on the upstream side (opposite side of the combustion chamber 17). The air flowing into the intake manifold 20 passes through the intake manifold 20 and flows into the intake ports 12 and is sucked into the combustion chambers 17 through the intake ports 12. That is, the intake manifold 20 and the intake port 12 constitute a part of the intake passage of the internal combustion engine.

  As shown in FIG. 2, the internal combustion engine includes a combustion chamber 17 for the purpose of stabilizing the combustion of the fuel by atomizing the fuel in the combustion chamber 17, promoting the mixing of the fuel and air, and improving the fuel combustion speed. An intake air control device that controls the intake air flow is mounted in order to generate an air flow (intake air flow) such as a tumble flow. This intake control device is provided in the intake manifold 20 and controls an intake flow control valve 21 for controlling the degree of deflection of the intake flow, an actuator 22 for opening and closing the intake flow control valve 21, and a control for controlling the actuator 22. The apparatus 50 etc. are provided.

  The valve body 21a of the intake flow control valve 21 is made of a resin material and is formed in a substantially rectangular plate shape. A shaft 24 that is rotatably supported by the intake manifold 20 is fixed to the end of the valve body 21a. The shaft 24 is connected to the actuator 22 and is rotated around the axis by the actuator 22. A storage portion 23 is formed on the inner wall surface of the intake manifold 20 so as to protrude outward from other portions of the inner wall surface of the intake manifold 20. The valve body 21 a is disposed corresponding to the storage unit 23.

  The valve body 21a of the intake flow control valve 21 is rotated at the shaft 24 by the actuator 22 so as to be stored in the storage portion 23 to increase the flow path cross-sectional area in the intake manifold 20, and in FIG. As indicated by the dotted line, the valve is displaced between a valve closing position which is erected with respect to the storage portion 23 and reduces the flow passage cross-sectional area in the intake manifold 20 while biasing it.

  When the valve body 21a is displaced from the valve opening position to the valve closing position (two-dot chain line in FIG. 2), the intake manifold 20 is partially blocked, and the degree of deflection of the intake air flow is maximized. 20 and the air flowing into the combustion chamber 17 through the intake port 12 are sucked into the combustion chamber 17 in a biased state. As a result, a tumble flow which is a vortex flow of air is generated in the combustion chamber 17. On the other hand, when the valve body 21a is displaced from the valve closing position (two-dot chain line in FIG. 2) to the valve opening position, the intake manifold 20 is opened and the degree of deflection of the intake flow is minimized, and the intake manifold 20 and the intake port Inhalation of the air flowing into the combustion chamber 17 via 12 in a biased state is stopped. Thereby, generation | occurrence | production of the tumble flow in the combustion chamber 17 is also stopped.

  In the storage portion 23, a communication hole 25 communicating with the intake manifold 20 is formed at a portion facing the valve body 21 a when the valve body 21 a is in the valve open position. The communication hole 25 is formed at a position facing the surface of the storage portion 23 in the vicinity of the tip 21b (the end opposite to the end to which the shaft 24 is fixed) of the valve body 21a. The communication hole 25 has a circular shape when viewed from above. A pressure sensor 26 is connected to the communication hole 25, and the detected pressure P of the pressure sensor 26 is input to the control device 50.

  As shown in FIG. 3, in the valve body 21a made of a resin material, unlike the valve body made of a metal material, for example, the tip portion 21b may be damaged and chipped (in FIG. 3, a broken line). State shown). If the tip 21b is missing, it becomes difficult to appropriately control the intake flow by the intake flow control valve 21.

Therefore, in this embodiment, the breakage of the valve body 21a is detected in the following manner.
Normally, intake pulsation occurs in the intake manifold 20 in accordance with the opening / closing operation of the intake valve 12b, and the intake pressure in the intake manifold 20 also varies in accordance with the intake pulsation.

  Here, when the valve body 21a is not damaged and is in a normal state, in the state where the valve body 21a is in the valve open position, as shown in FIG. There is only a small gap between the opening of the communication hole 25 facing the valve body 21a, and the communication hole 25 is in a state of being blocked by the valve body 21a. Therefore, the fluctuation of the intake pulsation guided to the communication hole 25 becomes slight. Therefore, the detected pressure P detected by the pressure sensor 26 is displaced so as to draw a gentle waveform so as to correspond to the intake pulsation as shown by a solid line L1 in FIG. More specifically, the value (especially the minimum value) of the detected pressure P is higher than the change in the intake pressure in the intake manifold 20 indicated by the one-dot chain line L2 in FIG. The width is also smaller than the fluctuation range of the intake pressure in the intake manifold 20.

  On the other hand, when the intake flow control valve 21 is damaged and not in a normal state, the communication hole 25 is formed in the intake manifold 20 as shown in FIG. 3 in the state where the valve body 21a is in the valve open position. As a result, the fluctuation of the intake pulsation guided to the communication hole 25 is larger than that in the normal state of the valve body 21a. More specifically, the detected pressure P when the valve element 21a is broken changes as equivalent to the intake pressure in the intake manifold 20 as shown by the one-dot chain line L2 in FIG. The fluctuation range of the pressure P is also equal to the fluctuation range of the intake pressure in the intake manifold 20.

  Thus, in the state where the valve body 21a is not damaged and the state where it is damaged, the value and fluctuation range of the detected pressure P detected by the pressure sensor 26 when the valve body 21a is in the valve open position are different. Since it becomes very different, it is possible to detect breakage of the valve body 21a based on the detected pressure P.

  Therefore, the control device 50 reads the detected pressure P when the valve body 21a is in the valve opening position. If the detected pressure P (for example, the lowest value) is lower than a predetermined value, the valve body 21a is damaged. Judgment is made to the effect. As the predetermined value, a value that can appropriately detect the breakage of the valve body 21a is set in advance.

  Incidentally, the detected pressure P when the valve body 21a is in the valve open position is read, and when the fluctuation range of the detected pressure P is larger than a predetermined value, it is determined that the valve body 21a is damaged. May be. As the predetermined value at this time, a value that can appropriately detect the breakage of the valve body 21a is set in advance.

In the above embodiment, the following effects can be obtained.
(1) A communication hole 25 communicating with the intake manifold 20 was formed in the storage portion 23, and a pressure sensor 26 was connected to the communication hole 25. Therefore, when the valve body 21a is not damaged, the communication hole 25 is closed by the valve body 21a when the valve body 21a is in the open position, so that the detected pressure P detected by the pressure sensor 26 is within the intake manifold 20. Therefore, the fluctuation range of the detected pressure P is also reduced compared to the fluctuation range of the intake pressure in the intake manifold 20. On the other hand, when the valve body 21a is in the damaged state and the valve opening position is reached, the communication hole 25 is exposed in the intake manifold 20, so that the detected pressure P detected by the pressure sensor 26 is the intake pressure. Accordingly, the fluctuation range of the detected pressure P becomes equal to the fluctuation range of the intake pressure in the intake manifold 20. Thus, the value and fluctuation range of the detected pressure P detected when the valve body 21a is at the valve opening position are different between the state where the valve body 21a is not damaged and the state where the valve body 21a is damaged. Therefore, the breakage of the valve body 21a is detected based on the detected pressure P detected by the pressure sensor 26 when the valve body 21a is in the valve open position. Therefore, the breakage of the valve body 21a made of a resin material can be detected.

(Second Embodiment)
Next, a second embodiment in which the intake control device for an internal combustion engine according to the present invention is embodied will be described with reference to FIG. In the second embodiment described below, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the redundant description thereof is omitted or simplified.

  As shown in FIG. 5 (a), the valve body 21a in the present embodiment is also basically the same as the valve body 21a in the first embodiment, is made of a resin material, and is a substantially rectangular plate. It is formed in a shape.

  A seal member 31 is disposed in a portion surrounding the position facing the communication hole 25 in the valve body 21a. As shown in FIG. 5B, the seal member 31 has a circular shape when seen in a plan view, and a hole 31 a slightly larger than the communication hole 25 is formed at the center. The seal member 31 seals between the valve body 21a and the periphery of the opening of the communication hole 25 in a state where the valve body 21a is in the valve open position.

Therefore, according to the second embodiment, in addition to the same effect as the effect (1) of the first embodiment, the following effects can be obtained.
(2) If there is a gap between the valve body 21a at the valve opening position and the opening of the communication hole 25, the change in the detected pressure P when the valve body 21a is damaged or not (not damaged). And the determination accuracy when detecting breakage of the valve body 21a may be reduced. In this regard, in the present embodiment, the valve body 21a and the opening of the communication hole 25 are located in a position surrounding the position facing the communication hole 25 in the valve body 21a when the valve body 21a is in the valve open position. A seal member 31 that seals between the periphery is provided. Therefore, since the sealing member 31 enhances the airtightness between the valve body 21a at the valve opening position and the periphery of the opening of the communication hole 25, the change in the detected pressure P between when the valve body 21a is damaged and when it is not damaged. It appears clearly, and the determination accuracy when detecting the breakage of the valve body 21a is improved.

In addition, you may change each said embodiment as follows.
In the first embodiment, the valve body 21a of the intake flow control valve 21 is a substantially rectangular plate-shaped valve, which is a so-called butterfly valve. However, other valves such as a rotary valve are used. There may be. An example is shown in FIG. As shown in FIG. 6, a rotary valve 41 made of a resin material as an intake flow control valve is disposed in the intake manifold 20. The rotary valve 41 has a cylindrical shape and is disposed corresponding to the storage portion 42 formed on the wall surface of the intake manifold 20. The storage portion 42 is formed with the communication hole 25 as described above, and the pressure sensor 26 is connected to the communication hole 25. The rotary valve 41 is rotatable in the circumferential direction of the rotary valve 41 (the direction of the arrow R shown in FIG. 6), and is between the valve opening position shown in FIG. 6 and the valve closing position shown by a two-dot chain line in FIG. Displace at. Even in the intake control device for an internal combustion engine having such a configuration, when the rotary valve 41 is damaged and a part thereof is lost, the communication hole 25 is formed in the intake manifold 20 in a state where the rotary valve 41 is in the valve open position. Therefore, the same effect as the effect (1) of the first embodiment can be obtained.

  In 1st Embodiment, although the communicating hole 25 was formed in the site | part facing the front-end | tip part 21b of the valve body 21a, the formation site of the communicating hole 25 in the storage part 23 is not limited to such a site. Can be changed as appropriate. However, when changing the formation site, it is necessary to form the communication hole 25 at a site exposed in the intake manifold 20 in a state where the damaged valve body 21a is in the valve open position. Therefore, it is preferable to form the communication hole 25 at a position facing the portion of the storage portion 23 where the valve body 21a is likely to be damaged and chipped.

In the second embodiment, the seal member 31 may be disposed in a portion of the storage portion 23 surrounding the communication hole 25.
The intake flow control valve 21 is provided for forming a tumble flow, but may be provided for forming a swirl flow.

  DESCRIPTION OF SYMBOLS 12 ... Intake port which comprises an intake passage, 20 ... Intake manifold which comprises an intake passage, 21 ... Intake flow control valve, 21a ... Valve body, 23, 42 ... Storage part, 25 ... Communication hole, 26 ... Pressure sensor, 41 ... Rotary valve as intake flow control valve, E ... Engine body.

Claims (1)

Deflection of intake air flow is provided between an open position for increasing the flow passage cross-sectional area of the intake passage and a closed position for reducing the flow cross-sectional area of the intake passage. An intake control device for an internal combustion engine including an intake flow control valve having a valve body made of a resin material for controlling the degree,
The wall surface of the intake passage is formed with a storage portion that stores the valve body when the valve body is in the valve open position, and the valve body is in the valve opening position in the storage portion. A communication hole communicating with the intake passage is formed in a portion facing the valve body at the time, and a pressure sensor is connected to the communication hole,
An intake control device for an internal combustion engine, wherein breakage of the valve body is detected based on a detected pressure detected by the pressure sensor when the valve body is in the valve open position.

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