JP5310497B2 - Abnormality determination device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine the existence of failure in opening and closing operations for each of at least two valves, when a failure determining device of an internal combustion engine has at least two small valves in one or both sides of an intake side and an exhaust side in the same cylinder. <P>SOLUTION: The seating vibration of intake valves and exhaust valves prepared for two, respectively, in the same cylinder is detected by using a knock sensor 36. The device is provided with a means of determining the existence of the failure of the opening and closing operations of the intake valves and the exhaust valves based on the existence of a seating vibration. The device is also provided with a valve gear in which the shutting time of the intake valve and the exhaust valve are preliminarily set or adjustable to be different for each valve. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an abnormality determination device for an internal combustion engine.

  Conventionally, for example, Patent Document 1 discloses an abnormality detection device for an internal combustion engine that includes a variable valve mechanism that varies the opening / closing timing of at least one of an intake valve and an exhaust valve. In this conventional abnormality detection device, the vibration signal accompanying the seating of the intake valve is identified from various vibration signals superimposed on the detection signal of the knock sensor, and the abnormality of the variable valve mechanism is detected based on the timing at which the vibration signal is superimposed. Like to do.

JP 2009-138691 A JP 7-238822 A JP 2007-182760 A JP-A-11-148328

  In Patent Document 1 described above, when at least two valves are provided on one or both of the intake side and the exhaust side in the same cylinder, whether there is an abnormality in the opening / closing operation of the at least two valves on the intake side or the exhaust side There is no mention of determining for each valve.

  The present invention has been made to solve the above-described problems. When at least two valves are provided on one or both of the intake side and the exhaust side in the same cylinder, the opening / closing operation of the at least two valves is performed. An object of the present invention is to provide an abnormality determination device for an internal combustion engine that can determine whether or not there is an abnormality for each valve.

A first invention is an abnormality determination device for an internal combustion engine,
An internal combustion engine abnormality determination device including at least two valves on one or both of an intake side and an exhaust side in the same cylinder,
Valve seating vibration detecting means for detecting seating vibration of the at least two valves;
A valve abnormality determining means for determining the presence / absence of an abnormality in the opening / closing operation of the at least two valves based on the presence / absence of the seating vibration;
A valve operating device that is preset or adjustable so that the closing timing of the at least two valves is different for each valve;
Equipped with a,
The valve gear is a variable valve gear capable of individually adjusting the closing timing of the at least two valves,
When the valve abnormality determining means determines whether or not the opening / closing operation of the at least two valves is abnormal, the valve closing timing for controlling the variable valve operating system so that the closing timing of the at least two valves differs for each valve. further comprising wherein the Rukoto difference generation means.

According to the first invention, the seating vibration can be detected for each valve in a state in which the closing timing of the at least two valves is different for each valve. For this reason, it is possible to individually determine the abnormality of the opening / closing operation of the valve using the seating vibration for each valve.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a figure for demonstrating the abnormality determination method of the opening / closing operation | movement of the valve | bulb used in Embodiment 1 of this invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is sectional drawing of the 1st rocker arm with which an intake variable valve operating apparatus is provided, and a 2nd rocker arm. It is a side view of the 1st rocker arm. It is a side view of one 2nd rocker arm. It is a side view of the other 2nd rocker arm. It is sectional drawing of the 1st rocker arm with which an intake variable valve operating apparatus is provided, and a 2nd rocker arm. It is the figure which showed an example of operation | movement of each cylinder at the time of switching from a one-valve stop state to a both-valve drive state.

Embodiment 1 FIG.
[System configuration of internal combustion engine]
FIG. 1 is a diagram for explaining a system configuration according to the first embodiment of the present invention. The system shown in FIG. 1 includes an internal combustion engine 10. Although the number of cylinders and the cylinder arrangement of the internal combustion engine in the present invention are not particularly limited, in this embodiment, the internal combustion engine 10 is an in-line four-cylinder engine having four cylinders # 1 to # 4.

  A piston 12 is provided in each cylinder of the internal combustion engine 10. A combustion chamber 14 is formed on the top side of the piston 12 in each cylinder. An intake passage 16 and an exhaust passage 18 communicate with the combustion chamber 14.

  An air flow meter 20 that outputs a signal corresponding to the flow rate of air sucked into the intake passage 16 is provided in the vicinity of the inlet of the intake passage 16. A throttle valve 22 is provided downstream of the air flow meter 20. Each cylinder of the internal combustion engine 10 is provided with a fuel injection valve 24 for injecting fuel into the intake port and an ignition plug 26 for igniting the air-fuel mixture in the combustion chamber 14.

  Each cylinder of the internal combustion engine 10 is provided with two intake valves 28 and two exhaust valves 30. The intake valve 28 is driven by an intake variable valve operating device 32, and the exhaust valve 30 is driven by an exhaust variable valve operating device 34. Here, it is assumed that the variable intake valve operating device 32 is a device that can individually adjust the closing timing of the two intake valves 28 of each cylinder, and the variable exhaust valve operating device 34 is also similar to the two exhaust valves of each cylinder. It is assumed that the device can adjust the closing timing of the valve 30 individually. As such a variable valve operating apparatus, for example, each of the two intake valves 28 (or the exhaust valve 30) is driven by an individual cam (a cam whose profile is set so that the valve closing timing is different). A mechanically switchable device can be used, and furthermore, an electromagnetically driven valve device can be used.

  A knock sensor (vibration sensor) 36 for detecting vibration of the internal combustion engine 10 is attached to the cylinder block 10 a of the internal combustion engine 10. A crank angle sensor 38 for detecting the rotation angle (crank angle) of the crankshaft 10b and the engine speed is disposed in the vicinity of the crankshaft 10b of the internal combustion engine 10.

  The system of this embodiment includes an ECU (Electronic Control Unit) 40. Various sensors for controlling the internal combustion engine 10 such as the knock sensor 36 described above are electrically connected to the ECU 40. The ECU 40 is electrically connected to various actuators such as the fuel injection valve 24 described above. The ECU 40 controls the operating state of the internal combustion engine 10 based on those sensor outputs.

  The detection signal of the knock sensor 36 described above is superimposed with a seating vibration (sitting sound) signal accompanying the seating of the intake valve 28 and the exhaust valve 30 of each cylinder. Therefore, by detecting the seating vibration signal by the knock sensor 36 in a state corresponding to the crank angle detected by the crank angle sensor 38, whether or not the intake valve 28 or the exhaust valve 30 of each cylinder is seated, that is, these It is possible to determine whether there is an abnormality in the opening / closing operation of the intake / exhaust valves 28 and 30.

  FIG. 2 is a diagram for explaining an abnormality determination method for the opening / closing operation of the valve used in the first embodiment of the present invention. More specifically, FIG. 2 (A) is a diagram showing a conventional valve opening / closing operation abnormality determination method using seating vibration, and FIG. 2 (B) is a valve of the present invention using seating vibration. It is a figure which shows the abnormality determination method of the opening / closing operation | movement of the valve in a unit. Here, also in the conventional method shown in FIG. 2A, a general configuration in which each cylinder is provided with two intake valves (or exhaust valves) is assumed as a target valve configuration.

  The conventional method shown in FIG. 2A detects a seating sound (sitting vibration) when two valves (“front” and “rear”) are seated at the same time. For this reason, even if one of the valves is stuck in a closed state and the original function is lost, the abnormality cannot be detected. And the said conventional method can determine that abnormality has arisen for both valves for the first time by detecting that the seating sound is not emitted.

  On the other hand, in the method of the present embodiment, when the presence / absence of abnormality of the valve opening / closing operation is determined using the seating sound (sitting vibration), as shown in FIG. The valve timings of the valve 28 (or the exhaust valve 30) are controlled using the variable valve mechanisms 32 and 34 so that the closing timing differs between one valve (front) and another valve (rear).

  According to the method of the present embodiment described above, as shown in FIG. 2B, a seating sound can be detected for each of the two intake valves 28 (or exhaust valves 30) provided in each cylinder. It becomes like this. For this reason, it is possible to individually determine the abnormality of the opening / closing operation of the valve using the seating vibration for each valve. In addition, this makes it possible to determine whether the opening / closing operation is abnormal for each valve without having to mount a sensor (such as a lift sensor) for checking whether the opening / closing operation is performed for each valve of each cylinder. be able to.

Next, an example of specific processing of the present embodiment will be described with reference to FIG.
FIG. 3 is a flowchart showing a routine executed by the ECU 40 in order to determine whether the opening / closing operation is abnormal for each valve.
In the routine shown in FIG. 3, it is determined whether or not a predetermined abnormality determination condition for the opening / closing operation of the valve is satisfied (step 100). Incidentally, when the predetermined abnormality determination condition is established in this step 100, it corresponds to the time of switching the valve opening characteristics of the intake / exhaust valves 28, 30 by the variable valve gears 32, 34.

  When it is determined in step 100 that the abnormality determination condition is satisfied, the variable valve gears 32 and 34 are used to control the two intake valves 28 and the two exhaust valves 30 of each cylinder to the intake side. Further, the valve closing time is controlled to be different for each valve on the exhaust side (step 102).

  Next, in the state where the intake / exhaust valves 28 and 30 of each cylinder are controlled as in step 102 above, based on the detection signal of the knock sensor 36, it is determined whether there is an abnormality in the valve opening / closing operation using seating vibration. (Step 104).

  By the way, in the first embodiment described above, the variable valve operating devices 32 and 34 that can individually adjust the closing timing of the two intake valves 28 (exhaust valves 30) of the respective cylinders are provided, and each of the intake side and the exhaust side is provided. In FIG. 1, the valve is controlled so that the closing timing is different for each valve, and the presence / absence of an abnormality in the opening / closing operation is individually determined for each valve. However, the present invention is not limited to the above-described variable valve operating apparatus that performs abnormality determination for each valve. That is, the valve gear of the present invention is not limited to a variable valve gear, and in an internal combustion engine having at least two valves on one or both of the intake side and the exhaust side in the same cylinder, the closing timing of the at least two valves It may be a fixed valve operating device having a camshaft having a cam profile that makes the valve different for each valve.

  In the first embodiment described above, the seating vibration is detected based on the detection signal of the knock sensor (vibration sensor) 36. However, the method of detecting the seating vibration in the present invention is not limited to the above. That is, it is known that the detection signal of the in-cylinder pressure sensor that detects the in-cylinder pressure includes seating vibration (sitting sound) of the intake valve and the exhaust valve. For this reason, in the present invention, the seating vibration may be detected based on the detection signal of the in-cylinder pressure sensor.

In the first embodiment described above, the “valve seating vibration detecting means” and the “valve abnormality determining means” in the first aspect of the present invention are realized by the ECU 40 executing the processing of step 104. The variable valve operating devices 32 and 34 correspond to the “valve operating device” in the first aspect of the present invention.
Further, the “valve closing timing difference generating means” according to the first aspect of the present invention is realized by the ECU 40 executing the processing of step 102 described above.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS.
The system of the present embodiment is configured in the same manner as the system of the first embodiment described above, except that the configuration of the variable valve operating apparatus that drives the intake and exhaust valves 28 and 30 is different.

[Configuration of Variable Valve Operating Device of Embodiment 2]
First, with reference to FIG. 4 thru | or FIG. 8, the structure and operation | movement of the variable valve apparatus of this embodiment are demonstrated. In addition, since the intake variable valve operating device 42 and the exhaust variable valve operating device 44 have the same configuration, here, the intake variable valve operating device 42 will be described as an example.

FIG. 4 and FIG. 8 appearing later are sectional views of the first rocker arm 46 and the second rocker arms 48R and 48L provided in the variable intake valve operating device 42, respectively.
As shown in FIG. 4, the intake variable valve operating apparatus 42 includes a first rocker arm 46 and a pair of second rocker arms 48 </ b> R and 48 </ b> L disposed on both sides thereof. These rocker arms 46, 48 </ b> R, 48 </ b> L can swing around a common rocker shaft 50. The rocker shaft 50 is supported by the cylinder head of the internal combustion engine 10 via a pair of hydraulic lash adjusters 52.

FIG. 5 is a side view of the first rocker arm 46.
As shown in FIG. 5, the intake variable valve operating apparatus 42 has a camshaft 54. The camshaft 54 is connected to the crankshaft 10b via a timing chain or the like, and rotates at a half speed of the crankshaft 10b. The camshaft 54 includes a first lift cam 56 for driving the intake valve 28 (front) to open and close. On the other hand, the first rocker arm 46 is provided with a first roller 58. The first rocker arm 46 is biased counterclockwise in FIG. 5 by a torsion coil spring 60. The first roller 58 is pressed against the first lift cam 56 by this urging force. With such a configuration, the first rocker arm 46 swings as the first lift cam 56 rotates.

FIG. 6 is a side view of the second rocker arm 48R.
As shown in FIG. 6, the movable end of the second rocker arm 48R is in contact with the end of the valve stem of one intake valve 28 (front). The intake valve 28 (front) is urged in the valve closing direction by a valve spring 62. The cam shaft 54 includes a zero lift cam 64 at a position corresponding to the second rocker arm 48R. The zero lift cam 64 is a perfect circle having a radius equal to the base circle of the first lift cam 56. A second roller 66R is provided on the second rocker arm 48R. The outer diameter of the roller 66 </ b> R is equal to the outer diameter of the first roller 58 provided on the first rocker arm 46. The distance between the center of the rocker shaft 50 and the center of the second roller 66 </ b> R is equal to the distance between the center of the rocker shaft 50 and the center of the first roller 58. When the intake valve 28 (front) is closed, the second roller 66R is in contact with the zero lift cam 64.

FIG. 7 is a side view of the second rocker arm 48L.
As shown in FIG. 7, the movable end of the second rocker arm 48L is in contact with the end of the valve stem of one intake valve 28 (rear). The intake valve 28 (rear) is biased in the valve closing direction by a valve spring 62. The camshaft 54 includes a second lift cam 68 at a position corresponding to the second rocker arm 48L. The second lift cam 68 is a cam that opens and closes the intake valve 28 (rear) via the second rocker arm 48L. The profile of the second lift cam 68 is shown in FIG. 2B so that the closing timing of the intake valve 28 (rear) is different from the closing timing of the intake valve 28 (front) driven by the first lift cam 56. Set lift curve). The configuration of the second roller 66L is the same as the configuration of the second roller 66R.

  The intake variable valve operating apparatus 42 includes a valve stop mechanism 70 that switches between a state where the first rocker arm 46 and the second rocker arm 48R are connected and a state where they are separated. In such a switching operation, the valve stop mechanism 70 transmits the acting force of the first lift cam 56 to the second rocker arm 48R via the first rocker arm 46, and the acting force is applied to the second rocker arm 48R. The operation state of the intake valve 28 (front) can be switched between the valve operating state and the valve closed / stopped state by switching the state not transmitted to.

  As shown in FIG. 4, the first rocker arm 46 has a first support shaft 72 installed concentrically with the first roller 58, and the second rocker arms 48 </ b> R and 48 </ b> L have second rollers 66 </ b> R, The second support shafts 74R and 74L are provided concentrically with 66L.

  In the state shown in FIG. 4, a part of the first pin 76 that is mostly inserted into the first rocker arm 46 is inserted into the second support shaft 74 </ b> R of the second rocker arm 48 </ b> R. Thus, the first rocker arm 46 and the second rocker arm 48R are connected via the first pin 76. Accordingly, when the first rocker arm 46 swings with the rotation of the first lift cam 56, the second rocker arm 48R also swings with this, so that the intake valve 28 (front) opens and closes.

  One end of the second pin 78 inserted into the second support shaft 74R protrudes beyond the side surface of the second rocker arm 48R. One end of the protruding second pin 78 is in contact with the displacement member 82 of the driving means 80. The drive unit 80 is configured to be able to displace the displacement member 82 in the left-right direction in FIG. 4 in accordance with a command from the ECU 40.

  One end of the first support shaft 72 of the first rocker arm 46 is closed, and a return spring 84 is installed therein. The return spring 84 presses the first pin 76 rightward in FIG. Thereby, the first pin 76 and the second pin 78 are urged rightward in FIG.

  In the connected state shown in FIG. 4, when the displacement member 82 is displaced leftward in FIG. 4 by the force with which the driving means 80 overcomes the urging force of the return spring 84, the second pin 78 and the first pin 76 are shown in FIG. 4. To the left, and the state shown in FIG. 8 is obtained. In this state, the first pin 76 and the second pin 78 are in contact with each other in the gap between the first rocker arm 46 and the second rocker arm 48R. For this reason, even if the first rocker arm 46 swings as the first lift cam 56 rotates, the swing is not transmitted to the second rocker arm 48R. The second roller 66R of the second rocker arm 48R is in contact with the zero lift cam 64 having no cam crest. For this reason, even if the camshaft 54 rotates, the second rocker arm 48R does not swing, and the intake valve 28 (front) is closed.

  Further, in the state shown in FIG. 8, that is, in the state where the first rocker arm 46 and the second rocker arm 48R are separated, the first roller 58 of the first rocker arm 46 is moved to the first lift cam 56 as shown in FIG. When touching the base circle, the centers of the two pins 76 and 78 coincide. At this time, it is possible to switch to the connected state shown in FIG. 4 by operating the driving means 80 and moving these pins 76 and 78 in the right direction in FIG.

  As described above, according to the intake variable valve operating apparatus 42, the intake valve 28 (rear) is always opened and closed using the second lift cam 68, while the first rocker arm 46 and the second rocker arm 48R. By switching between the connected state and the separated state, the operating state of the intake valve 28 (front) can be switched between the valve operating state and the closed valve stop state.

  More specifically, according to the intake variable valve operating system 42, the intake valve 28 (front) and the intake valve 28 (rear) are driven by the first lift cam 56 and the second lift cam 68, respectively. B) a state in which the closing timing is controlled to be different for each valve as shown in a lift curve (valve closing timing difference generation state), and the intake valve 28 (rear) is driven to open and close by the second lift cam 68. The valve opening characteristics of the intake valve 28 (front) and the intake valve 28 (rear) can be switched between the state in which the opening / closing operation of 28 (front) is stopped in a closed state (one-valve stop state). The same applies to the variable exhaust valve device 44.

[Performance time suitable for determining abnormality of valve opening / closing operation with respect to the configuration of the variable valve operating apparatus of Embodiment 2]
FIG. 9 is a diagram showing an example of the operation of each cylinder when switching from the one-valve stop state to the both-valve drive state, and the horizontal axis is the crank angle. In FIG. 8, a valve lift curve indicated by a dotted line indicates a one-valve stop state, and a valve lift curve indicated by a solid line indicates a both-valve drive state (the valve closing timing difference generation state). Here, it is assumed that the ignition order of the internal combustion engine 10 is in the order of # 1 → # 3 → # 4 → # 2.

  In the internal combustion engine 10, the one-valve stop state is selected under predetermined operating conditions. Then, when a predetermined return condition from the one-valve stop state is satisfied, the operation states of the intake and exhaust valves 28 and 30 are switched so that the both-valve drive state (the valve closing timing difference generation state) is established. More specifically, at the time of this switching, as shown in FIG. 9, the operating states of the intake and exhaust valves 28 and 30 of each cylinder are sequentially switched according to the above ignition sequence.

  In the system of this embodiment in which the operation state of the intake / exhaust valves 28, 30 is switched in the above-described manner, the opening / closing operation of the intake / exhaust valves 28, 30 using the seating vibration (seat noise) is performed at the following timing. It is preferable to perform abnormality determination. That is, first, when switching to the one-valve stop state, it is preferable to perform abnormality determination using seating vibration in order to confirm whether the switching has been performed normally. In this case, if normal, only the seating sound of one of the valves (the intake valve 28 (rear) and the exhaust valve 30 (rear)) is detected. On the other hand, if there is an abnormality in the switching, the seating sound of the intake valves 28 (or the exhaust valves 30) of both (front and rear) having different closing timings will be detected. Can be determined.

  In addition, when switching from the one-valve stop state to the both-valve drive state (the valve closing timing difference generation state), an abnormality determination using seating vibration is performed to check whether the switching has been performed normally. Is preferred. In this case, if normal, the seating sound of the intake valves 28 (or the exhaust valves 30) of both (front and rear) having different closing timings is detected. On the other hand, when an abnormality occurs in switching, only the seating sound of one valve (the intake valve 28 (rear) or the exhaust valve 30 (rear)) is detected. Can be determined. In addition, when the opening / closing operation of both valves is stopped for some reason, it can be determined that the seating sound is not detected at all so that it is abnormal.

  By the way, in Embodiment 2 mentioned above, the variable valve which can switch the operation state of the intake / exhaust valves 28 and 30 between the one-valve stop state and the both-valve drive state (the valve closing timing difference generation state). The apparatus 42 and 44 have been described as examples. However, the present invention is not limited to this. That is, in the case where at least two valves are provided on one or both of the intake side and the exhaust side in the same cylinder, the all-valve stop state in which all of the at least two valves are stopped, and the at least 2 When a variable valve gear is provided that can switch the valve operating state between the valve closing timing difference generation states that are controlled so that the closing timing of each valve differs for each valve, all valve stop states When switching from the valve closing timing difference generation state to the valve closing timing difference generation state, it may be determined whether there is an abnormality in the opening / closing operation of the at least two valves.

  Further, in the present invention, as a configuration of a variable valve apparatus that can be applied to abnormality determination of a valve opening / closing operation using seating vibration, for example, the following variable valve apparatus can be applied. That is, the configuration of the variable valve device 42 shown in FIGS. 4 to 8 is modified, and not only the second rocker arm 48R but also the second rocker arm 48L based on the operation of the driving means 80, the first rocker arm 48L. 46 is configured to be switchable between a state connected to 46 and a state separated from it. 2B, the lift cam contacting the second roller 66R of the second rocker arm 48R and the lift cam contacting the second roller 66L of the second rocker arm 48L are obtained. Set up each profile. According to the variable valve apparatus thus obtained, in the state where the connection between the first rocker arm 46 and the second rocker arms 48R and 48L is released based on the operation of the driving means 80, FIG. The valve lift curve shown in B) can be obtained, and the abnormality determination of the opening / closing operation can be performed for each valve.

  In the first or second embodiment described above, an example in which two intake and exhaust valves 28 and 30 are provided on both the intake side and the exhaust side in the same cylinder has been described. However, the configuration of the valve in the present invention is not limited to this, and the number of intake valves or exhaust valves arranged in the same cylinder may be three or more. In addition, at least two of the intake valves and the exhaust valves arranged in the same cylinder, not both on the intake side and the exhaust side, may be provided.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 10a Cylinder block 16 Intake passage 18 Exhaust passage 24 Fuel injection valve 26 Spark plug 28 Intake valve 30 Exhaust valve 32, 42 Intake variable valve operating device 34, 44 Exhaust variable valve operating device 36 Knock sensor 38 Crank angle sensor 40 ECU (Electronic Control Unit)
46 First rocker arm 48L, 48R Second rocker arm 54 Camshaft 56 First lift cam 64 Zero lift cam 68 Second lift cam 70 Valve stop mechanism 76 First pin 78 Second pin 80 Driving means 82 Displacement member 84 Return spring

Claims (1)

An internal combustion engine abnormality determination device including at least two valves on one or both of an intake side and an exhaust side in the same cylinder,
Valve seating vibration detecting means for detecting seating vibration of the at least two valves;
A valve abnormality determining means for determining the presence / absence of abnormality in the opening / closing operation of the at least two valves based on the presence / absence of the seating vibration;
A valve operating device that is preset or adjustable so that the closing timing of the at least two valves is different for each valve;
Equipped with a,
The valve gear is a variable valve gear capable of individually adjusting the closing timing of the at least two valves,
When the valve abnormality determining means determines whether or not the opening / closing operation of the at least two valves is abnormal, the valve closing timing for controlling the variable valve operating system so that the closing timing of the at least two valves differs for each valve. abnormality determination device for an internal combustion engine according to further comprising wherein Rukoto difference generation means.

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