JP5515775B2 - Knock detection device - Google Patents

Description

  The present invention relates to a knocking detection device, and more particularly to a knocking detection device that detects knocking in an internal combustion engine in an automobile or the like.

  As a conventional knocking detection device, for example, a device described in Patent Document 1 is known. The knocking detection device includes a knocking detection unit that detects knocking in an internal combustion engine that includes a cylinder deactivation mechanism (valve operation state switching device) that deactivates some cylinders.

JP 2004-340077 A

  However, in the knocking detection device as described above, when the valve operation state switching device is out of order, knocking detection by the knocking detection unit is prohibited, and the internal combustion engine is operated so that knocking does not always occur (for example, ignition delay angle). Control), the fuel consumption and power consumption may be deteriorated. Therefore, in recent knocking detection devices, there is a demand for a device that can accurately detect knocking even when the valve operation state switching device is out of order and can appropriately set the ignition timing to the state of the internal combustion engine, for example. .

  Therefore, an object of the present invention is to provide a knocking detection device capable of accurately detecting knocking even when the valve operation state switching device is out of order.

  In order to solve the above problems, a knocking detection device according to the present invention includes a plurality of cylinders having intake and exhaust valves, and intake and exhaust valves provided between the intake and exhaust valves of each of the plurality of cylinders between a valve drive mode and a valve stop mode. A knock detection device for detecting knocking in an internal combustion engine comprising a plurality of valve operation state switching devices for switching the operation modes of the plurality of valve operation state switching devices, and a failure detection unit for detecting failure information relating to a failure of the plurality of valve operation state switching devices; A knocking detection unit that detects the occurrence of knocking when a detection value related to cylinder vibration is greater than a threshold value, and a failure detection unit that detects failure information and a plurality of cylinders in an operating state and a cylinder in a dormant state And a threshold value setting unit that sets a threshold value based on the combination.

  In this knocking detection device, when the valve operation state switching device is out of order, the threshold value is changed based on the combination of the operating cylinder and the non-operating cylinder among the plurality of cylinders. An occurrence is detected. Therefore, even when the valve operation state switching device fails, the threshold value can be set with high accuracy and knocking can be detected with high accuracy.

  At this time, the failure detection unit detects, as failure information, at least one of the number and the position of the cylinders provided with the failed valve operation state switching device among the plurality of cylinders, and the threshold setting unit responds to the failure information. The threshold value may be changed. In this case, the threshold value is set according to at least one of the number and position of the cylinders provided with the failed valve operation state switching device. Therefore, even when the valve operation state switching device fails, the threshold value is accurately set. Knocking can be detected accurately.

  According to the present invention, knocking can be accurately detected even when the valve operation state switching device is out of order.

It is a schematic block diagram which shows the knocking detection apparatus which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a schematic block diagram showing a knocking detection device according to an embodiment of the present invention. As shown in FIG. 1, the knocking detection device 1 of the present embodiment detects knocking in an engine (internal combustion engine) 10 of a vehicle such as an automobile, and a CPU (Central Control Unit) 11 of an engine control ECU (Electronic Control Unit) 11 Processing Unit) 12 is provided.

  The engine 10 here has a cylinder deactivation function (cylinder deactivation system) for deactivating some or all of the cylinders according to the operating state of the engine 10. Specifically, the engine 10 includes a plurality of intake / exhaust valve solenoids 13 provided in intake / exhaust valves (intake valves and exhaust valves) of a plurality of cylinders (here, four cylinders). The intake / exhaust valve solenoid 13 constitutes a valve stop mechanism, and includes a valve drive mode in which the valve body of the intake / exhaust valve is opened and closed, and a valve stop mode in which the valve body of the intake / exhaust valve is held closed. The operation mode of the intake / exhaust valve is switched between.

  The knocking detection device 1 includes a valve stop request processing unit 2, a valve failure detection unit 3, a solenoid drive processing unit 4, a threshold setting unit 5, a knocking detection unit 6, and an ignition control unit 7. Based on the crank angle detected by the crank angle sensor 14 and the accelerator opening detected by the accelerator opening sensor 15, the valve stop request processing unit 2 serves as an energization start / end request for a predetermined intake / exhaust valve solenoid 13. The presence or absence of a valve stop request (hereinafter simply referred to as “valve stop request”) is processed.

  The valve failure detection unit 3 detects failure information regarding the failure of the intake / exhaust valve solenoid 13 based on the in-cylinder pressure detected by the in-cylinder pressure sensor 16 provided in each of the plurality of cylinders. Here, as the failure information, the number and position of the cylinders provided with the failed intake / exhaust valve solenoid 13 and the positional relationship between them are detected.

  The solenoid drive processing unit 4 drives the intake / exhaust valve solenoid 13 based on the valve stop request from the valve stop request processing unit 2 and the failure information from the valve failure detection unit 3. The threshold setting unit 5 sets a threshold for detecting knocking based on the failure information from the valve failure detection unit 3 and the threshold correction map 8 stored in advance (details will be described later).

  This threshold value correction map 8 performs various pattern tests in advance on an offline engine bench or the like, and performs threshold values on the operation mode of the intake / exhaust valve, the number of cylinders provided with the failed intake / exhaust valve solenoid 13, and the position (location). Can be obtained by grasping how the changes. In this threshold correction map 8, the threshold is increased if the number of cylinders provided with the failed intake / exhaust valve solenoid 13 is large. In the threshold correction map 8, the threshold value also changes depending on the mounting position of a vibration sensor 17 described later.

  The knocking detection unit 6 detects the occurrence of knocking when the amplitude of the cylinder head vibration detected by the vibration sensor 17 is larger than a threshold value. The ignition control unit 7 controls the ignition timing by the ignition plug 18 based on whether or not the occurrence of knocking is detected by the knocking detection unit 6.

  In the present embodiment configured as described above, for example, during normal running, a valve stop request is not output from the valve stop request processing unit 2, and the intake / exhaust valve solenoid 13 is controlled by the solenoid drive processing unit 4 so that the intake / exhaust valve is controlled. Is set to the valve drive mode, and the threshold value setting unit 5 sets the threshold value to a normal value (valve drive mode value). When the amplitude of the cylinder head vibration detected by the vibration sensor 17 is larger than the threshold value, the occurrence of knocking is detected, and the ignition control unit 7 controls the ignition plug 18 to retard the ignition.

  At this time, when failure information is detected by the valve failure detection unit 3, the threshold is set (changed) so as to increase according to the number, position, and positional relationship of the failed cylinder in the failure information based on the threshold correction map 8. Is done. As a result, even when failure information is detected by the valve failure detection unit 3, the detection of the occurrence of knocking by the knocking detection unit 6 is continued.

  On the other hand, at the time of low load traveling, for example, a valve stop request is output from the valve stop request processing unit 2, and at least a part of the intake / exhaust valve solenoid 13 is controlled by the solenoid drive processing unit 4. In addition, the threshold value setting unit 5 sets the threshold value to the valve stop mode value. When the amplitude of the cylinder head vibration detected by the vibration sensor 17 is larger than the threshold value, the occurrence of knocking is detected, and the ignition control unit 7 controls the ignition plug 18 to retard the ignition.

  At this time, when failure information is detected by the valve failure detection unit 3, the threshold is set (changed) so as to increase according to the number, position, and positional relationship of the failed cylinder in the failure information based on the threshold correction map 8. Is done. As a result, detection of the occurrence of knocking by the knocking detection unit 6 is continued.

  By the way, conventionally, when the intake / exhaust valve solenoid 13 has failed, the threshold value of the cylinder provided with the intake / exhaust valve solenoid 13 is changed regardless of whether the intake / exhaust valve solenoid 13 is actually inactive, and knocking may be erroneously detected. is there. Therefore, if the intake / exhaust valve solenoid 13 fails, it may be considered that the knocking detection itself is stopped. In this case, however, it is necessary to always perform engine operation (ignition retarding control) so that knocking does not occur. In addition, fuel consumption is reduced. In order to suppress such a decrease, VVT control, EGR control, fuel pressure control, etc. can be supplemented, but each control requires extra computation, increasing the processing load and driving the actuator extra in each control. Electric power increases.

  In this regard, in the present embodiment, as described above, the threshold value is changed according to the failure information (the number, position, and positional relationship of the cylinder in which the failed intake / exhaust valve solenoid 13 is provided). That is, when a failure occurs in the intake / exhaust valve solenoid 13 (when the failure information is detected by the valve failure detection unit 3), a combination of an operating cylinder and a non-operating cylinder among a plurality of cylinders is substantially achieved. The threshold value is set based on the above. Therefore, even when the intake / exhaust valve solenoid 13 fails, it is possible to accurately detect the knock by setting the threshold with high accuracy, and to eliminate the need for constant ignition retard control and the like.

  That is, in this embodiment, when a failure of the intake / exhaust valve solenoid 13 is detected, the knocking detection threshold is changed according to the number and location of the failure (in other words, the intake and exhaust valves that are operating are stopped. The threshold used for knocking detection is set according to the pattern of the intake and exhaust valves), so that knocking detection can be continued accurately and control of ignition timing etc. is performed appropriately to prevent a decrease in output and fuel consumption. It becomes possible to do.

  In the present embodiment, as described above, the threshold value is variable between the normal operation (valve drive mode) and the cylinder deactivation operation (valve stop mode). Therefore, knocking detection accuracy can be further increased.

  As mentioned above, although preferred embodiment of this invention was described, the knocking detection apparatus which concerns on this invention is not restricted to the said knocking detection apparatus 1 which concerns on embodiment, The range which does not change the summary described in each claim It may be modified by or applied to others.

  For example, in the above embodiment, the failure information is detected based on the in-cylinder pressure detected by the in-cylinder pressure sensor 16, but the failure information may be detected by detecting the presence or absence of seating noise of the intake / exhaust valve. Further, if the threshold can be made variable when a failure of the intake / exhaust valve solenoid 13 is detected, the threshold may not be changed between the normal operation and the cylinder deactivation operation.

  In addition, the specifications and types of the sensors 14 to 16 in the above embodiment are not limited, and various types can be used.

  In the above, the valve stop request processing unit 2, the solenoid drive processing unit 4 and the intake / exhaust valve solenoid 13 constitute the valve operation state switching device in the claims, and the valve failure detection unit 3 and the in-cylinder pressure sensor 16 detect the failure in the claims. The knocking detection unit 6 and the vibration sensor 17 constitute the knocking detection unit in the claims.

  DESCRIPTION OF SYMBOLS 1 ... Knocking detection apparatus, 2 ... Valve stop request | requirement process part (valve operation state switching apparatus), 3 ... Valve failure detection part (failure detection part), 4 ... Solenoid drive processing part (valve operation state switching apparatus), 5 ... Threshold Setting unit, 6 ... Knocking detection unit, 10 ... Engine (internal combustion engine), 13 ... Intake / exhaust valve solenoid (valve operation state switching device), 16 ... In-cylinder pressure sensor (failure detection unit), 17 ... Vibration sensor (knocking detection unit) ).

Claims (2)

A plurality of cylinders having intake and exhaust valves, and a plurality of valve operation state switching devices that are provided in the intake and exhaust valves of each of the plurality of cylinders and switch the operation mode of the intake and exhaust valves between a valve drive mode and a valve stop mode; A knocking detection device for detecting knocking in an internal combustion engine comprising:
And about the failure of the plurality of valves operating state switchover unit, and a failure detection unit for detecting the number and position of the cylinder where the valve operating state switching device is provided which has failed among the plurality of cylinders as failure information,
A knock detection unit that detects the occurrence of knocking when a detection value related to vibration of the cylinder is greater than a threshold;
A threshold setting unit configured to set the threshold based on the failure information and a threshold correction map stored in advance when the failure information is detected by the failure detection unit;
A knocking detection device comprising: 2. The knocking detection device according to claim 1, wherein the threshold correction map is set such that the threshold value increases as the number of cylinders provided with the failed valve operation state switching device increases.

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