JP2005344533A - Method for detecting clogging of air cleaner for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely detect clogging with a simple means. <P>SOLUTION: In an air cleaver for an engine having an intake pipe 2 including a throttle valve 5 and a fuel supply means connected to each cylinder and having common single inlet of an air cleaner 3, a pressure sensor 6b is installed on a downstream side of the throttle valve 5 of one of the intake pipes 2, pressure in the intake pipe 2 is detected by the pressure sensor 6b. If a plurality of sudden drops of pressure in the intake pipe during one cycle of an engine 1 are observed, clogging of the air cleaner 3 is determined. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for detecting clogging of an air cleaner disposed in an intake pipe of an engine, and in particular, an intake pipe having a throttle valve and fuel supply means is connected to each cylinder such as an outboard engine or a two-wheeled vehicle engine. The present invention relates to a clogging detection method for detecting clogging of an air cleaner and allowing a driver to recognize the clogging of the air cleaner having a single air cleaner installed at the inlet.

  As a clogging detection device for an engine air cleaner, for example, as described in Japanese Patent Application Laid-Open No. Sho 62-150064, the pressure upstream of the throttle valve in the intake pipe is compared with the exhaust pressure in the exhaust pipe. What is determined to be clogged when a predetermined value or more is known. This is intended to detect clogging by utilizing the correlation between the air cleaner ventilation resistance and the exhaust pressure. This clogging detection device is a large and complex device using a diaphragm that is displaced by the pressure difference between the pressure of the intake pipe and the exhaust pressure, and a reed switch that detects the amount of displacement and notifies clogging. Depending on the engine, installation may be difficult.

  On the other hand, in Japanese Patent Application Laid-Open No. 2004-19455, a throttle valve opening sensor installed for engine electronic control is used to detect an actual value detected by a throttle valve opening corresponding to a reference load set for each throttle valve opening. It is described that a deviation from a load is calculated and it is determined that clogging has occurred when the deviation is larger than a predetermined value.

  Further, JP-A-6-299916 includes a throttle valve opening sensor, a vehicle speed sensor, a rotation speed sensor, an ECT ECU, and an engine ECU. When the engine is in a predetermined output state, the actual throttle valve opening and the reference opening It is described that clogging occurs when the deviation between the two is larger than a predetermined value.

  However, in small engines with a small number of cylinders, such as outboard engine and two-wheeled vehicle engine, not only the throttle valve opening sensor, but also an electronic control device with high processing capability and various types of engine operation states input to this. Usually it does not have a sensor.

Therefore, in order to detect the clogging of the air cleaner using each means described in the above Japanese Patent Application Laid-Open No. 2004-19455 and Japanese Patent Application Laid-Open No. 6-299916, a number of new sensors are added or a high performance is added. Therefore, it is necessary to prepare an expensive electronic control device, which is not a preferable means in this type of engine that requires a low price.
Japanese Patent Laid-Open No. 62-150064 JP 2004-19455 A JP-A-6-299916

  As described above, the present invention is such that each cylinder such as an outboard engine or a two-wheeled vehicle engine is provided with an intake pipe having a throttle valve and fuel supply means and a single air cleaner is provided at the inlet thereof. Therefore, it is possible to reliably detect clogging of the air cleaner without incurring a significant increase in price without requiring an electronic control device with a high processing capacity and a large number of sensors. The challenge is to do so.

  The present invention relates to an engine air cleaner in which an intake pipe having a throttle valve and a fuel supply means is connected for each of a plurality of cylinders, and an air cleaner installed at the inlet of the plurality of intake pipes is a single unit. , Detecting the intake pipe pressure downstream of the throttle valve for one of the plurality of intake pipes, and determining that clogging has occurred when the intake pipe pressure has fallen multiple times in one cycle of the engine. did.

  If an air cleaner is not clogged when one cylinder of the engine is in the intake stroke, the pressure in the intake pipe connected to that cylinder, that is, the negative pressure, will affect the pressure in the intake pipe connected to the other cylinder. Does not reach. However, if the air cleaner is clogged, the pressure in the intake pipe connected to the cylinder in the intake stroke will not recover, and the next cylinder will enter the intake stroke. Therefore, one intake pipe is used during one cycle of the engine. When the pressure falls once, the number of times falls according to the number of cylinders. Therefore, the occurrence of clogging of the air cleaner can be accurately known by monitoring the number of pressure falls in one engine cycle of one intake pipe.

  Here, regarding the clogging detection, as another means, the cycle from the start of the intake stroke to the start of the next intake stroke of the cylinder to which the intake pipe for detecting the intake pipe pressure is connected is defined as one cycle, and the non-intake stroke in this cycle The fall of the pressure was detected by sampling the intake pipe pressure inside.

  In other words, since it is natural that the intake pipe pressure falls during the intake stroke, the clogging detection can be determined more accurately by a simple method of checking whether the intake pipe pressure recovers during the non-intake stroke. can do.

  In addition, when the number of cylinders of the engine is large, the number of times the intake pipe pressure falls per cycle when clogging occurs increases according to the number of cylinders, and the vertical width of each fall decreases, and the pressure recovery is in progress. It becomes difficult to determine whether or not. Therefore, the present invention is preferably implemented for an air cleaner for a two-cylinder or three-cylinder engine having a small number of cylinders.

  Further, in carrying out the present invention, it is preferable to notify the driver of the occurrence of clogging and prompt the replacement of the air cleaner element.

  As described above, according to the present invention in which the occurrence of clogging of the air cleaner is determined by the characteristic falling of the intake pipe pressure for one intake pipe, the electronic control device having a high processing capacity and a large number of sensors are used. Therefore, it is possible to reliably detect clogging of the air cleaner without incurring a significant increase in price.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a layout of an engine system in which a clogging detection device 6 for carrying out the present invention is installed. The engine 1 is a two-cylinder two-cycle engine, and an intake pipe 2 having a carburetor 4 is provided for each cylinder. The two intake pipes 2 and 2 are formed as a single unit at the inlet side. An air cleaner 3 is connected.

  And the pressure sensor 6b is installed in the carburetor 4 downstream of one intake pipe 2, and this detects the intake pipe pressure which generate | occur | produces in the downstream of the throttle valve 5, and inputs it into the electronic controller 6a. The electronic control device 6a is connected to a warning device 6c that notifies the driver of the occurrence of clogging. These pressure sensor 6b, electronic control device 6a, and warning device 6c constitute a clogging detection device 6.

  As the electronic control device 6a, a simple and low-priced device including a CPU having a low processing capacity, a ROM and a RAM having a small storage capacity is used, and the clogging determination in the present embodiment is performed on the ROM. The program is stored.

  The operation of the clogging detection device 6 in the present embodiment will be described below. In the present embodiment, the engine 1 is a two-cylinder two-cycle engine, and 1 for detecting clogging from the start of the intake stroke to the start of the next intake stroke of the cylinder to which the intake pipe 2 provided with the pressure sensor 6b is connected. It was defined as a cycle. When the air cleaner 3 is not clogged and allows air to pass normally, the negative pressure generated during the intake stroke, that is, the fall of the intake pipe pressure recovers when the intake stroke ends, and the other cylinder Not affected by negative pressure due to intake stroke. Therefore, the intake pipe pressure detected by the pressure sensor 6b is represented by the waveform shown in FIG.

    When clogging occurs in the air cleaner 3, the amount of air passing through decreases, so when the intake stroke of one cylinder ends and the other cylinder enters the intake stroke, the pressure in the intake pipe connected to the previous cylinder is restored. In the meantime, since the intake pipe on the other cylinder side sucks air, the intake pipe pressure on the previous cylinder side decreases again. Therefore, the intake pipe pressure detected by the pressure sensor 6b is represented by the waveform shown in FIG. 2B, and the pressure falls twice during one cycle.

  For this reason, by counting the number of falling times of the intake pipe pressure in one cycle and determining that clogging has occurred when the trailing edge is detected twice, an accurate determination can be made without misunderstanding. Specifically, the occurrence of clogging is determined by examining the change in the detection value of the pressure sensor 6b and counting the number of falling times, or by sampling the waveform shown in FIG. 2 and counting the number of falling times. Alternatively, since it is natural that negative pressure is generated in the intake pipe during the intake stroke, the occurrence of clogging can be accurately detected by sampling the intake pipe pressure during the non-intake stroke from the waveform. .

  When it is determined that clogging has occurred, the electronic control device 6a operates the warning device 6c to warn the driver. For example, a warning device 6c having a proper display function such as turning on a red light, displaying characters such as “the air cleaner is clogged”, and displaying this by voice is used. Also, depending on the degree of the fall of the intake pipe pressure that occurs the second time in one cycle, the lamp is lit in two stages, for example, yellow and red. “Replacement time of air cleaner element is near”, “Replace air cleaner element "Please do" or the like can be displayed in text or voice. In this way, the air cleaner 3 can be managed finely.

In the embodiment shown in FIG. 1, the carburetor 4 is used as the fuel supply means. Therefore, the throttle valve 5 is a component of the carburetor 4, but when the fuel supply means is a fuel injection valve, the throttle is provided. The valve 5 is provided in a known throttle body. By installing the pressure sensor 6b on the downstream side of the throttle valve 5, the fall of the intake pipe pressure is noticeable particularly in the small opening range of the throttle valve 5, and the occurrence of clogging is accurately determined. It can be.

  Further, as a different determination method, it is also possible to input and store a reference waveform when clogging occurs in the storage means, and to determine that clogging has occurred when a waveform similar to this is generated. However, in this case, a storage means having a predetermined capacity is required, and a relatively high processing capability is required for comparing the two waveforms and determining their approximation. In addition, regardless of which determination method is employed, it is preferable to set the determination level for occurrence of clogging at a level lower than the level at which the engine operation is disturbed.

  Next, an example of the operation of the electronic control device 6a in the present embodiment will be described with reference to the flowchart of FIG.

  The electronic control unit 6a starts clogging detection by starting the engine, and monitors the intake pipe pressure by an output signal from the pressure sensor 6b (A1). Then, the value of the monitored intake pipe pressure or the number of falling in the waveform representing the pressure change is counted every cycle (A2), and it is checked whether or not the number of falling is a plurality of times in one cycle. (A3).

  Then, when the number of falling times is a plurality of times, it is determined that clogging has occurred (A4), and a warning signal is output to the warning device 6c (A5) to prompt the driver to respond. On the other hand, when the number of times of falling is not a plurality of times, that is, once, it is determined that clogging has not occurred (B1), and no warning signal is output (B2). This operation is continuously performed while the engine is operating or is performed at appropriate intervals to monitor the occurrence of clogging of the air cleaner 3.

  As described above, according to this embodiment, the sensor for detecting the occurrence of clogging is only a pressure sensor provided in the intake pipe, and a small-capacity electronic control device has only to be prepared. It is possible to reliably detect the occurrence of clogging of the air cleaner without incurring price.

The layout which shows embodiment of this invention. (A) is a graph which shows the waveform of the intake pipe pressure at the time of normal, (B) is a graph which shows the waveform of the intake pipe pressure at the time of clogging generation | occurrence | production. Flowchart for explaining the operation of the electronic control device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine, 2 Intake pipe, 3 Air cleaner, 4 Vaporizer, 5 Throttle valve, 6 Clogging detection device, 6a Electronic control device, 6b Pressure sensor, 6c Warning device

Claims (5)

An engine air cleaner clogging detection method in which an intake pipe having throttle valves and fuel supply means is connected to each of a plurality of cylinders, and an air cleaner installed at the inlet of the plurality of intake pipes is a single unit. There,
Detecting the intake pipe pressure downstream of the throttle valve for one of the plurality of intake pipes, and determining that clogging has occurred when the number of falling of the intake pipe pressure in one cycle of the engine is multiple times;
A clogging detection method characterized by the above. The method for detecting clogging of an air cleaner for an engine according to claim 1,
The cycle from the start of the intake stroke to the start of the next intake stroke of the cylinder to which the intake pipe for detecting the intake pipe pressure is connected is defined as one cycle, and the intake pipe pressure during the exhaust intake stroke in this cycle is sampled to rise the pressure. It was supposed to detect the fall,
A clogging detection method characterized by the above. The clogging detection according to claim 1 or 2 is performed for an air cleaner for a 2-cylinder or 3-cylinder engine.
A clogging detection method characterized by the above.   The method for detecting clogging of an engine air cleaner according to claim 1 or 2, wherein when it is determined that clogging has occurred, a warning is given to the driver. 5. The method for detecting clogging of an engine air cleaner according to claim 4, wherein the notification warning content to the driver differs depending on the degree of falling of the intake pipe pressure that is determined to be clogged.

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