JP7268558B2 - Intake device - Google Patents

Description

The present invention relates to an intake system.

2. Description of the Related Art Conventionally, an intake path from an intake inlet to an engine is provided in an engine room of a vehicle. An airflow meter that detects the amount of intake air is disposed in the intake path, and air-fuel ratio control of the engine is performed based on the amount of intake air detected by the airflow meter (see, for example, Patent Document 1). ).

JP 2016-109625 A

In this intake path, static electricity generated by friction between intake air (air taken in from the intake inlet) and the inner pipe wall of the intake path causes detection signals of the intake path, the air flow meter provided in the intake path, and the air flow meter. The transmitting lead is positively charged.

When the airflow meter or the lead wire is charged, static noise is superimposed on the detection signal from the airflow meter, and the detection accuracy of the intake air amount based on the detection signal of the airflow meter is lowered. As a result, the accuracy of air-fuel ratio control of the engine based on the amount of intake air is degraded, which may lead to increased fluctuations in engine output and deterioration in fuel efficiency of the vehicle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air intake system that suppresses deterioration in detection accuracy of an intake air amount of an air flow meter due to electrification.

The intake device according to claim 1 comprises an intake path connected from an intake inlet to an engine, an airflow meter provided in the intake path for detecting an amount of intake air in the intake path, and an airflow meter connected to the intake path. , a lead wire for transmitting a detection signal of the airflow meter, and an air ionization self-discharge type static eliminator provided on the outer peripheral surface of the lead wire and capable of discharging static electricity into the air.

In this intake device, when static electricity is generated due to friction between air (intake air) sucked into the intake passage from the intake inlet and the inner pipe wall of the intake passage, the intake passage is charged. Also, an air flow meter provided in the intake path and a lead wire connected to the air flow meter and transmitting a detection signal from the air flow meter are charged.

As a result, noise due to charging of the lead wire is superimposed on the detection signal of the airflow meter, and the detection accuracy of the intake air amount may be lowered.

In this air intake device, an air ionization self-discharge type static eliminator that can discharge static electricity into the air is provided on the surface of the lead wire, so the amount of charge on the lead wire is reduced, and noise due to lead wire charge is reduced in the detection signal of the air flow meter. is reduced. That is, deterioration in detection accuracy of the amount of intake air of the air flow meter due to electrification of the lead wire is suppressed.

As described above, according to the intake device of claim 1 , it is possible to suppress deterioration in detection accuracy of the intake air amount of the air flow meter due to electrification.

1 is a schematic configuration diagram showing an intake device according to a first embodiment; FIG. FIG. 3 is a perspective view showing the vicinity of an air flow meter of the air intake device according to the first embodiment; FIG. 2 is a detailed perspective view showing the air ionization self-discharge type static eliminator arranged on the lead wire according to the first embodiment; 4 is a graph showing detected amounts of intake air in a comparative example without an air-ionizing self-discharge static eliminator in a lead wire and an example with an air-ionizing self-discharge static eliminator in a lead wire. FIG. 8 is a detailed perspective view showing an air ionization self-discharge type static eliminator arranged on a lead wire according to another example of the first embodiment; FIG. 8 is a detailed perspective view showing an air ionization self-discharge type static eliminator arranged on a lead wire according to still another example of the first embodiment; FIG. 11 is a perspective view showing the vicinity of an air flow meter of an air intake device according to a second embodiment; FIG. 11 is an explanatory view of the attachment state of the air ionization self-discharge type static eliminator to the air flow meter according to the second embodiment; FIG. 11 is an explanatory view of the attachment state of the air ionization self-discharge type static eliminator to the airflow meter according to another example of the second embodiment;

[First embodiment]
An intake device according to a first embodiment will be described with reference to FIGS. 1 to 6. FIG.

(composition)
The overall configuration of the intake device 10 will be described.

As shown in FIG. 1, an intake device 10 includes an intake pipe 12 that draws air from the outside, an air cleaner 14 that removes foreign matter from the air (intake air) taken in through the intake pipe 12, an air cleaner 14, and an intake manifold 18. , an intake manifold 18 connected to the air cleaner hose 16 and supplying intake air to the engine 20 , and the engine 20 . An airflow meter 22 is provided on the outlet side of the air cleaner 14 to detect the amount of intake air. Furthermore, an ECU 24 is provided for controlling the air-fuel ratio of the engine 20 based on the detection signal of the airflow meter 22 .

A path from an intake inlet 12A to the engine 20, ie, an intake pipe 12, an air cleaner 14, an air cleaner hose 16, and an intake manifold 18, corresponds to an "intake path".

The intake pipe 12 is made of a non-conductive resin and supplies the air cleaner 14 with intake air introduced from the intake inlet 12A.

As shown in FIG. 1, the air cleaner 14 includes an air cleaner body 28 in which an air filter 26 is disposed, and an air cleaner body 28 connected to the air cleaner hose 16 on the downstream side of the air cleaner body 28 and having a passage cross-sectional area larger than that of the air cleaner body 28 . a small outlet 30; The air cleaner 14 is also made of non-conductive resin.

The air cleaner hose 16 is made of non-conductive rubber or resin, and has one end connected to the air cleaner 14 (outlet 30 ) and the other end connected to the intake manifold 18 .

The intake manifold 18 is also made of non-conductive resin and supplies intake air to each cylinder of the engine 20 .

The airflow meter 22 is provided at the outlet 30 of the air cleaner 14 . As shown in FIG. 2, the airflow meter 22 is attached to the outlet 30 via screws 32, 32, and a sensor (not shown) is inserted into the outlet 30 to detect the amount of intake air.

The airflow meter 22 is also connected to a lead wire 36 via a connector 34, as shown in FIG. As shown in FIG. 1, the lead wire 36 is provided with a connection terminal 38 at the end opposite to the connector 34 .

As shown in FIG. 3, the lead wire 36 includes a signal wire 40 made of copper, an insulator 42 surrounding the signal wire 40, and a coating made of resin or rubber which is a non-conductive material covering the outer periphery of the insulator 42. material 44;

An air ionization self-discharge type static eliminator 50 is provided on the airflow meter 22 side of the lead wire 36, as shown in FIG. As shown in FIG. 3, the air ionization self-discharge type static eliminator 50 is constructed by winding an aluminum foil tape around the outer peripheral surface of the coating material 44 of the lead wire 36 and adhering the ends of the tape together to form a wound portion. 52 and a protruding portion 54 protruding radially outward of the lead wire 36 from the end portion of the winding portion 52 .

Note that the air flow meter 22 is connected to the ECU 24 via a lead wire 36 and a signal wire 60, as shown in FIG. A fuel injection device (not shown) of the engine 20 and the ECU 24 are connected by a signal line 62 .

The ECU 24 detects the intake air amount based on the detection signal of the airflow meter 22 and adjusts the fuel injection amount of the engine 20 so that the engine 20 burns at a predetermined air-fuel ratio.

(Action)
Next, the action of the intake device 10 of this embodiment will be described.

In the intake device 10, when the engine 20 is driven, when the intake air passes through the intake pipe 12, the air cleaner 14, etc., static electricity is generated due to friction with the inner pipe wall, and the intake pipe made of non-conductive resin is generated. 12 and the air cleaner 14 are positively charged, and the airflow meter 22 disposed at the outlet 30 of the air cleaner 14 is also positively charged.

As the airflow meter 22 is charged, the coating 44 of the lead wire 36 connected to the airflow meter 22 and made of a non-conductive material is charged. As a result, noise due to the electrification of the covering material 44 is superimposed on the detection signal of the airflow meter 22 detected by the ECU 24 . As a result, an error may occur when the ECU 24 detects the intake air amount based on the detection signal of the airflow meter 22, and the detected intake air amount may increase or decrease in amplitude.

As shown in FIG. 4, in a comparative example in which the lead wire 36 of the air intake device 10 is not provided with the air ionization self-discharging static eliminator 50 (see the broken line in FIG. 4), the air flow meter 22 is The detection signal value (detected intake air amount) fluctuates greatly. This is because the charging of the covering material 44 of the lead wire 36 causes the detection signal of the airflow meter 22 transmitted through the signal line 40 of the lead wire 36 to be superimposed with noise due to the charging, and the detection signal value fluctuates greatly. It is considered to be for

On the other hand, in the air intake device 10 (see the solid line in FIG. 4) provided with the air ionization self-discharge type static eliminator 50, the detection signal value of the air flow meter 22 (detected intake air amount) is suppressed. In the air intake device 10, the lead wire 36 is provided with the air ionizing self-discharging static eliminator 50. Therefore, even if the covering material 44 of the lead wire 36 of the air flow meter 22 is charged, the air wound around the covering material 44 is ionized. Static electricity is discharged into the air from the protruding portion 54 of the self-discharging static eliminator 50, and static electricity is eliminated from the coating material 44 (the charge amount of the coating material 44 is reduced). As a result, the detection signal of the airflow meter 22 output to the ECU 24 is suppressed from being superimposed with noise due to the electrification of the covering material 44 .

As described above, in the intake device 10, the air ionization self-discharge type static eliminator 50 is provided on the surface of the covering material 44 of the lead wire 36, so that noise caused by charging is superimposed on the detection signal of the air flow meter 22 can be reduced. Therefore, the ECU 24 can accurately detect the amount of intake air.

Therefore, the ECU 24 can accurately control the fuel injection amount of the engine 20 based on the detected intake air amount and control the air-fuel ratio to a predetermined air-fuel ratio. Output fluctuation of the engine 20 is suppressed as compared with the comparative example in which the control was not performed. As a result, the steering stability of the vehicle is improved. In addition, the reduction in output fluctuation of the engine 20 suppresses the fluctuation in the fuel injection amount, thereby improving the fuel efficiency of the vehicle. Furthermore, in the air intake device 10, the air ionization self-discharge type static eliminator 50 made of aluminum foil tape can be simply wound around the lead wire 36, so that the above effects can be obtained at a low cost.

(variation)
In addition, as shown in FIG. 5, the air ionization self-discharge type static eliminator 50A has a pair of aluminum foil tapes wrapped around the covering material 44 of the lead wire 36 half a turn, and both ends of the tape are wound radially outwardly of the lead wire. The wound portion 52A and the pair of projecting portions 54A and 54B may be formed by sticking them together while protruding outward. The air ionization self-discharge type static eliminator 50A is provided with a pair of projecting portions 54A and 54B, thereby improving discharge performance.

Also, as shown in FIG. 6, it is conceivable to provide two air ionization self-discharge type static eliminators 50B and 50C on the lead wire 36 of the air flow meter 22 with a predetermined interval. Thus, by providing two air ionizing self-discharging static eliminators 50B and 50C on the lead wire 36, it is conceivable to improve discharge performance. Three or more air ionizing self-discharging static eliminators may be provided for one lead wire 36 .

[Second embodiment]
An intake device according to the second embodiment will be described with reference to FIGS. 7 to 9. FIG. Components similar to those of the intake system of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Also, the overall configuration of the intake device 70 is substantially the same as that of the intake device 10 shown in FIG. 1, and a description thereof will be omitted.

(composition)
As shown in FIG. 8 , the airflow meter 22 has a sensor portion 72 inserted inside the outlet 30 of the air cleaner 14 and an attachment portion 74 attached to the outlet 30 .

As shown in FIG. 7, the mounting portion 74 is formed of non-conductive resin in a substantially rectangular shape, and flange portions 76, 76 protruding from the ends thereof are fastened to a pedestal 80, which will be described later, of the outlet 30. Accordingly, the airflow meter 22 is attached to the outlet 30 .

Further, the mounting portion 74 is provided with a terminal portion (not shown) for connecting the connector 34 .

Further, below the mounting portion 74, a sensor portion 72 made of a non-conductive resin is provided that is inserted into the outlet 30 through an insertion hole 84 of a pedestal 80, which will be described later.

The sensor section 72 is provided with a flow path (not shown) and the like, and detects the amount of intake air based on the intake air introduced inside through the flow path.

As shown in FIG. 8, the outlet 30 of the air cleaner 14 is provided with a pedestal 80 projecting radially outward for mounting an air flow meter. The pedestal 80 is formed with an insertion hole 84 extending radially from the top surface 82 to the inside of the outlet 30 .

Therefore, the air flow meter 22 inserts the sensor portion 72 into the insertion hole 84 of the pedestal 80, mounts the mounting portion 74 on the top surface 82 of the pedestal 80, and attaches the flange portions 76, 76 to the top surface 82 of the pedestal 80. It is the structure attached to the outlet 30 by fastening.

Furthermore, an air ionization self-discharge type static eliminator 90 made of aluminum foil tape is attached to the top surface 78 of the mounting portion 74 via a conductive adhesive 86 .

(Action)
Next, the operation of the intake device 70 of this embodiment will be described.

When the engine 20 is driven, the intake device 70 generates static electricity due to friction with the inner pipe wall when passing through the intake pipe 12, the air cleaner 14, and the like. Air cleaner 14 is positively charged.

Also, the air flow meter 22 (mounting portion 74, sensor portion 72) made of non-conductive resin and attached to the pedestal 80 of the outlet 30 of the air cleaner 14 is positively charged.

However, the air ionization self-discharge type static eliminator 90 is joined via a conductive adhesive 86 to the top surface 78 of the mounting portion 74 of the air flow meter 22 made of non-conductive resin. Therefore, static electricity is discharged into the air from the air ionization self-discharge type static eliminator 90, thereby neutralizing the air flow meter 22 (the charge amount of the air flow meter 22 is reduced). As a result, noise due to charging of the air flow meter 22 is reduced, which is superimposed on the detection signal of the air flow meter 22 output to the ECU 24 .

In addition, since the air flow meter 22 (mounting portion 74) is neutralized by the air ionization self-discharging static eliminator 90, the charge amount in the vicinity of the air flow meter mounting position at the outlet 30 of the air cleaner 14 is also reduced. As a result, in the corresponding portion of the outlet 30, the separation flow of intake air due to positive charging is also suppressed. As a result, the flow of intake air to the sensor portion 72 of the airflow meter 22 is stabilized, and the detection accuracy of the amount of intake air by the airflow meter 22 is improved.

As a result, the amount of intake air detected by the airflow meter 22 is stabilized, and fluctuations in the output of the engine 20 are reduced. Therefore, the steering stability of the vehicle is improved. In addition, the reduction in output fluctuation of the engine 20 suppresses the fluctuation in the fuel injection amount, thereby improving the fuel efficiency of the vehicle. Furthermore, in the air intake device 10, the air ionization self-discharge static eliminator 90 made of aluminum foil tape can be simply attached to the air flow meter 22 (mounting portion 74) via the conductive adhesive 86. Therefore, the above effect can be obtained at a low cost. can be obtained.

In particular, since the air flow meter 22 is disposed at a portion of the air cleaner 14 which enters the outlet 30 having a relatively small flow passage cross-sectional area from the air cleaner main body 28 having a relatively large flow passage cross-sectional area, the intake air flows into the outlet 30. separation flow away from the inner wall of the pipe. However, by removing static electricity from the air flow meter 22 with the air ionization self-discharge type static eliminator 90, the separation flow of the intake air in the relevant portion of the outlet 30 can be suppressed, and the detection accuracy of the intake air amount by the air flow meter 22 can be improved. can.

(variation)
As shown in FIG. 9, an air ionization self-discharge type static eliminator 90 may be attached to the side surface 79 of the mounting portion 74 of the air flow meter 22 via a conductive adhesive 86 .

[others]
In the air intake device 10 of the first embodiment, the air ionization self-discharge type static eliminator 50 is provided on the lead wire 36 of the air flow meter 22. Although provided on the side 78 or the side 79, these may be combined.

Further, in the intake device 70 of the second embodiment, the air ionization self-discharge type static eliminator 90 is provided on the top surface 78 or the side surface 79 of the mounting portion 74 of the airflow meter 22, but it may be provided on both sides.

Furthermore, the air ionization self-discharge static eliminators 50, 50A to 50C of the first embodiment are not particularly limited in their arrangement position as long as they are exposed to the air on the surface of the covering material 44 of the lead wire 36. do not have. Also, the air ionization self-discharge type static eliminator 90 of the second embodiment is not particularly limited in its position as long as it is exposed to the air on the surface of the airflow meter 22 .

In addition, in the first and second embodiments, the intake pipe 12, the air cleaner 14, the air cleaner hose 16, the intake manifold 18, and the airflow meter 22 are all made of a non-conductive material. not a thing

Moreover, although the intake devices 10 and 70 according to the first and second embodiments have been described as being applied to a naturally aspirated engine, they can also be applied to an engine with a supercharger.

Although the embodiment has been described above, it is needless to say that the invention can be embodied in various forms without departing from the gist of the invention.

10, 70 intake device 12 intake pipe (intake path)
12A Intake inlet 14 Air cleaner (intake path)
16 Air cleaner hose (intake route)
18 intake manifold (intake path)
20 engine 22 airflow meter 36 lead wires 50, 50A, 50B, 50C, 90 air ionization self-discharge static eliminator

Claims (1)

an intake path connected from the intake inlet to the engine;
an airflow meter provided in the intake path for detecting an amount of intake air in the intake path;
a lead connected to the airflow meter and transmitting a detection signal of the airflow meter;
an air ionization self-discharge type static eliminator provided on the outer peripheral surface of the lead wire and capable of discharging static electricity into the air;
Intake device with.

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