JPH0710443U - Intake pipe placement sensor foreign matter adhesion prevention structure - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To reliably prevent foreign matter in the intake air from adhering to various sensors arranged in the intake pipe. A bypass passage that opens an intake passage 4 for introducing intake air into the negative pressure sensor 7 into the bore 2 at a position downstream of the throttle valve and bypasses the throttle valve during idling to supply intake air downstream of the throttle valve. 11 is connected to the intake air intake passage 4 so as to purge foreign substances that have entered during the idle operation, and further, the intake air intake 10 of the negative pressure sensor 7
Is projected from a wall surface continuous with the wall surface of the intake air intake passage 4 so that the moisture and oil components in the purge air do not enter the negative pressure sensor 7 even if they flow along the wall surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a foreign matter adhesion prevention structure for an intake pipe arrangement sensor that prevents foreign matter such as oil and water from adhering to a sensor that detects various states of intake air, such as an intake negative pressure sensor.

[0002]

[Prior art]

 Conventionally, for example, a negative pressure sensor for detecting intake negative pressure is connected to the throttle valve downstream position via a pressure introduction passage, but since blow-by gas is mixed in the intake air, this blow-by gas contains There was a problem that water and oil entered the negative pressure sensor through the pressure introduction passage due to pressure fluctuations in the intake pipe, etc., and these foreign substances adhered to the sensor, reducing detection accuracy and durability. .

Therefore, for example, in Japanese Unexamined Patent Application Publication No. 4-255539, a pressure introducing passage curved in an arc shape is extended upward from a negative pressure introducing port opening in the intake pipe, and is curved in the middle of the pressure introducing passage. It is disclosed that an oil trap groove that bulges in the centrifugal direction of the part is formed, and the oil is trapped by the trap groove by using a centrifugal separation operation so as not to reach the negative pressure sensor.

Further, in Japanese Patent Laid-Open No. 3-277935, a mixing chamber is formed in a connection portion between an intake port of a negative pressure sensor and an intake pipe, and a throttle valve is bypassed in the mixing chamber during idle operation to intake air. It is disclosed that an air supply port communicating with an idle port for supplying air is provided to generate an air flow from the mixing chamber toward the suction pipe to discharge the foreign matter that has entered the mixing chamber.

Further, as shown in FIG. 6, a groove serving as a negative pressure introduction port 23 is formed on the joint surface of the throttle body 21 with a surge tank (not shown) downstream of the throttle valve 22 and the intake air introduction is performed. A groove serving as an intake air introduction passage 24 is formed in a circular arc shape upward from the mouth 23, and a communication hole 25 is bored in the axial direction from the vicinity of the upper end of the groove to communicate with the communication hole 25 from the upper surface of the throttle body 21. The mounting hole 26 is formed as described above, the introduction portion 28 of the negative pressure sensor 27 mounted on the upper surface of the slot body 21 is fitted into the mounting hole 26, and the idle operation is performed at a position upstream of the throttle valve 22 of the throttle body 21. Occasionally, an inlet portion 30 at one end of a bypass passage 29 that bypasses the throttle valve 22 and supplies intake air is opened, and an orifice 31 is provided in the vicinity of the inlet portion 30. It is disclosed that the other end of the passage 29 is connected to the upper end of the intake introduction passage 24 so that foreign matter that has entered the intake introduction passage 24 is purged by intake air flowing through the bypass passage 29 during idle operation.

[0006]

[Problems to be solved by the device]

 However, as disclosed in Japanese Patent Application Laid-Open No. 4-255539, only trapping foreign matter in the trap groove provided in the pressure introducing passage does not have the function of discharging the foreign matter once entered, so that the passage will end up. Due to the oil and water accumulated inside, there is a problem that the pressure may not be accurately transmitted to the negative pressure sensor and the detection accuracy may be reduced, or the sensor itself may be damaged.

Further, in the configuration disclosed in Japanese Patent Application Laid-Open No. 3-277935 and the configuration shown in FIG. 6, foreign matter that has entered the mixing chamber or the intake introduction passage by the intake air flowing through the bypass passage during the idle operation is positively activated. Since foreign matter does not accumulate because it is purged dynamically, blow-by gas is mixed in the intake air that purges foreign matter, and the water content and oil content contained in this blow-by gas are mixed. Flow along the wall surface of the mixing chamber, the air intake introduction passage 24, the communication hole 25, and the wall surface of the mounting hole 26, and there is a high possibility that it will enter the negative pressure sensor 27, and again the pressure will not be transmitted to the negative pressure sensor. However, there is a problem that the sensor itself may be damaged.

In view of such conventional problems, the present invention provides a foreign matter adhesion prevention structure for an intake pipe arrangement sensor that can reliably prevent foreign matter in intake air from adhering to various sensors arranged in the intake pipe. The purpose is to do.

[0009]

[Means for Solving the Problems]

 According to the present invention, an intake air intake passage for introducing intake air into a sensor is opened in the intake pipe at a position downstream of the throttle valve, and a bypass passage for bypassing the throttle valve during idling to supply intake air downstream of the throttle valve is provided. It is characterized in that the intake air intake portion of the sensor is projected from a wall surface continuous with the wall surface of the intake air introduction passage.

[0010]

[Action]

 According to the present invention, the state of intake air can be detected by introducing the intake air into the sensor through the intake air intake passage, and during idle operation, the intake air flows from the bypass passage through the intake air intake passage to the downstream side of the throttle valve. By flowing toward, it is possible to purge foreign substances such as water and oil that have entered the intake passage, and at that time, the water and oil contained in the blow-by gas in the intake along the wall surface. Even if it flows, since the intake part of the sensor protrudes from the wall surface that is continuous with the wall surface of the intake introduction passage, it flows toward the intake pipe as it is without entering the sensor, so foreign matter in the air adheres to the sensor. Can be reliably prevented.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a throttle body that constitutes a part of an intake pipe, and a throttle valve (not shown) is arranged inside. An intake inlet 3 is formed by forming a wide groove facing the bore 2 on one side of a joint surface 1a of the throttle body 1 which is downstream of the throttle valve and connected to a surge tank (not shown). An intake air intake passage 4 is provided by forming a groove curved in an arc shape upward from the mouth 3. A communication hole 5 is formed in the axial direction from the vicinity of the upper end of the intake air intake passage 4, and a mounting hole 6 is formed so as to directly communicate with the communication hole 5 from the upper surface of the throttle body 1.

The negative pressure sensor 7 is attached to the upper surface of the throttle body 1 by inserting the introduction portion 8 into the mounting hole 6. Reference numeral 9 is a sealing material arranged on the outer peripheral surface of the introduction portion 8. A small-diameter intake inlet 10 is projected at the tip of the introduction portion 8, and the intake inlet 10 is connected to the wall surface of the intake introduction passage 4 through the wall surface of the communication hole 5 and the wall surface of the mounting hole 6. A space is formed around the leading end surface of the introduction portion 8 and around it.

Further, when the throttle valve is fully closed during idle operation, a bypass passage 11 for bypassing the throttle valve and supplying intake air is provided, and one end of the bypass passage 11 is opened at a position upstream of the throttle valve of the throttle body 1. are doing. The other end of the bypass passage 11 is connected to the upper end of the intake air introduction passage 4.

According to the above-mentioned configuration, the intake port 3 of the bore 2 of the throttle body 1 that is opened at one side downstream of the throttle valve is opened from the intake port 3 through the intake port 4, the communication hole 5, and the mounting hole 6. The intake pressure can be detected by introducing the intake pressure to the pressure sensor 7, and the intake air amount can be detected based on the intake pressure to control the fuel supply amount and the like.

Further, since the bypass passage 11 that bypasses the throttle valve and supplies the intake air at the time of idling is connected to the intake introduction passage 4, the blow-by gas contained in the intake air due to pressure fluctuations in the intake pipe and the like. Even if foreign matter such as water or oil enters the intake passage 4, it can be purged by the intake air flow flowing through the bypass passage 11 during the idle operation, and these foreign matters reach the negative pressure sensor 7 and are detected. There is no risk of reducing accuracy or causing a malfunction.

Further, during the purging, even if the water content or the oil content in the blow-by gas contained in the intake flow flows along the wall surface of the intake introduction passage 4 or the wall surface of the communication hole 5 or the mounting hole 8 continuous with the wall surface. Since the intake port 10 of the negative pressure sensor 7 projects from the wall surface continuous with the wall surface of the intake introduction passage 4, it does not enter the negative pressure sensor 7. Thus, it is possible to reliably prevent foreign matter in the suction from adhering to the negative pressure sensor 7.

Although the mounting hole 6 is directly communicated with the communication hole 5 and the small-diameter intake port 10 is projected from the tip of the introduction portion 8 in the above embodiment, as shown in FIG. A wall is provided between the hole 6 and the communication hole 5, a small diameter intake pipe 12 is fitted through the wall, and the tip of the intake pipe 12 is projected to the wall surface of the communication hole 5. Alternatively, foreign matter may be prevented from entering the mounting hole 6.

Further, as shown in FIG. 4, the intake intake port 13 is extended from the tip of the introduction part 8 of the negative pressure sensor 7, and the intake intake port 13 is provided between the mounting hole 6 and the communication hole 5. It is also possible to prevent foreign matter from entering the negative pressure sensor 7 by penetrating the wall of the above and projecting the tip thereof against the wall surface of the communication hole 5.

Further, as shown in FIG. 5, a step 14 is further provided on the wall surface portion of the communication hole 5 facing the intake port 10 so that foreign matter flowing along the wall surface does not enter the negative pressure sensor 7. May be.

In each of the above embodiments, the negative pressure sensor 7 is illustrated as the sensor for detecting the intake state, but the present invention is not limited to the sensor for detecting the intake negative pressure, and other intake states such as intake temperature may be detected. The same effect can be obtained by applying it to the detecting sensor.

[0022]

[Effect of device]

 According to the foreign matter adhesion prevention structure for the intake pipe arrangement sensor of the present invention, since the intake air introduction passage for introducing the intake air into the sensor is opened in the intake pipe at the position downstream of the throttle valve as described above, the intake air is introduced into the intake air passage. A bypass passage that is introduced into the sensor to detect the intake air condition and that bypasses the throttle valve during idle operation and supplies intake air downstream of the throttle valve is connected to the intake introduction passage. Foreign matter that has entered the intake air intake passage can be purged during idle operation, and the intake air intake portion of the sensor is further projected from the wall surface that is continuous with the wall surface of the intake air intake passage. Even if the water and oil components in the air flow along the wall surface, they will not enter the sensor. The Chakusuru can be reliably prevented.

[Brief description of drawings]

1A and 1B show an embodiment of a foreign matter adhesion preventing structure for an intake pipe arrangement sensor according to the present invention, FIG. 1A is a side view, and FIG.

FIG. 2 is a sectional view taken along the line II-II of FIG. 1 (b).

FIG. 3 is a sectional view similar to FIG. 2 of another embodiment of the present invention.

FIG. 4 is a sectional view similar to FIG. 2 of still another embodiment of the present invention.

FIG. 5 is a sectional view similar to FIG. 1 (b) of still another embodiment of the present invention.

6A and 6B show a foreign matter adhesion preventing structure of a conventional example, in which FIG. 6A is a side view, FIG. 6B is a sectional view taken along the line BB of FIG. FIG.

[Explanation of symbols]

 1 Throttle body 2 Bore (inside intake pipe) 3 Intake inlet 4 Intake passage 5 Communication hole 6 Mounting hole 7 Negative pressure sensor 10 Intake intake 11 Bypass passage 12 Intake intake pipe 13 Intake intake pipe port

Claims (1)

[Scope of utility model registration request] 1. An intake passage for introducing intake air into a sensor is opened in the intake pipe at a position downstream of the throttle valve, and a bypass passage for bypassing the throttle valve during idling to supply intake air downstream of the throttle valve is introduced. A foreign matter adhesion prevention structure for an intake pipe arrangement sensor, characterized in that the intake pipe of the sensor is connected to a passage and an intake portion of the sensor is projected from a wall surface continuous with the wall surface of the intake air passage.