Sensor unit

Abstract

The invention provides a sensor unit which actively generates flow of intake air in a passage communicating from a detection part of a sensor to an intake passage, suppresses or prevents freezing of liquid or liquid substances such as fuel, moisture and blow-by gas, and can detect state quantities (pressure and temperature) of the intake air with high precision. A sensor unit disposed in an intake pipe of an internal combustion engine is provided with: sensors (30, 40) for detecting the state quantity of intake air flowing through an intake passage (Ip1) demarcated by the intake pipe; and a housing (Ca) that houses the sensor, the housing (Ca) including: a first passage (24) and a second passage (25) that communicate with each other and open to the intake passage, respectively, such that the detection unit (Rc, 41) of the sensor is exposed to intake air flowing through the intake passage; and a collision wall (26a) which is located in the vicinity of the opening of the second passage and collides the intake air flowing through the intake passage.

Description

Technical Field

[0001] The present invention relates to a sensor unit used in an intake system of an internal combustion engine mounted on an automobile, a motorcycle, or other vehicles to detect a state quantity (pressure, temperature) of intake air, and the intake system of the internal combustion engine. Background Art

[0002] As a previous sensor unit, there is known a temperature sensor integrated pressure sensor device, which includes: a shell having a terminal embedded therein; a pressure detection element connected to the terminal and arranged in the shell; a port portion connected to the shell and having a pressure inlet hole connected to a pressure receiving chamber of the pressure detection element; and a temperature detection element connected to the terminal and arranged at the front end of the port portion (for example, Patent Document 1, Patent Document 2).

[0003] In the temperature sensor integrated pressure sensor device, the pressure introduction hole formed in the port portion is formed as a linear passage with a relatively large passage area. Therefore, if there is foreign matter in the intake manifold, there is a concern that the foreign matter may intrude into the pressure receiving chamber through the pressure introduction hole, thereby failing to accurately detect the intake air pressure.

[0004] In addition, as another sensor unit, there is known a pressure sensor device, which includes: a sensor storage container, which is composed of a base and a box-shaped outer shell; a pressure detection element, which is arranged in the outer shell; a pressure introduction path, which is formed by a base and a tube and is connected to the pressure introduction chamber of the pressure detection element; a temperature sensor, which is arranged in a temperature sensor storage protrusion formed on the base; and a circuit substrate, which is electrically connected to the pressure detection element and the temperature sensor and is arranged in the outer shell (for example, patent document 3).

[0005] In the pressure sensor device, a labyrinth structure with a reduced passage area is formed near the opening end of the pressure introduction passage to suppress foreign matter from entering the pressure introduction chamber through the pressure introduction passage. Therefore, in the area of ​​the labyrinth structure, there is a concern that liquids, such as blowback fuel, moisture in the intake air, blowby gas, and other liquids or liquid substances may adhere to the passage or freeze during cooling, further narrowing or clogging the passage and failing to correctly detect the intake air pressure.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2006-194683

[0009] [Patent Document 2] Japanese Patent Application Publication No. 2005-274412

[0010] [Patent Document 3] Japanese Patent Application Laid-Open No. 11-30535 Summary of the invention

[0011] [Problems to be solved by the invention]

[0012] The present invention is made in view of the above situation, and its purpose is to provide a sensor unit and an intake system of an internal combustion engine that actively generate a flow of intake air in a passage connected from a detection part of a sensor to an intake passage, thereby suppressing or preventing the adhesion or freezing of liquids or liquids such as fuel, moisture in the intake air, blowby gas, etc., and can detect the state quantity of the intake air with high precision.

[0013] [Technical means to solve the problem]

[0014] The sensor unit of the present invention is a sensor unit arranged in the intake pipe of an internal combustion engine, and is constructed to include: a sensor, which detects the state quantity of the intake air flowing in the intake passage defined by the intake pipe; and a shell, which accommodates the sensor, the shell including: a first passage and a second passage, which are interconnected and open to the intake passage respectively so that the detection part of the sensor is exposed to the intake air flowing in the intake passage; and a collision wall, which is located near the opening of the second passage and causes the intake air flowing in the intake passage to collide.

[0015] In the sensor unit, a configuration may be adopted in which the collision wall includes a guide portion that guides the intake air flowing through the intake passage toward the inside of the second passage.

[0016] In the sensor unit, a configuration may be adopted in which the guide portion includes a curved surface inclined toward the inside of the second passage.

[0017] In the sensor unit, a configuration may be adopted in which the guide portion includes side surfaces formed continuously to both sides of the curved surface.

[0018] In the sensor unit, the first passage may have a first opening opening at a first end face away from the inner wall face of the intake pipe toward the center, and the second passage may have a second opening opening at a second end face closer to the inner wall face of the intake pipe than the first opening.

[0019] In the sensor unit, the housing may include a sleeve extending in a predetermined axial direction, the sleeve includes a partition wall extending to define the first passage and the second passage so as to be adjacent to each other, and the partition wall includes a collision wall.

[0020] In the sensor unit, the following structure may also be adopted, wherein the sensor includes: a pressure sensor for detecting the pressure of the intake air; and a temperature sensor for detecting the temperature of the intake air, and the shell includes: a shell body for accommodating the temperature sensor and the pressure sensor; and a sleeve for being connected to the shell body and defining the first passage, the second passage and the collision wall.

[0021] In the sensor unit, the first passage and the second passage may be formed to extend from regions facing the detection portion of the temperature sensor to the intake passage, respectively, and the detection portion of the pressure sensor may be formed to face a middle of the second passage.

[0022] In the sensor unit, the housing body may include a recessed portion that exposes the detection portion of the temperature sensor, and the sleeve may include a protruding wall that is inserted into the recessed portion to define a portion of the first passage and the second passage in cooperation with the recessed portion.

[0023] In the sensor unit, the following structure can also be adopted, wherein the second passage includes a bent passage between an area facing the detection part of the pressure sensor and an area facing the detection part of the temperature sensor, and the first passage includes a bent passage midway from the area facing the detection part of the temperature sensor toward the first opening opening to the intake passage.

[0024] In the sensor unit, a configuration may be adopted in which the first passage and the second passage include a bent passage formed to be three-dimensionally bent.

[0025] In the sensor unit, a configuration may be adopted in which an inner wall surface of the curved passage is curved so as to be streamlined and continuous.

[0026] In the sensor unit, the detection portion of the pressure sensor may include a pressure receiving chamber exposed to the intake air, and the pressure receiving chamber may be formed to communicate with the second passage via a communication hole having an opening area smaller than a passage area of ​​the second passage.

[0027] In the sensor unit, a configuration may be adopted in which the communication hole is arranged to face a second opening portion of the second passage that opens to the intake passage in an extending direction of the second passage.

[0028] The sensor unit may have a structure including a circuit substrate to which the pressure sensor and the temperature sensor are electrically connected and housed in a housing body.

[0029] In the sensor unit, a structure may be adopted in which the temperature sensor is a surface mount type temperature sensor mounted on a circuit board.

[0030] In the sensor unit, the following structure may also be adopted, including a first connecting path and a second connecting path, the first connecting path includes: a first passage, which has a specified passage area and a first passage length; and a first ventilation hole, which is connected to the first passage and has an opening area smaller than the passage area of ​​the first passage, and the second connecting path includes: a second passage, which has a passage area equal to the passage area of ​​the first passage and a second passage length shorter than the first passage length; and a second ventilation hole, which is connected to the second passage and has an opening area smaller than the passage area of ​​the second passage.

[0031] In the sensor unit, the following structure can also be adopted, the sensor includes a pressure sensor for detecting the pressure of the intake air, the pressure sensor includes: a sensor main body, having a pressure-receiving part; and a sensor cover connected to the sensor main body to cover the pressure-receiving part and define a pressure-receiving chamber, and a first vent hole and a second vent hole are formed in the sensor cover.

[0032] In the sensor unit, a configuration may be adopted in which the first vent hole and the second vent hole are formed to be biased toward a side away from a central region of the pressure receiving chamber.

[0033] In the sensor unit, the following structure may be adopted, wherein the housing includes: a housing body including a joint surface joined to the intake pipe; and a cylindrical sleeve protruding from the housing body in a predetermined axial direction, and the first passage and the second passage are formed to extend inside the sleeve.

[0034] The sensor unit may include a temperature sensor for detecting the temperature of the intake air in the intake pipe, and the housing may include a second housing portion for housing the temperature sensor.

[0035] In the sensor unit, the following structure can also be adopted, wherein the shell includes: a shell body including a joint surface joined to the intake pipe; and a cylindrical sleeve protruding from the shell body in a specified axial direction, and the first passage, the second passage and the second housing portion are formed to extend within the sleeve.

[0036] In the sensor unit, the following structure may also be adopted, wherein the shell includes: a shell body, including a joint surface joined to the intake pipe; a sleeve, which protrudes from the shell body in a specified axial direction and defines a first passage, a second passage and a collision wall; and an annular groove formed on the outer periphery of the sleeve for an annular sealing component to be embedded.

[0037] In the sensor unit, the sleeve may include a large diameter cylindrical portion protruding from the joint surface and a small diameter cylindrical portion continuous with the large diameter cylindrical portion, and the annular groove may be formed in the large diameter cylindrical portion.

[0038] The intake system of the internal combustion engine of the present invention is constructed as follows, including: an intake pipe, which defines an intake passage that guides the intake air to the combustion chamber of the internal combustion engine; a fuel injection valve, which injects fuel into the middle of the intake passage or the combustion chamber; a throttle device, which is located in the middle of the intake pipe and opens / closes the intake passage; and a sensor unit, which detects the state quantity of the intake air flowing in the intake passage, and any sensor unit with the above structure is used as the sensor unit.

[0039] In the intake system of the internal combustion engine, a structure may be adopted in which the sensor unit is arranged in the intake pipe on the downstream side of the throttle device.

[0040] [Effects of the Invention]

[0041] By means of the sensor unit having the above-described structure, a flow of intake air is actively generated in the passage connecting from the detection part of the sensor to the intake passage, thereby suppressing or preventing the adhesion or freezing of liquids or liquid substances such as fuel, moisture in the intake air, and blowby gas, and the state quantity (pressure, temperature) of the intake air can be detected with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 1 is a system diagram showing an intake system of an internal combustion engine to which the sensor unit of the present invention is applied.

[0043] Figure 2 The figure shows the sensor unit of the first embodiment and is an external perspective view as viewed from the joining surface side of the housing joined to the intake pipe.

[0044] Figure 3 It is a partial cross-sectional view showing a state where the sensor unit according to the first embodiment is mounted on an intake pipe.

[0045] Figure 4 This is an exploded perspective view showing the sensor unit of the first embodiment disassembled and viewed from one side.

[0046] Figure 5 This is an exploded perspective view in which the sensor unit of the first embodiment is disassembled and viewed from the other side.

[0047] Figure 6 It is a perspective cross-sectional view showing a sleeve constituting a part of a housing in the sensor unit according to the first embodiment.

[0048] Figure 7 It is a perspective cross-sectional view showing a sleeve constituting a part of a housing in the sensor unit according to the first embodiment.

[0049] Figure 8 This is a cross-sectional view taken along a plane passing through a center line of a communication hole communicating with a detection portion (pressure receiving chamber) of a pressure sensor in the sensor unit of the first embodiment.

[0050] Fig. 9 It is a cross-sectional view of a surface including a bending passage constituting a part of a second passage communicating from a detection section of a pressure sensor to a detection section of a temperature sensor in the sensor unit of the first embodiment.

[0051] Fig.10 This is a cross-sectional view of the sensor unit according to the first embodiment, taken along a plane including a first passage opening from a detection portion of the temperature sensor to the intake passage.

[0052] Fig.11 It is a perspective cross-sectional view showing the flow of intake air in the second passage and the first passage from the collision wall in the sensor unit according to the first embodiment.

[0053] Fig.12 This is a schematic diagram for explaining the flow of intake air in the first passage and the second passage when the sensor unit is attached to the intake pipe in the sensor unit of the first embodiment.

[0054] Fig.13 It is a diagram showing a sensor unit according to a second embodiment and is an external perspective view as viewed from the joining surface side of a housing joined to an intake pipe.

[0055] Fig.14 It is a partial cross-sectional view showing a state where the sensor unit according to the second embodiment is attached to the intake pipe.

[0056] Fig.15 This is an exploded perspective view of the sensor unit according to the second embodiment, in which the sleeve is disassembled from the housing body and viewed from the sleeve side.

[0057] Fig.16 It is a perspective cross-sectional view showing a sleeve constituting a part of a housing in a sensor unit according to a second embodiment.

[0058] Fig.17 It is a perspective cross-sectional view showing the flow of intake air in the second passage and the first passage from the collision wall in the sensor unit according to the second embodiment.

[0059] Fig.18 This is a schematic diagram for explaining the flow of intake air in the first passage and the second passage when the sensor unit according to the second embodiment is attached to the intake pipe.

[0060] Fig.19 It is a diagram showing a sensor unit according to a third embodiment and is an external perspective view showing an enlarged view of a sleeve constituting a part of a housing.

[0061] Fig. 20 It is a perspective cross-sectional view showing a sleeve constituting a part of a housing in a sensor unit according to a fourth embodiment.

[0062] Fig.21 It is a perspective cross-sectional view showing a sleeve constituting a part of a housing in a sensor unit according to a fourth embodiment.

[0063] Fig. 22 It is a cross-sectional view of a surface including a bending passage constituting a part of a second passage communicating from a detection section of a pressure sensor to a detection section of a temperature sensor in a sensor unit according to a fourth embodiment.

[0064] Fig.23 It is a cross-sectional view taken along a plane including a first passage opening from a detection portion of a temperature sensor to an intake passage in a sensor unit according to a fourth embodiment.

[0065] Fig.24 It is a perspective cross-sectional view showing the flow of intake air in the second passage and the first passage from the collision wall in the sensor unit according to the fourth embodiment.

[0066] Fig.25 This is a schematic diagram for explaining the flow of intake air in the first passage and the second passage when the sensor unit according to the fourth embodiment is attached to the intake pipe.

[0067] Fig.26 It is a diagram showing a sensor unit according to a fifth embodiment and is an external perspective view of a housing as seen from the outside.

[0068] Fig. 27 It is a diagram showing a sensor unit according to a fifth embodiment and is an external perspective view as viewed from the joining surface side of a housing joined to an intake pipe.

[0069] Fig.28 It is a diagram showing a sensor unit according to a fifth embodiment and is a plan view of a joining surface of a housing joined to an intake pipe.

[0070] Fig.29 It is a partial cross-sectional view showing a state where the sensor unit according to the fifth embodiment is mounted on the intake pipe.

[0071] Fig.30 This is an exploded perspective view showing the sensor unit according to the fifth embodiment disassembled and viewed from one side.

[0072] Fig.31 This is an exploded perspective view of the sensor unit according to the fifth embodiment, which is exploded and viewed from the other side.

[0073] Fig.32 This is a cross-sectional view taken along a plane passing through the center line of the first vent hole and the center line of the second vent hole in the sensor unit according to the fifth embodiment.

[0074] Fig.33It is a cross-sectional view taken along a plane including the center line of a first passage forming a first communication passage and the center line of a first vent hole in the sensor unit according to the fifth embodiment.

[0075] Fig.34 It is a cross-sectional view taken along a plane including the center line of a second passage forming a second communication passage and the center line of a second vent hole in the sensor unit according to the fifth embodiment.

[0076] Fig.35 It is a perspective cross-sectional view of a pressure sensor (sensor main body, sensor cover) in a sensor unit according to a fifth embodiment.

[0077] Fig.36 This is an exploded perspective view showing a sensor main body and a sensor cover that constitute a pressure sensor in a sensor unit according to a fifth embodiment.

[0078] Fig.37 It is a cross-sectional view showing a temperature sensor accommodated in a second accommodation portion in a sensor unit according to a fifth embodiment.

[0079] Fig.38 It is a schematic diagram showing the relationship between the flow velocity distribution of intake air in the intake passage and the areas where the first communicating passage and the second communicating passage open when the sensor unit of the fifth embodiment is installed in the intake pipe downstream of the throttle device (butterfly-type throttle valve).

[0080] Fig.39 It is a schematic diagram showing the relationship between the flow velocity distribution of intake air in the intake passage and the areas where the first communicating passage and the second communicating passage open when the sensor unit of the fifth embodiment is installed in the intake pipe downstream of the throttle device (butterfly-type throttle valve).

[0081] Fig.40 A schematic diagram for explaining the flow of intake air in a communication passage (a first communication passage including a first passage and a first vent hole and a second communication passage including a second passage and a second vent hole) that communicates the pressure receiving chamber with the intake passage in the sensor unit of the fifth embodiment.

[0082] Fig.41 Schematic diagram showing the relationship between the flow velocity distribution of intake air in the intake passage and the areas where the first communication passage and the second communication passage open when the sensor unit according to another embodiment is mounted on the intake pipe.

[0083] Fig.42 A schematic diagram for explaining the flow of intake air in a communication passage (a first communication passage including a first passage and a first vent hole and a second communication passage including a second passage and a second vent hole) that communicates a pressure receiving chamber with an intake passage in a sensor unit according to still another embodiment.

[0084] [Explanation of Symbols]

[0085] E: Internal combustion engine

[0086] C: Combustion chamber

[0087] IP: Intake pipe

[0088] W: inner wall surface

[0089] Ip1: Intake passage

[0090] Ac: Air Purifier

[0091] M: Throttling device

[0092] m1: throttle valve

[0093] U: Sensor unit

[0094] Ca: shell

[0095] Ca1: Junction surface

[0096] 10: Shell body (shell)

[0097] 11: Joint surface

[0098] 12: Fitting recess

[0099] 13: concave part

[0100] 20: Sleeve (housing)

[0101] S: Axis

[0102] 21: Chimeric part

[0103] 21b: Joint surface

[0104] 22: Large diameter cylindrical part

[0105] 22a: Annular groove

[0106] 23: Small diameter cylinder

[0107] 23a: First end face

[0108] 23b: Second end face

[0109] 24: First Passage

[0110] At: The area facing the detection part of the temperature sensor

[0111] 24a: First opening

[0112] 24b: Flexion Pathway

[0113] 25: Second Passage

[0114] Ap: The area facing the detection part of the pressure sensor

[0115] 25a: Second opening

[0116] 25b: Flexion Pathway

[0117] 26: Next door

[0118] 26a: Collision Wall

[0119] 27: Protruding wall

[0120] 30: Pressure sensor

[0121] 32c: Connecting hole

[0122] L: Straight line

[0123] Rc: Pressure chamber (detection part)

[0124] 40: Temperature sensor

[0125] 41: Inspection Department

[0126] 50: Circuit board

[0127] 60: Terminal

[0128] 70: Molded resin

[0129] Sr: Annular sealing member

[0130] 120: Sleeve

[0131] 126: Next door

[0132] 126a: collision wall (curved surface, guide portion)

[0133] 126b: Side (guide)

[0134] 220: Sleeve

[0135] 224: First Passage

[0136] 224a: First opening

[0137] 224b: Buckling Pathway

[0138] 224b1: Inner wall surface

[0139] 225: Second Passage

[0140] 225a: Second opening

[0141] 225b: Buckling Pathway

[0142] 225b1: Inner wall surface DETAILED DESCRIPTION

[0143] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0144] The sensor unit U of the present invention is, for example, a sensor unit that is incorporated into an intake system of an internal combustion engine E mounted on a vehicle such as an automobile or a motorcycle.

[0145] like Figure 1 As shown, the internal combustion engine E includes: a cylinder block 1, a piston 2, a cylinder head 3, an intake valve 4a for opening / closing an intake port 3a, an exhaust valve 4b for opening / closing an exhaust port 3b, a spark plug 5, the intake valve 4a and a cam mechanism 6 for driving the exhaust valve 4b, etc.

[0146] The intake system of the internal combustion engine E includes an intake pipe Ip connected to the cylinder head 3 so as to communicate with the intake port 3a, a throttling device M connected to the middle of the intake pipe Ip, an air cleaner Ac connected to the upstream end of the intake pipe Ip, a fuel injection valve Iv arranged on the downstream side of the intake pipe Ip, and a sensor unit U arranged in the intake pipe Ip at a position downstream of the throttling device M and upstream of the fuel injection valve Iv.

[0147] The intake pipe Ip defines an intake passage Ip1 for guiding intake air to the combustion chamber C of the internal combustion engine E. As shown in FIG.

[0148] The throttle device M includes a butterfly-type throttle valve m1 for opening and closing the intake passage Ip1 , a bypass passage m2 for bypassing the throttle valve m1 , and the like.

[0149] The exhaust system of the internal combustion engine E includes an exhaust pipe Ep connected to the cylinder head 3 so as to communicate with the exhaust port 3b, a catalytic converter Cc disposed in the middle of the exhaust pipe Ep, an oxygen sensor Os, and the like.

[0150] like Figures 2 to 12 As shown, the sensor unit U of the first embodiment includes a case body 10 as a case Ca, a sleeve 20 extending in the axis S direction, a pressure sensor 30 , a temperature sensor 40 , a circuit board 50 , a plurality of terminals 60 , and a molded resin material 70 .

[0151] The case body 10 is molded using a resin material and includes a joint surface 11 constituting a part of a joint surface Ca1 of the case Ca, a fitting recess 12 , a recess 13 , a receiving portion 14 , a receiving portion 15 , a flange portion 16 , and a connector 17 .

[0152] like Figure 3 As shown, the joining surface 11 is formed as a flat surface joined to the outer wall of the intake pipe Ip.

[0153] The fitting recess 12 is a region where the sleeve 20 is fitted and engaged, is formed as an annular recess, and includes a thinned portion 12 a for positioning in a part of its inner peripheral surface.

[0154] The recess 13 is formed to be recessed from the bottom surface 12 b of the fitting recess 12 in a substantially rectangular shape, into which the protruding wall 27 of the sleeve 20 is inserted, and defines the detection portion 41 of the temperature sensor 40 continuously with the bottom surface 13 a thereof.

[0155] The housing portion 14 is a region for housing and holding the pressure sensor 30 , and is formed in a region adjacent to the bottom surface 12 b of the fitting recess 12 .

[0156] The housing portion 15 is a region for housing and holding the circuit board 50 , and is formed in a region on the opposite side to the bonding surface 11 .

[0157] The flange portion 16 defines a portion of the joint surface 11 and includes a circular hole 16a through which a fastening screw (not shown) screwed into a screw hole of the intake pipe Ip passes.

[0158] The connector 17 is formed to protrude in a direction perpendicular to the axis S, and exposes and surrounds a plurality of (four in this case) terminals 60 connected to the circuit board 50 , and is connected to the outside.

[0159] The sleeve 20 is molded using a resin material and is formed into a cylindrical shape extending along the axis S direction, and includes a fitting portion 21, a large diameter cylindrical portion 22, a small diameter cylindrical portion 23, a first passage 24, a second passage 25, a partition wall 26 separating the first passage 24 from the second passage 25, and a protruding wall 27 protruding from the fitting portion 21 in the axis S direction.

[0160] The fitting portion 21 is formed in a disk shape and includes a positioning protrusion 21a formed on a portion of its outer circumference, an annular joint surface 21b that is flush with the joint surface 11 to form a portion of the joint surface Ca1, and an end surface 21c that is in close contact with the bottom surface 12b of the fitting recess 12 of the housing body 10. The sleeve 20 is joined to the housing body 10 by fitting the fitting portion 21 in close contact with the fitting recess 12 of the housing body 10, thereby defining the housing Ca.

[0161] The large diameter cylindrical portion 22 is a region fitted into the fitting hole H of the intake pipe Ip, protrudes from the joint surface 21b of the fitting portion 21, and includes an annular groove 22a formed on its outer periphery for fitting the annular sealing member Sr.

[0162] The annular sealing member Sr is formed into an annular shape using a rubber material having excellent heat resistance and swelling resistance, and is embedded in the annular groove 22a. Figure 3As shown, in a state where the sensor unit U is mounted on the intake pipe Ip, the annular seal member Sr seals between the fitting hole H of the intake pipe Ip and the sleeve 20 .

[0163] The small diameter cylindrical portion 23 is a region formed continuously with the large diameter cylindrical portion 22 and arranged to protrude into the intake passage Ip1 in a state of being joined to the intake pipe Ip.

[0164] In addition, the small diameter cylindrical portion 23 includes a first end face 23a and a second end face 23b. The first end face 23a is located on the front end side in the direction of the axis S and defines a first opening portion 24a of the first passage 24. The second end face 23b is located closer to the large diameter cylindrical portion 22 than the first end face 23a and defines a second opening portion 25a of the second passage 25.

[0165] Furthermore, when the sensor unit U is mounted on the intake pipe Ip, Figure 3 As shown, the first end surface 23a and the first opening portion 24a are positioned closer to the center of the intake passage Ip1 than the inner wall surface W of the intake pipe Ip, and the second end surface 23b and the second opening portion 25a are positioned closer to the inner wall surface W of the intake pipe Ip than the first end surface 23a.

[0166] The first passage 24 is formed to extend from a region At (the recessed portion 13 into which the protruding wall 27 is inserted) facing the detection portion 41 of the temperature sensor 40 in the direction of the axis S to a first opening portion 24a opening at the first end surface 23a so that the detection portion of the sensor is exposed to the intake air flowing in the intake passage Ip1.

[0167] In addition, if Figure 7 and Fig.10 As shown, the first passage 24 includes a curved passage 24b defined by a curved inner wall surface midway from the region At facing the detection portion 41 of the temperature sensor 40 toward the first opening 24a.

[0168] like Figure 6 and Fig. 9 As shown, the bending passage 24b is formed to be bent two-dimensionally in the XY plane.

[0169] The second passage 25 is formed to extend from a region At (the recessed portion 13 into which the protruding wall 27 is inserted) facing the detection portion 41 of the temperature sensor 40 in the direction of the axis S to a second opening portion 25a opening at the second end surface 23b so that the detection portion of the sensor is exposed to the intake air flowing in the intake passage Ip1.

[0170] In addition, the second passage 25 is as follows Figure 8 As shown in FIG. 1 , the second opening 25a extends linearly along the straight line L in the direction of the axis S to the region Ap facing the detection portion (pressure receiving chamber Rc) of the pressure sensor 30. Fig. 9As shown, the curved passage 25 b defined by the curved inner wall surface is included between the region Ap facing the detection portion (pressure receiving chamber Rc) of the pressure sensor 30 and the region At facing the detection portion 41 of the temperature sensor 40 .

[0171] like Figure 7 and Fig.10 As shown, the bending passage 25b is formed to be bent two-dimensionally in the XZ plane.

[0172] That is, the first passage 24 and the second passage 25 are formed to communicate with each other in the area At facing the detection portion 41 of the temperature sensor 40 and to open to the intake passage Ip1 respectively, and within the range from the area Ap facing the detection portion (pressure receiving chamber Rc) of the pressure sensor 30 through the area At facing the detection portion 41 of the temperature sensor 40 to the area midway of the first passage 24, as shown in FIG. Fig.11 As shown, the curved passage 24b and the curved passage 25b are formed to be three-dimensionally curved.

[0173] As described above, by including the three-dimensionally bent bending passage 24b and the bent passage 25b, compared with the case where the two passages as the first passage and the second passage are only formed as two-dimensionally bent passages, the two passages (the first passage 24 and the second passage 25) can be concentratedly arranged near the center, and the sleeve 20 can be reduced in diameter and miniaturized.

[0174] The partition wall 26 extends in the axis S direction to partition the first passage 24 from the second passage 25 , and is formed to include a collision wall 26 a near the second opening 25 a on the front end side in the axis S direction.

[0175] like Figure 3 As shown, in a state where the sensor unit U is mounted on the intake pipe Ip, the collision wall 26a is formed as a flat surface arranged toward the upstream side of the intake passage Ip1 so as to cause the intake air flowing in the intake passage Ip1 to collide with the collision wall.

[0176] As described above, by forming a part of the partition wall 26 also serving as the collision wall 26a, the shape of the sleeve 20 can be simplified compared to a structure in which a collision wall is separately provided immediately after the second opening.

[0177] The protruding wall 27 is formed as a substantially rectangular piece that protrudes from the end surface 21c of the fitting portion 21 in the direction of the axis S. Furthermore, when the sleeve 20 is engaged with the housing body 10, the protruding wall 27 is inserted into the recess 13 of the housing body 10 to partially divide the area At in the recess 13 into two, thereby defining a portion of the first passage 24 and a portion of the second passage 25 in cooperation with the recess 13.

[0178] As described above, by inserting the protruding wall 27 into the recess 13 to define a portion of the first passage 24 and a portion of the second passage 25 , the shape of the recess 13 of the case body 10 can be simplified, and demolding is facilitated when molding the case body 10 .

[0179] like Figure 4 , Figure 5 , Figure 8 , Fig.11 As shown, the pressure sensor 30 is composed of a sensor body 31 and a sensor cover 32 .

[0180] The sensor main body 31 includes a pressure receiving portion 31 a such as a diaphragm including a semiconductor strain gauge, a lead wire 31 b extending from the pressure receiving portion 31 a , and an annular portion 31 c surrounding the pressure receiving portion 31 a .

[0181] The sensor cover 32 includes a disc-shaped bottom 32a, an annular outer wall portion 32b, and a communication hole 32c. The communication hole 32c is formed as a circular hole having an opening area smaller than the passage area of ​​the second passage 25. The sensor cover 32 is connected to the sensor body portion 31 by inserting the annular portion 31c into the annular outer wall portion 32b, so as to function as a protective cover covering the pressure receiving portion 31a and define a pressure receiving chamber Rc as a detection portion.

[0182] The pressure sensor 30 outputs a change in resistance in accordance with the amount of deformation of the pressure receiving portion 31 a caused by the pressure of the intake air introduced into the pressure receiving chamber Rc through the communication hole 32 c as an electric signal.

[0183] Here, the pressure receiving chamber Rc as the detection portion of the pressure sensor 30 is formed to face the middle of the second passage 25 via the communication hole 32c.

[0184] In addition, if Figure 8 As shown, the communication hole 32 c is arranged to face the second opening portion 25 a of the second passage 25 that opens to the intake passage Ip1 on the straight line L, that is, in the extension direction of the second passage 25 .

[0185] The pressure sensor 30 detects the pressure of the intake air flowing in the intake passage Ip1 on the downstream side of the throttle device M in a state where the sensor unit U is assembled to the intake pipe Ip.

[0186] As described above, by making the pressure receiving chamber Rc communicate with the second passage 25 via the communication hole 32c, it is possible to prevent foreign matter mixed in the intake air from entering the pressure receiving chamber Rc.

[0187] Furthermore, since the communication hole 32c is disposed to face the second opening 25a of the second passage 25 on the straight line L, the intake air flowing in from the second opening 25a can be actively guided to the pressure receiving chamber Rc while suppressing passage resistance.

[0188] The temperature sensor 40 is a surface mounted temperature sensor constituting a semiconductor chip, such as Figure 5 As shown, the surface is packaged on the circuit substrate 50. When the circuit substrate 50 is accommodated in the accommodating portion 15, as shown in FIG. Figure 8 , Fig.10 , Fig.11 As shown, the detection portion 41 is defined adjacent to the bottom surface 13 a of the recessed portion 13 .

[0189] The detection portion 41 is exposed to the intake air flowing through the intake passage Ip1 via the first passage 24 and the second passage 25 in the region of the recessed portion 13 .

[0190] The temperature sensor 40 detects the temperature of the intake air flowing through the intake passage Ip1 on the downstream side of the throttle device M in a state where the sensor unit U is assembled to the intake pipe Ip.

[0191] As described above, by using a surface mount type temperature sensor as the temperature sensor 40 , it is possible to achieve miniaturization of the sleeve 20 and concentration and miniaturization of components in the case Ca.

[0192] The surface of the circuit substrate 50 is packaged with printed wiring and various electronic components (not shown), such as Figure 4 and Figure 5 As shown, it includes three through holes 51 electrically connected to the wires 31 b of the pressure sensor 30 , and four through holes 52 electrically connected to the four terminals 60 .

[0193] Furthermore, the circuit board 50 is disposed in the housing portion 15 of the case body 10 during assembly, the lead wires 31 b and the terminals 60 are electrically connected, and then covered and sealed with the mold resin material 70 .

[0194] The terminal 60 is formed of a conductive metal material, such as Figure 4 and Fig. 9 As shown, it is arranged to be embedded in the housing body 10 , and one end portion is connected to the through hole 52 of the circuit board 50 , and the free end side is exposed in the connector 17 and is surrounded by the connector 17 .

[0195] The molded resin material 70 is a sealing material such as epoxy resin, and is injected into the shell body 10 and cured in a manner to fill the gap space while the pressure sensor 30 and the circuit substrate 50 encapsulating the temperature sensor 40 and other electronic components (not shown) are respectively accommodated and held in the accommodation portion 14 and the accommodation portion 15 of the shell body 10.

[0196] Next, the principle of exposing the sensor detection parts (the pressure receiving chamber Rc of the pressure sensor 30 and the detection part 41 of the temperature sensor 40) to the intake air flowing in the intake passage Ip1 via the first passage 24 and the second passage 25 in the sensor unit U having the above structure will be described.

[0197] When the intake air flowing in the intake passage Ip1 is not at an ultra-high speed, it is a non-viscous and incompressible fluid, and can be approximated using Bernoulli's theorem that kinetic energy + pressure energy + position energy = constant.

[0198] Specifically, assuming the density of the fluid is ρ(kg / m 3 ), velocity V (m / s), pressure P (pa), acceleration due to gravity g (m / s 2 ), when the height position is Z, it is expressed as ρV 2 / 2+P+ρgZ=constant. In the flow of intake air in the intake pipe Ip, the position energy can be ignored, so it can be approximated as ρV 2 / 2+P=constant.

[0199] That is, in the intake passage Ip1, the following relationship holds: if the flow velocity V becomes larger (faster), the pressure P becomes smaller (lower), and if the flow velocity V becomes smaller (slower), the pressure P becomes larger (higher).

[0200] Here, when the collision wall 26a is arranged in parallel with the flow direction of the intake air and the sensor unit U is installed in the intake pipe Ip, the intake air flowing in the intake passage Ip1 does not collide with the collision wall 26a. In this case, the following relationship is established between the pressure P1 near the first opening 24a (first end face 23a) of the first passage 24 and the pressure P2 near the second opening 25a (second end face 23b) of the second passage 25: Pressure difference ΔPo (=P2-P1=(V1 2 -V2 2 ) / 2).

[0201] On the other hand, Figure 3 As shown, when the sensor unit U is installed on the intake pipe Ip in a state where the collision wall 26a is directed toward the upstream side of the intake flow so that the intake air flowing in the intake passage Ip1 collides with the collision wall 26a, a stagnation area Sa is generated near the second opening portion 25a, i.e., a stagnation area Sa where the intake air collides with the collision wall 26a and the speed of the intake air becomes zero (V2=0).

[0202] Therefore, if Fig.12 As shown, the pressure difference between the vicinity of the second opening 25a and the vicinity of the first opening 24a where the stagnation area Sa is generated is ΔPa=P2-P1=V1 2 / 2.

[0203] That is, the relationship of ΔPa>ΔPo holds. Furthermore, due to the pressure difference ΔPa, the intake air flowing in the intake passage Ip1 flows from the second opening 25a into the second passage 25, passes through the area Ap facing the detection portion (pressure receiving chamber Rc) of the pressure sensor 30 and the area At facing the detection portion 41 of the temperature sensor 40, flows through the first passage 24, and flows out from the first opening 24a to the intake passage Ip1 again.

[0204] Thus, in the sensor unit U, by generating a flow of intake air in the first passage 24 and the second passage 25, it is possible to suppress or prevent liquid or liquid-like substances such as fuel, moisture in intake air, and blowby gas from adhering to the passage, and to prevent freezing of the adhering substances, etc. Therefore, the pressure sensor 30 can detect the pressure of the intake air guided to the detection portion (pressure receiving chamber Rc) with high accuracy, and the temperature sensor 40 can detect the temperature of the intake air guided to the detection portion 41 with high accuracy.

[0205] Here, the detection portion (pressure receiving chamber Rc) of the pressure sensor 30 communicates with the second passage 25 via the communication hole 32c having an opening area smaller than the passage area of ​​the second passage 25, thereby preventing foreign matter mixed in the intake air from entering the pressure receiving chamber Rc.

[0206] In addition, even if the temperature sensor 40 is packaged in the circuit substrate 50 and the detection part 41 is arranged on the inner side of the shell Ca, since the second passage 25 and the first passage 24 are connected to the area At facing the detection part 41, the intake air flowing in the intake passage Ip1 can be guided to the area At and the detection part 41 can be reliably exposed to the intake air.

[0207] Next, the detection operation of the sensor unit U in the internal combustion engine E including the sensor unit U will be described.

[0208] First, when the internal combustion engine E is in the idling range, the throttle valve m1 closes the intake passage Ip1, and the intake air flowing in the intake passage Ip1 flows through the bypass passage m2 to bypass the throttle valve m1 and flows out to the downstream intake passage Ip1 again.

[0209] On the other hand, when the internal combustion engine E is in an operation range other than the idling operation range, the throttle valve m1 is in a predetermined opening range, and the intake passage Ip1 is opened.

[0210] Therefore, the intake air flowing through the intake passage Ip1 flows through the intake passage Ip1 and is sucked into the internal combustion engine E without passing through the bypass passage m2.

[0211] Then, in the operating state of the internal combustion engine E, the pressure and temperature as state quantities of the intake air are detected by the sensor unit U on the downstream side of the throttle device M.

[0212] That is, the pressure sensor 30 detects the pressure of the intake air flowing in the intake passage Ip1 via the second passage 25 and the communication hole 32c. In addition, the communication hole 32c can prevent foreign matter from entering the pressure receiving chamber Rc.

[0213] In addition, the temperature of the intake air is detected by the temperature sensor 40 at the region At where the second passage 25 makes a U-turn toward the first passage 24 .

[0214] As described above, the pressure of the intake air is detected by the pressure sensor 30, and the temperature of the intake air is detected by the temperature sensor 40. The detected information is acquired as control information of the electronic control unit (ECU), thereby controlling the internal combustion engine E appropriately.

[0215] As described above, the sensor unit U is constructed to include: a sensor (pressure sensor 30 and temperature sensor 40) for detecting the state quantity of the intake air flowing in the intake passage Ip1 defined by the intake pipe Ip; and a housing Ca for accommodating the sensor, the housing Ca including: a first passage 24 and a second passage 25, which are interconnected and respectively open to the intake passage Ip1 so that the detection part of the sensor (pressure receiving chamber Rc, detection part 41) is exposed to the intake air flowing in the intake passage Ip1; and a collision wall 26a, which is located near the opening of the second passage 25 and causes the intake air flowing in the intake passage Ip1 to collide.

[0216] Accordingly, a pressure difference ΔPa is generated between the vicinity of the first opening portion 24a of the first passage 24 and the vicinity of the second opening portion 25a of the second passage 25, thereby generating the following continuous flow of intake air: the intake air flowing in the intake passage Ip1 flows into from the second opening portion 25a and flows from the second passage 25 to the first passage 24, and flows out from the first opening portion 24a to the intake passage Ip1.

[0217] Therefore, it is possible to suppress or prevent stagnation in the flow of intake air in the region Ap facing the detection portion (pressure receiving chamber Rc) of the pressure sensor 30 and the region At facing the detection portion 41 of the temperature sensor 40. Therefore, the flow of intake air is actively generated in the passages (first passage 24 and second passage 25) connected from the detection portions (pressure receiving chamber Rc, detection portion 41) of the sensors (pressure sensor 30 and temperature sensor 40) to the intake passage Ip1, and freezing of liquid or liquid substances such as fuel, moisture in the intake air, blowby gas, etc. can be suppressed or prevented, and the state quantity (pressure, temperature) of the intake air can be detected with high accuracy through the sensors (pressure sensor 30 and temperature sensor 40).

[0218] Figures 13 to 18 1 is a diagram showing a sensor unit U according to a second embodiment. The sensor unit U according to the second embodiment has the same structure as the sensor unit U according to the first embodiment except that the sleeve 20 is replaced with a sleeve 200 . The same structures are denoted by the same reference numerals and their description is omitted.

[0219] The sensor unit U of the second embodiment includes a case body 10 as a case Ca, a sleeve 200 extending in the axis S direction, a pressure sensor 30 , a temperature sensor 40 , a circuit board 50 , a plurality of terminals 60 , and a molded resin material 70 .

[0220] The sleeve 200 is molded using a resin material and is formed into a cylindrical shape extending along the axis S direction, and includes a fitting portion 21, a large diameter cylindrical portion 22, a small diameter cylindrical portion 23, a first passage 24, a second passage 25, a partition wall 126 separating the first passage 24 from the second passage 25, and a protruding wall 27 protruding from the fitting portion 21 in the axis S direction.

[0221] The partition wall 126 extends in the axis S direction to partition the first passage 24 from the second passage 25 , and is formed to include a collision wall 126 a near the second opening 25 a on the front end side in the axis S direction.

[0222] like Fig.14 As shown in FIG. 1 , in a state where the sensor unit U is mounted on the intake pipe Ip, the collision wall 126a is arranged toward the upstream side of the intake passage Ip1 so as to cause the intake air flowing in the intake passage Ip1 to collide with the collision wall 126a, and is formed into a curved surface inclined toward the second passage 25. Therefore, the collision wall 126a functions as a guide portion that guides the intake air flowing in the intake passage Ip1 toward the second passage 25.

[0223] Here, the collision wall 126a is formed as a curved surface as a whole, but may be formed to partially include a curved surface.

[0224] Moreover, if Fig.18As shown in FIG. 1 , when the sensor unit U is mounted on the intake pipe Ip in a state where the collision wall 126a is directed toward the upstream side of the intake air flow so that the intake air flowing in the intake passage Ip1 collides with the collision wall 126a, Fig.12 Compared with the first embodiment shown, the amount of intake air flowing into the second passage 25 from the second opening 25a increases.

[0225] As a result, the pressure difference ΔPb between the vicinity of the second opening 25a and the vicinity of the first opening 24a is greater than the pressure difference ΔPa in the first embodiment. That is, the relationship ΔPb>ΔPa>ΔPo holds. Moreover, due to the pressure difference ΔPb, the intake air flowing from the intake passage Ip1 into the second passage 25 increases compared with the first embodiment.

[0226] Thus, in the sensor unit U, by generating a flow of intake air in the first passage 24 and the second passage 25, it is possible to suppress or prevent liquid or liquid-like substances such as fuel, moisture in intake air, and blowby gas from adhering to the passage, and to prevent freezing of the adhering substances, etc. Therefore, the pressure sensor 30 can detect the pressure of the intake air guided to the detection portion (pressure receiving chamber Rc) with high accuracy, and the temperature sensor 40 can detect the temperature of the intake air guided to the detection portion 41 with high accuracy.

[0227] Fig.19 1 is a diagram showing a sensor unit U according to a third embodiment. The sensor unit U according to the third embodiment is obtained by partially changing the sleeve 200 of the sensor unit U according to the second embodiment, and the same components are denoted by the same reference numerals and their description is omitted.

[0228] The sleeve 200 of the sensor unit U of the third embodiment is formed so that the partition wall 126 partitioning the first passage 24 and the second passage 25 includes side surfaces 126 b formed continuously to both sides of the curved surface as collision walls 126 a .

[0229] The side surface 126 a functions as a guide portion that guides the intake air flowing through the intake passage Ip1 toward the second passage 25 together with the curved surface of the collision wall 126 a .

[0230] According to the third embodiment, the intake air flowing in the intake passage Ip1 is restrained from flowing from the peripheral edge of the collision wall 126a toward the downstream side of the intake passage Ip1 after colliding with the collision wall 126a by the side surface 126b, and the flow rate flowing toward the second opening 25a is increased.

[0231] Thus, similarly to the above, by generating the flow of intake air in the first passage 24 and the second passage 25, it is possible to suppress or prevent liquid or liquid-like substances such as fuel, moisture in the intake air, and blowby gas from adhering to the passages, and to prevent freezing of the adhering substances, etc. Therefore, the pressure sensor 30 can detect the pressure of the intake air guided to the detection portion (pressure receiving chamber Rc) with high accuracy, and the temperature sensor 40 can detect the temperature of the intake air guided to the detection portion 41 with high accuracy.

[0232] Figure 20 to Figure 25 1 is a diagram showing a sensor unit U according to a fourth embodiment. The sensor unit U according to the fourth embodiment has the same structure as the sensor unit U according to the second embodiment except that the sleeve 200 is replaced by a sleeve 220 . The same structures are denoted by the same reference numerals and their description is omitted.

[0233] The sensor unit U of the fourth embodiment includes a case body 10 as a case Ca, a sleeve 220 extending in the axis S direction, a pressure sensor 30 , a temperature sensor 40 , a circuit board 50 , a plurality of terminals 60 , and a molded resin material 70 .

[0234] The sleeve 220 is molded using a resin material and is formed into a cylindrical shape extending along the axis S direction, and includes a fitting portion 21, a large diameter cylindrical portion 22, a small diameter cylindrical portion 23, a first passage 224, a second passage 225, a partition wall 126 separating the first passage 224 from the second passage 225, and a protruding wall 27 protruding from the fitting portion 21 in the axis S direction.

[0235] The first passage 224 is formed to extend from a region At (the recess 13 into which the protruding wall 27 is inserted) facing the detection portion 41 of the temperature sensor 40 in the direction of the axis S to a first opening 224a opening at the first end surface 23a so that the detection portion of the sensor is exposed to the intake air flowing in the intake passage Ip1.

[0236] In addition, if Fig.21 and Fig.23 As shown, the first passage 224 includes a curved passage 224b defined by a curved inner wall surface 224b1 midway from the region At facing the detection portion 41 of the temperature sensor 40 toward the first opening 224a.

[0237] like Fig.21 As shown, the curved passage 224b is curved two-dimensionally in the XY plane, and its inner wall surface 224b1 is curved to be streamlined and continuous.

[0238] The second passage 225 is formed to extend from an area At (the recess 13 into which the protruding wall 27 is inserted) facing the detection portion 41 of the temperature sensor 40 in the direction of the axis S to a second opening portion 225a opening at the second end surface 23b so that the detection portion of the sensor is exposed to the intake air flowing in the intake passage Ip1.

[0239] In addition, if Fig. 22 As shown, the second passage 225 extends linearly along the straight line L in the direction of the axis S from the second opening portion 225a to the area Ap of the detection portion (pressure chamber Rc) facing the pressure sensor 30, and includes a curved passage 225b defined by a curved inner wall surface 225b1 between the area Ap facing the detection portion (pressure chamber Rc) facing the pressure sensor 30 and the area At facing the detection portion 41 of the temperature sensor 40.

[0240] like Fig. 20 As shown, the curved passage 225b is curved two-dimensionally in the XZ plane, and the inner wall surface 225b1 thereof is curved to be streamlined and continuous.

[0241] That is, the first passage 224 and the second passage 225 are formed to communicate with each other in the area At facing the detection portion 41 of the temperature sensor 40 and to open to the intake passage Ip1 respectively, and within the range from the area Ap facing the detection portion (pressure receiving chamber Rc) of the pressure sensor 30 through the area At facing the detection portion 41 of the temperature sensor 40 to the area midway of the first passage 224, as shown in FIG. Fig.24 As shown, it includes a three-dimensionally curved passage 224b and a curved passage 225b.

[0242] As described above, by including the three-dimensionally bent bending passage 224b and the bent passage 225b, compared with the case where the two passages as the first passage and the second passage are only formed as two-dimensionally bent passages, the two passages (the first passage 224 and the second passage 225) can be concentratedly arranged near the center, thereby achieving a smaller diameter and miniaturization of the sleeve 220.

[0243] In particular, the inner wall surface 224b1 and the inner wall surface 225b1 of the curved passage 224b and the curved passage 225b are curved to form a streamlined continuous structure. Fig.24 and Fig.25 As shown, the intake air flows in a streamlined manner. As a result, the passage resistance can be reduced, and the flow rate of the intake air flowing in the first passage 224 and the second passage 225 can be increased.

[0244] Figures 26 to 40 1 is a diagram showing a sensor unit U according to a fifth embodiment. The sensor unit U includes a case Ca, a pressure sensor 30 , a temperature sensor 40 , a circuit board 50 , a plurality of terminals 60 , a mold resin material 70 , and an annular sealing member Sr.

[0245] The case Ca is molded using a resin material and includes a case body 10 , a cylindrical sleeve 20 , a first housing portion 14 , a second housing portion 18 , a third housing portion 15 , a first passage 24 , a second passage 25 , an annular groove 22 a , and a connector 17 .

[0246] like Fig. 27 and Fig.29 As shown, the housing body 10 has a flat joint surface 11 joined to the outer wall of the intake pipe Ip, and a flange portion 16 including a circular hole 16a for passing a fastening screw (not shown) screwed into a screw hole of the intake pipe Ip.

[0247] The sleeve 20 is formed into a two-stage cylindrical shape extending in the direction of the axis S perpendicular to the joint surface 11 of the housing body 10. That is, the sleeve 20 is formed to include a large diameter cylindrical portion 22, a small diameter cylindrical portion 23 continuous with the large diameter cylindrical portion 22, a first end face 23a, a second end face 23b, and a front end outer wall portion 23e.

[0248] The large diameter cylindrical portion 22 is a region to be fitted into the fitting hole H of the intake pipe Ip, and an annular groove 22a into which the annular sealing member Sr is fitted is formed on the outer periphery thereof.

[0249] The small diameter cylindrical portion 23 is a region that is arranged so that a part thereof protrudes into the intake passage Ip1 in a state of being joined to the intake pipe Ip.

[0250] The first end surface 23a defines an opening end of the first passage 24 that opens to the intake passage Ip1.

[0251] The second end surface 23b is located away from the first end surface 23a in the axis S direction, that is, close to the inner wall surface W of the intake pipe Ip, and defines an opening end for the second passage 25 to open to the intake passage Ip1.

[0252] The front end outer wall portion 23 e is formed in a hemispherical shape so as to protrude from the first end surface 23 a in the direction of the axis S, and defines the outer wall of the second housing portion 18 .

[0253] Moreover, if Fig.29 As shown, the configuration is such that when the sensor unit U is assembled to the intake pipe Ip, the large diameter cylindrical portion 22 is embedded in the embedding hole H of the intake pipe Ip, and a portion of the small diameter cylindrical portion 23 protrudes into the intake passage Ip1 of the intake pipe Ip, that is, the second end face 23b is close to the inner wall surface W, and the area including the first end face 23a and the front end outer wall portion 23e protrudes from the inner wall surface W into the intake passage Ip1.

[0254] like Fig.30 , Figure 32 to Figure 34As shown, the first housing portion 14 is a region for housing and holding the pressure sensor 30 , and is formed in an inner region of the housing body 10 .

[0255] like Fig.37 As shown, the second housing portion 18 is a region for housing the temperature sensor 40 and is formed in a region extending from the inner region of the housing body 10 to the inner side of the sleeve 20 to the inner side of the front end outer wall portion 23 e.

[0256] like Fig.30 As shown, the third housing portion 15 is a region for housing and holding the circuit substrate 50 , and is formed in an inner region of the housing body 10 .

[0257] like Fig.32 and Fig.33 As shown, the first passage 24 is formed to have a first passage length Ls1 inside the sleeve 20 and to extend linearly from the first end surface 23a of the sleeve 20 along the axis S direction to the first receiving portion 14 of the housing body 10 with a certain passage area. Moreover, the inner opening end of the first passage 24 is connected to the first vent hole 32d formed in the sensor cover 32 of the pressure sensor 30.

[0258] like Fig.32 and Fig.34 As shown, the second passage 25 is formed to have a second passage length Ls2 shorter than the first passage length Ls1 (Ls2 < Ls1) on the inner side of the sleeve 20 and to extend linearly from the second end surface 23b along the axis S direction to the first accommodation portion 14 of the housing body 10 adjacent to the first passage 24 with a certain passage area. In addition, the inner opening end of the second passage 25 is connected to the second vent hole 32e formed in the sensor cover 32 of the pressure sensor 30.

[0259] Here, the first passage 24 and the second passage 25 have the same passage area and different passage lengths (first passage length Ls1>second passage length Ls2). For example, the first passage length Ls1 of the first passage 24 is 1.2 to 1.3 times the second passage length Ls2 of the second passage 25.

[0260] The first passage 24 is formed so that the pressure receiving chamber Rc of the pressure sensor 30 communicates with the intake passage Ip1 of the intake pipe Ip via the first vent hole 32d, and the second passage 25 is formed so that the pressure receiving chamber Rc of the pressure sensor 30 communicates with the intake passage Ip1 of the intake pipe Ip via the second vent hole 32e.

[0261] like Fig.29 , Fig.31 , Fig.32As shown, the annular groove 22a is formed in a region of the large diameter cylindrical portion 22 of the sleeve 20 of the housing Ca in a manner where the outer circumference is thinned in an annular shape so that the annular sealing member Sr can be inserted.

[0262] like Fig.33 and Fig.34 As shown, the connector 17 is formed to protrude from the housing body 10 in a direction perpendicular to the axis S, and exposes and surrounds a plurality of (four in this case) terminals 60 connected to the circuit board 50 , and is connected to the outside.

[0263] like Fig.35 and Fig.36 As shown, the pressure sensor 30 is composed of a sensor body 31 and a sensor cover 32 .

[0264] The sensor main body 31 includes a pressure receiving portion 31 a such as a diaphragm including a semiconductor strain gauge, a lead wire 31 b extending from the pressure receiving portion 31 a , and an annular portion 31 c surrounding the pressure receiving portion 31 a .

[0265] The sensor cover 32 includes a disc-shaped bottom 32a, an annular step portion 32f, an annular outer wall portion 32b, a first vent hole 32d, and a second vent hole 32e. The sensor cover 32 is connected to the sensor body 31 by embedding the annular portion 31c in the annular outer wall portion 32b, so as to function as a protective cover covering the pressure receiving portion 31a and define the pressure receiving chamber Rc.

[0266] The pressure sensor 30 outputs a change in resistance in the form of an electric signal according to the amount of deformation of the pressure receiving portion 31 a caused by the pressure of the intake air introduced into the pressure receiving chamber Rc through the first vent hole 32 d and the second vent hole 32 e .

[0267] In addition, the pressure sensor 30 detects the pressure of the intake air flowing in the intake passage Ip1 on the downstream side of the throttle device M in a state where the sensor unit U is assembled to the intake pipe Ip.

[0268] Here, the first ventilation hole 32d is formed as follows Fig.33 and Fig.35 As shown, the circular hole has a passage length Lc corresponding to the wall thickness of the bottom 32a and an opening area (inner diameter Ds) sufficiently smaller than the passage area of ​​the first passage 24, and communicates with the first passage 24.

[0269] The second vent hole 32e is formed as follows Fig.34 and Fig.35 As shown, it has a passage length Lc equivalent to the wall thickness of the bottom 32a and is a circular hole with an opening area (inner diameter Ds) sufficiently smaller than the passage area of ​​the second passage 25 and the same opening area as the first vent hole 32d, and is connected to the second passage 25.

[0270] According to the structure, the connecting passage that connects the pressure chamber Rc of the pressure sensor 30 with the intake passage Ip1 of the intake pipe Ip is formed to include: a first connecting passage Cp1, having a prescribed passage length L1 (= Ls1 + Lc), so as to open to an area away from the inner wall surface W of the intake pipe Ip toward the center side; and a second connecting passage Cp2, having a passage length L2 (= Ls2 + Lc) shorter than the passage length L1 of the first connecting passage Cp1, so as to open to an area close to the inner wall surface W of the intake pipe Ip.

[0271] Specifically, the first connecting passage Cp1 is formed to include: a first passage 24 having a specified passage area and a first passage length Ls1; and a first ventilation hole 32d, which is connected to the first passage 24 and has an opening area smaller than the passage area of ​​the first passage 24, and the second connecting passage Cp2 is formed to include: a second passage 25 having a passage area equal to the passage area of ​​the first passage 24 and a second passage length Ls2 shorter than the first passage length Ls1; and a second ventilation hole 32e, which is connected to the second passage 25 and has an opening area smaller than the passage area of ​​the second passage 25.

[0272] Here, the first connecting passage Cp1 is formed with a prescribed passage length L1 so as to open to an area away from the inner wall surface W of the intake pipe Ip toward the center side, and the second connecting passage Cp2 is formed with a passage length L2 shorter than the passage length L1 of the first connecting passage Cp1 so as to open to an area close to the inner wall surface W of the intake pipe Ip.

[0273] However, when the sensor unit U is arranged on the downstream side of the throttle device M (throttle valve m1) with respect to the intake pipe Ip, the flow of the intake air in the intake passage Ip1 is as follows: Fig.38 and Fig.39 As shown in the figure, in the opening range of the throttle valve m1 where the opening is small, the maximum flow velocity (V max On the other hand, if the throttle valve m1 is fully opened, as shown by the two-dot chain line, the maximum flow velocity (V max ) flow.

[0274] Furthermore, when the intake air flowing in the intake passage Ip1 is not at an ultra-high speed, it is considered to be a non-viscous and incompressible fluid, and Bernoulli's theorem that kinetic energy + pressure energy + position energy = constant can be used for approximation.

[0275] Specifically, assuming the density of the fluid is ρ(kg / m 3 ), velocity V (m / s), pressure P (pa), acceleration due to gravity g (m / s 2), when the height position is Z, it is expressed as ρV 2 / 2+P+ρgZ=constant. In the flow of intake air in the intake pipe Ip, the position energy can be ignored, so it can be approximated as ρV 2 / 2+P=constant.

[0276] That is, in the intake passage Ip1, the following relationship holds: if the flow velocity V becomes larger (faster), the pressure P becomes smaller (lower), and if the flow velocity V becomes smaller (slower), the pressure P becomes larger (higher).

[0277] Therefore, the first communication passage Cp1 is configured to open to the first area A1 where the flow of intake air is fast (at a speed of V1) in the intake passage Ip1, and the second communication passage Cp2 is configured to open to the second area A2 where the flow of intake air is slower (at a speed of V2) than in the first area A1 in the intake passage Ip1, thereby generating a pressure difference ΔP (=P2-P1=(V1)) between the pressure P1 at the opening end (first end face 23a) of the first communication passage Cp1 and the pressure P2 (>P1) at the opening end (second end face 23b) of the second communication passage Cp2. 2 -V2 2 ) / 2).

[0278] The pressure difference ΔP generates a trigger flow sucked from the first communication passage Cp1 into the intake passage Ip1 starting from the pressure receiving chamber Rc, and a follow-up flow flows from the intake passage Ip1 into the pressure receiving chamber Rc via the second communication passage Cp2 following the trigger flow.

[0279] Thus, in the sensor unit U, by generating a flow of intake air in the communication passage (the first communication passage Cp1 and the second communication passage Cp2), it is possible to suppress or prevent liquid or liquid substances such as fuel, moisture in intake air, and blowby gas from adhering to the communication passage, and to prevent freezing of the adhering substances, etc. Therefore, the pressure sensor 30 can detect the pressure of the intake air guided to the pressure receiving chamber Rc with high accuracy.

[0280] On the other hand, regarding the passage resistance (pressure loss) of the connecting passage, assuming that the passage pressure loss is Δp (Pa), the friction coefficient of the passage is λ (dimensionless), the passage length is L (m), the inner diameter of the passage is D (m), and the density of the fluid is ρ (kg / m 3 ), when the flow velocity is V (m / s), it is expressed as Δp = λLρV 2 / 2D. That is, the pressure loss Δp is inversely proportional to the inner diameter D of the passage, and is proportional to the passage length L. In addition, as the passage length L increases, the pressure loss Δp increases.

[0281] Here, the relationship between the first passage length Ls1 of the first passage 24 and the second passage length Ls2 of the second passage 25 is Ls1>Ls2, so that the pressure loss Δp1 of the first passage 24 is larger than the pressure loss Δp2 of the second passage 25 (Δp1>Δp2).

[0282] That is, when only the first passage 24 and the second passage 25 are compared, the first communication passage Cp1 has a passage form in which the passage resistance is larger than that of the second communication passage Cp2.

[0283] However, in the communication passage, the pressure difference ΔP between the first communication passage Cp1 and the second communication passage Cp2 is ensured to such an extent that the passage resistance can be ignored. Therefore, as described above, the flow of intake air is generated in the communication passage (the first communication passage Cp1 and the second communication passage Cp2), and the liquid or liquid matter such as fuel, moisture in the intake air, and blowby gas can be suppressed or prevented from adhering to the communication passage, and freezing of the adhering matter can be prevented, and the pressure sensor 30 can detect the pressure of the intake air guided to the pressure receiving chamber Rc with high accuracy.

[0284] Here, the first communication passage Cp1 and the second communication passage Cp2 are formed adjacent to each other and open at different positions relative to the intake passage Ip1, that is, the first passage 24 opens at the first end face 23a arranged in the first area A1 where the flow of the intake air is fast, and the second passage 25 opens at the second end face 23b arranged in the second area A2 where the flow of the intake air is slower than the first area A1. The first end face 23a and the second end face 23b are separated from each other in the direction of the axis S, and open to areas close to each other as areas within the intake passage Ip1.

[0285] Therefore, the pressure difference ΔP can be appropriately adjusted only by appropriately setting the position of the opening end (first end face 23a) of the first connecting passage Cp1 and the position of the opening end (second end face 23b) of the second connecting passage Cp2, and the flow rate of the intake air flowing in the connecting passages (the first connecting passage Cp1 and the second connecting passage Cp2) can be easily adjusted.

[0286] The first vent hole 32d and the second vent hole 32e are formed to have opening areas smaller than the passage areas of the first passage 24 and the second passage 25, thereby playing a role in preventing foreign matter mixed in the intake air from entering the pressure receiving chamber Rc (trapping function).

[0287] In particular, Fig.35 As shown in FIG. 1 , the first vent hole 32d and the second vent hole 32e are formed to be offset by a distance Cd to the side away from the central region including the center line CL of the pressure receiving chamber Rc.

[0288] Therefore, even if foreign matter or the like intrudes into the pressure-receiving chamber Rc through the first vent hole 32d and the second vent hole 32e, the foreign matter or the like can be prevented from directly colliding with the pressure-receiving portion 31a, and the pressure caused by the impact of the foreign matter or the like or the influence of the dynamic pressure corresponding to the flow rate of the intake air can be suppressed or prevented, thereby detecting the pressure with high precision.

[0289] Furthermore, since the first ventilation hole 32d and the second ventilation hole 32e are formed as circular holes, they are easier to process than those formed as irregular-shaped holes.

[0290] The pressure sensor 30 having the above structure is arranged in the mold and molded integrally when the housing Ca is molded from a resin material using a mold so as to be accommodated in the first accommodation portion 14 of the housing body 10. Then, the lead wire 31b of the pressure sensor 30 is electrically connected to the circuit board 50, and then covered and sealed with the mold resin material 70.

[0291] Alternatively, the pressure sensor 30 may be embedded in the first housing portion 14 of the case Ca that is previously molded from a resin material in a subsequent process and sealed with the mold resin material 70 .

[0292] like Fig.30 , Fig.31 , Fig.37 As shown, the temperature sensor 40 is a lead type sensor, for example, composed of a temperature sensing element 40a such as a thermistor and a lead wire 40b extending from the temperature sensing element 40a. That is, the temperature sensor 40 is inserted into the second receiving portion 18 of the housing Ca, the temperature sensing element 40a is arranged in the inner area of ​​the front end outer wall portion 23e of the sleeve 20, and the lead wire 40b is electrically connected to the circuit substrate 50, and then covered and sealed by the molded resin material 70.

[0293] Then, in a state where the sensor unit U is assembled to the intake pipe Ip, the temperature sensor 40 detects the temperature of the intake air flowing through the intake passage Ip1 on the downstream side of the throttle device M.

[0294] The surface of the circuit substrate 50 is packaged with printed wiring and various electronic components (not shown), such as Fig.30 and Fig.31 As shown, it includes three through holes 51 electrically connected to the wires 31 b of the pressure sensor 30 and four through holes 52 electrically connected to the wires 40 b of the temperature sensor 40 .

[0295] Furthermore, the circuit board 50 is disposed in the third housing portion 15 of the case body 10 during assembly, the lead wires 31 b and the lead wires 40 b are electrically connected, and then covered and sealed with the mold resin material 70 .

[0296] The terminal 60 is formed of a conductive metal material, such as Fig.33 and Fig.34 As shown, it is arranged to be embedded in the housing body 10 , one end of which is connected to the through hole 52 of the circuit board 50 , and the free end side is exposed in the connector 17 and is surrounded by the connector 17 .

[0297] The molded resin material 70 is a sealing material such as epoxy resin, and is injected into the shell Ca and cured in a manner to fill the gap space while the pressure sensor 30, the temperature sensor 40 and the circuit substrate 50 are respectively accommodated and held in the first accommodation portion 14, the second accommodation portion 18 and the third accommodation portion 15 of the shell Ca.

[0298] Therefore, if Fig.32 , Fig.33 , Fig.34 , Fig.37 As shown, the first housing portion 14 , the second housing portion 18 , and the third housing portion 15 are sealed by filling with a mold resin material 70 in a state where the pressure sensor 30 , the temperature sensor 40 , and the circuit board 50 are disposed respectively.

[0299] The annular sealing member Sr is made of a rubber material having excellent heat resistance and swelling resistance, such as Figure 32 to Figure 34 As shown, it is formed into an annular shape and is fitted into an annular groove 22a formed on the outer periphery of the sleeve 20 of the case Ca.

[0300] Moreover, if Fig.29 As shown, in a state where the sensor unit U is assembled to the intake pipe Ip, the annular seal member Sr seals between the fitting hole H of the intake pipe Ip and the sleeve 20 .

[0301] Next, the detection operation of the sensor unit U in the internal combustion engine E including the sensor unit U will be described.

[0302] First, when the internal combustion engine E is in the idling range, the throttle valve m1 closes the intake passage Ip1, and the intake air flowing in the intake passage Ip1 flows through the bypass passage m2 to bypass the throttle valve m1 and flows out to the downstream intake passage Ip1 again.

[0303] On the other hand, when the internal combustion engine E is in an operation range other than the idling operation range, the throttle valve m1 is in a predetermined opening range, and the intake passage Ip1 is opened.

[0304] Therefore, the intake air flowing through the intake passage Ip1 flows through the intake passage Ip1 and is sucked into the internal combustion engine E without passing through the bypass passage m2.

[0305] Then, in the operating state of the internal combustion engine E, the pressure and temperature as state quantities of the intake air are detected by the sensor unit U on the downstream side of the throttle device M.

[0306] That is, the temperature of the intake air is detected by the temperature sensor 40. Specifically, since the temperature sensing element 40a is arranged near the inner side of the front end outer wall portion 23e protruding from the first end surface 23a of the sleeve 20, the temperature of the intake air flowing in the intake passage Ip1 is detected in an area away from the wall surface of the intake pipe Ip. As a result, the influence of the wall surface temperature of the intake pipe Ip can be suppressed.

[0307] The pressure sensor 30 detects the pressure of the intake air flowing in the intake passage Ip1 via the first communication passage Cp1 including the first passage 24 and the first vent hole 32d and the second communication passage Cp2 including the second passage 25 and the second vent hole 32e.

[0308] Specifically, when comparing the flow ease of the first connecting passage Cp1 and the second connecting passage Cp2, the first connecting passage Cp1 is arranged in the first area A1 where the flow of intake air is fast, and the second connecting passage Cp2 is arranged in the second area A2 where the flow of intake air is slower than that in the first area A1. Therefore, compared with the second connecting passage Cp2, it is easier to suck out the intake air in the pressure chamber Rc in the first connecting passage Cp1.

[0309] Therefore, if Fig.40 As shown, the intake air in the pressure receiving chamber Rc is sucked into the intake passage Ip1 via the first communication passage Cp1, and in conjunction with the flow of the intake air, the intake air in the intake passage Ip1 flows into the pressure receiving chamber Rc via the second communication passage Cp2.

[0310] By continuously performing the above flow, intake air is supplied to the pressure receiving chamber Rc, and the pressure of the intake air is detected by the pressure receiving portion 31a. In addition, by the above flow of intake air, liquids or liquids such as fuel, moisture in the intake air, and blowby gas can be suppressed or prevented from adhering to the inner wall surfaces of the first communication passage Cp1 and the second communication passage Cp2, thereby suppressing or preventing them from freezing. In addition, by the first vent hole 32d and the second vent hole 32e, foreign matter can be prevented from intruding into the pressure receiving chamber Rc.

[0311] As described above, the pressure of the intake air is detected by the pressure sensor 30, and the temperature of the intake air is detected by the temperature sensor 40. The detected information is acquired as control information of the electronic control unit (ECU), thereby controlling the internal combustion engine E appropriately.

[0312] As described above, the sensor unit U is constructed to include: a pressure sensor 30 for detecting the pressure of the intake air in the intake pipe Ip; and a housing Ca, which includes a first housing portion 14 for accommodating the pressure sensor 30, and a connecting passage that connects the pressure-receiving chamber Rc of the pressure sensor 30 with the intake passage Ip1 of the intake pipe Ip, the connecting passage including: a first connecting passage Cp1, which is configured to open to a first area A1 in the intake passage Ip1 where the flow of the intake air is fast; and a second connecting passage Cp2, which is configured to open to a second area A2 in the intake passage Ip1 where the flow of the intake air is slower than that in the first area A1.

[0313] Accordingly, a pressure difference is generated between the opening ends of the first communication passage Cp1 and the second communication passage Cp2 to generate a trigger flow in the first communication passage Cp1, thereby generating a flow in the second communication passage Cp2 in conjunction with the trigger flow, thereby generating a flow in the entire communication passage.

[0314] Therefore, in the regions of the first communication passage Cp1 , the pressure receiving chamber Rc, and the second communication passage Cp2 , it is possible to suppress or prevent the occurrence of stagnation in the flow of the intake air.

[0315] Therefore, the intake air in the intake passage Ip1 can be always supplied to the pressure receiving chamber Rc, and the intrusion of foreign matter and the adhesion or freezing of liquids or liquid substances such as fuel, moisture in the intake air, and blowby gas can be suppressed or prevented, and the pressure of the intake air can be detected with high precision through the pressure receiving portion 31a.

[0316] In the above embodiment, the intake pipe Ip is a straight pipe defining a linear intake passage Ip1, but the present invention is not limited thereto. Fig.41 As shown, the intake pipe Ip may be a curved pipe defining a curved intake passage Ip1.

[0317] In the above-described embodiment, the flow velocity distribution of the intake air flowing in the intake passage Ip1 is such that the flow velocity becomes faster on the outer inner wall surface Wo side and becomes slower on the inner inner wall surface Wi side.

[0318] Therefore, the first communication passage Cp1 is arranged to open to the outer first region A1 where the flow of intake air is fast in the intake passage Ip1, and the second communication passage Cp2 is arranged to open to the second region A2 where the flow of intake air is slower than the first region A1 in the intake passage Ip1.

[0319] That is, the first connecting passage Cp1 has a short passage length so as to open to an area close to the inner wall surface Wo of the intake pipe Ip, and the second connecting passage Cp2 has a longer passage length than the first connecting passage Cp1 so as to open to an area away from the inner wall surface Wo of the intake pipe Ip toward the center side.

[0320] In the above case, as described above, a pressure difference is generated between the open end of the first connecting passage Cp1 and the open end of the second connecting passage Cp2, thereby generating a trigger flow in the first connecting passage Cp1, thereby interlocking with the above flow, and also generating a flow in the second connecting passage Cp2, thereby generating a flow in the entire connecting passage.

[0321] In the above embodiment, the first vent hole 32d and the second vent hole 32e formed in the sensor cover 32 are shown as the first vent hole and the second vent hole, but the present invention is not limited thereto and the first vent hole and the second vent hole formed in the sleeve of the housing may be used.

[0322] For example, the first ventilation hole may be provided at a position dividing the first passage into two, and the second ventilation hole may be provided at a position dividing the second passage into two.

[0323] In addition, as the first ventilation hole and the second ventilation hole, the first ventilation hole 32d and the second ventilation hole 32e in the form of circular holes are shown, but the present invention is not limited to this, and the first ventilation hole and the second ventilation hole in the form other than circular holes with the same opening area may also be used.

[0324] In the above embodiment, as the first vent hole and the second vent hole, the first vent hole 32d and the second vent hole 32e having the same opening area are shown, but the present invention is not limited thereto. Fig.42 As shown, the opening area of ​​the first ventilation hole 132d may be larger than the opening area of ​​the second ventilation hole 32e.

[0325] In the above embodiment, the passage resistance of the first vent hole 132d is smaller than that of the first vent hole 32d, and the flow is easier in the first communication passage Cp1 (the first passage 24 and the first vent hole 132d) than in the second communication passage Cp2 (the second passage 25 and the second vent hole 32e).

[0326] In the embodiment, the first connecting passage Cp1 and the second connecting passage Cp2 are formed adjacent to each other and are formed to open at different positions relative to the intake passage Ip1, that is, the first passage 24 opens at the first end surface 23a, and the second passage 25 opens at the second end surface 23b, but it is not limited to this. As long as the pressure difference can be set between the opening end of the first connecting passage and the opening end of the second connecting passage, other forms can also be used.

[0327] In the embodiment, a sensor unit U is shown which includes a pressure sensor 30 and a temperature sensor 40 and includes a circuit substrate 50 which electrically connects the pressure sensor 30 and the temperature sensor 40. However, the present invention is not limited to this. A sensor unit may be used which eliminates the temperature sensor 40 and includes the circuit substrate 50 and the pressure sensor 30, or may be used which eliminates the temperature sensor 40 and the circuit substrate 50 and includes only the pressure sensor 30.

[0328] In the embodiment, a sensor unit U is shown which includes a sleeve 20 forming a first passage 24 and a second passage 25 as a part of a first connecting passage and a second connecting passage for connecting a pressure receiving chamber Rc of a pressure sensor 30 with an intake passage Ip1 of an intake pipe Ip. However, the present invention is not limited to this. If the structure includes the first connecting passage and the second connecting passage, a sensor unit including a shell in other forms other than a sleeve may also be used.

[0329] In the embodiment, as a cylindrical sleeve protruding from the shell body 10 in the direction of the axis S, a sleeve 20 having a large diameter cylindrical portion 22 and a small diameter cylindrical portion 23 and having a two-stage cylindrical shape is shown, but it is not limited to this, and a cylindrical sleeve having the same outer diameter may also be used.

[0330] In the above embodiment, the pressure sensor 30 including a semiconductor strain gauge is shown as the pressure sensor, but the present invention is not limited to this. An electrostatic capacitance type pressure sensor may be used. As long as it includes a pressure receiving portion that receives the pressure of the intake air, other types and forms of pressure sensors may be used.

[0331] In addition, in the embodiment, as a pressure sensor, a pressure sensor 30 including a sensor body 31 and a sensor cover 32 is shown, but it is not limited to this. A pressure sensor without a sensor cover and with the pressure-receiving portion exposed to the outside may be used, or a first housing portion that accommodates the pressure sensor may be provided, and the pressure-receiving chamber may be defined by the cooperation of the pressure sensor and the inner wall surface of the first housing portion of the shell.

[0332] In the embodiment, the following structure is shown, the first passage 24, the first opening portion 24a of the first passage 224, and the first opening portion 224a open at the first end face 23a, the second passage 25, the second opening portion 25a of the second passage 225, and the second opening portion 225a open at the second end face 23b located at a position different from the first end face 23a, and the collision wall 26a and the collision wall 126a are formed as a part of the partition wall 26 and the partition wall 126, but are not limited to this.

[0333] For example, the following structure may be adopted, in which the first opening of the first passage and the second opening of the second passage are opened on the same end face, and the collision wall is formed to protrude continuously with the second end face on the side of the second opening, and the first opening and the second opening are arranged in a direction perpendicular to the flow direction of the intake air, so that the intake air collides with the collision wall.

[0334] In the above-described embodiment, the first passage 24, the first passage 224 and the second passage 25, the second passage 225 are formed to cooperatively define the three-dimensionally curved flexure passage 24b, the curved flexure passage 25b, the curved flexure passage 224b, the curved flexure passage 225b, but the present invention is not limited thereto. The three-dimensionally curved flexure passage may be defined by only one of the first passage and the second passage, or the first passage and the second passage may separately define the three-dimensionally curved flexure passage.

[0335] In the embodiment, the following sensor unit U is shown, which includes a pressure sensor 30 and a temperature sensor 40 as sensors for detecting the state quantity of the intake air, and includes a circuit substrate 50 that electrically connects the pressure sensor 30 and the temperature sensor 40, but is not limited to this. A structure including one of the pressure sensor 30 and the temperature sensor 40 may also be adopted.

[0336] In the above embodiment, as a housing, a housing Ca including a housing body 10 and sleeves 20, 120, and 220 joined to the housing body 10 is shown, but the present invention is not limited thereto, and a housing in which a housing body and a sleeve are integrally formed may be used.

[0337] In addition, as the sleeve constituting the shell Ca, the sleeve 20, the sleeve 120, and the sleeve 220 having a two-stage cylindrical shape including a large-diameter cylindrical portion 22 and a small-diameter cylindrical portion 23 are shown, but it is not limited to this, and a cylindrical sleeve with the same outer diameter may also be used.

[0338] In the above-described embodiment, the temperature sensor 40 constituting a semiconductor chip (surface mount type temperature sensor) is shown as the temperature sensor, but the present invention is not limited thereto, and temperature sensors of other types and forms may be employed.

[0339] As described above, the sensor unit of the present invention actively generates a flow of intake air in the passage connecting from the detection portion of the sensor to the intake passage, thereby suppressing or preventing the adhesion or freezing of liquids or liquids such as fuel, moisture in the intake air, and blowby gas, and can detect the state quantity (pressure, temperature) of the intake air with high precision. Therefore, it can of course be applied to the intake system of internal combustion engines of automobiles, motorcycles, etc., and is also useful in internal combustion engines of other vehicles.

Claims

1. A sensor unit, arranged in an intake pipe of an internal combustion engine, wherein the sensor unit is characterized by comprising: a sensor for detecting a state quantity of intake air flowing in an intake passage defined by the intake pipe; as well as a housing accommodating the sensor, The shell includes: a first passage and a second passage, which are interconnected and open to the intake passage respectively so that the detection part of the sensor is exposed to the intake air flowing in the intake passage; and a collision wall, which is located near the opening of the second passage and causes the intake air flowing in the intake passage to collide.

2. The sensor unit according to claim 1, characterized in that The collision wall includes a guide portion that guides intake air flowing through the intake passage toward the second passage.

3. The sensor unit according to claim 2, characterized in that The guide portion includes a curved surface inclined toward the inside of the second passage.

4. The sensor unit according to claim 3, characterized in that The guide portion includes side surfaces formed continuously with both sides of the curved surface.

5. The sensor unit according to claim 1, characterized in that The first passage has a first opening portion opened at a first end surface away from the inner wall surface of the intake pipe toward the center side. The second passage has a second opening portion that opens at a second end surface that is closer to the inner wall surface of the intake pipe than the first opening portion.

6. The sensor unit according to claim 5, characterized in that The housing includes a sleeve extending along a predetermined axial direction. The sleeve includes a partition wall that defines the first passage and the second passage so as to extend adjacent to each other. The partition wall includes the collision wall.

7. The sensor unit according to claim 1, characterized in that The sensor comprises: a pressure sensor for detecting the pressure of the intake air; and a temperature sensor for detecting the temperature of the intake air. The housing includes: a housing body accommodating the temperature sensor and the pressure sensor; and a sleeve joined to the housing body and defining the first passage, the second passage, and the collision wall.

8. The sensor unit according to claim 7, characterized in that The first passage and the second passage are formed to extend from a region facing a detection portion of the temperature sensor to the intake passage, respectively. A detection portion of the pressure sensor is formed to face a middle of the second passage.

9. The sensor unit according to claim 8, characterized in that The housing body includes a recessed portion for exposing a detection portion of the temperature sensor. The sleeve includes a protruding wall that is inserted into the recess to define a portion of the first passage and the second passage in cooperation with the recess.

10. The sensor unit according to claim 8, characterized in that The second passage includes a curved passage between a region facing the detection portion of the pressure sensor and a region facing the detection portion of the temperature sensor. The first passage includes a bent passage midway from a region facing a detection portion of the temperature sensor toward a first opening portion that opens to the intake passage.

11. The sensor unit according to claim 10, characterized in that The first passage and the second passage include curved passages formed to be three-dimensionally curved.

12. The sensor unit according to claim 10, characterized in that The inner wall surface of the curved passage is curved so as to be streamlined and continuous.

13. The sensor unit according to claim 8, characterized in that The detection portion of the pressure sensor includes a pressure receiving chamber exposed to the intake air. The pressure receiving chamber is formed to communicate with the second passage via a communication hole having an opening area smaller than a passage area of ​​the second passage.

14. The sensor unit according to claim 13, characterized in that The communication hole is arranged to face a second opening portion of the second passage that opens into the intake passage in an extending direction of the second passage.

15. The sensor unit according to claim 7, characterized in that The circuit substrate includes a circuit board which is electrically connected to the pressure sensor and the temperature sensor and is accommodated in the housing body.

16. The sensor unit according to claim 15, characterized in that The temperature sensor is a surface mounted temperature sensor packaged on the circuit substrate.

17. The sensor unit according to claim 1, characterized in that comprising a first connecting path and a second connecting path, The first communication passage includes: the first passage having a predetermined passage area and a first passage length; and a first vent hole communicating with the first passage and having an opening area smaller than the passage area of ​​the first passage, The second connecting passage includes: the second passage having the same passage area as the first passage and a second passage length shorter than the first passage length; and a second vent hole connected to the second passage and having an opening area smaller than the passage area of ​​the second passage.

18. The sensor unit according to claim 17, characterized in that The sensor includes a pressure sensor for detecting the pressure of the intake air. The pressure sensor comprises: a sensor body having a pressure receiving portion; and a sensor cover connected to the sensor body to cover the pressure receiving portion and define a pressure receiving chamber, The first vent hole and the second vent hole are formed in the sensor cover.

19. The sensor unit according to claim 18, characterized in that The first vent hole and the second vent hole are formed to be biased toward a side away from a central area of ​​the pressure receiving chamber.

20. The sensor unit according to claim 18, characterized in that The housing includes: a housing body including a joint surface to be joined to the intake pipe; and a cylindrical sleeve protruding from the housing body in a predetermined axial direction. The first passage and the second passage are formed to extend inside the sleeve.

21. The sensor unit according to claim 18, characterized in that comprising a temperature sensor for detecting the temperature of the intake air in the intake pipe, The housing includes a second receiving portion for receiving the temperature sensor.

22. The sensor unit according to claim 21, characterized in that The housing includes: a housing body including a joint surface to be joined to the intake pipe; and a cylindrical sleeve protruding from the housing body in a predetermined axial direction. The first passage, the second passage, and the second housing portion are formed to extend inside the sleeve.

23. The sensor unit according to claim 1, characterized in that The shell includes: a shell body including a joint surface joined to the intake pipe; a sleeve protruding from the shell body in a specified axial direction and defining the first passage, the second passage and the collision wall; and an annular groove formed on the outer periphery of the sleeve for an annular sealing member to be embedded.

24. The sensor unit according to claim 23, characterized in that The sleeve includes: a large diameter cylindrical portion protruding from the joint surface; and a small diameter cylindrical portion continuous with the large diameter cylindrical portion. The annular groove is formed in the large-diameter cylindrical portion.

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