JP6275431B2 - Pressure detecting device and intake pressure measuring device using the same - Google Patents

Description

  The present invention relates to a pressure detection device and an intake pressure measurement device that detects intake pressure of an internal combustion engine using the pressure detection device.

Patent Document 1 discloses an intake pressure measuring device for measuring an intake air amount of an internal combustion engine.
In this intake pressure measuring device, an element portion which is a pressure detecting device is installed inside an air chamber formed in a case. A chip having a Si diaphragm is mounted on this element portion. An introduction hole is formed in the case, the intake pressure of the internal combustion engine is introduced into the air chamber from the introduction hole, and the pressure is detected by a chip mounted on the element portion. In the case, a convex portion serving as a weir is formed around the opening portion of the introduction hole.

  This intake pressure measuring device can prevent moisture condensed in the air chamber when used in winter or in a cold region from being blocked by the protrusions and entering the introduction hole.

JP 2000-186969 A

  In the intake pressure measuring device described in Patent Document 1, a convex portion that prevents moisture from entering the introduction hole is formed on the case side, but the element portion that is the pressure detection device has no countermeasure against moisture. It has not been.

  The element portion described in FIGS. 1 and 2 of Patent Document 1 has a structure in which a concave portion is formed on the surface, and a chip for detecting a pressure signal is accommodated in the concave portion. The element portion is only formed with a recess for housing the chip, and the surface is flat except for the recess. Since no measures are taken to guide the moisture adhering to the surface of the element portion to a region other than the concave portion, the moisture adhering to the element portion side tends to adhere to the surface of the chip in the concave portion.

  In particular, since the surface of the chip described in Patent Document 1 is arranged in a downward direction in which the surface of the chip in the concave portion faces the direction of gravity, the surface of the chip is accumulated until the water grows to a size that allows it to fall by its own weight. to continue. Therefore, it is a structure in which moisture attached to the surface of the chip is difficult to be removed.

  When moisture adheres to the chip, the mass of the moisture acts on the diaphragm of the chip, and accurate intake pressure measurement cannot be performed.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a pressure detection device having a structure in which moisture hardly adheres to a sensor storage portion in which a pressure sensor is stored, and an intake pressure measurement device using the pressure detection device. Yes.

The present invention provides a pressure detection device in which a pressure sensor is held in a housing.
An outer wall portion surrounding the detection space and an inner wall portion located inside the detection space are integrally formed in the housing, and a sensor storage portion and a relief space are partitioned by the inner wall portion in the detection space. Being formed,
The sensor storage portion is formed in a concave shape toward the rear, the pressure sensor is stored therein, and the pressure sensor is covered with an elastic body inside the sensor storage portion,
The escape space is located below the sensor storage portion in the direction of gravity , and the escape space is not provided with the same elastic body that covers the pressure sensor. .

  In the pressure detection device of the present invention, a concave sensor storage portion and a relief space at a position away from the sensor storage portion are formed in a detection space surrounded by an outer wall portion. Moisture that has entered the detection space or moisture that has been generated in the internal space easily moves to the escape space, and the probability that the influence of moisture directly acts on the pressure sensor housed in the sensor housing portion can be reduced.

  The present invention may be configured such that, in the sensor housing portion, the pressure sensor is covered with an elastic body. The surface of the elastic body is preferably a concave curved surface, and the surface of the elastic body is preferably formed up to the opening edge of the sensor housing portion.

  If the surface of the elastic body is a concave curved surface, and the surface is formed so as to be continuous with the opening edge, moisture attached to the surface of the elastic body can easily flow into the escape space, and the surface of the elastic body Moisture does not remain.

In the present invention, since the escape space is located below the sensor housing portion in the direction of gravity, the escape space is located below the sensor housing portion in the detection space surrounded by the outer wall portion. By arranging, moisture in the detection space can be guided to the escape space.

  In the present invention, the escape space can be configured as being formed in an escape recess that is recessed rearward from the front end portion of the inner wall portion that partitions the escape space and the sensor storage portion.

  In this case, it is preferable that the front end portion of the inner wall portion is located behind the front end portion of the outer wall portion.

  By forming the escape recess, it is easy to hold moisture that has flowed from the surface of the sensor storage portion in the escape space.

  Alternatively, in the present invention, a circuit arrangement portion is formed in the housing at a position away from the sensor housing portion, and the escape space is formed in front of the circuit arrangement portion.

  Furthermore, the intake pressure measuring device of the present invention is provided with a housing for holding the pressure detection device, and an intake hole for introducing the intake pressure of the internal combustion engine into the detection space is formed in the housing. It is a feature.

  The present invention is directed to, for example, a pressure detection device mounted on an intake pressure measurement device, in which moisture that has entered the detection space or moisture generated in the detection space can be guided to the escape space, so that It becomes easy to prevent adhesion.

  Since the pressure detection device is designed to allow moisture to escape from the pressure sensor, the pressure of the intake pressure measurement device equipped with the pressure detection device is reduced compared to the conventional measures that allow moisture to escape. It becomes easy to directly prevent the moisture from reaching the sensor housing portion housing the sensor.

  Therefore, malfunction of pressure detection is less likely to occur due to moisture, and high-precision pressure detection can be realized.

The perspective view of the pressure detection apparatus of the 1st Embodiment of the present invention, The front view of the pressure detection apparatus of 1st Embodiment, FIG. 3 is a cross-sectional view of the pressure detection device according to the first embodiment taken along the line III-III in FIG. 2, and a cross-sectional view showing a state in which the pressure detection device is held in the housing of the intake pressure measurement device; The front view of the pressure detection apparatus of the 2nd Embodiment of this invention, Sectional drawing which cut | disconnected the pressure detection apparatus of 2nd Embodiment by the VV line of FIG.

  1 to 3 show a pressure detection device 10 according to a first embodiment of the present invention, and FIG. 3 shows a part of an intake pressure measurement device 1 on which the pressure detection device 10 is mounted. Yes. In each figure, the X1 direction is forward, the X2 direction is backward, the Y1 direction is rightward, the Y2 direction is leftward, the Z1 direction is upward, and the Z2 direction is downward.

  An intake pressure measuring device 1 shown in FIG. 3 is attached to an internal combustion engine equipped in a two-wheeled vehicle, and a pressure detection device 10 and a throttle position sensor are mounted together on a housing 2. An intake pipe 3 is formed integrally with the housing 2, and the intake pressure of the internal combustion engine is applied to the pressure detection device 10 from the intake hole 4 inside the intake pipe 3.

  As shown in FIGS. 1 to 3, the pressure detection device 10 is provided with a housing 11. The housing 11 is made of PPS (polyphenylene sulfide) resin. Three terminal plates 12 and two plate portions 13 are embedded in the housing 11. The terminal board 12 and the board part 13 are copper plates.

  The housing 11, the terminal plate 12 and the plate portion 13 are integrated by a so-called insert molding method. In this molding method, the terminal plate 12 is formed on the first hoop material continuous in the Y direction at regular intervals, and on the second hoop material extending in the Y direction in parallel with the first hoop material, at regular intervals. A plate portion 13 is formed. The terminal plate 12 and the plate portion 13 are installed in the cavity of the molding die, and the molten resin of PPS is injected into the cavity to mold the housing 11, and the housing 11, the terminal plate 12 and the plate portion 13 are integrated. The Thereafter, the terminal plate 12 and the plate portion 13 are separated from the hoop material, respectively.

  As shown in FIG. 1, an outer wall portion 14 that projects forward (X1 direction) is integrally formed with the housing 11. The outer wall portion 14 is formed in a cylindrical shape, and the housing 11 has a detection space 15 in an inner region surrounded by the outer wall portion 14. As shown in FIG. 3, in the intake pressure measuring device 1, the printed wiring board 6 is installed inside the housing 2, and the terminal board 12 of the pressure detection device 10 is inserted into the through hole of the printed wiring board 6. The solder fillet 7 fixes the printed circuit board 6 to the land portion on the surface. The front end surface 14 a of the outer wall portion 14 is brought into close contact with the concave portion 5 on the inner surface of the housing 2 so that the intake pressure that has passed through the intake hole 4 is applied to the detection space 15.

  As shown in FIGS. 1 and 2, an inner wall portion 16 is formed inside the detection space 15. The front end surface 16a of the inner wall portion 16 is recessed backward (to the bottom side of the detection space 15) from the front end surface 14a of the outer wall portion 14. As shown in FIG. 2, the inner wall portion 16 is formed to be curved in a cylindrical shape, the right end portion 16 b is connected to the outer wall portion 14, and the left end portion 16 c is continuous to the outer wall portion 14. Between the right end portion 16b and the left end portion 16c (range α), the inner wall portion 16 is integrated with the outer wall portion 14, and the substantial inner wall portion 16 is limited to a range of β that is a region other than the range α. Yes.

  In the housing 11, a sensor storage portion 17 is formed in a concave shape in a region surrounded by the inner wall portion 16. As shown in FIG. 2, the sensor storage portion 17 has a circular opening when viewed from the front. As shown in FIG. 3, an IC package 22 including a pressure sensor 21 and an integrated circuit (ASIC) is fixed to the bottom of the sensor housing portion 17.

  The pressure sensor 21 has a MEMS (Micro Electro Mechanical Systems) structure, and includes a diaphragm portion that receives pressure, and a strain detection element such as a piezoresistive element or a piezoelectric element that detects deformation of the diaphragm portion. The integrated circuit in the IC package 22 includes an amplifier that amplifies the detection output from the pressure sensor 21, a temperature sensor, a temperature compensation circuit based on the temperature measured by the temperature sensor, and the like. Although the pressure sensor 21 and the IC package 22 are wired by wire bonding, illustration of wire bonding is omitted in each drawing.

  In the sensor storage portion 17, the IC package 22 is located on the upper side (Z1 side), and the pressure sensor 21 is located on the lower side (Z2 side). In the sensor storage portion 17, the pressure sensor 21 is disposed at a position close to the inner surface of the inner wall portion 16. On the center line O passing through the center of the pressure sensor 21, if the opening dimension of the sensor housing portion 17 is L1, and the distance between the pressure sensor 21 and the inner wall portion 16 is L2, the ratio (L2 / L1) is 1/3. It is as follows.

  As shown in FIG. 3, the pressure sensor 21 and the IC package 22 fixed to the bottom of the sensor housing portion 17 are covered with an elastic body 23. The elastic body 23 is a gel-like viscoelastic body, for example, a gel-like silicone resin or a fluororesin. Since the elastic body 23 is cured after the liquid resin material is supplied to the concave portion of the sensor housing portion 17, the surface 23 a becomes a concave curved surface.

  In the process in which the liquid resin material is supplied to the inside of the sensor housing portion 17 and cured, the surface of the resin material is subjected to the opening edge portion of the sensor housing portion 17 (the inner edge of the front end face 16a of the inner wall portion 16) by surface tension. Part or corner part). Therefore, as shown in part E of FIG. 3, the surface 23 a that is the concave curved surface of the elastic body 23 extends to the opening edge of the sensor storage part 17 (inner edge or corner of the front end face 16 a of the inner wall part 16). It is formed continuously. That is, the surface 23a and the front end face 16a are continuous so that there is no step at the boundary.

  Therefore, moisture attached to the surface 23a of the elastic body 23 is likely to flow out toward the front end face 16a.

  Inside the detection space 15 of the housing 11, a relief space 18 is formed in a region other than the sensor storage portion 17. As shown in FIG. 3, the escape space 18 forms a sensor housing portion 17 (divides the sensor housing portion 17) and is directed rearward (X2 direction) from the front end surface 16 a of the inner wall portion 16. It is formed in a recessed relief recess. As shown in FIG. 2, the escape space 18 is between the outer wall portion 14 and the inner wall portion 16 and extends from the right end portion 16 b to the left end portion 16 c where the inner wall portion 16 and the outer wall portion 14 are connected. Is formed.

  As shown in FIG. 2, the range β from the right end 16 b to the left end 16 c of the inner wall 16 is formed in a range of 180 degrees or more with respect to the center of the cylindrical inner wall 16, that is, the center of the sensor storage portion 17. Has been.

  As shown in FIGS. 1 to 3, when the intake pressure measuring device 1 is installed in an internal combustion engine such as a two-wheeled vehicle, the pressure detecting device 10 is installed with the terminal plate 12 facing upward (Z1 direction), and the outer wall portion. 14, the sensor storage portion 17 is positioned on the upper side (Z1 side), and the escape space 18 is positioned on the lower side (Z2 side), which is closer to gravity than the sensor storage portion 17. doing.

  In the intake pressure measuring device 1, the intake pressure of the internal combustion engine is introduced from the intake hole 4 of the housing 2, and the intake pressure is applied to the detection space 15 of the pressure detection device 10. The intake pressure is detected by the pressure sensor 21 via the gel-like elastic body 23, and the detected output is electrically processed by the integrated circuit in the IC package 22.

  Moisture contained in the intake air of the internal combustion engine, condensation due to a temperature difference, or the like may adhere to the inside of the detection space 15. Even if this moisture adheres to the surface 23a of the elastic body 23 of the sensor housing portion 17, the surface 23a of the elastic body 23 is a concave curved surface. It becomes easy to get in. Since the surface 23a of the elastic body 23 continues to the front end portion 16a of the inner wall portion 16 without a step, the moisture adhering to the surface 23a flows through the surface 23a to the front end surface 16a and further escapes to the escape space 18. Will be able to.

  Moreover, since the escape space 18 is formed in the escape recess that is recessed rearward from the front end surface 16a of the inner wall portion 16, the moisture that has entered the escape space 18 may flow back to the surface 23a of the elastic body 23. Absent.

  As shown in FIG. 2, the escape space 18 is formed in a range β of 180 degrees or more on the lower side of the cylindrical inner wall portion 16. Therefore, a sufficiently large volume of the escape space 18 in the detection space 15 can be secured, and moisture that has entered the detection space 15 or generated in the detection space 15 is retained in a lower area where the sensor housing portion 17 is not touched. It becomes easy. As a result, it becomes difficult for moisture to adhere to the front surface 23a of the elastic body 23, and it becomes easy to prevent the phenomenon that the pressure sensor 21 receives pressure of moisture and an error occurs in the pressure value that should be detected originally.

  The pressure detection device 110 according to the second embodiment of the present invention shown in FIGS. 4 and 5 is fixed in the casing 2 of the intake pressure measurement device 1 so that the terminal plate 112 faces downward. A cylindrical outer wall portion 114 is formed integrally with the housing 111 of the pressure detection device 110 toward the front, and a detection space 115 surrounded by the outer wall portion 114 is formed.

  A sensor storage portion 117 formed in a concave shape is formed in an upper portion of the detection space 115, and the pressure sensor 21 is fixed to the bottom of the sensor storage portion 117. The sensor housing 117 is filled with a gel-like elastic body 23 that covers the pressure sensor 21, and the surface 23a of the elastic body 23 is a concave curved surface. Also in this case, the surface 23a of the elastic body 23 is continuous without forming a step on the front end surface 116a of the inner wall portion 116 due to surface tension.

  As shown in FIGS. 4 and 5, a circuit arrangement portion 119 is formed on the lower side of the housing 111, which is in the direction toward gravity, with respect to the sensor housing portion 117. As shown in FIG. 5, the circuit arrangement part 119 is formed in a concave shape at the bottom of the detection space 115, and the IC package 22 is fixed to the bottom. And the recessed part which accommodated IC package 22 is block | closed with the resin material 119b.

  The front surface 119a of the circuit arrangement portion 119 has a substantially planar shape. The front surface 119a is located on substantially the same plane as the front end surface 116a of the inner wall portion 116 that defines the sensor storage portion 117.

  In the detection space 115 surrounded by the outer wall portion 114, the pressure sensor 21 is disposed on the upper side, and the circuit arrangement portion 119 containing the IC package 22 is formed on the lower side. A relief space 118 having a large internal volume is formed in a region in front of the front surface 119a of the portion 119.

  As shown in FIG. 5, the escape space 118 is formed in a range of a distance Lb from the lower edge portion of the sensor storage portion 117 to the lowermost end of the inner surface of the outer wall portion 114. The ratio (Lc / La) between the distance Lc from the center of the pressure sensor 21 to the uppermost end of the inner surface of the outer wall 114 and the upper and lower opening dimensions La of the detection space 115 is 1/4 or less, and the distance Lc and the distance Lb The ratio (Lc / Lb) is 1/3 or less.

  In the pressure detection device 110 according to the second embodiment, the escape space 118 having a large internal capacity is formed in front of the circuit arrangement portion 119 in which the IC package 22 is stored. The moisture generated in the detection space 115 is guided to the escape space 118, and the moisture is less likely to adhere to the front surface 23a of the elastic body 23.

  Since only the pressure sensor 21 is accommodated in the sensor accommodating portion 117, the area occupied by the sensor accommodating portion 117 is reduced, and a large internal capacity escape space is provided in a region other than the sensor accommodating portion 117 within the detection space 115. 118 is formed.

  The moisture adhering to the sensor housing portion 117 flows from the concave curved surface of the surface 23a of the elastic body 23 to the front end portion 116a of the inner wall portion 116 and flows out into the escape space 118 as it is, so that moisture remains on the front surface 23a of the elastic body 23. It becomes difficult.

  Therefore, it is easy to prevent a phenomenon in which the pressure value detected by the pressure sensor 21 becomes an incorrect value due to the presence of moisture.

DESCRIPTION OF SYMBOLS 1 Intake pressure measuring apparatus 2 Case 4 Intake hole 10 Pressure detection apparatus 11 Housing 12 Terminal board 14 Outer wall part 14a Front end part 15 Detection space 16 Inner wall part 16a Front end part 16b Right end part 16c Left end part 17 Sensor accommodating part 18 Escape space 21 Pressure Sensor 22 IC package 23 Elastic body 110 Pressure detection device 111 Housing 114 Outer wall portion 116 Inner wall portion 117 Sensor housing portion 118 Escape space 119 Circuit arrangement portion

Claims (8)

In the pressure detection device in which the pressure sensor is held in the housing,
An outer wall portion surrounding the detection space and an inner wall portion located inside the detection space are integrally formed in the housing, and a sensor storage portion and a relief space are partitioned by the inner wall portion in the detection space. Being formed,
The sensor storage portion is formed in a concave shape toward the rear, the pressure sensor is stored therein, and the pressure sensor is covered with an elastic body inside the sensor storage portion,
The relief space is located below the sensor housing portion in the direction of gravity , and the relief space is not provided with the same elastic body that covers the pressure sensor. . The surface of the elastic body is concave curved surface, the surface of the elastic body, pressure sensing device of claim 1, wherein the formed to the opening edge portion of the sensor housing portion. The pressure detection device according to claim 1, wherein a center of the sensor housing portion is located above a center of the detection space. The relief space, the pressure sensing device according to any one of 3 claims 1 a concave shape recessed rearward from the front end portion of the inner wall portion. The pressure detection device according to claim 4 , wherein a front end portion of the inner wall portion is located behind a front end portion of the outer wall portion. Said housing, said has circuit arrangement section at a position deviated from the sensor housing portion is formed, the relief space, according to any one of 3 claims 1 are formed in front of the circuit arrangement part Pressure sensing device. A housing for holding the pressure detection device according to any one of claims 1 to 6 is provided, and an intake hole for introducing the intake pressure of the internal combustion engine into the detection space is formed in the housing. Intake pressure measuring device. The intake pressure measuring device according to claim 7, wherein all end surfaces of the outer wall portion are in close contact with the casing.

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