JP2017058226A - Measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a loss of pressure due to an assembly that holds a humidity sensor, in a measurement device that is disposed in an intake passage.SOLUTION: A measurement device 1 comprises: a first projection part 10 holding a flow sensor 3 and projecting to the inner circumference of an intake passage, and a second projection part 11 holding a humidity sensor 5 and projecting in a shape of a rod to the inner circumference of an intake passage 2. The humidity sensor 5 is buried in the surface of the second projection part 11 and held so as to be exposed to the intake passage 2. The second projection part 11 projects to the inner circumference of the intake passage 2 in such a way that its longitudinal direction intersects the direction of flow of an intake air at right angles. Then, when a cross section perpendicular to the longitudinal direction out of cross sections of the second projection part 11 is called a vertical cross section, the circumferential edge of the vertical cross section exhibits a streamline shape to the flow of the intake air. Consequently, it is possible to suppress the loss of pressure due to the second projection part 11 that holds the humidity sensor 5 in the measurement device 1 disposed in the intake passage 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a measuring device for measuring the flow rate and humidity of intake air taken into an internal combustion engine.

2. Description of the Related Art Conventionally, a measuring device that includes a flow rate sensor and a humidity sensor arranged in an intake passage through which intake air flows and measures the flow rate and humidity of intake air is known.
In such a measuring apparatus, a configuration having a casing that holds a flow sensor and protrudes to the inner periphery of the intake passage and a humidity sensor provided on a side wall of the casing is known (for example, see Patent Document 1). .)

  However, in such a measuring apparatus, the heat of the internal combustion engine is conducted through the casing, and the temperature of the humidity sensor rises. As a result, the temperature of the humidity sensor differs from the temperature of the intake air, which adversely affects the detected value of the humidity of the intake air. For this reason, it is necessary to prevent heat conduction from the housing to the humidity sensor.

Therefore, a configuration is known in which an assembly for holding the humidity sensor is provided separately from the housing and protrudes from the housing to the inner periphery of the intake passage (see, for example, Patent Document 2).
In such a measuring apparatus, since the housing and the assembly are separated from each other, heat conduction from the housing to the humidity sensor can be prevented, and an increase in the temperature of the humidity sensor can be suppressed.
However, since the assembly of Patent Document 2 has a rectangular cross section perpendicular to the longitudinal direction, there is a possibility that a large pressure loss will occur with respect to the flow of intake air.

Patent Document 3 discloses a configuration in which a humidity sensor is covered with a cover.
According to the measuring apparatus of Patent Document 3, the cover is provided with two openings along the intake air flow. Then, intake air is introduced into the cover from the opening on the downstream side, passes through the sensor, and is returned to the intake passage from the opening on the upstream side.
For this reason, according to the measuring apparatus of Patent Document 3, it is expected that the effect of preventing the entry of foreign matter into the cover and protecting the humidity sensor can be expected, but the effect of suppressing the pressure loss cannot be expected.

JP-A-2015-87196 Japanese Patent No. 5445535 International Publication No. 2014/060161

  The present invention has been made in view of the above problems, and an object of the present invention is to suppress pressure loss due to an assembly that holds a humidity sensor in a measurement device disposed in an intake passage.

The measuring device of the present invention includes a flow rate sensor and a humidity sensor arranged in an intake passage through which intake air taken into the internal combustion engine flows, and measures the flow rate and humidity of the intake air flowing through the intake passage.
And the housing | casing which hold | maintains a flow sensor and protrudes to the inner periphery of an intake passage and the assembly which hold | maintains a humidity sensor and protrudes in the rod shape at the inner periphery of an intake passage away from a housing | casing are provided.
Hereinafter, the housing is referred to as a first protrusion, and the assembly is referred to as a second protrusion.

Here, the humidity sensor is embedded and held in the surface of the second protrusion so as to be exposed to the intake passage.
And the 2nd protrusion part protrudes to the inner periphery of an intake passage so that the longitudinal direction of self may be orthogonal to the direction of the flow of intake air.
Moreover, when the cross section perpendicular | vertical to a longitudinal direction is called a vertical cross section among the cross sections of a 2nd protrusion part, the periphery of a vertical cross section exhibits a streamline with respect to the flow of intake air.

Thereby, when the 2nd projection part is arranged in an intake passage, the eddy of the intake air etc. which occur on the surface of the 2nd projection part can be controlled.
For this reason, in the measuring device arranged in the intake passage, it is possible to suppress pressure loss due to the second projecting portion that holds the humidity sensor.

(A) Whole view of measuring apparatus seen from intake air flow upstream side, (b) Cross section of measuring apparatus along flow direction of intake air (Example). (A) Perspective view of the second protrusion, (b) a side view of the second protrusion viewed from a direction perpendicular to the longitudinal direction and the flow direction of intake air, and (c) a parallel sectional view of the second protrusion. (Example). It is a vertical sectional view of the 2nd projection part which meets the III-III line in Drawing 2 (a) (example). It is a perspective view of the 2nd projection part (modification).

  Hereinafter, modes for carrying out the invention will be described using examples. In addition, an Example discloses a specific example, and it cannot be overemphasized that this invention is not limited to an Example.

[Configuration of Example]
A measuring apparatus 1 according to the embodiment will be described with reference to FIGS.
The measuring device 1 is mounted on an intake passage 2 through which intake air drawn into an internal combustion engine for vehicle travel flows, and includes a flow rate sensor 3 and a humidity sensor 5 disposed in the intake passage 2, and an intake passage. Measure the flow rate and humidity of the intake air flowing through 2.
Hereinafter, the direction in which the intake air flows in the intake passage 2 may be referred to as a direction F.

In the intake passage 2, a mounting hole penetrating the inside and outside of the intake passage 2 is formed at a place where the measuring device 1 is mounted. The measuring device 1 is provided with a lid 6 that fits into the mounting hole.
Further, in the measuring apparatus 1, a first projecting portion 10 and a second projecting portion 11 described below project from the lid portion 6.
Here, the 1st protrusion part 10 and the 2nd protrusion part 11 are each provided integrally with the cover part 6, and protrude from the cover part 6 in the same direction, respectively.

The first protrusion 10 holds the flow rate sensor 3 and protrudes to the inner periphery of the intake passage 2.
And the 1st protrusion part 10 is provided with the resin material, and the channel | path is formed in the inside.
Here, the structure of the passage formed inside the first projecting portion 10 includes, for example, a bypass passage 12 and a sub bypass passage 13.

The bypass passage 12 is a passage through which a part of the intake air flowing through the intake passage 2 flows, and the passage is formed along the flow direction of the intake air in the intake passage 2. An intake port 12 a is provided on the upstream side of the bypass passage 12, and a discharge port 12 b is provided on the downstream side of the bypass passage 12.
A discharge port restrictor 12 c that restricts the flow of intake air passing through the bypass passage 12 is formed on the downstream side of the bypass passage 12.

  The sub-bypass passage 13 includes an inlet 13a into which a part of the intake air flowing through the bypass passage 12 throttled by the outlet throttle 12c flows, and an outlet 13b that returns the intake air that has passed through the sub-bypass passage 13 to the intake passage 2. Prepare. And the intake air which flowed in from the inlet 13a is rotated inside the 1st protrusion part 10, and is guide | induced to the outlet 13b.

The chip-type flow rate sensor 3 is a heat transfer type that measures the flow rate by the heat transfer of the intake air that passes through the sub-bypass passage 13, for example, and has a heating resistor and a resistance temperature detector on the surface. It becomes the composition of. A signal corresponding to the flow rate of the intake air is output to an ECU (not shown) or the like via a connection terminal in the connector 15.
The connector 15 is provided integrally with the lid portion 6.

The second protrusion 11 holds the chip-type humidity sensor 5 and protrudes in a bar shape from the first protrusion 10 away from the inner periphery of the intake passage 2. Further, the protruding direction is a direction in which the longitudinal direction of itself is orthogonal to the direction F.
The humidity sensor 5 is embedded and held on the surface of the second protrusion 11 so as to be exposed to the intake passage 2.
More specifically, the humidity sensor 5 is provided on the side surface of the second protrusion 11 that faces the road wall of the intake passage 2. The humidity sensor 5 is embedded in the second protrusion 11 so that its surface is parallel to the longitudinal direction and parallel to the direction F.

  The humidity sensor 5 is, for example, a capacitance type in which the capacitance changes according to humidity, and has a well-known configuration having a polymer film on the surface whose capacitance changes with humidity. A signal corresponding to the humidity of the intake air is output to the ECU or the like via the connection terminal in the connector 15.

The second protrusion 11 is formed by embedding the humidity sensor 5 supported by the support substrate 17 and lead terminals (not shown) electrically connected to the humidity sensor 5 in a resin material. Note that the lead terminal serves as a connection terminal by exposing the end portion in the connector 15.
Here, the support substrate 17 is made of a silicon substrate or the like, and the humidity sensor 5 that is weak in strength is fixed to itself, thereby facilitating the handling of the humidity sensor 5.

[Features of Examples]
Next, a characteristic configuration of the embodiment will be described with reference to FIGS.
First, a vertical cross section and a parallel cross section will be described.
The vertical cross section is a cross section perpendicular to the longitudinal direction among various cross sections of the second protrusion 11.
Of the various cross sections of the second protrusion 11, the parallel cross section is a cross section parallel to the longitudinal direction and parallel to the direction F.

The 2nd protrusion part 11 is rod-shaped, and the humidity sensor 5 is embedded in the surface of the front-end | tip part of a longitudinal direction. And the shape of the vertical cross section of a longitudinal direction is substantially the same (refer Fig.2 (a), (b)).
And the 2nd protrusion part 11 is exhibiting streamline with respect to the flow of an intake air in the periphery of a vertical cross section (refer FIG. 3).
More specifically, the width in the direction P perpendicular to the direction F in the peripheral edge of the vertical section gradually increases from the upstream side to the downstream side and then gradually decreases.

Moreover, the humidity sensor 5 exists in the position where the width | variety of the direction P is the largest among the periphery of a vertical cross section (refer FIG. 3).
Further, the second projecting portion 11 has a streamlined shape with respect to the flow of the intake air at the portion constituting the projecting end 11a in the peripheral edge of the parallel section (see FIG. 2C). Here, the protruding end 11a is the longitudinal tip of the second protruding portion 11.

[Effects of Examples]
According to the measuring apparatus 1 of the embodiment, the peripheral edge of the vertical section of the second protrusion 11 is streamlined with respect to the flow of intake air.
Thereby, when the 2nd protrusion part 11 is arrange | positioned in the intake passage 2, the eddy etc. of the intake air which generate | occur | produce on the surface of the 2nd protrusion part 11 can be suppressed.
For this reason, in the measuring device 1 arranged in the intake passage 2, pressure loss due to the second protrusion 11 can be suppressed.

According to the measuring apparatus 1 of the embodiment, the humidity sensor 5 is present at the position where the width in the direction P is the largest among the peripheral edges of the vertical cross section.
Thereby, the flow velocity of the intake air passing through the surface of the humidity sensor 5 can be increased.
For this reason, even if the temperature of the humidity sensor 5 rises, it can be quickly cooled and brought close to the temperature of the intake air, and the temperature of the humidity sensor 5 is different from the temperature of the intake air. Can be suppressed.

According to the measuring apparatus 1 of the embodiment, the portion constituting the protruding end 11a in the peripheral edge of the parallel section of the second protruding portion 11 is streamlined with respect to the flow of the intake air.
Thereby, the vortex of the intake air etc. which generate | occur | produce on the surface of the protrusion end 11a can be suppressed, and the pressure loss with respect to the intake air which flows through the surface of the protrusion end 11a can be reduced. For this reason, the pressure loss by the 2nd protrusion part 11 can be suppressed more.

[Modification]
Various modifications can be considered for the present invention without departing from the gist thereof.
For example, according to the embodiment, the second protrusion 11 has the same vertical cross-sectional shape at any position in the longitudinal direction. However, as shown in FIG. Good. Thereby, the intensity | strength of the 2nd protrusion part 11 can be increased.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Intake path 3 Flow sensor 5 Humidity sensor 10 1st protrusion part
11 Second protrusion

Claims (4)

A measuring device comprising a flow rate sensor (3) and a humidity sensor (5) disposed in an intake passage (2) through which intake air drawn into the internal combustion engine flows, and measuring the flow rate and humidity of the intake air flowing through the intake passage In (1),
A first protrusion (10) that holds the flow sensor and protrudes to the inner periphery of the intake passage;
A second protrusion (11) that holds the humidity sensor and protrudes in a rod shape on the inner periphery of the intake passage away from the first protrusion;
The humidity sensor is embedded and held in the surface of the second protrusion so as to be exposed to the intake passage,
The second protrusion protrudes into the inner periphery of the intake passage so that its longitudinal direction is perpendicular to the direction of the flow of intake air,
Of the cross sections of the second protrusions, when a cross section perpendicular to the longitudinal direction is referred to as a vertical cross section, the peripheral edge of the vertical cross section exhibits a streamline shape with respect to the flow of intake air. The measuring apparatus according to claim 1,
The said humidity sensor exists in the position where the width | variety of the direction perpendicular | vertical to the flow direction of intake air is the largest among the peripheral edges of the said vertical cross section. In the measuring apparatus according to claim 1 or 2,
Of the cross sections of the second protrusions, a cross section parallel to the longitudinal direction and parallel to the flow direction of the intake air is referred to as a parallel cross section, and the tip of the second protrusion is referred to as a protrusion end (11a). The measuring device, wherein a portion of the peripheral edge of the cross section that forms the protruding end exhibits a streamline shape with respect to a flow of intake air. In a measuring apparatus comprising a flow rate sensor and a humidity sensor arranged in an intake passage through which intake air sucked into an internal combustion engine flows, and measuring the flow rate and humidity of intake air flowing through the intake passage,
A first protrusion that holds the flow sensor and protrudes to the inner periphery of the intake passage;
A second protrusion that holds the humidity sensor and protrudes in a rod shape on the inner periphery of the intake passage away from the first protrusion;
The humidity sensor is embedded and held in the surface of the second protrusion so as to be exposed to the intake passage,
The second protrusion protrudes into the inner periphery of the intake passage so that its longitudinal direction is perpendicular to the direction of the flow of intake air,
Of the cross sections of the second protrusions, a cross section parallel to the longitudinal direction and parallel to the flow direction of the intake air is referred to as a parallel cross section, and a tip of the second protrusion is referred to as a protrusion end. Of these, the portion forming the protruding end exhibits a streamlined shape with respect to the flow of intake air.

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