JP3681627B2 - Flow rate and flow rate measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device for measuring various quantities relating to a flow, and more particularly to a flow rate and flow velocity measuring device using a temperature-dependent detection element and / or a detection element integrally formed on a semiconductor chip, for example, a vehicle or The present invention relates to a mass flow sensor for combustion control of an industrial engine, a mass flow sensor for an industrial air conditioning system or a compressor compressed air supply system, and a measuring device suitably applied as an air-fuel ratio control flow sensor for a household gas stove.
[0002]
[Prior art]
In a mass flow sensor for engine combustion control for a vehicle, a change in output due to accumulation of contaminants on the detection element is a big problem. In order to solve this problem, Japanese Patent Application Laid-Open No. Hei 8-193863, for example, states that “an auxiliary passage for diverting a part of the air from the main air flow and an appropriate opening in the housing structure can prevent contamination of the detection element. It has been proposed to “prevent the effects of accumulation and backflow”.
[0003]
[Problems to be solved by the invention]
However, the sensor housing structure disclosed in JP-A-8-193863 is effective in preventing the accumulation of contaminants having a density much higher than that of the measurement fluid, but for contaminants having a relatively low density, There is a risk that it may enter the branch flow path and accumulate on the detection element. In addition, in this sensor, it is difficult to measure the backflow because the influence of the backflow is excluded.
[0004]
However, in recent years, in order to meet emission regulations and the like, a mass flow sensor for combustion control with higher performance, for example, a sensor capable of detecting both forward flow and reverse flow is desired. Conventionally, a sensor flow path structure that can detect backflow has been proposed, but when measuring backflow, detection output at the same level as forward flow is not obtained, and detection output correction by the control circuit is not possible. It is considered necessary.
[0005]
The object of the present invention is to provide a measuring device for the flow in which the accumulation of contaminants on the detection element is prevented. It is a further object of the present invention to provide a measurement device relating to a flow that can measure a reverse flow as well as a forward flow.
[0006]
[Means for Solving the Problems]
A measuring apparatus according to a first aspect of the present invention includes a shunt pipe having a shunt pipe basically curved in a U-shape into which a flow in a main stream pipe to be detected is introduced, and the shunt pipe Formed on the outer peripheral side of the main flow pipe and opened in a plane substantially orthogonal to the flow direction in the main flow pipe, the partition formed in the flow diversion pipe, and the branch flow pipe so as to branch and merge with each other. Arranged to be exposed to the flow in the branch channel formed on the outer peripheral side of the branch pipe among the plurality of branch channels and the plurality of branch channels divided by the partition, and detects the quantity related to the flow Detecting element.
[0007]
In this measuring device, the direction of the measurement fluid introduced into the branch flow pipe is largely changed in the branch pipe until it reaches the branch flow path inlet with the detection element. For this reason, contaminants with large inertia are prevented from entering the branch flow path with the detection element. In addition, by further dividing the flow in the flow dividing pipe, the number of lay nozzles of the flow toward the detection element can be reduced (because the cross-sectional area of the flow path is reduced), and the flow in the vicinity of the detection element is rectified, High-precision detection can be performed. That is, according to this measuring apparatus, by effectively branching and turning the measuring fluid, both the pollutant having a density higher than that of the measuring fluid mixed in the measuring fluid and the pollutant having a relatively lower density are related. Therefore, it is possible to provide a measuring device that prevents any of these contaminants from accumulating on the detection surface of the detection element, has excellent contamination resistance, and has little change in detection output over a long period of time.
[0008]
In the measuring apparatus according to the second aspect of the present invention, the shunt pipe has a flow path structure that is basically symmetrical about the detection element. As described above, according to the flow path structure having a symmetrical structure, the flow in the shunting pipe for the forward flow and the flow in the shunting pipe with respect to the backflow are symmetric, so that the detection output in the case of the backflow is significantly corrected. There is no need. In particular, by configuring the measurement apparatus based on the first viewpoint and the second viewpoint, it is possible to obtain the same detection output level for both forward flow and reverse flow as well as excellent contamination resistance.
[0009]
The measuring device according to the third aspect of the present invention is disposed so as to be exposed to the flow in the branch channel formed on the inner peripheral side or the middle part of the branch pipe among the plurality of branch channels, and the quantity relating to the flow And a throttling formed in the flow path between the inlet of the branch pipe and the inlet of the branch flow path where the detection surface of the detection element is exposed to the flow. In this way, when the detection element is exposed to the inner peripheral side or the middle branch channel where the direction change of the flow introduced into the branch pipe introduction port is relatively small compared to the outer branch channel, By providing the diaphragm, accumulation of contaminants on the detection element is preferably prevented.
[0010]
A measuring apparatus according to a fourth aspect of the present invention includes a shunt pipe having a shunt pipe basically curved in a U-shape into which a flow in a main stream pipe to be detected is introduced, and the shunt pipe Formed at the outer peripheral side of the one end of the main flow pipe and opened at a plane substantially orthogonal to the flow direction in the main flow pipe, and formed at the top of the other end of the flow diversion pipe and substantially in the flow direction in the main flow pipe. An outlet of the branch pipe that opens in a parallel plane; a partition that is formed in the branch pipe and has one end extending to the vicinity of the inlet and the other end extending away from the outlet; and Arranged to be exposed to a plurality of branch channels formed by the partition so as to branch and merge with each other and a flow in the branch channel formed on the outer peripheral side of the branch pipe among the plurality of branch channels. And a detection element for detecting an amount related to the flow. Since this measuring device has an asymmetric channel structure, it is particularly suitable for measuring forward flow.
[0011]
A measuring apparatus according to a fifth aspect of the present invention is a flow dividing pipe formed with each other such that the flow introduced into the flow dividing pipe is redirected and the detection element flows into the branch flow channel exposed to the flow. And an inlet of the branch channel.
[0012]
The measuring device according to the sixth aspect of the present invention is configured so that the flow introduced into the flow dividing pipe is redirected and the detection element flows into the branch flow channel exposed to the flow, And a throttle formed in the flow path between the inlets of the branch flow paths.
[0013]
In the measuring device according to the seventh aspect of the present invention, the flow path of the branch channel in which the detection element is arranged from the upstream side to the downstream side of the detection element is provided on the wall surface facing the detection element of the partition. The venturi is provided so as to be the narrowest in the vicinity of the center.
[0014]
The other viewpoints and features of the present invention are as described in the respective claims, and duplication of the description is omitted with reference thereto. Thus, each feature of each claim is considered to be described herein. Each dependent claim can be applied to each independent claim as long as it does not violate the principle of the invention described in each independent claim, and a dependent claim can be applied to other dependent claims.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
[0016]
In a preferred embodiment of the present invention, the end of the partition does not extend to a position immediately below the inlet of the flow dividing pipe, and the inlet of the outer peripheral branch channel where the detection element is exposed to the flow is the introduction of the flow dividing pipe. There is no opening right under the mouth. This prevents contaminants from going straight from the branch pipe inlet toward the branch flow path inlet.
[0017]
In a preferred embodiment of the present invention, a bypass channel is formed that short-circuits the inlet and outlet of the branch pipe without going through a plurality of branch channels. As a result, the flow introduced into the flow dividing pipe is stabilized, and the measurement fluid (flow in the main flow pipe) is easily taken into the flow dividing pipe. In particular, when the flow path structure of the shunt pipe is formed symmetrically about the detection element, by providing an orifice with a reduced flow cross-sectional diameter of the bypass flow path or the bypass flow path, both forward flow and reverse flow are provided. The flow reaching the detection element can be stabilized.
[0018]
In a preferred embodiment of the present invention, an orifice is provided in the bypass flow path, and the flow rate of the measurement fluid toward the detection element is set by the projection amount or orifice opening area of the flow path wall forming the orifice. Thereby, it is possible to quantitatively control the flow rate toward the detection element.
[0019]
In a preferred embodiment of the present invention, there is provided means for forming a flow that strikes at an angle toward the detection surface of the detection element in the shunt pipe. It is considered that the flow to be detected is constantly supplied to the detection surface of the detection element by the flow control means, and the flow to be detected surely flows on the detection surface. In addition, it is considered that the detection accuracy and reproducibility are improved because the occurrence of eddy currents and separation near the detection surface is suppressed.
[0020]
In a preferred embodiment of the present invention, the flow control means for forming a flow that strikes the detection surface of the detection element obliquely (down flow) or a flow that flows obliquely with respect to the detection surface is at least upstream or upstream of the detection element. And / or the flow path surface which protrudes from the detection surface is provided downstream. As the form of the bulge, any form may be used as long as it can form a flow that strikes the detection surface at an angle. Preferably, the bulge is bulged in a concave or convex shape, or the bulging surface is a linear, polygonal or concave curved inclined surface. Is done.
[0021]
In a preferred embodiment of the present invention, the detection surface of the detection element is exposed in the flow dividing section of the flow dividing pipe (detection pipe). More preferably, an inflection pipe (a shunt pipe) is attached in a direction orthogonal to the main flow pipe (measurement target pipe), and a detection element is provided at an inflection portion (a bent portion, a portion where the flow path is bent) of the inflection tube. Provided. Alternatively, the detection element is arranged in a portion where the flow of the shunt pipe is reversed or a portion where the flow direction is largely changed or in the vicinity thereof. Preferably, the detection surface of the detection element is exposed to a portion where the flow in the shunt pipe is fast. Preferably, the flow is constricted in the flow dividing pipe, and the detection surface of the detection element is exposed to a portion where the flow is subsequently changed or in the vicinity thereof.
[0022]
In a preferred embodiment of the present invention, the following detection element is used. That is, the detection element is basically a semiconductor chip provided with four thin film resistors. More specifically, a diaphragm portion and a rim portion are provided on the semiconductor layer. The diaphragm section is provided with (1) an upstream temperature sensor, (2) a downstream temperature sensor, and (3) a heater disposed between the upstream temperature sensor. On the other hand, (4) an ambient temperature sensor is provided in the rim portion. The diaphragm portion is extremely thin and is thermally insulated.
[0023]
Next, the detection principle of various quantities relating to flow such as flow velocity and flow rate using this detection element will be described below.
(1) The power supplied to the heater is controlled so that the heater always has a constant temperature difference with respect to the ambient temperature.
(2) Therefore, when there is no flow, the temperatures of the upstream temperature sensor and the downstream temperature sensor are substantially equal.
(3) However, when there is a flow, the temperature of the upstream temperature sensor decreases because heat escapes from the surface. Since the temperature of the downstream temperature sensor increases the heat input from the heater, the temperature change is smaller than that of the upstream temperature sensor. Note that the temperature of the downstream temperature sensor may rise.
(4) The flow rate and flow velocity are detected based on the temperature difference between the upstream temperature sensor and the downstream temperature sensor, and the flow direction is detected from the sign of this temperature difference. The temperature difference can be detected based on a change in electrical resistance due to temperature.
[0024]
In a preferred embodiment of the present invention, the sensing element measures a quantity relating to the flow at least including a flow rate and / or a flow rate based on the temperature.
[0025]
In a preferred embodiment of the present invention, the measuring device according to the present invention is installed in an intake system of an engine of various vehicles, and is applied to measurement of an intake amount of an engine mounted on a two-wheel or four-wheel vehicle. Can do. For example, the measuring device according to the present invention is installed between an air cleaner and a throttle valve in an intake system of an engine mounted on a four-wheel vehicle. The measuring device according to the present invention is attached to a two-wheeled vehicle intake pipe (air funnel) connected to a cylinder in an intake system of an engine mounted on a two-wheeled vehicle to measure the flow rate or flow velocity of intake air. .
[0026]
【Example】
In order to further clarify the preferred embodiment of the present invention described above, an embodiment of the present invention will be described below with reference to the drawings.
[0027]
[Example 1]
FIG. 1 is an explanatory view of a measuring apparatus according to Embodiment 1 of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe. Referring to FIG. 1, a main flow M as a measurement target flows in the main flow tube 1. A branch pipe 2 is attached to the pipe wall of the main flow pipe 1 so as to be able to take in the branch flow D separated from the main flow M, perpendicular to the pipe axis direction of the main flow pipe 1. In the diversion pipe 2, a diversion pipe curved in a substantially U shape is formed by an introduction plate 4 (main separator) extending in a direction substantially perpendicular to the flow direction of the main flow M (main flow pipe 1 pipe axis direction). Has been. At one end of the outer wall 3 of the branch pipe 2, an inlet (also referred to as outlet) 5 is formed that opens in a plane substantially orthogonal to the flow direction of the main stream M, and extends along the axial direction of the main pipe 1 of the branch pipe 2. On the existing outer wall of the top portion, there is formed a lead-out port (also serving as an inlet port) 6 that opens in a plane substantially parallel to the flow direction of the main flow M.
[0028]
Further, a partition 7 that is curved in accordance with the curved shape of the flow dividing tube 2 is formed in the flow dividing tube 2. In the branch pipe 2, a plurality of branch flow paths 8 a and 8 b that branch and merge with each other are formed by the partition 7. A detection element 11 is attached to the bottom outer wall of the branch pipe 2 through the substrate 10 so as to be exposed to the flow in the outer peripheral branch flow path 8a. As described above, the detection element 11 is disposed at the inflection portion of the flow dividing pipe 2 and is located outside the main flow pipe 1 so as to be easily exchanged.
[0029]
FIG. 2 is a partially enlarged view in which the vicinity of the inlet 5 of the branch pipe 2 shown in FIG. 1 is enlarged. As shown in FIG. 2, the end portion on the introduction port 5 side of the partition 7 is at a position retracted by a distance L from the inner wall of the partition 7 side opening of the introduction port 5. That is, the end portion of the partition 7 does not extend to the position immediately below the introduction port 5, and at least the inlet of the outer peripheral branch flow path 8 a is not opened directly below the introduction port 5.
[0030]
Further, on the outer wall 3 that forms the outer peripheral branch flow path 8a, ridges 3a and 3b that protrude toward the center of the flow cross section of the branch flow path 8a are formed on both sides of the detection element 11. A protruding portion 7 a that protrudes toward the detection surface is formed at a portion of the partition 7 that faces the detection surface of the detection element 11. The flow path surfaces on the raised portions 3a and 3b are formed in a concave curved surface. The flow path surface of the protruding portion 7 a is formed as a convex curved surface that is convex toward the detection element 11. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 11 is formed.
[0031]
Subsequently, the operation of this measuring apparatus will be described. FIG. 3 is a partial enlarged operation view in which the vicinity of the inlet 5 of the flow dividing pipe 2 shown in FIG. 1 is enlarged.
[0032]
Referring to FIGS. 1 and 3, the diversion D separated from the main flow M is taken into the diversion pipe 2 from the introduction port 5. The flow of the diversion D is changed in the diversion pipe 2, and flows into the branch flow paths 8a and 8b on the outer peripheral side and the inner peripheral side. However, the pollutant P having a density higher than that of the measurement fluid cannot completely follow the change of the flow direction, and advances straight due to inertia and accumulates directly under the inlet 5 or the branch flow path 8b on the inner peripheral side. To invade. The reason is that the end flow paths of the branch flow paths 8a and 8b extend in a direction substantially orthogonal to the flow direction of the branch flow D, so that the contaminant P having a density higher than that of the measurement fluid is changed in the flow direction. This is because it is possible to prevent the contamination P from entering the branch flow path 8a on the outer peripheral side near the introduction port 5 in particular. This prevents the contamination P from accumulating on the detection element 11 arranged on the outer peripheral side branch flow path 8a (requiring a sudden change of direction of flow). In addition, according to the flow path structure of the branch pipe 2, the forward flow flowing from the inlet 5 toward the outlet 6 can be measured suitably.
[0033]
[Examples 2 to 4]
Next, various modified examples of the first embodiment will be described as the second to fourth embodiments. 4-6 is the elements on larger scale which expanded the vicinity of a diversion pipe | tube inlet, in order to demonstrate the measuring apparatus which concerns on Examples 2-4 of this invention in order, respectively. In the devices according to the second to fourth embodiments, structures other than the portions illustrated in FIGS. 4 to 6 are basically the same as those of the device according to the first embodiment.
[0034]
Referring to FIG. 4, in the measuring apparatus according to the second embodiment, an undulating portion 12 is formed on the inner side of the outer wall 3 of the shunt pipe in the vicinity of the inlet 5 so as to close the inlet of the outer branch side flow path 8 a. . The top of the undulating portion 12 protrudes from the inner peripheral flow path surface of the outer peripheral branch flow path 8a formed on the partition 7 toward the introduction plate 4 by a height H1. By this undulating portion 12, a restriction is formed in the flow path between the inlet 5 of the flow dividing pipe 2 and the inlet of the outer peripheral branch flow path 8a where the detection element 11 is arranged. Such a flow path structure further prevents contamination of the detection element 11.
[0035]
Referring to FIG. 5, in the measuring apparatus according to the third embodiment, a concave curved surface is provided on the inner circumferential side flow path wall (between the introduction plate and the outer wall at the top of the diversion pipe) below the introduction port 5. A undulating portion 13 having a channel surface is formed. As a result, the flow toward the branch flow paths 8a and 8b is rectified. In addition, such an undulating portion 13 can form a throttle, and can also guide contaminants toward the inner peripheral branch flow path 8b where the detection element 31 is not disposed.
[0036]
Referring to FIG. 6, in the measuring apparatus according to the fourth embodiment, an undulation portion 14 is formed on the inner wall on the introduction port 5 side of the introduction plate 4 so as to close the inlet of the branch channel 8 b on the inner peripheral side. The top of the undulating portion 14 protrudes from the outer peripheral side channel surface of the inner peripheral side branch channel 8b formed on the partition 7 by a height H2 toward the outer wall 3. This undulating portion 14 forms a throttle in the flow path between the inlet 5 of the branch pipe 2 and the inlet of the inner peripheral branch flow path 8b, and a pool is formed on the left side of the undulating portion 14 in FIG. Is formed. With such a flow channel structure, it is possible to dispose the detection element toward the inner peripheral branch flow channel 8b.
[0037]
[Example 5]
7 (A) and 7 (B) are explanatory views of a measuring apparatus relating to the flow according to the fifth embodiment of the present invention, and FIG. 7 (A) is a longitudinal section along the axial direction of the main flow tube, FIG. (B) has shown the BB cross section in FIG. 7 (A). Referring to FIGS. 7A and 7B, a main flow M as a measurement target flows in the main flow tube 1. A branch pipe 20 is mounted on the pipe wall of the main flow pipe 1 so as to be able to take in a branch flow D separated from the main flow M, perpendicular to the pipe axis direction of the main flow pipe 1. In the diversion pipe 20, a diversion pipe curved in a substantially U shape is formed by an introduction plate 24 (main separator) extending in a direction substantially perpendicular to the flow direction of the main flow M (main pipe 1 pipe axis direction). Has been. At both ends of the outer wall 23 of the flow dividing pipe 20, an inlet (also referred to as outlet) 25 and an outlet (also referred to as inlet) 26 are formed to face each other in a plane substantially perpendicular to the flow direction of the main flow M. A bypass channel 34 is formed between the top outer wall 29 of the flow dividing pipe 20 and one end of the introduction plate 24, and short-circuits between the introduction port 25 and the outlet port 26. As will be described later, the first diversion D1 in which the diversion D is largely redirected substantially at right angles and the content of contaminants is small flows toward the inlets of a plurality of diverging channels 28a and 28b described later, Contaminants having a relatively high density are conveyed to the second branch flow D2 and travel straight from the inlet 25 to the outlet 26 via the bypass channel 34 and are discharged out of the branch pipe 20 (and vice versa). The same is true).
[0038]
Further, a partition 27 that is curved according to the curved shape of the flow dividing tube 20 is formed in the flow dividing tube 20. In the branch pipe 20, a plurality of branch flow paths 28 a and 28 b that branch and merge with each other are formed by the partition 27. On both inner sides of the outer wall 23 (near the inlet 25 and outlet 26), undulations 32 and 33 are formed so as to block the inlet and outlet of the branch channel 28a on the outer peripheral side, respectively. By the undulating portions 32 and 33, throttles are respectively formed in the flow path between the inlet 25 and the inlet of the outer branching flow path 28a and the flow path between the outlet 26 and the outlet of the outer branching flow path 28a. A substantially “Ω” -shaped channel is formed between the mouth 25 and the outlet 26.
[0039]
A detection element 31 is attached to the bottom outer wall of the branch pipe 20 via the substrate 30 so as to be exposed to the flow in the outer peripheral branch flow path 28a. As described above, the detection element 31 is disposed at the inflection portion of the flow dividing pipe 20 and is located outside the main flow pipe 1 so as to be easily replaced. Further, on the inner side of the bottom of the outer wall 23, ridges 23a and 23b are formed on both sides of the detection element 31 so as to protrude toward the center of the flow cross section of the branch flow path 28a. A protrusion 27 a that protrudes toward the detection surface is formed at a portion of the partition 27 that faces the detection surface of the detection element 31. The flow path surfaces on the raised portions 23a and 23b are formed in a concave curved surface. The flow path surface of the protrusion 27 a is formed in a convex curved surface that is convex toward the detection element 31. With such a flow channel structure, a downflow DW that flows obliquely toward the detection surface of the detection element 31 is formed.
[0040]
Subsequently, the operation of this measuring apparatus will be described again with reference to FIGS. 7 (A) and 7 (B).
(1) The diversion D separated from the main flow M is taken into the diversion pipe 20 from the inlet 25.
(2) The diversion D is a flow (direction-changed flow) D1 substantially orthogonal to the flow direction of the main flow M and the flow direction of the main flow M before the entrance of the plurality of branch flow paths 28a and 28b. The flow is divided into a substantially parallel flow D2.
(3a) The flow D1 is increased in flow velocity by the restriction formed by the undulating portion 32 and flows into the plurality of branch flow paths 28a and 28b. Here, since the contaminant having a relatively higher density than the measurement fluid cannot follow the rapid change of direction of the flow after being squeezed, the contaminant enters the inner peripheral branch channel 28b due to inertia. Therefore, the measurement fluid with very few contaminants flows into the outer peripheral branch flow path 28 a having the detection element 31. And the flow which strikes diagonally with respect to the detection surface of the detection element 31, ie, the downflow DW, arises.
(3b) The flow D2 flows into the bypass flow path 34.
(4) The flow D1 flowing into the plurality of branch flow paths 28a and 28b is drawn out by the flow D2 that has passed through the bypass flow path 34, and returned to the main flow pipe 1 from the outlet 26.
[0041]
Further, in this branch pipe 20, a symmetrical flow path structure is formed around the detection element 31 along the flow direction in the substantially U-shaped branch pipe. Therefore, according to the flow dividing pipe 20, it is possible to measure both forward flow and reverse flow at the same detection output level while preventing accumulation of contaminants in the detection element 31.
[0042]
[Example 6]
Next, as a sixth embodiment, a modification of the fifth embodiment will be described. FIGS. 8A and 8B are explanatory views of an apparatus according to Embodiment 6 of the present invention, and FIG. 8A is a partially enlarged sectional view of the vicinity of the outer wall of the shunt pipe and one end of the introduction plate. FIG. 8B is a sectional view orthogonal to FIG. 8A. In the device according to the sixth embodiment, the structure other than the portions shown in FIGS. 8A and 8B is basically the same as that of the device according to the fifth embodiment.
[0043]
8 (A) and 8 (B), between the top outer wall 29 of the flow dividing pipe and one end of the introduction plate 24, that is, the bypass flow path of the fifth embodiment (34 in FIG. 7 (A)). The orifice member 35 is attached or integrally formed. By adjusting the orifice diameter W2 with respect to the flow cross-sectional direction diameter W1 of the bypass flow path, the flow rate toward the branch flow path where the detection element is arranged can be quantitatively controlled.
[0044]
[Examples 7 to 9]
Next, various modified examples of the sixth embodiment will be described as the seventh to ninth embodiments. 9 (A) to 9 (C) are partial enlarged views showing the vicinity of an orifice that bypasses the branch pipe inlet and the outlet for sequentially explaining the apparatuses according to the seventh to ninth embodiments of the present invention. . In the devices according to the seventh to ninth embodiments, the structure other than the portion shown in the drawing is basically the same as that of the device according to the sixth embodiment.
[0045]
Referring to FIG. 9A, triangular projections 40a and 41a are formed on one end of the introduction plate 41 and the top outer wall 40 facing the one end, respectively, and these projections 40a and 41a form the inlet of the flow dividing tube. An orifice is formed in the bypass channel that short-circuits the outlet.
[0046]
Referring to FIG. 9B, one end 43a of the introduction plate 43 has a rectangular shape, and a polygonal protrusion 42a is formed on the top outer wall 42 facing the one end 43a. The one end 43a and the polygonal protrusion An orifice is formed in the bypass channel that short-circuits the inlet and outlet of the branch pipe by 42a.
[0047]
Referring to FIG. 9C, one end 45a of the introduction plate 45 has a rectangular shape, and a curved (semicircular) protrusion 44a is formed on the top outer wall 44 facing the one end 45a. An orifice is formed in the bypass channel that short-circuits the inlet and outlet of the shunt pipe by means of the projection 44a.
[0048]
[Comparison between Comparative Example 1 and Example 5]
Next, the sensor (detection) output of the measurement apparatus according to Comparative Example 1 and the sensor output of the measurement apparatus according to Example 5 will be described in comparison with each other particularly with respect to the measurement of the backflow. First, the structure of the measurement apparatus according to Comparative Example 1 will be described mainly with respect to the differences from the measurement apparatus according to Example 5. FIG. 10 is an explanatory diagram of the measuring apparatus according to Comparative Example 1, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 10, a branch pipe 52 is attached to the pipe wall of the main flow pipe 1 so as to be able to take in a branch flow D separated from the main flow M, perpendicular to the pipe axis direction of the main flow pipe 1. In the diversion pipe 52, a diversion pipe curved in a substantially U shape is formed by an inner wall 54 (main separator). On the side of the outer wall 53 of the diversion pipe 52, a curved diversion pipe introduction port (also serving as an outlet) 55 is formed in a plane substantially orthogonal to the flow direction of the main flow M. One main flow pipe of the diversion pipe 52 On the top outer wall extending along the axial direction, a branch pipe outlet (also referred to as an inlet) 56 that opens in a plane substantially parallel to the flow direction of the main flow M is formed. The shunt pipe is reduced in diameter toward the detection element 61 in the vicinity of the introduction port 55 along the flow direction from the introduction port 55 to the discharge port 56 (a reduced diameter portion 63 is formed). And the outlet 56 are enlarged in diameter (the enlarged diameter portion 64 is formed).
[0049]
Further, on the outer wall 53 of the flow dividing pipe 52, ridges 53a and 53b are formed on both sides of the detection element 61 so as to protrude toward the center of the flow cross section of the flow dividing pipe. The flow path surfaces on the raised portions 53a and 53b are formed in a concave curved surface. A protruding portion 54 a that protrudes toward the detection surface is formed at a portion of the inner wall 54 of the flow dividing pipe 52 that faces the detection element 61. The flow path surface of the protrusion 54 a is formed as a convex curved surface that is convex toward the detection element 61. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 61 is formed.
[0050]
FIG. 11 is a graph showing the flow characteristics of the apparatus according to Comparative Example 1 shown in FIG. Referring to FIG. 10, according to the measuring apparatus according to Comparative Example 1, since an asymmetric channel structure is formed around the detection element 61 along the flow direction, forward flow (from the inlet 55 to the outlet 56) is performed. Both the forward flow and the reverse flow (flow from the outlet 56 to the inlet 55) cannot be detected at the same detection output level.
[0051]
On the other hand, FIG. 12 is a diagram showing the apparatus according to the fifth embodiment described with reference to FIGS. 7A and 7B, and FIG. 13 shows the apparatus according to the fifth embodiment. It is a graph which shows a flow characteristic. Referring to FIG. 12, a symmetric flow path structure is formed in the branch pipe 20 of the measuring apparatus according to the fifth embodiment around the detection element 31 along the flow direction. Referring to FIG. 13, therefore, by using this branch pipe 20, both forward flow (flow from the inlet 25 to the outlet 26) and reverse flow (flow from the outlet 26 to the inlet 25) are equivalent. It can be measured at the detection output level.
[0052]
Hereinafter, various Examples 10-15 of the measuring device by this invention are described. In addition, in the following description regarding Examples 10-15, in order to avoid duplication of description, the difference from the measurement device regarding the flow according to Example 5 will be mainly described, and the same points will be described with respect to the example. Reference to 5 shall be referred to. In addition, the flow path configurations in the shunt pipes according to Examples 10 to 14 are all symmetrical about the detection element along the flow direction, and both forward flow and reverse flow can be measured with the same detection output level. In addition, the measurement apparatus according to Example 15 is suitable for forward flow measurement.
[0053]
[Example 10]
FIG. 14 is an explanatory diagram of a measuring apparatus according to Example 10 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 14, a diversion pipe curved in a substantially U shape is formed in the diversion pipe 92 by an introduction plate 94 extending in a direction substantially orthogonal to the flow direction of the main flow M. At both ends of the outer wall of the diversion pipe 92, an inlet port 95 and an outlet port 96 are formed so as to face each other in a plane substantially perpendicular to the flow direction of the main flow M. Further, a plurality of branch flow paths 98 a and 98 b branch and merge with each other are formed in the branch pipe 92 by a curved partition 97. The detection element 101 is attached to the bottom of the outer wall 93 of the diversion tube 92 through the substrate 100. Further, on the inner side of the outer wall 93, raised portions 93a and 93b are formed on both sides of the detection element 101. The partition 97 is formed with a protrusion 97 a that protrudes toward the detection surface of the detection element 101. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 101 is formed. A triangular protrusion 99 a is formed inside the top outer wall 99 facing one end of the introduction plate 94, and an orifice 104 is formed in a bypass channel that short-circuits the introduction port 95 and the discharge port 96.
[0054]
[Example 11]
FIG. 15 is an explanatory diagram of a measuring apparatus according to Example 11 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 15, in the diversion pipe 112, a diversion pipe curved in a substantially U shape is formed by an introduction plate 114 extending in a direction substantially orthogonal to the flow direction of the main flow M. At both ends of the outer wall of the flow dividing pipe 112, an inlet 115 and an outlet 116 that are opened in a plane substantially perpendicular to the flow direction of the main flow M are formed to face each other. Furthermore, a plurality of branch flow paths 118a, 118c, and 118b that branch and merge with each other in order from the outer peripheral side to the inner peripheral side are formed in the branch pipe 112 by curved partitions 137 and 138. Relief portions 122 and 123 are formed on the inner sides of both ends of the outer wall 113 (in the vicinity of the inlet 115 and outlet 116) so as to block the inlet and outlet of the branch channels 118 a and 118 c, respectively. By the undulating portions 122 and 123, throttles are respectively formed in the channel between the inlet 115 and the inlet of the branch channels 118a and 118c, and the channel between the outlet 116 and the outlet of the branch channels 118a and 118c. A substantially “Ω” -shaped flow path is formed between 115 and the outlet 116. A detection element 121 is attached to the bottom of the outer wall 113 of the shunt pipe 112 via a substrate 120. Further, on the inner side of the outer wall 113, raised portions 113a and 113b are formed on both sides of the detection element 121. The outer partition 137 is formed with a protruding portion 137 a that protrudes toward the detection surface of the detection element 121. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 121 is formed. A bypass channel 124 that short-circuits the inlet 115 and the outlet 116 is formed at one end of the inlet plate 114 and the inner side of the top outer wall 119 opposite thereto.
[0055]
[Example 12]
FIG. 16 is an explanatory diagram of a measuring apparatus according to Example 12 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 16, in the diversion pipe 142, a diversion pipe curved in a substantially U shape is formed by an introduction plate 144 extending in a direction substantially orthogonal to the flow direction of the main flow M. An inlet port 145 and an outlet port 146 are formed at the top outer wall of the shunt pipe 142 and at both ends of the outer peripheral portion of the outer wall 143. The inlet port 145 and the outlet port 146 open on a plane substantially parallel to and substantially perpendicular to the flow direction of the main flow M. The diversion D is introduced into the diversion pipe 142 mainly from an oblique direction. Further, a plurality of branch flow paths 148 a and 148 b that branch and merge with each other are formed in the branch pipe 142 by a curved partition 147. On both inner sides of the outer wall 143 (near the inlet 145 and outlet 146), undulating portions 152 and 153 are formed so as to block the inlet and outlet of the outer branching channel 148a, respectively. By the undulating portions 152 and 153, throttles are respectively formed in the channel between the inlet 145 and the inlet of the outer branching channel 148a and the channel between the outlet 146 and the outlet of the outer branching channel 148a. A substantially “Ω” -shaped flow path is formed between 145 and the outlet 146. A detection element 151 is attached to the bottom of the outer wall 143 of the shunt pipe 142 via a substrate 150. Further, on the inner side of the outer wall 143, raised portions 143a and 143b are formed on both sides of the detection element 151. A protruding portion 147 a that protrudes toward the detection surface of the detection element 151 is formed at an intermediate portion of the partition 147. With such a flow channel structure, a downflow DW that flows obliquely toward the detection surface of the detection element 151 is formed.
[0056]
[Example 13]
FIG. 17 is an explanatory diagram of a measurement apparatus according to Example 13 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 17, a diversion pipe curved in a substantially U shape is formed in the diversion pipe 162 by an introduction plate 164 extending in a direction substantially orthogonal to the main flow pipe 1 pipe axis direction. At both ends of the outer wall 163 of the flow dividing pipe 162, an inlet 165 and an outlet 166 that are opened in a plane substantially orthogonal to the main flow M are formed to face each other. Further, a plurality of branch flow paths 168 a and 168 b that branch and merge with each other are formed in the branch pipe 162 by a curved partition 167. On both inner sides of the outer wall 163 (near the inlet 165 and outlet 166), undulating portions 172 and 173 are formed so as to block the inlet and outlet of the branch channel 168a on the outer peripheral side, respectively. By these undulating portions 172 and 173, throttles are respectively formed in the flow path between the inlet 165 and the inlet of the outer branching flow path 168 a and the flow path between the outlet 166 and the outlet of the outer branching flow path 168 a. A substantially “Ω” -shaped channel is formed between the mouth 165 and the outlet 166. Both sides of one end of the introduction plate 164 are expanded toward the introduction port 165 and the lead-out port 166, and the introduction port 165 and the guide port 165 are guided between the expansion portion and the top outer wall 169 facing the bottom surface of the expansion portion. A bypass flow path 174 that short-circuits the outlet 166 is formed. A detection element 171 is attached to the bottom of the outer wall 163 of the shunt pipe 162 via a substrate 170. Further, on the inner side of the outer wall 163, raised portions 163a and 163b are formed on both sides with the detection element 171 interposed therebetween. A protruding portion 167 a that protrudes toward the detection surface of the detection element 171 is formed at an intermediate portion of the partition 167. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 171 is formed.
[0057]
[Example 14]
FIG. 18 is an explanatory diagram of a measurement apparatus according to Example 14 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 18, a diversion pipe curved in a substantially U shape is formed in the diversion pipe 182 by an introduction plate 184 extending in a direction substantially orthogonal to the main flow pipe 1 pipe axis direction. At both ends of the outer wall 183 of the flow dividing pipe 182, an inlet 185 and an outlet 186 are formed so as to face each other in a plane substantially orthogonal to the flow direction of the main flow M. Further, a plurality of branch flow paths 188 a and 188 b branching and joining each other are formed in the branch pipe 182 by a curved partition 187. On both inner sides of the outer wall 183 (near the inlet 185 and outlet 186), undulating portions 192 and 193 are respectively formed so as to close the inlet and outlet of the branch channel 188a on the outer peripheral side. On both sides of the intermediate portion of the introduction plate 184, undulating portions 202 and 203 that protrude toward the inside of the outer wall 183 are formed. Due to the undulations 192, 202, 193, 203, there are multiple stages in the flow path between the inlet 185 and the inlet of the inner peripheral branch flow path 188b and the flow path between the outlet 186 and the outlet of the inner peripheral branch flow path 188b. Each of the apertures is formed with a substantially “Ω” -shaped flow path. A bypass channel 194 that short-circuits the inlet 185 and the outlet 186 is formed between one end of the inlet plate 184 and the top outer wall 189 facing the one end. A detection element 191 is attached to the inflection portion of the partition 187 so that its detection surface is exposed to the flow in the inner peripheral branch flow path 188b. At the other end of the introduction plate 184, a curved projection 184a that projects toward the detection surface of the detection element 191 is formed. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 191 is formed.
[0058]
[Example 15]
FIG. 19 is an explanatory diagram of a measuring apparatus according to Example 15 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe. Referring to FIG. 19, a branch pipe that is curved in a substantially U shape is formed in the branch pipe 222 by an introduction plate 224 that extends in a direction substantially orthogonal to the flow direction of the main flow M. The outer wall 223 of the branch pipe 222 is formed with an inlet 225 that opens in a plane substantially perpendicular to the flow direction of the main flow M, and the top outer wall of the branch pipe 222 opens in a plane substantially parallel to the flow direction of the main flow M. A lead-out port 226 is formed. Furthermore, a plurality of branch flow paths 228 a and 228 b that branch and merge with each other are formed in the branch pipe 222 by a curved partition 227. The other end on the outlet 226 side of the partition 227 is far away from the outlet 226 compared to the one end on the inlet 225 side. In the vicinity of the inlet 225 inside the outer wall 223, a undulating portion 232 is formed so as to close the inlet of the branch channel 228a on the outer peripheral side. On the other hand, the undulating portion 242 is also formed in the vicinity of the introduction port 225 of the introduction plate 224. A restriction is formed in the flow path between the inlet 225 and the inlet of the branch flow path 228a by the undulating portions 232 and 242. A detection element 231 is attached to the bottom of the outer wall 223 of the shunt tube 222 via a substrate 230. Further, on the inner side of the outer wall 223, raised portions 223a and 223b are formed on both sides of the detection element 231. A protruding portion 227 a that protrudes toward the detection surface of the detection element 231 is formed at an intermediate portion of the partition 227. With such a flow path structure, a downflow DW that flows obliquely toward the detection surface of the detection element 231 is formed.
[0059]
[Example 16]
FIG. 20 is an explanatory diagram of the measurement apparatus according to Example 16 of the present invention. In addition, the present Example 16 is a modification of the said Example 5, Comprising: The same referential mark as the said Example 5 is provided to the element similar to the said Example 5 in this Example 16. FIG. In the following description of the sixteenth embodiment, the description of the fifth embodiment may be referred to as appropriate for a portion where the measurement device of the sixteenth embodiment has the same configuration and function as the measurement device of the fifth embodiment. It shall be possible.
[0060]
Referring to FIG. 20, a venturi (venturi wall portion) 250 is provided on the wall surface of the partition 27 facing the detection element 31 from the upstream side to the downstream side of the detection element 31. By this venturi 250, the flow path of the outer peripheral branch flow path 28a in which the detection element 31 is arranged is narrowest in the vicinity of the center of the detection element 31 (this is referred to as “the narrowest portion N”). Such a flow path structure suppresses the turbulence of the flow on the detection surface of the detection element 31, and a strong and stable flow that strikes the detection surface of the detection element 31 obliquely is formed. Be improved.
[0061]
FIG. 21 is an explanatory diagram of the measurement apparatus according to Example 17 of the present invention and is a partially enlarged view in the vicinity of the detection element. In addition, this Example 17 is a modification of the said Example 16, Comprising: In the following description, the part from which the measuring apparatus of this Example 17 and the said Example 16 differs is demonstrated, and both are the same structure and function. The description of the above-described Example 16 can be referred to as appropriate for the part having
[0062]
Referring to FIG. 21, the partition 270 forms an outer peripheral branch flow path 278a and an inner peripheral branch flow path 278b in the shunt pipe. A detection element 281 is attached to the bottom wall of the branch pipe via the substrate 280, and is exposed to the flow in the outer peripheral branch flow path 278a. On the wall surface of the partition 270 facing the detection element 281, a venturi 290 is provided from upstream to downstream of the detection element 281. By this venturi 290, the flow path of the outer peripheral branch flow path 278a in which the detection element 281 is disposed is the narrowest in the vicinity of the center of the detection element 281 (this is referred to as “the narrowest portion N”). Further, a smooth transition is made between the channel surface in the left-right direction in FIG. 21 of the partition 270 (the channel surface in the direction perpendicular to the main flow M (see FIG. 20)) and the channel surface on the venturi 290.
[0063]
【The invention's effect】
According to the present invention, there is provided a measuring device relating to a flow in which the accumulation of contaminants on the detection element is prevented. Moreover, according to this invention, the measuring apparatus regarding the flow which can measure a backflow similarly to a forward flow is provided.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a measuring apparatus according to a first embodiment of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 2 is a partially enlarged view in which the vicinity of the inlet 5 of the flow dividing pipe 2 shown in FIG. 1 is enlarged.
FIG. 3 is a partially enlarged operation view in which the vicinity of the inlet 5 of the flow dividing pipe 2 shown in FIG. 1 is enlarged.
FIG. 4 is a partially enlarged view in which the vicinity of a diversion pipe inlet is enlarged in order to explain each of the apparatuses according to Embodiment 2 of the present invention.
FIG. 5 is a partially enlarged view in which the vicinity of a diversion pipe introduction port is enlarged in order to explain each of apparatuses according to Embodiment 3 of the present invention.
FIG. 6 is a partially enlarged view in which the vicinity of a diversion pipe introduction port is enlarged in order to explain each of the apparatuses according to Embodiment 4 of the present invention.
FIGS. 7A and 7B are explanatory views of a flow measuring apparatus according to Embodiment 5 of the present invention, FIG. 7A is a longitudinal section along the axial direction of a mainstream pipe, and FIG. A cross-section BB in A) is shown.
FIGS. 8A and 8B are explanatory views of an apparatus according to Embodiment 6 of the present invention, in which FIG. 8A is a partially enlarged cross-sectional view of the vicinity of the outer wall of the shunt flow path and one end of the introduction plate (B shows a cross section parallel to the flow cross section of D), and (B) is a cross section orthogonal to (A).
FIGS. 9A to 9C are partial enlarged views showing the vicinity of an orifice that bypasses the branch pipe inlet and the outlet for sequentially explaining the apparatuses according to the seventh to ninth embodiments of the present invention, respectively. FIGS. .
10 is an explanatory diagram of a measuring apparatus according to Comparative Example 1, and shows a longitudinal section along the axial direction of the mainstream pipe. FIG.
11 is a graph showing a flow rate characteristic of the apparatus according to Comparative Example 1 shown in FIG.
FIG. 12 is a diagram showing a device according to the fifth embodiment described with reference to FIGS. 7A and 7B again.
13 is a graph showing the flow characteristics of the apparatus according to Example 5 shown in FIG.
FIG. 14 is an explanatory diagram of a measuring apparatus according to Embodiment 10 of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 15 is an explanatory view of a measuring apparatus according to an eleventh embodiment of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 16 is an explanatory diagram of a measuring apparatus according to a twelfth embodiment of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 17 is an explanatory diagram of a measuring apparatus according to Embodiment 13 of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 18 is an explanatory diagram of a measurement apparatus according to Embodiment 14 of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 19 is an explanatory diagram of a measurement apparatus according to Embodiment 15 of the present invention, and shows a longitudinal section along the axial direction of a mainstream pipe.
FIG. 20 is an explanatory diagram of a measurement apparatus according to Embodiment 16 of the present invention, and shows a longitudinal section along the axial direction of the mainstream pipe.
FIG. 21 is an explanatory diagram of a measurement apparatus according to Embodiment 17 of the present invention, and is a partially enlarged view in the vicinity of a detection element.
[Explanation of symbols]
1 Main pipe
2 Shunt pipe
3 Outer wall (housing) of shunt pipe
3a, 3b ridge
4 Introduction plate (main separator)
5 introduction port
6 Outlet
7 partition
7a Protruding part
8a, 8b Branch flow path
10 Board (circuit board, control board)
11 Detection element
12, 13, 14 Concavity and convexity
20 Shunt pipe
23 Outer wall of shunt pipe
23a, 23b ridge
24 Introduction plate (main separator)
25 Inlet
26 Outlet
27 Partition
27a Protrusion
28a, 28b Branch flow path
29 Top outer wall
30 Board (circuit board, control board)
31 Detection element
32, 33 Concavity and convexity
34 Bypass channel
35 Orifice member
40, 42, 44 Top outer wall
40a, 42a, 44a Projection
41, 43, 45 Introduction plate
41a Protrusion
43a, 45a One end of the introduction plate
92 Shunt pipe
93 Outer wall of shunt pipe
93a, 93b ridge
94 Introduction plate (main separator)
95 Introduction port
96 Outlet
97 partition
97a Protruding part
98a, 98b Branch flow path
99 Top outer wall
99a Protrusion
100 board (circuit board, control board)
101 Detection element
104 Orifice
112 Shunt pipe
113 Outer wall of shunt pipe
113a, 113b protuberance
114 Introduction plate (main separator)
115 Introduction
116 Outlet
119 Top outer wall
118a, 118b, 118c Branch flow path
120 board (circuit board, control board)
121 Detection element
122, 123 undulations
124 Bypass channel
137,138 Multiple partitions
137a Projection
142 shunt pipe
143 Shunt pipe outer wall
143a, 143b ridge
144 Introduction plate (main separator)
145 introduction
146 Outlet
147 divider
147a protrusion
148a, 148b Branch flow path
150 board (circuit board, control board)
151 detecting element
152,153 undulations
162 Shunt pipe
163 Outer wall of shunt pipe
163a, 163b ridge
164 Introduction plate (main separator)
164a Expanding part
165 introduction port
166 Outlet
167 partition
167a Protrusion
168a, 168b Branch flow path
169 Top outer wall
170 Board (circuit board, control board)
171 Detection element
172,173 undulations
174 Bypass channel
182 Shunt pipe
183 Shunt pipe outer wall
184 Introduction plate (main separator)
184a Protrusion
185 introduction port
186 outlet
187 divider
188a, 188b Branch flow path
189 Top outer wall
191 Detection element
192, 193 Concavities and convexities
194 Bypass channel
202, 203 undulations
222 Shunt pipe
223 Outer wall of shunt pipe
223a, 223b ridge
224 Introduction plate (main separator)
224a protrusion
225 introduction port
226 Outlet
227 divider
227a protrusion
228a, 228b Branch flow path
230 substrates
231 sensing element
232,242 Concavity and convexity
250 Venturi
270 divider
278a, 278b Branch flow path
280 substrate
281 Detection element
290 Venturi
M mainstream
D Shunt
D1 Flow flowing into multiple branch channels
D2 Flow through bypass channel
DW downflow
P Contaminants (particulate matter, PM)
L Distance between the partition end and the opening inner wall on the partition side of the inlet
H1 The height at which the undulations protrude from the channel surface defining the branch channel formed on the partition
H2 The height at which the undulations protrude from the channel surface defining the branch channel formed on the partition
W1 Flow cross-sectional direction diameter W1 of the bypass channel
W2 Orifice diameter
N narrowest part

Claims (24)

A flow dividing pipe having a flow dividing pipe basically curved in a U-shape into which a flow in a main flow pipe to be detected is introduced;
An inlet of the branch pipe formed on the outer peripheral side of the branch pipe and opening in a plane substantially orthogonal to the flow direction in the main pipe;
A partition formed in the flow dividing pipe;
A plurality of branch flow passages divided and formed by the partition so as to branch and merge with each other in the branch pipe;
A detection element that is disposed so as to be exposed to the flow in the branch flow path formed on the outer peripheral side of the branch pipe among the plurality of branch flow paths, and detects a quantity related to the flow;
An apparatus for measuring a flow characterized by comprising: The inlet of the diversion pipe and the inlet of the outer peripheral branch flow path in which the detection element is arranged are opened at surfaces that are basically orthogonal to each other, and the flow introduced into the diversion pipe is redirected. The flow measuring device according to claim 1, wherein the flow measuring device flows into the branch flow path. The end of the partition does not extend directly under the inlet of the flow dividing pipe,
The flow measuring device according to claim 1, wherein at least an inlet of the outer peripheral branch flow path is not opened immediately below an inlet of the branch pipe. The flow measuring device according to claim 1, wherein a restriction is formed in a flow path between an inlet of the branch pipe and an inlet of the outer peripheral branch flow path. An introduction plate is provided for forming the curved branch pipe in the branch pipe;
5. The flow measuring device according to claim 4, wherein the throttle is defined by a undulation formed on one or more of the inner wall of the flow dividing pipe, the partition, and the introduction plate. 6. The flow measuring device according to claim 5, wherein the undulation portion formed on the inner side of the outer wall of the branch pipe protrudes from the inner peripheral flow path surface in the vicinity of the inlet of the outer peripheral branch flow path. An introduction plate is provided for forming the curved branch pipe in the branch pipe;
2. The flow-related measuring device according to claim 1, wherein a flow path surface having a concave curved surface is formed by undulating an inner peripheral flow path wall forming the flow diversion pipe below the inlet of the flow diversion pipe. . 2. The flow measuring apparatus according to claim 1, wherein the flow dividing pipe has a flow path structure that is basically symmetrical about the detection element. The flow measuring device according to claim 1, wherein a restriction is formed in a flow path between the outlet of the branch pipe and the outlet of the outer branching flow path. An introduction plate is provided for forming the curved branch pipe in the branch pipe;
10. The flow measuring device according to claim 9, wherein the restriction is defined by a undulation formed on one or more of the inner wall of the flow dividing pipe, the partition, and the introduction plate. 11. The flow measuring device according to claim 10, wherein the undulation portion formed on the inner side of the outer wall of the branch pipe protrudes from the inner peripheral side flow path surface in the vicinity of the outlet of the outer peripheral branch flow path. Restrictions are respectively formed in the flow path between the inlet of the branch pipe and the inlet of the outer branching channel, and in the flow path between the outlet of the branch pipe and the outlet of the outer branch branch. Was it,
The flow measuring device according to claim 1, wherein the shunt pipe has a substantially “Ω” shape by the restriction. The outlet of the branch pipe is formed on the outer peripheral side of the branch pipe so as to open on a surface substantially orthogonal to the flow direction in the main pipe facing the inlet of the branch pipe,
An introduction plate is provided for forming the curved branch pipe in the branch pipe;
2. A flow measuring device according to claim 1, wherein a bypass flow path for short-circuiting the inlet and outlet of the branch pipe is formed between one end of the inlet plate and the top outer wall of the branch pipe. . An orifice is provided in the bypass channel,
The flow measurement device according to claim 13, wherein the flow rate of the measurement fluid toward the detection element is set by the amount of protrusion of the flow path wall forming the orifice or the orifice opening area. 15. The flow path wall forming the orifice is protruded toward the center of the orifice, and the cross-sectional shape of the flow path surface of the protruding portion is any one of a polygonal surface, a curved surface, and a complex curved surface. Measuring device for the described flow. The flow measuring device according to claim 1, further comprising a flow control unit that is provided in the branch flow path in which the detection element is disposed and forms a flow that strikes the detection surface of the detection element obliquely. On the wall surface of the partition facing the detection element, a venturi is provided from the upstream side to the downstream side of the detection element. 2. The flow measuring device according to claim 1, wherein the measuring device is narrowest in the vicinity. A flow dividing pipe having a flow dividing pipe basically curved in a U-shape into which a flow in a main flow pipe to be detected is introduced;
A partition formed in the flow dividing pipe;
A plurality of branch flow passages divided and formed by the partition so as to branch and merge with each other in the branch pipe;
A detection element that is arranged to be exposed to the flow in the branch flow path formed on the inner peripheral side or the middle part of the branch pipe among the plurality of branch flow paths,
A restriction formed in a flow path between the inlet of the branch pipe and the inlet of the branch flow path where the detection surface of the detection element is exposed to the flow;
An apparatus for measuring a flow characterized by comprising: 19. The flow measuring apparatus according to claim 18, wherein the detection element is provided in the partition. A flow dividing pipe having a flow dividing pipe basically curved in a U-shape into which a flow in a main flow pipe to be detected is introduced;
An inlet of the diversion pipe formed on the outer peripheral side of one end of the diversion pipe and opening in a plane substantially perpendicular to the flow direction in the main flow pipe;
An outlet of the branch pipe formed at the top of the other end of the branch pipe and opening in a plane substantially parallel to the flow direction in the main pipe;
A partition formed in the branch pipe, one end of which extends to the vicinity of the inlet, and the other end of the partition extending away from the outlet;
A plurality of branch flow passages divided and formed by the partition so as to branch and merge with each other in the branch pipe;
A detection element that is disposed so as to be exposed to the flow in the branch flow path formed on the outer peripheral side of the branch pipe among the plurality of branch flow paths, and detects a quantity related to the flow;
An apparatus for measuring a flow characterized by comprising: An introduction plate is provided for forming the curved branch pipe in the branch pipe;
In the vicinity of the inlet of the diversion pipe, a undulation is formed on one or more of the inner wall of the diversion pipe, the partition and the introduction plate, and the undulation causes the introduction of the diversion pipe and the outer peripheral branch. 21. The flow measuring device according to claim 20, wherein a restriction is formed in the flow path between the flow path inlet and the flow path inlet. A flow dividing pipe having a flow dividing pipe basically curved in a U-shape into which a flow in a main flow pipe to be detected is introduced;
A partition formed in the flow dividing pipe;
A plurality of branch flow passages divided and formed by the partition so as to branch and merge with each other in the branch pipe;
A detection element that is arranged to be exposed to a flow in any one of the plurality of branch channels, and detects an amount related to the flow;
The flow introduced into the diversion pipe is redirected so that the detection element flows into the branch flow path exposed to the flow, between the inlet of the diversion pipe and the inlet of the branch flow path. A restriction formed in the flow path;
An apparatus for measuring a flow characterized by comprising: A flow dividing pipe having a flow dividing pipe basically curved in a U-shape into which a flow in a main flow pipe to be detected is introduced;
An inlet of the diversion pipe formed on the outer peripheral side of one end of the diversion pipe and opening in a plane substantially perpendicular to the flow direction in the main flow pipe;
Formed on the outer peripheral side of the other end of the diversion pipe, the outlet of the diversion pipe opening in a plane substantially orthogonal to the flow direction in the main flow pipe, and a partition formed in the diversion pipe,
A plurality of branch flow passages divided and formed by the partition so as to branch and merge with each other in the branch pipe;
A detection element that is disposed so as to be exposed to the flow in the branch flow path formed on the outer peripheral side of the branch pipe among the plurality of branch flow paths, and detects a quantity related to the flow;
Restrictions formed in the flow path between the inlet of the branch pipe and the inlet of the outer branching channel, and in the flow path between the outlet of the branch pipe and the outlet of the outer branch When,
Provided on the wall surface of the partition facing the detection element so that the flow path of the branch flow path in which the detection element is arranged is narrowest near the center of the detection element from upstream to downstream of the detection element. With the venturi
An apparatus for measuring a flow characterized by comprising: Measuring device according to the flow of any one of claims 1 to 23, characterized in that installed in an intake system of an internal combustion engine mounted on a vehicle.

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