JP2000213974A - Heating resistance type flow measurement device and internal combustion engine control device - Google Patents

Abstract

(57) [Summary] (Modifications) [Problem] To provide a heating resistance type flow rate measuring device that minimizes the influence of intake pulsation and backflow and that can obtain accurate measurement even in a small-diameter main passage. To provide. SOLUTION: An opening 101 in which a bypass type sub-passage 5 is opened in a plane perpendicular to a main flow direction 8 in an intake pipe 7.
And a first flow path 10 extending substantially parallel to the main flow direction 8 from the inlet opening 101 and inside which the heating resistor 1 is installed.
2. A detour channel 103 for reversing the flow from the main flow direction 8 in the opposite direction, extending from the detour channel 103 in parallel with the first flow channel 102 and substantially parallel to the direction opposite to the main flow direction 8. A second flow path 104 that guides the flow through the second flow path 104, and an outlet opening 105 that opens on both sides of the second flow path 104 in a direction substantially perpendicular to the main flow direction 8. A device in which a resistor 1 is provided to measure a flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate measuring apparatus using a heating resistor as a detecting element, and more particularly to a flow rate measuring apparatus suitable for measuring a flow rate when the flow rate has a large pulsation such as an intake air flow rate of an internal combustion engine. About.

[0002]

2. Description of the Related Art In recent years, in the case of internal combustion engines such as gasoline engines, measurement of intake air flow rate has become almost indispensable for controlling fuel supply from the viewpoint of exhaust gas pollution and energy saving. It can be said that an engine control device having an intake air flow meter is dominant.

One type of measuring device used for measuring the fluid flow rate is a heating resistor type flow rate measuring device, which is widely used for engine control because of its excellent responsiveness and high reliability. ing.

A characteristic of a general internal combustion engine is a pulsation of the intake air flow rate. For this reason, as a heating resistor type flow rate measuring device, a sub-passage system (a sub-passage system using a sub-passage to reduce the influence of pulsation) is used. A heating resistor type flow rate measuring device of the bypass type) has been conventionally used.

Also, in this sub-passage type heating resistor type flow rate measuring device, for example, in Japanese Patent Application Laid-Open No. Hei 8-5427, the sub-passage is integrated with a part of a flow rate measuring circuit module to form a heating resistor type air flow measuring device. For example, in Japanese Patent Publication No. 4-75385, the air passage by the sub passage is smaller than the length of the sub passage member in the main flow direction. Each has proposed a technology to increase the overall length of the.

[0006]

In the above prior art, it cannot be said that sufficient consideration has been given to improving the performance of the sub-passage type heating resistor type flow rate measuring device, and the sub-passage is further shortened to reduce the influence of pulsation. There has been a problem that the user is still dissatisfied with the point that it is further promoted and that the mountability to an intake pipe or the like is further improved.

For example, in the prior art disclosed in Japanese Patent Application Laid-Open No. H8-5427, the sub-passage itself is made shorter,
The reduction of the output error caused by the pulsation is not sufficiently considered, and the prior art disclosed in Japanese Patent Publication No. 4-75385 cannot be said that the sub-passage itself is sufficiently short. It cannot be said that the attachment to an intake pipe or the like is sufficiently considered.

A sub-passage shape capable of reducing a flow rate measurement error caused by a pulsating flow generated by an internal combustion engine or the like, and a measurement of an intake air flow rate in an intake pipe having a very small diameter which is found in a small displacement vehicle or the like, or In order to obtain a heating resistance type flow measurement device capable of measuring even the amount of secondary air and EGR, the following problems must be solved.

(1) The total length of the flow passage is made longer than the distance between the entrance and the exit of the sub passage viewed in the main flow direction, and the height of the sub passage is reduced in the insertion direction of the sub passage. (2) Use a passage structure that prevents backflow. (3) To increase the air flow velocity inside the sub-passageway and obtain a stable flow without variation. (4) The projecting length of the structure is suppressed outside the main passage to reduce the height.

[0010] The present invention has been made in view of these problems, and an object thereof is to minimize the influence of intake air pulsation and backflow, and to perform accurate measurement even in a small-diameter main passage. An object of the present invention is to provide a heating resistance type flow rate measuring device which can be obtained.

[0011]

The above object is achieved by taking the following measures. (1) Open the sub passage on a plane perpendicular to the main flow direction of the main passage,
A first flow path substantially parallel to the main flow direction, a bypass at the downstream end thereof, a second flow path that guides the flow in a direction substantially opposite to the main flow direction in a flow path substantially parallel to the first flow path, and a second flow path. A bypass type sub-passage having an outlet opening that merges in a direction substantially perpendicular to the main flow direction.

The outlet opening may be divided into two parts in the direction perpendicular to the direction in which the sub-passage is inserted into the intake pipe and may be opened, or the cross-sectional shape of the first flow path provided with the heating resistor may be substantially semicircular. In order to further reduce the height, measures such as shortening in the direction of inserting the sub-passage into the intake pipe and lengthening in the direction perpendicular to the direction of inserting the sub-passage into the intake pipe further reduce the height, Improved wearability.

[0013] Furthermore, by arranging the inlet opening and the outlet opening so as to overlap each other in the insertion direction of the auxiliary passage, the flow can be reduced, and the area of the second flow passage and the outlet opening can be increased. did.

(2) The component of the bypass sub-passage located downstream from the outlet opening is different from the component of the bypass sub-passage located upstream from the outlet opening in a stepped or rounded bulge. With this configuration, the structure is such that backflow is less likely to enter from the outlet opening.

(3) The flow rate in the heating resistor portion is increased by adopting the contraction flow structure. Or, it was configured wider than the second flow path. Further, a rectifying guide was provided at a branch point toward the outlet opening.

(4) The electronic circuit and the circuit module are arranged outside the main passage substantially parallel to the main flow direction, and the sub-passage is attached to the bottom of the circuit module to form a T-shape as a whole from the front.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heating resistance type flow rate measuring apparatus according to the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 shows a first embodiment of the present invention, in which 1 is a heating resistor, 2 is a temperature-sensitive resistor, and in this embodiment, these heating resistor 1 and temperature-sensitive resistor 2 are It is attached to the terminal wire 3 and is electrically connected to the electronic circuit 4. Next, reference numeral 5 denotes a bypass type sub-passage.
Are mounted on a case member 6 which also serves to hold the terminal wire 3 and protect the electronic circuit 4.

Reference numeral 7 denotes an intake pipe constituting a main passage. The intake pipe 7 constitutes a part of an intake air passage of an engine.
The air to be measured is circulated in the main flow direction indicated by the arrow 8 therein.
While being held by the case member 6, it is inserted into the intake pipe 7 through a hole provided in the side wall of the intake pipe 7 as shown in the drawing.

In the bypass type sub-passage 5, first, an inlet opening 1 opened in a plane perpendicular to the main flow direction 8 in the intake pipe 7.
01 and a first flow path 1 which extends from the inlet opening 101 substantially in parallel with the main flow direction 8 and in which the heating resistor 1 is installed.
02, a bypass flow path 103 for reversing the flow from the main flow direction 8 in the opposite direction is formed.

Further, in the bypass type sub-passage 5, a parallel flow from the bypass flow passage 103 to the first flow passage 102 and the main flow direction 8
A second flow path 104 extending substantially parallel to the opposite direction to guide the flow, and an outlet opening on both sides of the second flow path 104 in a direction substantially perpendicular to the main flow direction 8 A portion 105 is formed.

Therefore, a part of the air flowing into the intake pipe 7 along the main flow direction 8 flows from the inlet opening 101 through the arrow 8.
-1 flows into the first flow path 102 as shown by -1 and passes through the bypass flow path 103 as shown by the arrow 8-2.
4 through the outlet openings 105 on both sides, flows out of the sub-passage 5 as indicated by arrows 8-5, and merges with the air in the intake pipe 7.

As a result, the flow of the air in the first flow path 102 is averaged, and the influence of the pulsation of the flow rate in the intake pipe 7 on the measurement of the flow rate by the heating resistor 1 and the temperature-sensitive resistor 2 is suppressed. Accurate flow rate measurement can be obtained. At this time, the longer the air flow passage formed by the sub-passage 5, the stronger the above-mentioned averaging action can be obtained.

However, according to this embodiment, the outlet opening 105 is, as apparent from FIG.
4 are opened at right angles to the main flow direction 8 on both sides of the main flow direction 4, and by diverting the air flowing through the second flow path 104 to both sides, the length of the outlet in each main flow direction can be set to a required outlet. It can be reduced while securing the area,
The second flow path 104 can be made long, and as a result, a sufficient length of the auxiliary passage 5 can be easily obtained without increasing the size of the apparatus.

In this embodiment, as shown in FIG. 2, the first passage 102 and the second passage 103 forming the sub passage 5 are inserted in the sub passage 5 in a direction perpendicular to the main flow direction 8. , The size of the detour type sub-passage 5 shown in the drawing as the flow path installation range in the inner diameter direction of the intake pipe 7, that is, the so-called low profile can be sufficiently obtained. As a result, the present invention can be easily applied to a small-output internal combustion engine having a small-diameter intake air pipe.

This will be described more specifically with reference to FIGS. 16 and 17 and FIG. 3. First, FIG.
17 is applied to an intake pipe 9 having a smaller diameter than the intake pipe 7, and FIG. 17 is an embodiment applied to an elliptical intake pipe 10. Next, FIG.

In the first embodiment, the first flow path 102
In the detour direction from the flow path to the second flow path 104, that is, the detour flow path 10
3 is the same as the insertion direction of the sub-passage 5 into the intake pipe 7 (as viewed from top to bottom in FIG. 3), as is apparent from the AA cross-sectional view of FIG. 7
It is branched in two directions on both sides in a direction perpendicular to the main flow direction 8 in the inside and also in a direction perpendicular to the insertion direction of the sub-passage 5.

The reason why the outlet opening 105 is opened at right angles to the direction in which the sub passage 5 is inserted into the intake pipe 7 is that the sub passage 5 has a small diameter as shown in FIGS. When the measurement is performed by inserting into various intake pipes such as the intake pipe 9 or the elliptical intake pipe 10, the clearance W from the outlet opening 105 to the wall of the intake pipe is larger than the clearance H in the auxiliary passage insertion direction. , So that it can be large.

That is, according to this embodiment, the relation between the clearance W and the clearance H is easily expressed as W> H.
As a result, the interference between the air flowing out of the outlet opening 105 and the inner wall surface of the intake pipe (9 or 10) can be sufficiently suppressed, and the interference with the small-diameter intake pipe can be achieved. Also, there is no fear that the flow velocity of the air flowing through the inside of the sub-passage decreases, and good measurement accuracy can always be maintained.

As described above, according to the first embodiment of the present invention, the height of the auxiliary passage can be sufficiently reduced.
It can be easily applied to extremely small diameter intake pipes found in small displacement engine cars, etc., and enables highly accurate intake flow rate measurement.

Next, according to the detour type sub-passage structure according to the first embodiment, a flow rate measurement error caused by the engine pulsation flow can be further reduced. The measurement error due to the influence of the pulsation will be described.

The air flowing through the intake pipe of the engine becomes a pulsating flow in accordance with the opening and closing of the intake valve of the engine. The magnitude of the pulsation at this time depends on the throttle valve of the engine.
When the opening of the (throttle valve) is small, it is relatively small, increases as the opening of the throttle valve increases, and further increases as the suction flow rate increases. When the pulsation increases to some extent, a negative error occurs due to the non-linear characteristic of the flow rate measurement by the heating resistor and the response delay characteristic of the heating resistor itself.

If the pulsation amplitude further increases, the flow will be accompanied by a backflow in the intake pipe. However, it is difficult to detect the flow direction by the heating resistor because of its structure. Since the forward flow or the backward flow is simply detected as a flow velocity, when a back flow occurs, the heating resistor also detects the reverse flow as a flow velocity, and as a result, a plus error occurs.

These positive and negative output errors further attenuate the intake pulsation reaching the inside of the sub-passage, and have a structure in which even if a backflow occurs, the backflow does not enter the inside of the sub-passage. Can be reduced.

This can be achieved by increasing the inertia of the airflow flowing inside the sub-passage. Specifically, the distance between the entrance and exit of the sub-passage in the main flow direction is increased. It is most effective to make the overall length longer.

That is, the bypass type sub-passage structure according to the first embodiment of the present invention can be said to be an ideal passage structure for reducing the height of the sub-passage and reducing the flow rate measurement error due to the influence of the pulsating flow.

Next, a second embodiment of the present invention will be described.
This will be described with reference to FIG. In the embodiment of FIG. 4, as shown in the drawing, the inlet opening 101 and the outlet opening 105 are overlapped with each other in the direction in which the auxiliary passage 5 is inserted into the intake pipe 7, that is, the direction perpendicular to the main flow direction 8 as shown in the drawing. The other configuration is the same as that of the embodiment of FIG. 1, and therefore, the illustration of the intake pipe 7 is omitted.

In the embodiment of FIG. 4, while the height of the auxiliary passage 5 is reduced, the flow is further restricted in the flow path portion where the heating resistor 1 is present, so that the air flow velocity is increased in this portion. Variations in the detection signal of the air flow rate are reduced.

FIG. 5 shows a specific structure of the bypass type sub-passage 5 in the second embodiment.
As is clear from the cross-sectional view taken along the line -B, the cross-sectional dimensions of the first flow path 102 in which the heating resistors 1 are arranged are as follows: a dimension H in the sub-passage insertion direction indicated by an arrow and a dimension W in a direction perpendicular thereto. , W> H, and the cross section of the first flow path 102 is formed in a shape close to a semicircle, whereby the portion where the heating resistor 1 is disposed is formed. The aperture effect can be further increased.

Next, FIG. 6 shows a third embodiment of the present invention. In this embodiment, the height of each of the flow paths forming the sub-passage 5 is such that the bypass flow path 103 is the highest. It was made. In FIG. 6, the illustration of the intake pipe 7 is omitted.

In the case of the bypass type sub-passage system, the bypass portion has the largest airflow resistance in the sub-passage 5. Therefore,
In the embodiment of FIG. 6, the height of the bypass flow path 103 is made larger than the other flow paths, thereby reducing the ventilation resistance of the entire sub-passage 5 and increasing the air flow rate. Variations are further suppressed.

Next, FIG. 7 shows a fourth embodiment of the present invention.
This embodiment includes a rectifying guide 106 for smoothly branching the flow from the second flow path 104 to the outlet opening 105, as is apparent from the cross-sectional view taken along the line CC in FIG.
The rectifying guide 106 is provided in the second flow path 1.
It prevents the air flow passing through the wall from colliding perpendicularly to the wall surface, and works so that there is no high pressure part near the outlet opening 105.

If a high-pressure portion exists in the sub-passage 5, the flow near the outlet opening 105 becomes poor, and the flow velocity of the entire sub-passage 5 decreases. The decrease is suppressed, and as a result,
Since the flow velocity of the air flowing through the inside is increased, variation in the air flow signal, that is, output noise is reduced, and accurate flow detection can be obtained.

FIG. 8 is a front view showing a fifth embodiment of the present invention. In the embodiment of FIG. 8, an electronic circuit 4 (not shown) is provided, and a drive circuit module 60 for protecting the electronic circuit 4 is disposed outside the intake pipe 7. And drive circuit module 6
0 is substantially parallel, that is, it is arranged so as to be a flat horizontal type outside the intake pipe 7.

Then, on the bottom surface of the drive circuit module 60, the drive circuit module 60 is set at a predetermined position in the intake pipe 7.
A bypass sub-passage 5 is attached, whereby the entire device is configured to be T-shaped in a direction perpendicular to the cross section of the intake pipe 7, that is, when viewed from the front.

Therefore, according to the embodiment of FIG. 8, the height of the flow measurement device can be reduced not only inside the intake pipe 7 but also outside the intake pipe 7. For example, the flow measurement device can be installed in the engine room of an automobile. Therefore, even when the space that can be secured is small, such as when installing the camera, the degree of freedom of the mounting position can be increased.

Next, FIG. 9 shows a sixth embodiment of the present invention. As shown in the sectional view taken along the line DD of FIG. Exit opening 1
Bulges 108 and 109 at portions located downstream of
Is provided.

The bulges 108 and 109 are formed so as to bulge to the downstream side with a step from immediately downstream of the outlet opening 105, and thereby, for example, the intake pipe of the internal combustion engine is formed. Even if a backflow occurs, the backflow is prevented from entering the sub-passage 5. As a result, according to this embodiment, the error included in the air flow signal at the time of the backflow can be minimized.

Next, FIG. 10 shows a seventh embodiment of the present invention. In contrast to the upper sectional side view, the lower figure is a plan view of the auxiliary passage 5 viewed from the lower side. The circular dashed line indicates the insertion hole 11 of the sub passage 5 formed in the intake pipe 7.

In the embodiment shown in FIG. 10, the bypass sub-passage 5 has an outer shape in which the upstream end face 5A and the downstream end face 5B in the main flow direction have rounded cylindrical faces when viewed from the bottom. . At this time, the shape of each of the end faces 5A and 5B is further characterized in that the shape is in conformity with the shape according to the insertion hole 11.

As a result, according to the embodiment shown in FIG. 10, the length of the bypass sub-passage by the sub-passage 5 is increased by each end face 5A,
By the bulging of 5B, the size limited by the insertion hole 11 can be secured as long as possible, so that the flow measurement error due to the pulsating flow can be reduced by that much, and the end faces 5A, 5
The swelling of B works to make the shape of the sub passage 5 close to a streamline with respect to the main flow in the intake pipe 7, so that the pressure loss in the intake system can be reduced.

Next, FIG. 11 shows an eighth embodiment of the present invention.
02 is composed of two parts. When trying to mold the bypass type sub-passage 5 with a resin mold, there may be a part that cannot be removed from the mold.

Therefore, in the embodiment shown in FIG. 11, the sub-passage 5 is
It consisted of individual parts. In addition, as a method of forming the bypass type sub-passage by these two parts, the second flow path 104
And a method of dividing the auxiliary passage 5 into two parts from the center of the front.

FIG. 12 is an enlarged view of a portion E in the embodiment of FIG. 11, and when a member to be used by being inserted into the intake system such as the sub-passage 5 is constituted by a plurality of parts, the fixing between the parts is ensured. If you don't do this,
There is a possibility of getting caught on a throttle valve etc. and leading to a serious accident.

Therefore, in this embodiment, as shown in FIG. 12, a spherical convex portion 203 is provided on the back plate 202, and the convex
3 is provided so as to be positioned at a regular position by entering the flow passage member 201.
And the back plate 202 are positioned and fixedly attached by a push-fit mechanism that fits by utilizing the elasticity of the resin.

Further, in this embodiment, as is apparent from FIG. 12, the back plate 202 and the flow path component 2
01 is provided with a groove 205 at the time of fitting, and an adhesive 206 is applied in advance in the groove 205 at the time of fitting.
Thus, a double-system fixing method in which the adhesive fixing by the above method is used is obtained.

Therefore, according to the embodiment shown in FIGS. 11 and 12, the back plate 202 can be reliably prevented from falling off, and the effect of preventing air leakage inside and outside the sub-passage 5 can be obtained. it can.

Next, FIG. 13 shows a ninth embodiment of the present invention, which is different from the embodiments described with reference to FIGS.
A corner rectifying member 207 is provided on the inner surface of the back plate 202.
Is only provided. This corner rectifying member 20
Reference numeral 7 denotes a member for making the bent portion of the detour channel 103 into a shape that requires less airflow resistance, that is, a smooth curved surface shape with no corners, and is integrated with the back plate 202. Note that the inner surface of the back plate 202 may have a curved shape.

In the embodiment shown in FIG. 13, since the corner rectifying member 207 is provided, the ventilation resistance in the bypass passage 103 where the ventilation resistance increases in the auxiliary passage 5 is reduced. It is possible to suppress a decrease in flow velocity as a whole.

FIG. 14 shows a tenth embodiment of the present invention. In the tenth embodiment of the present invention, a flange portion 301 is provided at an end on the inner surface side of the intake pipe 7 in a hole for inserting the auxiliary passage 5 provided in the intake pipe 7. The other configuration is the same as the embodiment of FIG.

This flange portion 301 is formed by
It functions to prevent the bypass type sub-passage 5 formed by combining the back cover 202 and the back plate 202 from dropping into the intake pipe 7. Like the back plate 202,
If the auxiliary passage 5 falls off, it is highly likely that a serious accident will occur. Therefore, it is essential to take measures to prevent the auxiliary passage itself from falling off. However, according to the embodiment shown in FIG.
According to 1, the falling off of the auxiliary passage 5 can be easily and reliably prevented.

Next, FIG. 15 shows an embodiment in which the flow rate measuring device according to the present invention is applied to an internal combustion engine of the electronic fuel injection system. The air 52 is supplied to a suction duct 53,
Throttle body 54 and injector (fuel injection valve)
The air is sucked into a cylinder 57 of the engine through an intake manifold 56 provided with 55. On the other hand, the gas 58 generated in the cylinder 57 of the engine is discharged into the atmosphere via an exhaust manifold 59.

Between the air cleaner 51 and the suction duct 53, the heating resistance type flow measuring device according to the above-described embodiment is provided. The air flow signal output from the drive circuit module 60 and the air flow signal output from the intake air temperature sensor 61 are provided. Temperature signal, a throttle valve angle signal output from a throttle angle sensor 62, an oxygen concentration signal output from an oximeter 63 provided in an exhaust manifold 59, and an engine speed output from an engine tachometer 64. The signals and the intake air pressure signals input from various sensors (not shown) are input to the control unit 65.

Therefore, the control unit 65 receives these signals and sequentially calculates them to obtain an optimum fuel injection amount and an idle air control valve opening, and uses the values to obtain the injector 55 and the idle control valve 66. Is controlled.

At this time, according to the heating resistance type flow rate measuring device according to the above-described embodiment, a highly accurate intake air flow rate signal which is not affected by the pulsation of the engine intake can be obtained. Can do
It is possible to sufficiently promote exhaust gas purification and save energy. Further, at this time, according to the heating resistance type flow rate measuring device according to the above-described embodiment, an effect that it can be easily applied to a small engine can be obtained.

[0065]

According to the present invention, the height of the bypass-type sub-passage can be reduced, that is, the size of the bypass-type sub-passage can be reduced. The flow rate can be measured with high accuracy at all times.

As a result, according to the present invention, it is possible to measure the intake air amount of the engine by applying the present invention to a small-diameter intake pipe or an elliptical intake pipe found in a small-displacement automobile or the like. The present invention can be applied to measurement of the flow rate of the secondary air and the flow rate of the EGR air, and the engine can be controlled with higher accuracy.

Further, according to the present invention, the height of the circuit module can be reduced even outside the main passage, and the size of the entire device can be reduced. The device can be installed, and as a result, a high degree of freedom in installation can be obtained even in an engine room where the use is further expanded and the engine room becomes overcrowded.

Further, according to the present invention, since a high-precision flow measuring device having a bypass type sub-passage can be easily obtained, it is possible to reduce the influence of, for example, intake pulsation or backflow caused by an internal combustion engine. As a result, it is possible to reduce the flow measurement error caused by these, and therefore, it is not necessary to correct the air flow signal having the error inside the drive circuit module or the control unit, which further increases the system cost of the intake system. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a heating resistance type flow rate measuring device according to the present invention.

FIG. 2 is a sectional view showing details of the first embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line AA showing a specific passage configuration according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a sectional view taken along line BB, showing a specific passage configuration according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a third embodiment of the present invention.

FIG. 7 is a cross-sectional view taken along line CC, showing a specific configuration of a passage according to a fourth embodiment of the present invention.

FIG. 8 is a front view showing a fifth embodiment of the present invention.

FIG. 9 is a cross-sectional view taken along line DD, showing a specific configuration of a bypass passage in a sixth embodiment of the present invention.

FIG. 10 is a sectional view and a plan view showing a seventh embodiment of the present invention.

FIG. 11 is a sectional view showing an eighth embodiment of the present invention.

FIG. 12 is an enlarged view of a portion E according to an eighth embodiment of the present invention.

FIG. 13 is a sectional view showing a ninth embodiment of the present invention.

FIG. 14 is a sectional view showing a tenth embodiment of the present invention.

FIG. 15 is an explanatory diagram showing an embodiment of an internal combustion engine control device using the heating resistor type flow rate measuring device according to the present invention.

FIG. 16 is a front view showing an example of a mounting state of the present invention.

FIG. 17 is a front view showing another example of the mounting state of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating resistor 2 Temperature sensitive resistor 3 Terminal 4 Electric circuit 5 Detour type sub-passage 5A, 5B Round end surface 6 Case member 7 Main passage 8 Main flow direction 9 Small diameter intake pipe 10 Elliptical intake pipe 11 Insert sub-passage Hole 51 Air cleaner 52 Intake air 53 Intake duct 54 Throttle body 55 Injector 56 Intake manifold 57 Engine cylinder 58 Gas 59 Exhaust manifold 60 Drive circuit module 61 Intake air temperature sensor 62 Throttle angle sensor 63 Oxygen concentration meter 64 Rotational speed meter 65 Control unit 66 Idle Air control valve 101 Inlet opening 102 First flow path 103 Detour flow path 104 Second flow path 105 Outlet opening 106 Rectification guide 108, 109 Swelling part 201 Flow path constituent member 202 Back plate 203 Spherical Protrusions 204 through hole 205 bonding grooves 206 adhesive 207 corner rectifying member 301 flange member

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Chihiro Kobayashi 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Inside the Automotive Equipment Division of Hitachi, Ltd. F term in car engineering (reference) 2F035 AA02 EA03 EA04

Claims (20)

[Claims] 1. A heating resistor for detecting a flow rate of a fluid, an electronic circuit electrically connected to the heating resistor and outputting a signal corresponding to the flow rate of the fluid, and a case for protecting the interior of the electronic circuit. A sub-passage having at least one bent portion is fixed to a circuit module integrated with a member so that the heating resistor is located inside the sub-passage, and the sub-passage is provided in a main passage which is a fluid flow conduit. Is located, wherein the electronic circuit is mounted so as to be located outside the main passage, wherein the sub-passage opens in a plane perpendicular to the main flow direction of the main passage, and is substantially parallel to the main flow direction. A first parallel flow path, a second flow path that bypasses the downstream end and guides flow in a direction substantially opposite to the main flow direction in a flow path that is substantially parallel to the first flow path, and a main flow direction from the second flow path. Opening outlet that merges almost vertically And a bypass type sub-passage having a portion, wherein the sub-passage length in the sub-passage insertion direction into the main passage is approximately the sum of the lengths of the first flow passage and the second flow passage in the insertion direction, or A heating resistance type flow rate measuring device, wherein the length of the auxiliary passage is made shorter and the length of the sub-passage is reduced. 2. The sub-passage according to claim 1, wherein an outlet of the sub-passage is opened in a plane parallel to the sub-passage insertion direction, and the sub-passage is connected to an upper end of the entrance opening with respect to the sub-passage insertion direction. A heating resistance type flow rate measuring device is formed between the lower end of the outlet opening. 3. The outlet opening according to claim 1, wherein the outlet opening is branched in at least two directions after detouring from the first flow path to the second flow path, and the outlet opening is formed in at least two directions. An exothermic resistance type flow rate measuring device which is divided and arranged at two or more locations. 4. The bypass passage according to claim 1, wherein an inlet opening and an outlet opening of the bypass sub-passage overlap with each other in a direction in which the sub-passage is inserted into the main passage. An exothermic resistance type flow rate measuring device, characterized in that it is arranged in a vertical position. 5. The cross-sectional shape perpendicular to the flow direction of the first flow path, the second flow path, or both flow paths, in which the heating resistor is arranged, according to claim 1, wherein A heating resistance type flow rate measuring device characterized in that it is short in the direction in which the sub-passage is inserted into the main passage and is long in the direction perpendicular to the direction in which the sub-passage is inserted into the main passage. 6. The cross-sectional area of each of the flow paths constituting the sub-passage according to claim 1, wherein a cross-sectional area of each of the flow paths constituting the sub-passage is larger than that of the first flow path and the second flow path in the main flow direction. Wherein the bypass flow path that guides the flow in the vertical direction is wider than the other. 7. The heating resistance type flow rate measuring device according to claim 1, wherein the bypass direction of the sub-passage is a direction in which the sub-passage is inserted into the main passage. . 8. The heating element according to claim 1, wherein the first flow path of the sub-passage controls a flow rate of the heating resistor portion from the entrance opening toward the heating resistor installation portion. An exothermic resistance type flow rate measuring device, characterized in that the flow rate is increased. 9. The method according to claim 1, wherein a fluid is smoothly guided from the inside of the second flow path to the outlet opening near the outlet opening of the second flow path. A heat-generating resistance type flow rate measuring device characterized by providing a rectifying guide. 10. The flow path according to claim 8, wherein a lower end surface of the inlet opening is tapered toward a downstream side of the first flow path, and the heating resistor portion of the first flow path is a narrowest part of the flow path. A heating resistance type flow rate measuring device characterized in that the flow rate measuring device is configured so as to have a contraction structure so as to be a maximum flow velocity portion in a flow path. 11. The outlet according to claim 9, wherein the rectifying guide divides the second flow path into two parts in a direction parallel to a direction in which the auxiliary path is inserted into the main path, that is, in a vertical direction, and opens at two positions on the left and right sides. An exothermic resistance type flow measurement device characterized in that the fluid is smoothly guided toward the opening. 12. The flow path according to claim 10, wherein a cross-sectional shape of the flow path perpendicular to the flow direction in the contraction portion of the first flow path is shorter in a direction in which the auxiliary passage is inserted into the main passage.
The heating resistance type flow rate measuring device is configured to be longer in the direction perpendicular to the direction, wherein the second flow path and the flow path width in the vertical direction with respect to the insertion direction of the sub-passage into the main passage are equal. . 13. The method according to claim 1, wherein:
In the paragraph, the electronic circuit and the circuit module that internally protects the electronic circuit are placed outside the main passage and at a position substantially parallel to the main flow direction of the main passage, and on a bottom surface side of the circuit module. A heating resistance type flow rate measuring device, wherein the bypass-type sub-passage is mounted so as to be positioned in the main passage, so that the entire device is formed in a T-shape from the front. 14. The method according to claim 1, wherein
In the paragraph, the component of the bypass-type sub-passage located downstream of the outlet opening is a stepped or rounded bulge with respect to the bypass-type sub-passage component located upstream of the exit opening. A heating resistance type flow measuring device characterized by having: 15. The method according to claim 1, wherein:
In the paragraph, the outer shape of the bypass type sub-passage has a round shape along the sub-passage insertion hole opened in the main passage at the most upstream and the most downstream end faces in the main passage, and is formed in a streamlined manner. A heating resistance type flow rate measuring device characterized in that: 16. The method according to claim 1, wherein:
In the paragraph, the bypass-type sub-passage is composed of at least two or more resin molded parts. 17. The push-fit mechanism according to claim 16, wherein the bypass sub-passage is formed of two parts, a flow path constituent member and a passage cover, and applies a resin elasticity to prevent the passage cover from falling off. Adhesive 2
An exothermic resistance type flow rate measuring device, wherein a weight fixing method is used. 18. The corner rectifying member according to claim 17, wherein a rounded corner rectifying member is formed in the passage cover so as to form a bend in the bypass passage connecting the first passage to the second passage in a smooth streamline. A heating resistance type flow rate measuring device characterized by being integrally molded. 19. The method according to claim 1, wherein:
The heating resistance type flow rate measuring device according to any one of the preceding claims, further comprising a mechanism for preventing the flow path component from falling off on the side of the main passage. 20. An internal combustion engine control device for controlling an internal combustion engine using any of the bypass type sub-passages according to claim 1. Description: