JP3995386B2 - Intake device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake device, and for example, relates to an intake device that measures an intake flow rate introduced into an engine using a thermal flow meter.
[0002]
[Prior art]
2. Description of the Related Art An intake device that introduces air into an engine such as an automobile uses a thermal flow meter as a flow meter for measuring an intake flow rate. The thermal flow meter senses the flow velocity at a part of the flow path cross section based on the change in the amount of heat transfer from the heating resistor having a smaller physique than the flow path diameter, and measures the entire intake flow rate. Since the thermal flow meter can directly detect the mass of air, there is an advantage that the intake flow rate can be measured with high accuracy.
[0003]
[Problems to be solved by the invention]
Since the thermal flow meter measures even a slight disturbance in the intake flow as a change in the intake flow rate, if disturbance occurs in the intake flow upstream of the thermal flow meter, the output fluctuation increases and the intake flow rate is measured with high accuracy. I can't. In an intake device in which an air cleaner is disposed in the vicinity of the upstream side of the thermal flow meter, it is difficult to measure the intake flow rate with high accuracy because the intake flow tends to be disturbed when passing through the cleaner element.
[0004]
In order to reduce such disturbance of the intake flow, in the intake device disclosed in Japanese Patent Laid-Open No. 7-128107, the outlet pipe 103 of the air cleaner 100 is provided upstream of the thermal flow meter 105 as shown in FIG. A rectifying member 104 for rectifying the intake flow is provided. Here, to rectify the intake flow means to arrange the intake flow flowing in an irregular direction so as to flow in the same direction.
[0005]
However, when the intake air that has passed through the element 101 is bent at a substantially right angle to the element axial direction 101a as in the conventional axial flow type air cleaner 100 disclosed in the above publication, or the flow changes suddenly near the outlet portion 102 of the air cleaner. When the turbulence of the intake air flow that has passed through the air cleaner 100 is large, such as when there is a section (steep bend), the rectifying member 104 provided on the outlet pipe 103 of the air cleaner 100 is difficult to obtain an effect, and the rectification improves the effect. For the member 104, it is necessary to take measures such as providing a large number of rectifying grids. However, since the flow passage area of the outlet pipe 103 of the air cleaner 100 is small, the ventilation resistance increases when the rectifying member 104 described above is provided. Therefore, for example, in an internal combustion engine, there is a problem that the intake flow rate introduced into the engine decreases and the engine output decreases.
[0006]
In view of the above-described points, an object of the present invention is to provide an intake device that can reduce intake flow turbulence on the upstream side of a flow meter without reducing the intake flow rate and can measure the intake flow rate with high accuracy. .
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, according to the intake device of the first aspect of the present invention, the intake air in the cleaner case that is connected to the opening of the cleaner case and passes through each part of the element is combined with the intake air. In an intake system in which a flow meter for detecting an intake flow rate is disposed in an intake duct that forms a bent intake passage so as to guide it in a direction substantially perpendicular to the flow direction of the A rectifying unit that rectifies the flow of intake air that has passed through the element, and the rectifying unit is provided only at an inner position in the bending direction of the intake passage, and has a curved surface having a curved shape along the bending direction ; And a rectifying plate for rectifying the flow of the intake air, and the rectifying plate is formed so as to overlap with the upper surface of the curved surface portion .
[0008]
The turbulence generating portion of the intake air flow mainly includes a portion that merges after passing through each portion of the element, and a connection portion between the cleaner case and the intake duct that suddenly changes the intake air flow in the cleaner case.
[0009]
The rectifying unit arranged at the position described above is rectified at the position where the turbulence of the intake air flow that passes after passing through each part of the element, that is, at the downstream part of the element, and further changes suddenly at the connection part between the cleaner case and the intake duct. It is possible to guide the intake passage in the bending direction without disturbing the intake flow.
[0010]
In other words, the rectifying unit described above rectifies and guides the intake air turbulence at the position immediately after the occurrence of the turbulence, so that the ventilation resistance can be effectively increased despite the arrangement of the resistor as the rectifying unit in the intake passage. Rectifying while suppressing.
[0011]
Therefore, the disturbance of the intake flow passing through the flow meter disposed in the intake duct is reduced, and the intake flow rate can be measured with high accuracy.
[0013]
Further, since the curved surface portion of the rectifying portion is provided only at the inner corner portion in the bending direction of the intake passage and has a curved surface shape along the bending direction, intake air turbulence generated by the inner corner portion is suppressed.
[0014]
In addition, the curved surface portion arranged from the downstream portion of the element to the opening of the cleaner case can smoothly guide the intake air flow in the direction of the intake duct along the curved surface of the element, and rectifies the disturbance of the intake air flow. And, there is an effect of reducing ventilation resistance by reducing intake air turbulence.
[0016]
In addition, since the rectifying part is composed of a curved part and a rectifying plate, and the rectifying plate is formed so as to overlap the upper surface of the curved part, even if the turbulence of the intake air flow is large, the synergistic effect of the curved part and the rectifying plate Thus, it is possible to provide an intake device that has an effect of reducing disturbance of the intake flow and ventilation resistance.
[0017]
According to the intake device of the second aspect of the present invention, the rectifying portion is integrally formed with the intake duct. By integrally molding, there is no joining step between the intake duct and the rectifying unit, and the ventilation resistance is reduced. Moreover, it can be set as the intake device with a reduced cost by reducing the number of parts.
[0018]
According to the intake device of the third aspect of the present invention, the rectifying unit is integrally formed with the cleaner case. By integrally molding, there is no joining step between the cleaner case and the rectifying portion, and the ventilation resistance is reduced. Moreover, it can be set as the intake device with a reduced cost by reducing the number of parts.
[0019]
According to the intake device of the fourth aspect of the present invention, the rectifying unit is integrally formed with the cleaner case and the intake duct. By integrally molding, there is no junction step between the cleaner case and the intake duct and the rectifying unit, and the ventilation resistance is reduced. Moreover, it can be set as the intake device with a reduced cost by reducing the number of parts.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment in which a technology capable of measuring an intake air flow rate with high accuracy in an intake device of the present invention is applied to an intake device for an automobile engine will be described with reference to the drawings.
[0021]
FIG. 1 is a detailed view showing an intake device according to an embodiment of the present invention. The air intake apparatus shown in FIG. 1 shows an example in which a rectifying unit that reduces disturbance of intake air flow is configured by a curved surface part 8 and a rectifying plate 7.
[0022]
Reference numeral 1 denotes an axial air cleaner (hereinafter referred to as an air cleaner), in which a hollow cylindrical element 2 is housed in a cleaner case composed of a resin case body 3 and a case lid portion 4. An intake duct 5 is integrally connected to the air cleaner 1 on the downstream side of the air cleaner 1. A thermal flow meter 6 is provided in the intake duct 5.
[0023]
The air cleaner 1 and the intake duct 5 are connected by integrally molding the case lid portion 4 and the intake duct 5 with a resin material. The downstream side of the intake duct 5 is connected to the engine and forms an intake passage.
[0024]
The intake duct 5 is bent in order to guide the intake flow 11 in the axial direction of the element 2 that has passed through each part of the element 2 (intake flow 10) and merged in a direction substantially orthogonal to the intake flow direction 11. An air intake passage is formed.
[0025]
In the intake device having the above-described configuration, the foreign substance in the intake air is removed by causing the central axis of the element 2 to stand upright, and then the foreign substance is dropped downward without clogging the element. Thereafter, the intake air is bent by the intake duct 5 in a substantially orthogonal direction, so that it can be stored together with the engine in a limited space.
[0026]
Further, the rectifying unit for rectifying the turbulence of the intake air flow of the present invention is constituted by the curved surface part 8 and the rectifying plate 7, and the opening 4A of the case lid part 4 of the air cleaner case and the downstream part 1A of the element 2, that is, the element 2 It is provided between the downstream portion collecting portion where the intake air flow 10 having passed through each portion gathers.
[0027]
When the air cleaner 1 and the intake duct 5 are configured separately, the rectification unit is molded integrally with the air cleaner 1 or the intake duct 5 side, or is rectified to the air cleaner 1 or the intake duct 5 side. The parts are assembled separately so that they do not have ventilation resistance.
[0028]
The curved surface portion 8 is provided at the inner corner portion on the inner peripheral side in the bending direction of the intake passage (in this case, the left direction) in the bent portion 9 of the intake passage described above, and is formed in a curved surface shape along the bending direction.
[0029]
The rectifying plate 7 is provided continuously with the curved surface portion 8, and in the present embodiment, an example in which the rectifying grids 7a are arranged in a direction substantially parallel to the intake flow 12 in the direction of the intake duct 5 is shown. In addition to this example, the direction of the rectifying grid 7a can be arranged in a direction substantially orthogonal to the intake flow 12 in the direction of the intake duct 5 or in a combination of these (FIGS. 3 and 4).
[0030]
Thus, when the rectifying grid 7a is arranged in a direction substantially parallel to or substantially orthogonal to the intake flow 12 in the direction of the intake duct 5, the rectifying grid 7a twists the intake flow 11 in the axial direction of the element 2 (swirl flow). Instead, the flow can be rectified as a non-disturbed intake flow 12 along the intake duct 5 direction.
[0031]
Although the rectifying effect is improved when the number of the rectifying grids 7a is increased, the ventilation resistance is increased. Therefore, the optimum number of rectifying grids 7a is selected according to the degree of intake air disturbance.
[0032]
Next, the intake flow inside the above-described intake device, that is, the intake passage will be described.
[0033]
The intake air is guided from the intake inlet 13 of the air cleaner 1, and the intake air flows 10 that have passed through each part of the element 2 collide with each other and turn in the downstream direction of the intake duct 5 to become turbulent. The intake air flow 11 in the axial direction is guided to the rectifying units 7 and 8.
[0034]
The intake air flow 11 described above is rectified in the same direction by flowing along the rectifying grid 7a of the rectifying plate 7 at a position immediately after the occurrence of the turbulence. Furthermore, the intake turbulence generated by the inner corner of the bent portion 9 at the boundary between the cleaner cases 3 and 4 and the intake duct 5 is reduced by providing the curved surface portion 8 and suddenly changes at the bent portion 9. The intake air flow 11 is smoothly guided to the left of the intake duct 5 along the curved surface of the curved surface portion 8 to obtain a rectified intake air flow 12, and the airflow resistance is reduced by reducing intake air turbulence.
[0035]
The rectified intake air flow 12 enables the thermal flow meter 6 to measure the intake air flow with high accuracy.
[0036]
FIG. 5 shows a comparison between the case (b) where the output fluctuation of the thermal flow type 6 by the intake device described above is (a), and the case where the rectifiers 7 and 8 are not mounted in the intake device (b).
[0037]
As shown by the characteristic line (a) in FIG. 5, by providing the rectifying sections 7 and 8, the disturbance of the intake flow passing through the thermal flow meter 6 disposed in the intake duct 5 is reduced, and the output fluctuation is It can be suppressed. As a result, the intake flow rate can be measured with high accuracy, and the intake resistance can be reduced by reducing intake air turbulence, thereby reducing the intake flow rate.
[0038]
( Reference Example) In the embodiment, the rectifying unit is constituted by the curved surface part 8 and the rectifying plate 7, but in this reference example, the rectifying unit is only the rectifying plate 7 as shown in FIG. Show. Components that are substantially the same as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0040]
As shown in FIG. 2, a rectifying plate 14 that rectifies the intake air may be additionally arranged on the intake upstream side of the thermal flow meter 6 within a range in which an increase in the ventilation resistance of the intake passage is allowed. By combining the rectifying plate 14 and the rectifying units 7 and 8 of the present invention, a more excellent rectifying effect can be obtained.
[0041]
Although not shown, the rectifying unit may be configured with only the curved surface part 8. In that case, the intake air turbulence generated by the inner corner of the bent portion 9 at the boundary between the cleaner cases 3 and 4 and the intake duct 5 is reduced to a rectified intake air flow 12, and the airflow resistance is reduced by reducing the intake turbulence. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a detailed view showing an intake device according to an embodiment of the present invention.
(A) It is sectional drawing which shows an intake device.
(B) It is an arrow line view which shows the rectification | straightening part seen from the X direction in Fig.1 (a).
FIG. 2 is a detailed view of an intake device according to a reference example.
(A) It is sectional drawing which shows an intake device.
(B) It is an arrow line view which shows the rectification | straightening part seen from the X direction in Fig.2 (a).
FIG. 3 is a top view showing a rectifying unit according to a modification of the embodiment of the present invention.
FIG. 4 is a top view showing a rectifying unit according to a modification of the embodiment of the present invention.
FIG. 5 is an output fluctuation comparison characteristic diagram of a thermal flow rate type of one embodiment of the present invention and a conventional example.
FIG. 6 is a cross-sectional view showing a conventional intake device.

Claims (4)

A cleaner case that houses an element that removes foreign matter in the air intake;
Connected to the opening of the cleaner case, a bent intake passage is formed to guide the intake air in the cleaner case that has merged through each part of the element in a direction substantially perpendicular to the flow direction of the intake air. An air intake duct,
A flow meter disposed in the intake duct for detecting an intake flow rate;
Between the opening of the cleaner case and the downstream portion of the element, a rectification unit that rectifies the flow of the intake air that has passed through the element,
The rectifying unit includes a curved surface part that is provided only at an inner position in a bending direction of the intake passage and has a curved shape along the bending direction, and a rectifying plate that rectifies the flow of the intake air, and the rectifying plate Is formed to overlap with the upper surface of the curved surface portion . The intake device according to claim 1 , wherein the rectifying unit is integrally formed with the intake duct. The intake device according to claim 1 , wherein the rectifying unit is integrally formed with the cleaner case. The intake device according to claim 1 , wherein the rectifying unit is integrally formed with the cleaner case and the intake duct.

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