JP4132169B2 - Intake device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake device, for example, 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 a 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. Even when the air cleaner is not disposed in the vicinity of the upstream side of the thermal flow meter, the intake flow is disturbed by the shape of the flow path member disposed on the upstream side of the thermal flow meter. In order to reduce such disturbance of the intake flow, in the intake devices disclosed in Japanese Patent Application Laid-Open No. 57-103016 and Japanese Patent Application Laid-Open No. 7-128107, the outlet pipe of the air cleaner is provided upstream of the thermal flow meter. A rectifying member for rectifying the intake flow is provided. Here, rectifying the intake flow means to rectify the intake flow flowing in an irregular direction so as to flow in the same direction.
[0004]
However, since the flow passage area of the outlet pipe of the air cleaner is small, the intake resistance is increased by providing the rectifying member. Therefore, there is a problem that the intake flow rate introduced into the engine decreases and the engine output decreases.
In the air intake apparatus disclosed in Japanese Patent Application Laid-Open No. 7-128107, the rectifying plate is disposed so as to be orthogonal to the sensor portion that is directly exposed in the flow path. That is, the intake flow on the downstream extension of the rectifying plate rectified along the rectifying plate is orthogonal to the sensor unit.
[0005]
In such an intake device, the rectifying plate is provided on the diameter of the flow path, and the turbulence is further reduced as the intake flow is closer to the downstream extension along the rectifying plate. Although the sensor unit is usually located on the diameter of the flow path, the position is easily displaced in the diameter direction due to a processing error, an assembly error, or the like. If the sensor unit and the flow straightening plate are orthogonal, the sensor unit will be easily separated from the intake flow on the downstream extension of the flow straightening plate, and the highly disturbed intake flow will be measured. It becomes difficult to measure.
[0006]
Even when the sensor unit is arranged in the bypass channel without exposing the sensor unit in the channel, if the bypass member forming the bypass channel and the rectifying plate are orthogonal to each other, processing errors, assembly errors, etc. Since the intake inlet of the bypass flow path is easily separated from the intake flow on the downstream extension of the rectifying plate, and the turbulent intake flow flows into the bypass flow path, the intake flow rate can be measured with high accuracy. It becomes difficult.
[0007]
An object of the present invention is to provide an intake device that can reduce the disturbance of the intake flow upstream of the flow meter without reducing the intake flow rate and can measure the intake flow rate with high accuracy.
Another object of the present invention is to provide an intake device that can reduce the displacement of the intake flow on the extension in the downstream direction of the rectifying plate and the protruding portion of the flowmeter, and can measure the intake flow rate with high accuracy. is there.
[0008]
[Means for Solving the Problems]
According to the intake device of the first aspect of the present invention, the flow path member forms the intake flow path, and is located on the upstream side of the first flow path portion and the first flow path portion. A channel member having a larger channel area than the first channel unit and having a second channel unit having an enlarged diameter portion connected to the first channel unit; and in the second channel unit In the same manner, the cleaner element installed on the upstream side of the enlarged diameter portion, the flow meter disposed in the first flow path portion for measuring the intake flow rate, and the intake flow from the enlarged diameter portion to the flow meter are the same. A rectifying unit that rectifies in the direction is provided on the downstream side of the cleaner element in the second flow path unit, and passes through the rectification unit on the upstream side of the first flow path unit and on the downstream side of the rectification unit. e Bei a straightener member intake flow is provided communicating unit for merging, wherein the rectifying member is a rectifying plate, switching on the downstream side of the rectifier plate And wherein the forming the communicating portion by providing the.
[0009]
According to the above configuration, since the rectifying member is disposed on the downstream side of the cleaner element, it is possible to reduce the disturbance of the intake air flow that is likely to occur when passing through the cleaner element. Furthermore, since the intake flow that has passed through the rectification unit joins the upstream side of the first flow channel unit, the rectification unit can rectify the intake flow in the flow channel having a large flow channel area. As a result, the intake resistance due to the rectification unit can be reduced, and the reduction of the intake flow rate introduced into the engine can be prevented.
Moreover, according to the intake device having the above-described configuration , since the intake flow is rectified by the rectifying plate, the disturbance of the intake flow can be easily rectified along the rectifying plate.
[0010]
Furthermore, according to the intake device having the above-described configuration, the communication portion can be easily formed by providing a notch on the downstream side of the rectifying plate.
According to the intake device of the second aspect of the present invention, the rectifying plate is disposed on a virtual plane along the alignment direction of the intake port and the intake port of the flow meter and along the protruding direction of the protruding portion of the flow meter. Therefore, even if there are processing errors, assembly errors, etc., the displacement of the intake flow on the extension in the downstream direction of the rectifying plate rectified along the rectifying plate and the overhanging part of the flow meter is suppressed. Can do. Here, the overhang portion of the flow meter represents the sensor portion when the sensor portion is directly exposed to the flow path, and represents the bypass member when the bypass member that forms the bypass flow path projects over the flow path. .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example showing an embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, and FIG.
As shown in FIG. 1, the cleaner case 11 of the air cleaner 10 of the intake device 1 is connected to the upstream side of the outlet pipe 15 as the first flow path portion. The flow passage area of the cleaner case 11 as the second flow passage portion is larger than the flow passage area of the outlet pipe 15. The cleaner case 11 and the outlet pipe 15 constitute a flow path member that forms an intake flow path, and the cleaner case 11 and the outlet pipe 15 are sealed with a welded portion 25 as shown in FIG. . The cleaner case 11 has the same diameter part 12 and an enlarged diameter part 13 that expands from the outlet pipe 15 toward the same diameter part 12, and a cleaner element 14 is mounted in the same diameter part 12.
[0012]
As shown in FIG. 1, the flow meter 20 is attached to the outlet pipe 15, and a bypass member 21 as an overhanging part projects from the flow path of the outlet pipe 15. The bypass member 21 forms a U-shaped bypass passage 21a indicated by a dotted line in FIG. 1, and a pair of heating resistors (not shown) are attached in the bypass passage 21a. The circuit unit 22 detects the intake air flow rate from the difference between the heat generation amounts of the pair of heating resistors.
[0013]
As shown in FIGS. 1 and 2, the rectifying plate 30 as a rectifying member is disposed between the cleaner element 14 and the flow meter 20. Further, the rectifying plate 30 is disposed on a virtual plane 100 along the alignment direction of the intake inlet and the intake outlet of the bypass channel 21 a and along the extending direction of the bypass member 21. As shown in FIG. 3, the rectifying plate 30 has a rectifying portion 31 and an attachment portion 32 and is formed in a U shape. The rectifying unit 31 is a rectangular plate provided between the pair of attachment units 32, and is disposed in the air cleaner 11 on the upstream side of the output pipe 15. There are an intake inlet and an intake outlet of the bypass channel 21 a on the downstream side extension of the intake flow along the rectifying unit 31.
[0014]
The rectifying plate 30 is integrally formed in the opening of the outlet pipe 15 on the air cleaner 10 side. The two attachment portions 32 of the rectifying plate 30 are respectively connected to two places on the diameter of the circular opening of the outlet pipe 15 and extend from the opening to the air cleaner 10 side.
The rectifying plate 30 has a notch 30a formed on the downstream side, and a communication portion 35 having a length L is formed on the upstream side of the outlet pipe 15 and on the downstream side of the rectifying unit 31 by the notch 30a. The communicating portion 35 is a space where the intake air flow that has passed through the rectifying portion 31 is merged, and is located in the enlarged diameter portion 13 of the cleaner case 11.
[0015]
As shown in FIG. 1, the intake air flow from which foreign substances in the intake air are removed by the cleaner element 14 has a disorder 40 in which the intake air flow direction is irregular. When this disturbance 40 flows along the current plate 30, the current is rectified in the same direction. Since the rectified intake flow flows into the bypass channel 21a, the intake flow rate can be measured with high accuracy.
[0016]
As shown in FIG. 4, when the length L of the communication portion 35 is increased, the peak value of the output fluctuation of the intake flow rate measured by the flow meter 20 is increased, and the measurement accuracy is lowered. This is because the intake flow whose turbulence is reduced by the rectification unit 31 is disturbed again by increasing the distance from when the intake flow passes through the rectification unit 31 and merges at the communication unit 35 to flow into the outlet pipe 15. Because it occurs.
[0017]
Further, as shown in FIG. 5, when the length L of the communication portion 35 is shortened and the rectifying portion 31 approaches the outlet pipe 15, the pressure loss increases. This is because when the rectifying unit 31 approaches the outlet pipe 15, the flow passage area at the position where the rectifying unit 31 is disposed approaches the flow passage area of the outlet pipe 15 and the intake resistance increases.
In order to reduce the peak value of the output fluctuation and the pressure loss to a predetermined value or less, as can be seen from FIGS. 4 and 5, the rectifying unit may be disposed within the range of 5 mm ≦ L ≦ 15 mm. With the rectifying plate 30 arranged in this way, the output fluctuation of the flow meter can be reduced regardless of the intake flow rate as shown in FIG.
[0018]
In the above-described example showing the embodiment of the present invention described above, since the rectifying unit 31 is disposed in the cleaner case 11 having a large flow path area, the intake resistance by the rectifying unit 31 is reduced. Therefore, a decrease in the intake flow rate introduced into the engine can be prevented, and a decrease in engine output can be prevented.
Further, since the rectifying plate 30 is disposed on the virtual plane 100, the intake flow with the least turbulence in the intake flow that has passed through the rectifying unit 31 flows into the bypass flow path 21a. Therefore, the intake flow rate can be measured with high accuracy. Furthermore, even if the intake inlet of the bypass flow passage 21a is displaced in parallel with the rectifying plate 30 due to processing errors, assembly errors, etc., the intake inlet of the bypass flow passage 21a is located on the extension of the rectifying plate 30, so that the measurement variation is reduced. Can be reduced.
[0019]
In the above embodiment, the flow straightening plate 30 as the flow straightening member is attached to the outlet pipe 15 as the first flow path, but the cleaner case 11 as the second flow path located on the downstream side of the cleaner element 14 is attached. A rectifying member may be attached. Further, although the flow straightening member is constituted by a single plate, the flow straightening member may be constituted by a plate material assembled in a lattice form as long as it is disposed in the cleaner case 11 located on the downstream side of the cleaner element 14.
[0020]
Further, if the flowmeter 20 is disposed on the virtual plane 100 along the alignment direction of the intake inlet and the intake outlet of the flow meter 20 and along the protruding direction of the bypass member 21, the outlet pipe on the upstream side of the bypass member 21. A rectifying plate may be disposed in the 15. Moreover, in the said Example, although the outlet pipe 15 which is a 1st flow path part, and the cleaner case 11 which is the 2nd flow path part which accommodates the cleaner element 14, it connected the cleaner element as a reference example. You may make it the structure which connects the 2nd flow path part which is not accommodated to a 1st flow path part. Even if the cleaner element is not accommodated in the second flow path portion, the flow path is bent, and the intake flow is disturbed at the corners of the flow path. The intake flow rate can be measured with high accuracy by the total 20.
[0021]
In the above embodiment, the present invention is applied to an intake device that introduces air into an engine of a vehicle or the like. However, the intake device is not limited to an engine as long as it can arrange a flow meter for measuring an intake flow rate in a flow path. The present invention can be applied to any field.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an intake device according to an embodiment of the present invention.
FIG. 2 is a view taken in the direction of the arrow II in FIG.
FIG. 3 is a partial cross-sectional view showing the periphery of a current plate in the present embodiment.
FIG. 4 is a characteristic diagram showing the relationship between the length L of the communicating portion and the output fluctuation peak value in this embodiment.
FIG. 5 is a characteristic diagram showing the relationship between the length L of the communicating portion and the pressure loss in this example.
FIG. 6 is a characteristic diagram showing the relationship of the output fluctuation with respect to the intake air flow rate between the present embodiment and a conventional example in which a rectifying plate is not provided.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Intake device 10 Air cleaner 11 Cleaner case (2nd flow-path part, flow-path member)
12 same diameter part 13 enlarged diameter part 14 cleaner element 15 outlet pipe (first flow path part, flow path member)
20 Flowmeter 21 Bypass member 30 Rectifier plate (rectifier member)
30a Notch 31 Rectification part 32 Attachment part 35 Communication part 40 Air intake turbulence

Claims (2)

A flow path member that forms an intake flow path, and has a first flow path portion and a flow path area that is located upstream of the first flow path portion and is larger than the first flow path portion. A flow path member having a second flow path portion having an enlarged diameter portion connected to the first flow path portion;
A cleaner element installed on the upstream side of the enlarged diameter portion in the second flow path portion;
A flow meter disposed in the first flow path portion for measuring an intake flow rate;
A rectifying unit that rectifies the intake air flow from the enlarged-diameter portion to the first flow path portion in the same direction on the downstream side of the cleaner element in the second flow path portion; upstream and e Bei and a rectifying member in which the intake flow is provided communicating unit for merging which has passed through the rectifying portion on the downstream side of the rectification section of,
The rectifying member is a rectifying plate,
An air intake apparatus characterized in that the communication portion is formed by providing a notch on the downstream side of the rectifying plate . The flow meter has a projecting portion that projects into the flow channel of the first flow channel unit, and the rectifying plate is along an alignment direction between the intake inlet and the intake outlet of the flow meter, and the projecting The intake device according to claim 1 , wherein the intake device is disposed on a virtual plane along a protruding direction of the portion .

Images