JPS6127693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a pair of introduction pipes for introducing intake air into an engine, and detects the frequency of occurrence of vortices occurring at the confluence point where the intake air flowing through the introduction pipes joins. The present invention relates to an intake air amount detection device for an engine that detects the flow rate of the intake air.

An engine intake air amount detection device that detects the amount of intake air flowing in the conduit by installing a vortex generation column in the conduit and detecting the frequency of occurrence of Karman vortices generated downstream of the column was developed in 1987-5008. Or JP-A-51-
Many such devices have been proposed, such as 130718, and have also been put to practical use as intake air amount detection devices for automobile engines.
When such a conventional Karman vortex flowmeter is used to configure an engine intake air amount detection device, an air cleaner element (paper) 2 is placed upstream of the Karman vortex flowmeter 1 as shown in Fig. 1. and is configured to purify the air flowing in from the air inlet 3. Therefore, the intake air introduced into the Karman vortex flowmeter 1 flows through the shortest path between the air introduction port 3 and the introduction port 4 of the Karman vortex flowmeter 1. In other words, the air flows concentratedly around the center of the air cleaner element 2. As a result,
Only this central portion becomes heavily contaminated, and may even become deformed due to the flow of the intake air. The present invention solves these problems and provides an engine intake air amount detection device that uses a vortex flow meter equipped with a vortex generating section that is inexpensive and has a simple configuration.

The figure will be explained below. FIG. 1 is a block diagram of a conventional intake air amount detection device using a Karman vortex flow meter. FIG. 2 is a configuration diagram showing an embodiment of the present invention, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. 4 is a sectional view taken along line BB in FIG. 2. It is.

In Figures 2 to 4, 6 is an air cleaner case;
7 is the air inlet, 8 is the eclina element, 9
is the main body of the intake air amount detection device, and the upstream opening has a pair of introduction pipes 10 for introducing intake air;
11 and the introduction pipes 10 and 11 each have a rectifier 1.
It is equipped with 2,13. In addition, the introduction pipes 10 and 1
1 has a rectangular cross section with approximately equal passage cross-sectional areas. At the junction of the pair of introduction pipes 10 and 11, a vortex generating portion 1 is formed at a part of the wall of the introduction pipes 10 and 11.
4 is formed. 15, 15', 15'' are vortex stabilizers (plates) for improving the generation of vortices generated in the vortex generating section 14, and are arranged downstream of the vortex generating section 14 at desired intervals. 1.
6 and 16' are vortex detectors for detecting the frequency of vortices.

In the above configuration, when the engine (not shown) is started, the intake air of the engine passes through the air cleaner element 8 from the air inlet 7, and the rectifiers 12, 13.
The flow is rectified by the flowchart and introduced into a pair of introduction pipes 10 and 11, respectively. When the intake air introduced into the introduction pipes 10 and 11 respectively join together, a vortex is generated by the vortex generating section 14. In order to make the generation of this vortex continuous, stable and good, the vortex stabilizer 1
5, 15', and 15'' are arranged, and periodic vortices corresponding to the flow velocity of the intake air are generated downstream of the vortex stabilizer 15''. The frequency of occurrence of this vortex is detected by vortex detectors 16, 16', and the flow velocity or flow rate of the intake air is detected. After the flow rate is detected, it is introduced into the engine.

As described above, the present invention includes a pair of introduction pipes 10 and 11 for introducing intake air, and forms a vortex generating section 14 at the confluence point where the intake air flowing through the introduction pipes 10 and 11 joins. Since the flow rate of the intake air is detected by detecting the frequency of occurrence of vortices occurring downstream of the vortex generator 14, the air introduced from the air introduction port 7 is divided into two directions, the introduction pipes 10 and 11. Since the air passing through the air cleaner element 8 does not flow concentratedly in one place, the air cleaner element 8 is not locally contaminated, and deformation due to the concentrated flow of air is also prevented. We were able to. Further, since the vortex generating section is provided at the confluence point where vortices are likely to be generated, a portion of the tube wall of the pair of introduction pipes 10 and 11 can be used as the vortex generating section 14, resulting in a simple configuration. In addition, the pair of introduction pipes 1
0 and 11 are advantageous in forming the vortex generating portion 14 if they are rectangular in cross section.

On the other hand, the vortex stabilizers 15' and 15'' are effective in cases where the flow rate varies greatly, such as in intake air of an engine.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a conventional device, Fig. 2 is a block diagram showing an embodiment of the present invention, Fig. 3 is a sectional view taken along line A-A in Fig. B-
It is a sectional view taken along the B line. In the figure, 1 is the Karman vortex flowmeter body, 2 is the air cleaner element, 5 is the air cleaner case, and 6
1 is the air cleaner case, 8 is the air cleaner element, 9 is the main body of the intake air amount detection device, 10, 1
1 is a pair of introduction pipes, 14 is a vortex generating section, 15, 1
5' and 15'' are vortex stabilizers, and 16 and 16' are vortex detectors. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 The cleaner element provided in the cleaner case and the passage provided on the downstream side of the cleaner case have approximately the same cross-sectional area and have a rectangular cross section, and are formed by part of the pipe wall of a pair of inlet pipes for introducing intake air. An intake air amount detection device for an engine, which includes a vortex generating section and a plate-shaped or rod-shaped vortex stabilizer that stabilizes the generation of vortices at a confluence point of intake air.