JP2000002570A - Air flow rate-measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a safe heat-generating resistance body type air flow rate- measuring apparatus which prevents a mesh and a mesh-fixing material from dropping by holding the mesh-fixing material between an air cleaner and an air flowmeter body and further fixing with screws. SOLUTION: A mesh 7 for rectifying a flow of an air 13 is arranged in one body with a mesh-fixing material 8 at an upstream part of a body 1 of this heat-generating resistance body type air flow rate-measuring apparatus. The mesh 7 is caulked at an outer periphery by the mesh-fixing material 8, and the mesh-fixing material 8 has mount holes formed at the same points as mount holes of the body 1. When the body 1 is to be mounted to an air cleaner 11 with mount screws 12, the mesh-fixing material 8 is held therebetween, so that the mesh 7 and the mesh-fixing material 8 can be fixed surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating resistor type air flow meter provided in a flow path, and more particularly to a heating resistor type air flow measurement device suitable for measuring an air flow rate of an internal combustion engine.

[0002]

2. Description of the Related Art An air rectifying mesh and a mesh fixing material are fixed to an intake air inlet of a body by heat crimping or the like, as disclosed in Japanese Patent Application Laid-Open No. Hei 6-341878.

[0003]

In the above conventional method,
The mesh fixing material is fixed by crimping, but there is a concern about the mechanical strength when fixing by caulking, etc., and in the worst case there is a risk that the mesh will fall off, so a reliable fixing method is desired .

[0004]

According to the present invention, the mesh fixing member is sandwiched between the air cleaner and the body of the air flow meter, and further fixed by screws, so that the mesh fixing member can be securely fixed. Furthermore, the dimensional accuracy at the time of attaching the collar can be improved by fixing the collar, which has conventionally been inserted into the plastic body and used to prevent creep of the plastic material, from being attached to the metal mesh fixing member attachment hole.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 taking a heating resistor type air flow measuring device as an example.

FIG. 1 is a front view of a heating resistor type air flow measuring device showing one embodiment of the present invention, and FIG.
FIG. 3 is a detailed sectional view taken along line BB of FIG. 1.

As components of the heating resistor type air flow measuring device, there are a housing member having a built-in circuit board constituting a drive circuit and a sub air passage forming member 2 formed of a non-conductive member. In the member 2, a heating resistor 4 for detecting an air flow rate, and a temperature sensing resistor 5 for compensating an intake air temperature are electrically connected to a circuit board via a support made of a conductive member. These are arranged so as to be connected to each other, and are configured as an integral module 6 of a heating resistor type air flow measuring device, such as a housing, a circuit board, a sub air passage, a heating resistor, and a temperature sensing resistor.

A hole is formed in a wall surface of the body 1 which is a main air component constituting the intake pipe, and a sub air passage portion of the heating resistor type air flow measuring device is externally inserted through the hole. Then, the wall surface of the sub air passage constituting member and the housing member are fixed with screws or the like so as to maintain mechanical strength. In addition, a sealing material is attached between the sub air passage component 2 and the body 1 to maintain airtightness.

In the upstream part of the body 1, a mesh 7 for rectifying the flow of the air 13 is arranged integrally with the mesh fixing member 8. The mesh 7 is formed by caulking the outer periphery with a mesh fixing material 8. Further, the mesh fixing material 8 is provided with mounting holes 10 at the same locations as the mounting holes of the body 1. Thus, when the body 1 is attached to the air cleaner 11 with the attachment screws 12, the mesh fixing member 8 is sandwiched therebetween, so that the mesh 7 and the mesh fixing member 8 can be securely fixed and the mesh can be prevented from falling off.

FIG. 4 shows an example of application, in which the mesh fixing member 8 is formed integrally with the body 1. FIG.
Is an example of a further application, in which a collar 9 for mounting screws is fixed to a mounting hole 10 of a mesh fixing member 8, and a collar 9 used for preventing creep of a plastic material is fixed to the body 1 by press fitting or the like.

FIG. 6 shows an application example of FIG. 5, in which the collar 9 is fixed to the mounting hole 10 of the mesh fixing member 8 and is integrally formed with the body 1. In any of the above-mentioned application examples, since the mounting screw 12 is fixed through the mounting hole 10 of the mesh fixing material 8, the structure in which the mesh 7 and the mesh fixing material 8 do not fall off is obtained.

[0012]

According to the present invention, it is possible to prevent the mesh and the mesh fixing member of the heating resistor type air flow measuring device from falling off, and to provide a safer heating resistor type air flow measuring device.

[Brief description of the drawings]

FIG. 1 is a sectional view of an air flow measuring device showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a cross-sectional view of an air flow measuring device showing another embodiment of the present invention.

FIG. 5 is an assembled sectional view of an air flow measuring device showing another embodiment of the present invention.

FIG. 6 is a sectional view of an air flow measuring device showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body, 2 ... Sub air passage constituent member, 3 ... Sub air passage, 4 ... Heating resistor, 5 ... Temperature sensitive resistor, 6 ... Module, 7 ... Mesh, 8 ... Mesh fixing material, 9 ... Color,
10: mounting hole, 11: air cleaner, 12: mounting screw,
13 ... air.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Chihiro Kobayashi 2520 Oji Takaba, Hitachinaka-shi, Ibaraki F-term in the Automotive Equipment Division of Hitachi, Ltd. (Reference) 2F030 CA10 CC14 CE13 CF01 CF04 2F035 AA02 EA03 EA04 EA10

Claims (5)

[Claims] An air flow measuring device for measuring an amount of air taken into an internal combustion engine, wherein a mesh for air rectification and a mesh for fixing the mesh at an inlet of a body forming a part of a main air passage. An air flow measuring device comprising: a fixing member; and a mesh fixing member having a mounting hole for fitting a screw or the like used for fixing the air cleaner to the body. 2. The air flow measuring device according to claim 1, wherein the mesh fixing member according to claim 1 is sandwiched between the body and the air cleaner, and the air cleaner and the body are fixed with screws or the like. 3. The air flow measuring device according to claim 1, wherein the mesh fixing member according to claim 1 is formed integrally with a plastic body, and the air cleaner and the body are fixed by screws or the like. 4. An air flow measuring device according to claim 1, wherein a collar for the mounting screw is fixed to the mesh fixing member and fixed to the plastic body later by heat caulking or the like. 5. An air flow measuring device according to claim 1, wherein the collar for the fixing screw is fixed to the mesh fixing member and is integrally formed with the plastic body.