JPH08304137A - Structure of supporting body for heat sensitive resistor element - Google Patents

Abstract

PURPOSE: To achieve the reduction of the dispersion of welding positions and the securing of the welding strength by forming the welding surface of each supporting body for welding and fixing each attaching pin of a heat sensitive resistor element into an arc shape. CONSTITUTION: At the heat sensitive part comprising a heat sensitive resistor element 1, attaching pins 2 and supporting bodies 3, a part of the cross section of each supporting body 3 facing each pin 2 for welding and fixing each pin 2 is formed into an arc shape. When the part is formed in this way, the contact point becomes one point because the cross-sectional shape of the pin 2 has a circular shape and the welding surface of the supporting body 3 becomes an arc intersecting the pin 2 at a right angle. Therefore, current is concentrated at one point when the electric welding is performed. Thus, the welding position and the welding strength are stabilized. Furthermore, since the only welding surface is in the arc shape, the supporting body 3 can be formed by press working without providing a special step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for a heat-sensitive resistance element, and more particularly to a support structure for a heat-sensitive resistance element for measuring an air flow rate of an internal combustion engine.

[0002]

2. Description of the Related Art As a support structure for a heat-sensitive resistance element of a conventional heat-resistance-type air flow rate measuring device, an actual open-air pedestal is 5-3073.
There is an example shown in 4.

[0003]

In the above prior art, the metal frame for supporting the heat-sensitive resistance element is composed of two members, and the member for welding the heat-sensitive resistance element is a wire and is electrically connected to the other circuit board. The one to be formed was formed by pressing a plate material, and both were joined in the middle.

However, in this structure, there is a step of joining two members, which is one of the factors that the mass productivity cannot be improved. Therefore, in order to omit this step, when the support that supports the metal frame and the thermal resistance element is integrally formed from the plate material by press working, the cross-sectional shape of the support becomes square and the mounting pin of the thermal resistance element becomes The welding area of becomes large.

The attachment pin of the heat-sensitive resistance element and the support are joined by welding. However, if the area of the welded portion of the support is large at this time, problems such as variations in welding position and reduction in welding strength may occur. is there. In particular, in the heat resistance resistance type air flow rate measuring device, it has been known that the characteristics fluctuate due to the fluctuation of the welding position, which is one of the factors directly affecting the performance, and it is necessary to take measures.

An object of the present invention is to obtain a support structure for a heat-sensitive resistance element by press molding in which the welding position accuracy of the heat-sensitive resistance element is good and welding strength has little variation.

[0007]

In the present invention, in order to achieve the above object, the coupling surface of the mounting pin of the heat-sensitive resistance element having a support cross section is formed in an arc shape.

[0008]

By making the connecting surface of the mounting pin of the heat-sensitive resistance element having the sectional shape of the support into an arcuate shape, variations in welding position can be reduced and welding can be performed at one point, so that sufficient welding strength can be secured. Further, in the heating resistance type air flow meter, variations in characteristics can be reduced and the yield can be improved in mass production.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

At the heat-sensitive portion consisting of the heat-sensitive resistance element 1, the mounting pin 2 and the support 3, the mounting pin 2 is faced,
In addition, a part of the cross-sectional shape of the surface to be welded and fixed to the support body 3 has an arc shape. Since the mounting pin 2 has a circular cross-sectional shape and the welding surface of the support body 3 is also an arc orthogonal to the mounting pin 2, the number of contact points is one. Since electric current is concentrated at one point when electric welding is used to connect them, the welding position and welding strength are stabilized.

Since only the welding surface has an arcuate shape, the support 3 can be manufactured by press working, and can be manufactured without providing a special manufacturing step.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIGS.

FIG. 3 is a cross-sectional view of the heat generation resistance type air flow meter 4 for detecting the intake air flow rate of the internal combustion engine, and FIG. 4 is a cross section of the air flow rate detection portion of the heat generation resistance type air flow meter 4.
The heating resistance type air flow meter 4 includes a body 41 and a module 42.
This module 42 consists of a body 41
The flow rate of air flowing inside is detected by the heat generating resistance element 44 and the heat sensitive resistance element 45 arranged in the bypass air passage 43.
In addition, the heating resistance element 44 and the heat-sensitive resistance element 45 are connected to the support 3
Is electrically connected to a circuit board 46 by a metal frame 5 including a metal frame 5. The metal frame 5 is fixed by a resin mold 46 which is a part of the module 42 inserted in the body 41.

In the metal frame 5 among them, four supporting members 3 are constructed so that the mounting pins 2 of the heat generating resistance element 44 and the heat sensitive resistance element 45 can be welded thereto, as shown in FIGS. 5 and 6. As described above, it is integrally formed of a plate material together with the support body 3, and is manufactured by pressing. At this time, by forming the welding surface of the support body 3 provided on the metal frame 5 with the mounting pin 2 in an arc shape, it is possible to prevent the above-mentioned harmful effects such as the variation of the welding position and the reduction of the welding strength. it can. Further, the influence of the welded portion is one of the factors that directly affect the performance such as the change of the characteristic, but the influence can be sufficiently reduced also in that portion.

Further, it is known that, in detecting the air flow rate, it is possible to improve the accuracy by preventing the air from being disturbed in the detecting portion as much as possible. According to the present invention, since the portion facing the air flow is arcuate, it does not disturb the air flow, and therefore the air flow rate can be detected with high accuracy.

Further, by making the cross-sectional shape of the support body streamlined as shown in FIGS. 7 and 8, peeling around the support body can be prevented even with a high Reynolds number. The air flow rate can be accurately detected without disturbing the air flow.

[0017]

According to the present invention, it is possible to provide a support structure for a heat-sensitive resistance element in which variations in the welding position of the heat-sensitive resistance element can be reduced and sufficient welding strength can be ensured. Further, in the air flow meter using the present invention, it is possible to reduce variations in performance in manufacturing and improve detection accuracy.

[Brief description of drawings]

FIG. 1 is an external view of a structure of a support for a temperature-sensitive resistance element of the present invention.

FIG. 2 is a top view of the support structure of the temperature-sensitive resistance element of the present invention.

FIG. 3 is a cross-sectional view of a heating resistance type air flow meter including a support structure of the temperature-sensitive resistance element of the present invention.

FIG. 4 is an enlarged view of an air flow rate detection unit of a heat generation resistance type air flow meter including a support structure of a temperature-sensitive resistance element of the present invention.

FIG. 5 is a side view of a metal frame including the present invention.

FIG. 6 is a top view of a metal frame including the present invention.

FIG. 7 is a top view of the support structure of the temperature-sensitive resistance element of the present invention.

FIG. 8 is a top view of another support structure of the temperature-sensitive resistance element of the present invention.

[Explanation of symbols]

1: Heat-sensitive resistance element, 2: Mounting pin, 3: Support, 4: Heating resistance type air flow meter, 41: Body, 42: Module, 43: Bypass air passage, 44: Heating resistance element, 4
5: Thermal resistance element, 46: Resin mold, 5: Metal frame

Claims (4)

[Claims] 1. A support for a heat-sensitive resistance element, which comprises a heat-sensitive resistance element and is electrically connected to a circuit board, wherein a part of a cross-sectional shape of a surface facing a mounting pin of the heat-sensitive resistance element and fixed by welding is: A support structure for a thermal resistance element, which is characterized by having an arc shape. 2. A support for a heat-sensitive resistance element that includes a heat-sensitive resistance element and is electrically connected to a circuit board, wherein a mounting pin of the heat-sensitive resistance element and a pointed end of the support contact at a point. The support structure of the heat sensitive resistance element. 3. A support structure for a heat-sensitive resistance element, comprising a heat-sensitive resistance element and electrically connected to a circuit board, wherein a cross-sectional shape of the support is streamlined. . 4. A heating resistance type air flow rate measuring device for measuring an air flow rate by a heating resistance element and a heat sensitive resistance element, wherein the support structure according to any one of claims 1 to 3 has the heating resistance element and the heating resistance element. An exothermic resistance type air flow rate measuring device, which is used as a support for both of the thermal resistance elements and measures the air flow rate.