JP2000314647A - Air flow-rate measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a connector terminal from dropping off, and reduce cost and size of an air flow-rate meter by providing a rectangular shape connector terminal with a recess part and molding the part by resin. SOLUTION: In the middle of connector terminal 2 and in the part molded in a module 11 with resin, a recess 1 is provided. Molding resin is completely filled in the recess part and the connector terminal 2 is fixed to the module 11. The connector terminal part 2 is formed in a shape comparatively close to a rectangle to minimize the mold area. The module 11 is fixed with screws 17 to the body 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow meter for measuring an intake air flow rate of an internal combustion engine, and more particularly to a heating resistance type air flow meter suitable for measuring an air flow rate sucked into an automobile engine.

[0002]

2. Description of the Related Art An air flow meter for a vehicle is provided with a connector terminal for supplying power or outputting power to a control unit for controlling the vehicle.

Conventionally, in order to prevent the connector terminal from dropping off from the air flow meter due to the force when the connector is inserted or removed, the area covered with the resin of the connector terminal is increased, the connector terminal is formed in a V shape, or the connector terminal is three-dimensional. In this case, it was bent or bent, and the portion was covered with resin to prevent the resin from falling off.

[0004]

[0005] A connector terminal for an automobile may be rusted due to the temperature and humidity environment in which it is used, and may be fixed to a mating terminal. For this reason, a large force is applied when connecting and disconnecting connectors during inspections, etc.
Since there is a possibility that the connector terminal of the air flow measuring device may fall off, a sufficient bonding strength between the connector terminal and the air flow meter supporting the connector terminal is required.

[0005] However, if the connector terminals are largely covered with resin in order to increase the bonding strength, the need for miniaturization of the air flow meter is defeated.

On the other hand, from the viewpoint of cost, the shape of the connector terminal is desirably a rectangular shape or a planar structure having no bending step after the die cutting in order to minimize the die cutting area.

[0007]

[Means for solving the problems] To prevent the connector terminals from falling off,
In order to achieve cost reduction and downsizing of the air flow meter, it can be achieved by providing a counterbore on the rectangular connector terminal and covering the counterbore portion with the resin portion of the air flow meter.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an air flow measuring device 3 according to an embodiment of the present invention, and FIG. 2 is a sectional view of the air flow measuring device when FIG. 1 is viewed from the side (right side). FIG. 3 is an external view of only the connector terminal 2 used in FIG.

In a body 4 constituting a passage of the heating resistance type air flow measuring device 3, a heating resistor 7 for detecting an air flow and an intake air temperature are provided in a sub air passage constituting member 6 which crosses the main air passage 5 in a bridge shape. A sub-air passage 9 provided with a temperature-sensitive resistor 8 for detecting the pressure is provided. The heating resistor 7 and the temperature-sensitive resistor 8 are electrically connected to a module 11 having a built-in circuit board 14 including a start-up circuit via a pointing member 10 made of a conductive member, and a signal obtained from the heating resistor 7 is transmitted. The air flow signal is transmitted from the circuit board 14 to the control unit via the wire 15 and the connector terminal 2.
Although the circuit board 14 is protected by the cover 18, FIG.
Here, a partial cross-sectional view is shown for explanation.

The center of the connector terminal 2 is molded on the module 11 and integrated with the module 11. The counter terminal 1 has a counterbore 1 in a molded portion 16 at the center thereof, the molding resin enters the counterbore 1 without any gap, and the connector terminal 2 is fixed to the module 11. The connector 2 has a shape relatively close to a rectangle in order to minimize the die-cut area.
The module 11 is fixed to the body 4 with screws 17.

FIG. 4, FIG. 5 and FIG. 6 are views for explaining the shape of the conventional connector terminal 2. FIG.

FIG. 4 shows the connector terminal 2 having a relatively rectangular shape in order to minimize the die-cutting area. When the connector is inserted, the force of the connector terminal 2 moving to the left in the drawing is shown. However, the module 11 can hold the connector terminal 2, but there is a drawback that the connector terminal 2 falls off due to the force to move the connector terminal 2 to the right in the drawing such as disconnecting the connector.

FIG. 5 shows a structure in which the module 11 can hold the connector terminal 2 against a force in the left-right direction. Only two connector terminals are shown for explanation. The connector terminal 2 has a square shape and is effective against left and right forces. However, there is a disadvantage described in FIG.

FIG. 6 is a diagram for explaining the number per unit area when the connector terminal 2 shown in FIG. 5 is pulled out by a mold. FIG. 7 is a diagram showing the number per unit when the connector terminal 2 of the present invention shown in FIG. It is a figure explaining a number. In FIG. 6, nine connector terminals 2 can be manufactured per unit, but in FIG. 7, 11 connector terminals can be manufactured, and the shape problem of the present invention can solve the cost problem.

In die cutting, the distance between products must be maintained to some extent.

FIG. 8 shows another embodiment of the present invention.

A hole 12 is provided at the center of the connector terminal 2 integrated with the module 11. When the connector terminal 2 is integrated with the module 11, the resin forming the module 11 flows into the hole 12 and can hold the connector terminal 2 even if a strong force is applied to the connector terminal 2. The shape of the hole is not particularly limited as long as the resin can sufficiently enter the hole.

FIG. 9 shows another embodiment of the present invention.
0 is a sectional view of FIG.

Connector 2 integrated with module 11
There is an indentation 13 in the center. By covering the periphery of the recess 13 with the resin of the module 11, the connector 11 can be held even when a force is applied.

FIG. 11 shows an embodiment in which the present invention is applied to an electronic fuel injection type internal combustion engine. The intake air 101 drawn from the air cleaner 100 is drawn into an engine cylinder 107 via an intake duct 103, an air flow measuring device 104, a throttle valve 118, and a manifold 106 having an injector 105 for supplying fuel. On the other hand, the gas 108 generated in the engine cylinder 107
Is discharged through the exhaust manifold 109.

The air flow signal 115 output from the air flow measuring device 104 is output from a connector terminal having a counterbore provided on a module 112 in the air flow measuring device 104.
It is sent to the control unit 102 via 113.

The rotational speed signal 117 obtained from the engine tachometer 111 and the oxygen concentration signal 1 output from the oximeter 110 provided in the exhaust manifold 109 are used.
The control unit 102 that inputs 16 determines the optimal fuel injection amount in accordance with the air flow rate signal 115 and uses the value as an injector control signal 117 to control the injector 105.

[0024]

According to the present invention, it is possible to provide an air flow measuring device with high reliability of connector terminals.

[Brief description of the drawings]

FIG. 1 is an external view of an air flow measuring device having a counterbore in a connector terminal according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view as viewed from the right in FIG.

FIG. 3 is a connector terminal diagram of FIG. 1;

FIG. 4 is a diagram illustrating a conventional connector terminal shape.

FIG. 5 is a diagram illustrating a conventional connector terminal shape.

FIG. 6 is a view for explaining the number of die cuts per unit of a conventional connector terminal.

FIG. 7 is a view for explaining the number of die cuts per unit of the connector terminal of the present invention.

FIG. 8 is a diagram illustrating a connector terminal shape according to an embodiment of the present invention.

FIG. 9 is a diagram illustrating a connector terminal shape according to an embodiment of the present invention.

FIG. 10 is a sectional view seen from below in FIG. 9;

FIG. 11 is a control system diagram of an internal combustion engine using the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Counterbore, 2 ... Connector terminal, 3 ... Air flow measuring device, 4 ... Body, 5 ... Main air passage, 6 ... Sub air passage constituent member, 7 ... Heating resistor, 8 ... Temperature sensitive resistor, 9 ... Sub Air passage, 10 ... indicating member, 11, 112 ... module, 12
... Holes, 13 recesses, 14 circuit boards, 15 wires, 16 parts covered with resin, 17 screws, 18
... cover, 100 ... air cleaner, 101 ... intake air,
102: control unit, 103: intake duct,
104: air flow measuring device, 105: injector, 1
06: Manifold, 107: Engine cylinder, 10
8: gas, 109: exhaust manifold, 110: oxygen concentration meter, 111: engine speed meter, 113: connector terminal, 114: engine speed signal, 115: air flow rate signal, 116: oxygen concentration signal, 117: injector control Signal, 118 ... Throttle valve.

Claims (4)

[Claims] 1. An air flow measuring device for measuring an air flow introduced into an internal combustion engine, wherein a connector terminal mounted on the air flow measuring device has a counterbore shape. 2. The air flow measuring device according to claim 1, wherein a counterbore portion of the connector terminal of the air flow measuring device according to claim 1 is covered by the air flow measuring device. 3. An air flow measuring device for measuring an air flow introduced into an internal combustion engine, wherein a hole is formed in a connector terminal provided in the air flow measuring device, and the hole is covered with the air flow measuring device and fixed. An air flow measurement device characterized by being performed. 4. An air flow measuring device for measuring an air flow introduced into an internal combustion engine, wherein a recess is provided in a connector terminal provided in the air flow measuring device, and the recess is covered and fixed by the air flow measuring device. An air flow measurement device characterized by being performed.