JP3144943B2 - Air flow measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow measuring device used for measuring the intake air flow of an internal combustion engine for an automobile or the like, which has a function of independently detecting the temperature of the intake air.

[0002]

2. Description of the Related Art A conventional air flow measuring device is disclosed in
As shown in JP-A-916, the heating resistor for detecting the intake air temperature and the temperature-sensitive resistor for compensating the intake air temperature are provided in an integral support medium, and are disposed in a bypass air passage branched into the main passage of the intake system. Although there is a function, it only functions for intake air temperature compensation for detecting the intake air amount, and has no function of detecting and outputting the intake air temperature. Further, as disclosed in Japanese Patent Application Laid-Open No. 62-237320, a temperature-sensitive resistor that compensates for the intake air temperature is separately supported and is disposed in a main passage of an intake system. There was no function to detect and output the intake air temperature.

On the other hand, an element of the intake air temperature is indispensable for controlling an engine such as an internal combustion engine. At present, a temperature sensitive element for detecting the intake air temperature is provided independently by an air cleaner disposed upstream of the intake air flow measuring device. And the engine is controlled by the output signal.

[0004]

For this reason, despite the provision of a temperature-sensitive resistor capable of detecting the intake air temperature in the intake air flow rate measuring device, the output of the intake air temperature is limited due to restrictions on the circuit configuration. However, since the temperature sensing element for detecting the intake air temperature is separately arranged in the air cleaner or the like, there is a problem that the number of parts increases and the price increases.
On the other hand, there is a type in which a temperature sensing resistor for compensating intake air temperature is provided separately from a heating resistor for detecting intake air flow rate. Even if one of the air temperature compensating temperature sensitive resistors is formed on the same supporting medium, each detecting element has two systems, and the structure becomes complicated and the assembling workability is deteriorated. SUMMARY OF THE INVENTION An object of the present invention is to integrate a temperature sensing element for detecting an intake air temperature into an air flow measuring device in order to solve the above-mentioned problem, thereby reducing the number of parts, reducing the cost, and facilitating assembly work. .

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suction air flow.
Heating resistor for quantity detection and temperature sensing resistor for intake air temperature compensation
And a control unit in which the heating resistor and the temperature-sensitive resistor are connected.
Outputs the flow signal from the control circuit and the control circuit to the outside.
Air flow measuring device having a connector
And a sensor for detecting the intake air temperature separately from the temperature-sensitive resistor.
-Mister, lead of the heating resistor and the temperature-sensitive resistor
And the lead of the thermistor are integrally molded
And a heat generating resistor through the support.
The antibody, the temperature-sensitive resistor, and the thermistor control the control circuit.
Connected to the road and controlling the signal from the thermistor
Output to the outside via the circuit section and the connector section
It is achieved by doing so. The above purpose is
Heating resistor for detecting the incoming air flow rate and feeling for compensating the intake air temperature
A temperature resistor, the heating resistor and the temperature-sensitive resistor are connected
Control circuit unit, and a flow rate signal from the control circuit unit.
Air flow measuring device having connector part for outputting to outside
Detecting the intake air temperature separately from the temperature-sensitive resistor.
Thermistor, the lead of the heating resistor and the temperature sensing
The lead of the resistor and the lead of the thermistor are integrated
And a cooled support, and the support
The heating resistor, the temperature-sensitive resistor, and the thermistor are
The thermistor is connected to a control circuit, and the thermistor is provided in the control circuit.
A processing circuit for processing a signal from the
Output the output of the logic circuit to the outside via the connector section
This is achieved by doing so.

[0006]

According to the present invention, a signal for detecting the intake air temperature can be output by the function of the intake air temperature detecting element provided in the air flow measuring device.

Further, by disposing the above-mentioned temperature sensing element for detecting the intake air temperature in the counterbore of the resistor supporting portion for the intake air temperature compensating provided in the air flow measuring device, the heating resistor for detecting the intake air flow rate can be provided. Unaffected by heat from self-heating,
The intake air temperature can be detected stably and accurately.

[0008]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. This figure 1
The main air passage 2 and the bypass air passage 3 are arranged in the body 1, and the heating resistor 4 and the temperature-sensitive resistor 5 are supported by the same support medium 6 in the bypass air passage 3. I have. A temperature sensing element 7 for detecting the temperature of the intake air is supported by the support medium 6, and is connected to the control circuit 11 via the support medium 6. FIG. 2 is a detailed view seen from the direction P in FIG. 1, and FIG. 3 is a side view thereof.
The temperature-sensitive element 7 is supported by a counterbore 13 of a temperature-sensitive resistor support portion 12 at an intermediate portion between the heat-generating resistor 4 and the temperature-sensitive resistor 5. In this example, the temperature-sensitive element 7 is provided on a ceramic substrate 8. It is composed of a thick or thin film resistor 9. The thick film or thin film resistor 9 is supported on both sides by metal leads 10, and the leads 10 are integrally molded with the support medium 6,
It is connected to the control circuit 11 via this mold.
As a result, there is an effect that a temperature-sensitive element 7 having a small number of connection portions and excellent connection reliability can be supplied. Further, since there is no lead as a resistor, there is an effect that the device can be made compact. 4 and 5 show another embodiment of FIGS. 2 and 3,
Since the chip thermistor 14 is used as the temperature sensing element 7 and a proven thermistor is used as the temperature sensing element 6, there is an effect that high reliability can be obtained.

FIGS. 6, 7, 8 and 9 show another embodiment corresponding to FIGS. 2 and 3. FIGS. 6 and 7 show a case where a thermistor 15 with a lead is used as the temperature sensing element 7. This is because the lead portion of the thermistor 15 with a lead is integrally formed with the mold of the supporting medium 6. Since the thermistor itself has a lead, there is no need to newly provide a lead, and this has the effect of being inexpensive. 8 and 9 show a case where a bobbin type resistor 16 with a lead is used as the temperature sensing element 7. In this case, the same resistor as the heating resistor 4 and the temperature sensing resistor 5 is used and provided on the support medium 6. Since the intake air temperature is detected by a configuration welded to the supporting medium 17, it is not necessary to use a resistor directly at right angles to the flow direction, and the resistors are arranged in parallel to the flow direction. This has the effect of improving productivity by using the same elements as the heating resistor 4 for detecting the air flow rate and the temperature-sensitive resistor 5 for compensating for the air temperature. FIG. 10 shows a thin-film bobbin type resistor 18 as the temperature-sensitive element 7 in FIG.
With the structure using, the resistance value as a temperature sensing element can be increased, and there is an effect that high precision can be obtained by improving resolution. FIG. 11 shows another embodiment of the present invention, which is called an axial flow bypass type and shows the same reference numerals or the same elements as those in FIG. This embodiment has an L-shaped simplified passage structure, and the same effects as those of the embodiment of FIG. 1 can be expected. FIG. 12 shows another embodiment of the present invention, which is called a main type. A sub-passage 19 is provided in a main air passage 2 provided in a body 1, and a heating resistor 4, a heat-sensitive resistor 5, and a heat-sensitive element 7 are fixed to the same supporting medium 6 therein. The effect of can be expected.

FIGS. 13 and 14 are block diagrams showing an embodiment of the present invention. In the case of the signal processing of the temperature sensing element 7 shown in FIG.
By taking out the output of the resistance value itself, the control circuit of the air flow measuring device can be simplified. Further, in the case of FIG. 14, since the resistance value is converted and output as an electric signal in the control circuit, the added value is increased.

[0011]

According to the present invention, with a simple structure, accuracy can be improved.
Can provide information about good air temperatures to the outside world.
come.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a plan view showing details of FIG. 1;

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a plan view showing another embodiment of FIG. 2;

FIG. 5 is a side view showing another embodiment of FIG. 3;

FIG. 6 is a plan view showing another embodiment of FIG. 2;

FIG. 7 is a side view showing another embodiment of FIG. 3;

FIG. 8 is a plan view showing another embodiment of FIG. 2;

FIG. 9 is a side view showing another embodiment of FIG. 3;

FIG. 10 is a side view showing another embodiment of FIG. 9;

FIG. 11 is a longitudinal sectional view showing another embodiment of the present invention.

FIG. 12 is a longitudinal sectional view showing another embodiment of the present invention.

FIG. 13 is a block diagram of an embodiment of the present invention.

FIG. 14 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

1 ... body, 2 ... main air passage, 3 ... bypass air passage,
4 ... heating resistor, 5 ... temperature-sensitive resistor, 6 ... support medium, 7 ...
Temperature sensing element, 8: ceramic substrate, 9: thick or thin film resistor, 10: metal lead, 11: control circuit, 12: thermosensitive resistor support, 13: counterbore, 14: chip thermistor, 15 ... Chip thermistor with lead, 16: bobbin type resistor with lead, 17: support, 18: thin film bobbin type resistor, 19: sub-passage.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-100423 (JP, A) JP-A-4-278423 (JP, A) JP-A-61-239119 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01F 1/68-1/699

Claims (3)

(57) [Claims] 1. A heating resistor for detecting an intake air flow rate, a temperature sensing resistor for compensating intake air temperature, a control circuit unit connected to the heating resistor and the temperature sensing resistor, and the control circuit unit An air flow measuring device having a connector part for outputting a flow signal from the outside to the outside, a thermistor for detecting an intake air temperature separately from the temperature-sensitive resistor, a lead of the heating resistor and the temperature-sensitive resistor A support body in which a body lead and a thermistor lead are integrally molded, and the heating resistor, the temperature-sensitive resistor, and the thermistor are connected to the control circuit unit via the support, An air flow measuring device, wherein a signal from the thermistor is output to the outside via the control circuit section and the connector section. 2. A heating resistor for detecting an intake air flow rate, a temperature sensing resistor for intake air temperature compensation, a control circuit unit connected to the heating resistor and the temperature sensing resistor, and the control circuit unit. An air flow measuring device having a connector part for outputting a flow signal from the outside to the outside, a thermistor for detecting an intake air temperature separately from the temperature-sensitive resistor, a lead of the heating resistor and the temperature-sensitive resistor A support body in which a body lead and a thermistor lead are integrally molded, and the heating resistor, the temperature-sensitive resistor, and the thermistor are connected to the control circuit unit via the support, An air flow measuring device, wherein a processing circuit for processing a signal from the thermistor is provided in the control circuit section, and an output of the processing circuit is output to the outside via the connector section. 3. The air flow measuring device according to claim 1, wherein the counterbore is provided in the support, and the thermistor is disposed in the counterbore.