JP3394426B2 - Heating resistance type flow measurement device, temperature error correction system and correction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for correcting a flow rate measurement error caused by a temperature change of a fluid when a mass flow rate of the fluid is measured by using a heat generation resistance type flow rate measuring apparatus, and particularly to an internal combustion engine. The present invention relates to a system that measures an intake air flow rate and controls an engine according to the air flow rate.

[0002]

2. Description of the Related Art As a known example close to the present invention, there is disclosed a heating resistance type flow rate measuring device described in Japanese Patent Application Laid-Open No. 8-278178 in which a temperature characteristic of a heating resistance type air flow rate measuring device is offset by a temperature characteristic of an electronic circuit. is there. The heating resistance type flow rate measuring device described in JP-A-8-278178 shows the dependence of the measurement error due to temperature change on the air flow rate in the temperature characteristic of the reference voltage generating circuit of the heating resistance type flow rate measuring device. It is corrected by having a flow rate dependency that cancels out.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned prior art, the electronic circuit has a temperature error which the output corresponding to the flow rate of the bridge circuit formed by the heating resistor, the temperature sensitive resistor, etc., caused by the temperature change of the fluid. This is offset by the temperature characteristics that it has. Therefore, when there is a difference between the temperature of the fluid and the temperature of the electronic circuit, there is a problem that the correction does not work.

The present invention makes it possible to easily correct the temperature error of the heating resistance type flow rate measuring device caused by the temperature change of the fluid by the temperature of the fluid.

[0005]

[Means for Solving the Problems] The above object is to install the auxiliary passage.
And the heating resistor provided in the auxiliary passage.
Detects the temperature and the reference resistor that is the heating reference of the thermal resistor.
Temperature detecting means, and at least a CPU and an A / D converter
And an electronic circuit having the electronic circuit
And the auxiliary passage is integrally formed with the housing.
A heating resistance type flow rate measuring device formed, comprising:
The flow rate signal digitally converted by the D converter
The measurement error for the quantity is almost constant regardless of the fluid temperature.
Of the temperature detected by the temperature detection means by the CPU.
The digitally converted flow signal based on the
This is achieved by correcting with an equation. Also, the above purpose
Is the amount of heat released from the heating resistor or the heated resistor
Heat resistance type flow rate measurement that measures the flow rate of the fluid based on the temperature of the
It is a correction device that corrects by inputting the flow rate signal from the means.
The flow rate signal has a measurement error with respect to the flow rate of the fluid.
It has almost constant characteristics regardless of the temperature of the
Detects the temperature in the fluid passage where the flow rate measuring means is installed
Based on the temperature signal from the temperature detection means, the flow rate signal
It is achieved by correcting with a linear equation. Also, above
The purpose is the amount of heat released from the heating resistor or the
A flow rate signal corresponding to the flow rate of the fluid is output based on the antibody temperature.
Heat resistance resistance type flow rate measuring means, and the heat generation resistance type flow rate
Temperature to detect the temperature in the fluid passage where the measuring means is installed
The flow rate signal from the detecting means and the heating resistance type flow rate measuring means.
Error correction system including a correction means for correcting the signal
And the flow rate signal has a measurement error with respect to the flow rate.
It has almost constant characteristics regardless of the fluid temperature.
The stage based on the temperature signal from the fluid temperature sensing means.
The flow rate signal from the flow rate measuring means can be corrected by a linear equation.
Achieved by.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows a block diagram of a control system using a temperature error correction means, which is a typical embodiment of the present invention.

The heating resistance type flow rate measuring device 1 is a temperature sensing resistor having a resistance value according to the temperature of the heating resistor 11 for detecting the flow rate and the fluid, and a reference resistor serving as a reference of the heating temperature of the heating resistor. 12 is attached so as to be located inside the fluid passage 40, and the heating resistor 11, the reference resistor 12 and the other resistors 17 and 18 form a bridge circuit, and the heating resistor 11 is the reference resistor. It is controlled so that the temperature of the fluid 12 is always higher than the temperature of the fluid being detected. Therefore, since a current is supplied to the heating resistor 11 so as to obtain a heating amount equal to the amount of heat radiated from the heating resistor 11 to the fluid, the current value flowing through the heating resistor 11 becomes a signal corresponding to the flow rate of the fluid. Become. This current is replaced with a voltage by a resistor 17 which is a fixed resistor, adjusted by an output characteristic adjusting circuit 14, and a flow rate signal 15 is output.

On the other hand, the fluid temperature detecting device 2 has a temperature sensitive resistor 21 such as a thermistor arranged in the fluid passage 40.
The resistance value itself or the voltage value when a constant current is supplied is output as the temperature signal 22.

The above flow rate signal 15 and temperature signal 22 are
It is input to the control unit 4 together with other signals 31. Each input signal is converted into a digital value by the A / D converter 7 and processed in the microcomputer 9. Here, since the flow rate signal is actually a non-linear voltage signal with respect to the flow rate, it is converted into a digital value and then converted into a linear flow rate value in the flow rate conversion unit 6, and further,
In the temperature correction unit 3, the flow rate signal is obtained by correcting the measurement error due to the temperature change of the fluid, and the flow rate value with the reduced temperature error is obtained. The temperature-corrected flow rate signal, temperature signal, and other signals can be input to the control unit 5, and the control signal 32 for the engine or equipment can be output by the control unit 4 via the interface 8 such as a D / A converter. it can.

Next, as an embodiment of the heat generation resistance type flow rate measuring apparatus used in the present invention, the structure of the heat generation resistance type air flow rate measuring apparatus for measuring the intake air flow rate of the internal combustion engine is shown in the cross section of FIG. This will be described with reference to the drawings and the external view seen from the upstream side of FIG.

The structure of the heating resistance type air flow rate measuring device does not need to be changed from the conventional product, and only the outline of this embodiment will be described here. The heat generation resistance type flow rate measuring device is composed of a housing 51 in which a circuit board 52 constituting an electronic circuit is housed, a sub-passage forming member 56 fixed to the housing 51, and a body 41 serving as a fluid passage. The heating resistor 11 and the reference resistor 12 for detecting the flow rate have conductive leads 5 at both ends.
4, the lead 54 is arranged and fixed inside the sub passage 43 by fixing both ends of the lead 54 to the terminal 53. The terminal 53 is a conductive member and communicates with the inside of the housing 51 and is connected to the circuit board 52 by a wire 57.
The intake air 44 to be measured has a fluid passage formed in the body 41 as a main passage 42, and a part of the flow is branched to a sub passage 43 to generate an electronic circuit based on a heat radiation amount of the heating resistor 11. Obtain a signal corresponding to the air flow rate. This signal is output from the connector 55 to an external device.

An electronic circuit diagram of the heating resistance type air flow rate measuring device is shown in FIG. The electronic circuit is the heating resistor 11
A control circuit 61 for controlling the heating temperature of No. 1 to obtain a signal 19 corresponding to the flow rate, and a temperature compensating circuit 62 for correcting the output change due to the temperature change by utilizing the temperature characteristics of the Zener diode 64 and the diode 65. It is roughly classified into an output characteristic adjusting circuit 63 for adjusting the zero level and gain of the signal 19 corresponding to the flow rate so as to match a predetermined flow rate characteristic.

The control circuit 61 has a different structure from that of the simple bridge circuit shown in FIG. 1, but controls the heating resistor 11 so as to have a constant temperature higher than the air temperature corresponding to the resistance value of the reference resistor 12. It has the same function as a simple bridge.

The temperature compensating circuit 62 utilizes the temperature characteristics of the Zener diode 64 and the diode 65 to make the resistance 66
Alternatively, by adjusting the resistance 67, the reference voltage 68 of the output characteristic adjusting circuit 63 having an arbitrary temperature characteristic can be obtained.

The output characteristic adjusting circuit 63 receives the signal 19 corresponding to the flow rate of the control circuit 61 and adjusts the zero span by the operational amplifier 69 to obtain the flow rate signal 15 that matches the predetermined flow rate characteristic. Here, since the reference voltage for zero point adjustment is adjusted to an arbitrary temperature characteristic by the temperature compensation circuit 62, the temperature characteristic of the flow rate signal 15 can be adjusted.

The temperature characteristic of the flow rate signal of the heating resistance type flow rate measuring device has an error of 0% in the output characteristic at 20 ° C.
As a measurement error when the temperature is changed to 80 ° C. and −40 ° C., the conventional temperature error adjustment is performed as shown in FIG.
7 to FIG.

FIG. 5 shows that only the fluid temperature is 80.degree. C. or -40.degree. C., ignoring the temperature characteristics of the resistors and elements on the circuit board.
It shows the measurement error when changing to. The flow rate measurement error when the temperature of the fluid changes is because the physical properties such as the thermal conductivity and the kinematic viscosity of the fluid change, and the thermal conductivity of the leads and the like are also affected. As shown in, there is a measurement error that depends on the flow rate, that is, flow rate dependence.

This measurement error can be adjusted by a resistor 13 arranged in series with the reference resistor 12, and conventionally, the resistance 13 is set to the extent shown in FIG. 5 so that the measurement error approaches zero in the entire flow rate range. Had been set.

On the other hand, the temperature characteristics of the resistors and elements on the circuit board appear as the sum of the temperature characteristics of each element and each resistor.
It can be adjusted by the temperature compensation circuit as described above. The temperature characteristic is a constant voltage regardless of the flow rate, but the measurement error when converted to the flow rate is large at low flow rate and small at high flow rate. Therefore, in order to cancel the flow rate dependency of the measurement error shown in FIG. 5 as much as possible, the temperature characteristic is adjusted to have a slight measurement error as shown in FIG.

From the above, the measurement error when the temperature of the fluid and the temperature of the circuit actually change is as shown in FIG. Since the heat generation resistance type flow rate measuring device measures the flow rate by the amount of heat radiation based on the fluid temperature, the measurement error due to temperature change is small compared to other flow rate measuring methods, and the maximum error shown in FIG. Therefore, it has not been regarded as a problem so far.

However, in recent years there has been a demand for higher precision, and it has become necessary to reduce measurement errors due to temperature changes. As one of the means, there is a heating resistance type flow rate measuring device described in Japanese Patent Laid-Open No. 8-278178 mentioned above as the prior art. This is to make the temperature characteristic of the reference voltage 68, which is the output of the temperature compensation circuit 62, have flow rate dependency so as to cancel the flow rate dependency of the measurement error caused by the fluid temperature change.

That is, although the measurement error due to the temperature change of the fluid is the same as the case where the above-mentioned conventional temperature error adjustment is performed (FIG. 8), the temperature characteristic of the circuit board can be adjusted as shown in FIG. The measurement error when the temperature of the fluid and that of the circuit change to the same temperature is almost 0% as shown in FIG.

However, the adjusting method described in Japanese Patent Application Laid-Open No. 8-278178 is also effective when the temperature of the fluid and the temperature of the circuit are substantially equal, but an appropriate correction cannot be performed if a temperature difference occurs between the two. For example, in a heating resistance type air flow rate measuring device that measures the flow rate of air drawn into an automobile engine, the heating resistance type air flow rate measuring device is installed in the engine room, and the circuit section is heated by receiving heat from the engine. The temperature of the intake air is 20 ° C when cold air is inhaled.
It is conceivable that the circuit part is heated to about 80 ° C. although the temperature is about the same. Also, after the engine has warmed up sufficiently, when it goes out in the cold outside, the circuit section is 2
It is possible that the temperature of the intake air is about -40 ° C even though it is about 0 ° C.

Therefore, in the above-mentioned example, the temperature characteristic of the circuit board remains as it is and becomes a measurement error of the flow rate signal. Appears as a measurement error of.

Therefore, according to the present invention, the measurement error caused by the temperature change of the fluid is reduced by correcting the temperature of the fluid, and the resistance of the circuit board and the temperature characteristic of the element are almost zero in the temperature compensation circuit 62. By adjusting the flow rate to be%, even when the temperature of the fluid and the temperature of the circuit portion are different, a flow rate value with a suppressed temperature error can always be obtained.

However, since the measurement error caused by the change in the temperature of the fluid has a flow rate dependency in the conventional adjustment as described above, it is necessary to perform the correction with a slight load such as obtaining the correction coefficient from the map of the flow rate and the temperature. Becomes

In the present invention, in order to make this correction very easily, the measurement error due to the temperature change of the fluid is fixed at a constant measurement error irrespective of the flow rate so as to eliminate the flow rate dependence without aiming at 0%. The heating resistance type flow rate measuring device is adjusted so as to be generated. On the contrary, the temperature characteristic of the circuit may be adjusted or set so that the measurement error does not occur (becomes almost 0%) without canceling the measurement error due to the temperature change of the fluid.

The adjustment of the measurement error due to the temperature change of the fluid is performed by, for example, the resistor 1 arranged in series with the reference resistor 12.
This can be done by changing the resistance value of 3. FIG. 11 shows the measurement error when the temperature of the fluid when the resistance value of the resistor 13 is changed from 20 ° C. to 80 ° C. or −40 ° C. is compared with the conventional adjustment. In the developed product in which the resistance value of the resistor 13 is changed, the measurement error due to the temperature change of the fluid is a minus error at 80 ° C, but it is almost a constant ratio regardless of the flow rate.
At 0 ° C, there is a positive error and the ratio is constant. The measurement error when the measurement error due to the temperature change of the fluid becomes flat without flow rate dependency is different depending on the constituent material and structure of the heating resistor 11 and the reference resistor 12, but from the viewpoint of performance and reliability. Since it can be difficult to make it flat at 0%,
The point of the present invention is to adjust so that the flow rate dependency is eliminated by changing the resistance value that is easy to set, even if it is not set to 0%.

Further, the measurement error of the constant ratio shows a substantially linear correlation with the temperature as shown in FIG. Therefore, the correction of the measurement error due to the temperature change of the fluid is performed by, for example, the actually measured fluid temperature and the reference temperature (20 in this embodiment).
12) is multiplied by the slope coefficient of Fig. 12 to obtain a correction error. If the flow rate obtained from the heating resistance type flow rate measuring device is corrected by the error, the temperature change of the fluid will be independent of the flow rate. The flow rate corrected for the measurement error due to is obtained. As described above, according to the present invention, since the measurement error due to the temperature change of the fluid can be corrected by a simple linear equation, the correction process is very easy and the load on the processing unit is small.

On the other hand, the temperature characteristic of the circuit is adjusted by the reference voltage circuit 62 so that the temperature characteristic of the circuit becomes almost 0% as described above, or the temperature characteristic of the resistor or the element is made almost zero. By setting, the measurement error is set to approximately 0% as shown in FIG.

Therefore, when the correction means for the measurement error due to the temperature change of the fluid is carried out by a processing device or a control device outside the heat generation resistance type flow measuring device, the total temperature error of the heat generation resistance type flow measuring device is shown in FIG. Thus, it is almost equal to the measurement error due to the fluid temperature. However, since the measurement error due to the fluid temperature is corrected by the correction processing unit based on the temperature of the fluid, the error due to the temperature change is almost 0% in the corrected flow rate value as shown in FIG. According to this method, since the influences of the fluid temperature and the circuit temperature are independently corrected, the flow rate with reduced measurement error due to the temperature can be obtained even in the environment where the fluid temperature and the circuit temperature are different as described above.

Next, an embodiment of a heat generation resistance type flow rate measuring device having the above-mentioned processing unit for correcting the measurement error due to the fluid temperature will be described with reference to FIG. 16 which is a cross sectional view of the heat generation resistance type flow rate measuring device. To do.

The heating resistor 11 for detecting the flow rate and the reference resistor 12 serving as a reference for the heating temperature of the fluid heating resistor are:
The electronic circuit 52 is disposed inside a sub passage 43 formed integrally with a housing 51 that houses the electronic circuit 52, and is electrically connected to the electronic circuit 52 via a terminal 53 and a wire 57.

The electronic circuit 52 includes the control circuit 61, the reference voltage circuit 62, the output characteristic adjusting circuit 63, and the cp circuit.
The u71, the A / D converter 72, the memory 73, the interface 74, and the like are provided, which enables digital conversion and arithmetic processing in an electronic circuit. Also,
A method of separately disposing a thermistor or the like can be considered for measuring the temperature of the fluid, but it is also possible to obtain the fluid temperature from the voltage across the reference resistor 12. Since the current flowing through the reference resistor 12 changes depending on the flow rate,
It is not possible to obtain the fluid temperature as it is. However, in the present embodiment, the calculation processing by the cpu71 is possible, and since the flow rate signal is obtained, the signal corresponding to the fluid temperature is obtained by calculating the value corresponding to the flow rate from the voltage across the reference resistor 12. It becomes possible to ask. Therefore, A /
As described above, the measurement error due to the temperature change of the fluid of the flow rate signal digitally converted by the D converter is adjusted to be a constant ratio regardless of the flow rate, and the cpu 71 corrects it based on the temperature of the fluid. It is possible to reduce the temperature error.

Further, in the present embodiment, since the circuit board 52 is installed inside the main passage 42, the circuit temperature is closer to the fluid temperature than when it is placed outside, so that the fluid temperature and the circuit temperature are substantially equal. As a matter of course, it is also possible to comprehensively correct the temperature error. However, since the circuit temperature is more likely to receive external heat than the fluid due to heat conduction through the housing, and because there is self-heating from the circuit resistance and elements, the fluid and the circuit are not at the same temperature. As for the temperature characteristics of the circuit, the temperature error is about 0% individually.
It is desirable to adjust so that

The flow rate signal and the fluid temperature signal thus calculated and corrected by the cpu 71 are output from the connector terminal 75 to the external device via the interface 74. Further, since numerical data such as coefficients for arithmetic processing are stored in the memory 73, it is possible to individually adjust by rewriting the data in the memory 73.

Finally, an embodiment in which the present invention is used for controlling an internal combustion engine will be described with reference to FIG. 17 which is a configuration diagram of the internal combustion engine.

The air taken into the engine cylinder 101 is controlled by the throttle valve 102 and the idle control valve 103. The intake air 110 is drawn into the air cleaner 104 from the outside, and the filter 10
After passing through the heat generation resistance type flow rate measuring device 1 and the throttle body 115, the gas is sucked into the engine cylinder 101 and is discharged as post-combustion exhaust gas 111. Further, an intake air temperature sensor 106 is installed inside the air cleaner 104, an air-fuel ratio sensor 107 is installed in the exhaust pipe, a crank angle sensor 108 is installed in the engine, and a throttle opening sensor 109 is installed in the throttle body 115. An air flow rate signal, an intake air temperature signal, an air-fuel ratio signal, a crank angle (engine speed) signal, and a throttle opening signal are input to 112. The control unit 112 outputs a fuel control signal for the injector 113 and an opening signal for the idle control valve 103 for optimally controlling the engine based on these input signals.

Here, by adjusting the measurement error caused by the change in the intake air temperature of the heat generation resistance type flow rate measuring device 1 so as to have a constant ratio regardless of the flow rate, the control unit 112 is based on the intake air temperature signal. Since correction is possible, a flow rate value with reduced measurement error due to intake air temperature is obtained, and more accurate control of the engine becomes possible.

[0041]

According to the present invention, the temperature change of the fluid
The temperature error of the generated heat resistance type flow rate measuring device is
Can be corrected easily .

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control system that is a typical embodiment of the present invention.

FIG. 2 is a cross-sectional view of an embodiment of a heating resistance type flow rate measuring device used in the present invention.

FIG. 3 is an external view of FIG. 2 viewed from the upstream side.

FIG. 4 is an electronic circuit diagram of the heating resistance type flow rate measuring device of FIG.

FIG. 5 is a conventional example of a measurement error due to a fluid temperature of a heating resistance type flow rate measuring device.

FIG. 6 shows a conventional example of circuit temperature characteristics of a heating resistance type flow rate measuring device.

FIG. 7 is a conventional example of a total temperature error of a heating resistance type flow rate measuring device.

FIG. 8 is a conventional example of a measurement error due to a fluid temperature of a heat generation resistance type flow rate measuring device.

FIG. 9 shows a conventional example of circuit temperature characteristics of a heating resistance type flow rate measuring device.

FIG. 10 is a conventional example of a total temperature error of a heating resistance type flow rate measuring device.

FIG. 11 is a measurement error due to the fluid temperature of the heating resistance type flow rate measuring device of the present invention.

FIG. 12 shows the relationship between the fluid temperature and the measurement error of the heating resistance type flow rate measuring device of the present invention.

FIG. 13 is a circuit temperature characteristic of the heating resistance type flow rate measuring device of the present invention.

FIG. 14 is a total temperature error before correction of the heating resistance type flow rate measuring device of the present invention.

FIG. 15 is an overall temperature error after correction of the heating resistance type flow rate measuring device of the present invention.

FIG. 16 is a cross-sectional view of an embodiment of a heating resistance type flow rate measuring device having a correction processing unit of the present invention.

FIG. 17 is a control system configuration diagram of an internal combustion engine using the present invention.

[Explanation of symbols]

1 ... Exothermic resistance type flow rate measuring device, 2 ... Fluid temperature detecting device,
3 ... Temperature correction part, 4 ... Control unit, 5 ... Control part, 6 ... Flow rate conversion part, 7 ... A / D converter, 8 ... Interface, 9 ... Microcomputer, 11 ... Heating resistor, 12
Reference resistor, 13 ... Resistance, 15 ... Flow signal, 16 ... Power supply terminal, 17 ... Bridge resistance 1, 18 ... Bridge resistance 2, 19 ... Bridge signal corresponding to flow rate, 21 ... Temperature sensitive resistor, 22 ... Temperature Signal, 40 ... Fluid passage, 41 ... Body, 42 ... Main passage, 43 ... Sub passage, 51 ... Housing,
53 ... Terminal, 54 ... Lead, 55 ... Connector, 5
6 ... Sub passage constituent member, 57 ... Wire, 61 ... Control circuit,
63 ... Output characteristic adjusting circuit, 64 ... Zener diode,
65 ... Diode, 66, 67 ... Resistance, 68 ... Reference voltage, 69 ... Operation amplifier, 101 ... Engine cylinder, 1
02 ... Throttle valve, 103 ... Idle control valve, 104 ... Air cleaner, 105 ... Filter,
115 ... Throttle body, 106 ... Intake air temperature sensor,
107 ... Air-fuel ratio sensor, 108 ... Crank angle sensor, 1
09 ... Throttle opening sensor, 110 ... Intake air, 11
1 ... Exhaust, 112 ... Control unit, 113 ... Injector.

Front page continued (72) Inventor Kenji Ota 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd. Automotive Equipment Division (72) Inventor Atsushi Sugaya 7-1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Works Hitachi Research Laboratory (72) Inventor Takashi Kakuhiro 2477 Takaba, Hitachinaka City, Ibaraki Hitachi Car Engineering Co., Ltd. (56) Reference JP 62-245924 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G01F 1/68

Claims (10)

(57) [Claims] 1. A heating resistor provided in a sub-passage, a reference resistor provided in the sub-passage and serving as a heating reference of the heating resistor, a temperature detecting means for detecting a temperature, and at least a CPU and an A. An exothermic resistance type flow rate measuring device, comprising: an electronic circuit having an A / D converter; and a housing that houses the electronic circuit, wherein the auxiliary passage is integrally formed in the housing. The converted flow rate signal has a characteristic that the measurement error with respect to the flow rate is substantially constant irrespective of the temperature of the fluid, and the CPU converts the digitally converted flow rate signal into a primary value based on the temperature detected by the temperature detecting means. A heating resistance type flow rate measuring device that corrects with a formula. 2. A correction device for inputting and correcting a flow rate signal from a heating resistance type flow rate measuring means for measuring the flow rate of a fluid based on the amount of heat radiated from the heating resistor or the temperature of the heated resistor. The flow rate signal has a characteristic that the measurement error with respect to the flow rate is substantially constant irrespective of the temperature of the fluid, and the temperature detection means for detecting the temperature in the fluid passage in which the heat generation resistance type flow rate measurement means is installed. A correction device that corrects the flow rate signal by a linear expression based on a temperature signal. 3. The correction device according to claim 2, wherein a fuel control signal of the internal combustion engine or an opening signal of an idle control valve based on the corrected flow rate is output. 4. The method of claim 3, the correction device for an A / D converter for converting the flow signal into a digital value, characterized in that a microcomputer for the correction to the transformed signal. 5. The claim 2 4, wherein the flow rate signal, at least at the temperature of the fluid 80 ° C. and -40 ° C., the correction measurement error for the flow rate, characterized in that it has an approximately constant characteristics apparatus. 6. The method of claim 2, the correction apparatus characterized by being furnished to a housing forming the auxiliary passage of the heating resistance flow rate measuring means. 7. A heating resistance type flow rate measuring means for outputting a flow rate signal corresponding to the flow rate of a fluid based on the amount of heat radiated from the heating resistor or the temperature of the heated resistor, and the heating resistance type flow rate measuring means. A temperature error correction system including temperature detection means for detecting the temperature in the fluid passage in which is installed, and correction means for correcting the flow rate signal from the heating resistance type flow rate measurement means, wherein the flow rate signal is The measurement error with respect to the flow rate has a substantially constant characteristic regardless of the temperature of the fluid, and the correction means corrects the flow rate signal from the flow rate measurement means by a linear expression based on the temperature signal from the fluid temperature detection means. Temperature error correction system. 8. The method of claim 7, the A / D converter for converting the flow signal into a digital value, the temperature error correction system characterized in that a microcomputer for the correction to the converted signal . 9. The temperature error correction system according to claim 7, wherein a fuel control signal of an internal combustion engine or an opening signal of an idle control valve based on the corrected flow rate is output. 10. The temperature error correction system according to claim 1, wherein the flow rate signal has a characteristic that a measurement error with respect to a flow rate is substantially constant at least at a fluid temperature of 80 ° C. and −40 ° C.