FREQUENCY TEST METHOD OF AIRFLOW MACHINE

Abstract

A frequency test method of an airflow machine for measuring flow data of an air flow meter is disclosed. A device under test is fixed on the airflow machine to test. In the frequency test method, a sampling program or a comparison program is chosen, and then a data is measured sequentially, which data comprises the value of static frequency, accelerating curve, air charge temperature, thermistor, atmospheric pressure, flow curve, and frequency amplitude, completing a frequency test procedure. Therefore, after the air flow meter is tested, the scale of the air flow meter is kept in standard scale to use.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates a frequency test method of an airflow machine. More particularly, a test method for checking if every brand of the air flow meter meets a qualified value is disclosed, so that the scale of the air flow meter is kept in standard scale to use.

Description of Related Art

Fresh air passes through the air inlet duct, the air cleaner, and the throttle to move to the engine. The throttle is the accelerator, which is the only one mechanism in the whole engine controlled by the user. The traditional throttle comprises a main air inlet channel and a throttle valve controlled by a spring. When the driver does not step on the gas pedal, the throttle valve is closed to keep out the air. When the driver steps on the gas pedal, the spring of the throttle valve is pulled by a throttle cable to open the throttle valve, so that the air passes through the air inlet duct into the engine.

Besides, an air flow meter, also called as air flow sensor, is responsible for detecting the changes of the air flow and converting the changes to a voltage signal to send to the electronic control unit for determining the basic injection quantity. When the cleaning air corresponding to the load of the engine is supplied, the air flow meter directly and indirectly estimates the mass of the air, and the air is mixed with the gas to form an optimum mixture. However, after the air flow meter is produced, there is not a proper testing machine to precisely test whether the air flow meter meets the standard.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a frequency test method of an airflow machine. More particularly, a test method for checking if every brand of the air flow meter meets a qualified value is disclosed, so that the scale of the air flow meter is kept in standard scale to use.

For the above object, a frequency test method of an airflow machine for measuring flow data of an air flow meter is disclosed. A device under test is fixed on the airflow machine to test. In the frequency test method, a sampling program or a comparison program is chosen, and then a data is measured sequentially, which data comprises the value of static frequency, accelerating curve, air charge temperature, thermistor, atmospheric pressure, flow curve, and frequency amplitude, completing a frequency test procedure. Therefore, after the air flow meter is tested, the scale of the air flow meter is kept in standard scale to use.

According to an embodiment, under the sampling program, after the inputting step, a multistage flow rate is set for measuring the data under different flow rate.

According to an embodiment, under the comparison program, a test mode or a batch/rework mode is chosen according to the amount of the air flow meter under testing.

According to an embodiment, under the test mode, after the inputting step, a measuring and comparison item is checked, and a parameter is set. After the comparison step, an error between a comparing data and a sampling data is calculated, and a report is printed.

According to an embodiment, under the batch/rework mode, after the inputting step, a serial number of a batch is inputted, and then a measuring and comparison item is checked and a parameter is set. After the comparison step, an error between a comparing data and a sampling data is calculated, and a report is printed.

According to an embodiment, under the batch/rework mode, the statistics and analysis of the measured data of the air flow meter under each serial number is processed and the statistics and analysis result is saved. Finally, a case report of the statistics and analysis result is printed According to an embodiment, every device under test (air flow meter) comprises a QR code for reading the testing data of the air flow meter immediately

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a flow chart I of a frequency test method of an airflow machine according to the embodiment of the present invention;

FIG. 1B is a flow chart II of a frequency test method of an airflow machine according to the embodiment of the present invention;

FIG. 1C is a flow chart III of a frequency test method of an airflow machine according to the embodiment of the present invention; and

FIG. 2 is a screen display of a frequency test method of an airflow machine under a sampling program according to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

First, when a frequency test method is carried out, a device under test is fixed on an airflow machine. The airflow machine comprises a blowing apparatus, an air inlet duct, a throttle, a testing jig, a flow sensor, and a filter. The foregoing structure of the airflow machine is the same as the traditional airflow machine, so it is not described again. Please refer to FIG. 1A-1C and FIG. 2, which are a flow chart of a frequency test method of an airflow machine and a screen display of a frequency test method of an airflow machine under a sampling program according to the embodiment of the present invention. In detail, please refer to FIG. 1A, when a frequency test method of an airflow machine is carried out, a device under test is fixed on the testing jig of the airflow machine which is connected with a computer control system (not shown in the figure). When the test is started, a sampling program or a comparison program is chosen according to the device under test. If the device under test is an airflow machine having new specification, the sampling program is run (please refer to FIG. 1B). If the sampling data is already recorded in the computer control system, the comparison program is run. When the sampling program is run, the program is initialized first, and the information of the device under test is inputted into the computer control system. Then, a multistage flow rate is set for measuring the data under different flow rate. Next, the sampling is started. The air is sucked into the air inlet duct from the filter via the action of the blowing apparatus, and blades of the throttle are opened by the control of a motor. The volume of air inflow is proportional to the open angle of the blades. Moreover, the flow rate of air inflow is measured by the flow sensor, and data of static frequency, accelerating curve, air charge temperature, thermistor, atmospheric pressure, flow curve, and frequency amplitude of the device under test are measured sequentially. The function and safety of the vehicle influenced by the foregoing measuring items are described in Table 1.

TABLE 1
Item	Object	Main Function	Abnormal Result
Static	Check the range	Electronic control	Abnormal static
frequency	of the static	unit receives the	frequency results
	frequency	signal of the static	that the engine
		frequency to adjust	trembles seriously
		the signal such as	or does not work;
		idle air control	when the serious
		(IAC) and	abnormal
		electronic throttle	condition is
		control (ETC)	happened, a
		before the engine	malfunction
		is started and	indicator lamp
		during the engine	and a fault code
		is starting.	of the air input
			system are
			displayed.
Acceleration	Mimic rapid	Use when rapid	The powerless of
curve	acceleration or	acceleration or	acceleration is
	deceleration of	deceleration of the	happened during
	the actual vehicle	vehicle, the	climbing or high
	and measure the	acceleration ability	speed, the control
	response speed of	during climbing or	time of enforced
	the product	high speed, and	kickdown
		control the time of	operation is too
		enforced kickdown	late, resulting in
		operation	poor driveability
			and big trembles
			during the shift.
Air charge	Measure the air	Confirm that the	The difference
temperature	charge	environment	between the
	temperature and	temperature of the	environment
	record	airflow test	temperature of
		machine during	the airflow test
		sampling and	machine during
		comparing is the	sampling and
		same.	comparing leads
			to erroneous
			judgement of the
			system, resulting
			in engine tremble
			of the actual
			vehicle or display
			of the
			malfunction
			indicator lamp.
Thermistor	Check the	Electronic control	The fuel spray is
	function of the	unit receives the	excessive or
	thermistor	thermistor voltage	insufficient, and
		to calculate the air	the malfunction
		charge temperature	indicator lamp
		in the air inlet duct,	and the fault code
		so as to fine-tuning	of the intake
		the signal of fuel	system are
		spray of the engine	displayed.
		due to the
		difference of the
		temperature and
		climate.
Atmospheric	Check the	Electronic control	The fuel spray is
pressure	function of	unit receives the	excessive or
	detection of the	voltage to adjust	insufficient. The
	atmospheric	the signal of fuel	vehicle stalls and
	pressure	spray according to	trembles easily
		the different	under idle RPM
		atmospheric	and is not easy to
		pressure, and the	start, and is
		idle RPM is	powerless when
		controlled by IAC	going on the
		or ETC.	mountain road.
			When the serious
			abnormal
			condition is
			happened, the
			malfunction
			indicator lamp
			and a fault code
			of the air input
			system are
			displayed.
Flow curve	Mimic the	Electronic control	The serious
	condition of the	unit receives the	abnormal
	actual vehicle	voltage signal	condition results
	and check the	(frequency) to	that the operation
	signal	control the air flow	of start, idle, air
	corresponding to	from start to idle	conditioner, and
	idle, gear change,	and the air flow	drive are not
	air conditioner	under different	smooth. The fuel
	and different	speed such as low	spray is excessive
	speed such as	speed, medium	or insufficient,
	low speed,	speed, and high	and the flashover
	medium speed,	speed, so as to	time is too fast or
	and high speed.	control the engine	too slow. When
		related elements	the serious
		such as the fuel	abnormal
		spray, the ignition	condition is
		time, and the gear	happened, the
		change time of the	malfunction
		transmission.	indicator lamp
			and a fault code
			of air input,
			exhaust and
			engine system are
			displayed.
Frequency	Check the peak	Electronic control	The peak value is
amplitude	value of the	unit receives the	too low to read by
	frequency signal	peak value of the	the electronic
		frequency to	control unit,
		control the drive	resulting that the
		signal from start to	engine does not
		idle.	work or is not
			easy to start. The
			peak value is too
			high resulting that
			the short circuits
			of electronic
			control unit.
			When the serious
			abnormal
			condition is
			happened, the
			malfunction
			indicator lamp
			and a fault code
			of air input
			system are
			displayed.

After the foregoing items are measured, the data is saved, and if the sampling step is not run again, the sampling program is quit. Otherwise, the sampling program is chosen again, and the sampling step is processed again according to the foregoing steps.

When a standard flow data of the air flow meter is set up in the computer control system according to the sampling data, the measuring data is compared with the standard data called out from the system in the comparison step. In detail, please refer to FIG. 1C, when the comparison program is chosen, a test mode or a batch/rework mode is chosen according to the amount of the device under test. If the device under test is single one, the test mode is chosen, and then the information of the device under test is inputted. According to the items of the flow rate which is need to measure, the comparison items are checked, and then the parameter is set. Next, the comparison step is started. The air is sucked into the air inlet duct from the filter via the action of the blowing apparatus, and blades of the throttle are opened by the control of a motor. The volume of air inflow is proportional to the open angle of the blades. The flow rate of air inflow is measured by the flow sensor, and data of static frequency, accelerating curve, air charge temperature, thermistor, atmospheric pressure, flow curve, and frequency amplitude of the device under test are measured sequentially. The object, the function, and the abnormal results of the measuring items are mentioned previously. The measuring data is compared with the sampling data, and an error between a comparing data and a sampling data is calculated after the comparison step. Finally, the report is printed. After printing, if the comparison step under the test mode is not run again, the program is quit. Otherwise, the comparison step under the test mode is chosen again, and the comparison step is processed again according to the foregoing steps.

Please refer to FIG. 1C, if the device under test is in large quantities, the batch/rework mode is chosen, and then the information and the serial number of the device under test are inputted. According to the items of the flow rate which is need to measure, the comparison items are checked, and then the parameter is set. Next, the comparison step is started. The air is sucked into the air inlet duct from the filter via the action of the blowing apparatus, and blades of the throttle are opened by the control of a motor. The volume of air inflow is proportional to the open angle of the blades. The flow rate of air inflow is measured by the flow sensor, and data of static frequency, accelerating curve, air charge temperature, thermistor, atmospheric pressure, flow curve, and frequency amplitude of the device under test are measured sequentially. After the measuring data is compared with the sampling data, an error between a comparing data and a sampling data is calculated, and the report is printed. Finally, statistics and analysis of the measuring data of the air flow meter under every serial number are processed, and then the statistics and analysis results are saved. After the batch measurement is completed, if the batch/rework mode is not run again, the case report of the statistics and analysis result is printed and the program is quit. Otherwise, the comparison step under the batch/rework mode is chosen again, and the comparison step is processed again according to the foregoing steps.

Furthermore, whether the flow data of the device under test meets the standard, all data are recorded in the data of its serial number, and each air flow meter comprises a QR code for reading the testing data of the air flow meter immediately. Moreover, when the device under test does not meet the standard, the data recorded in the QR code could be called out as the adjustment basis.

Claims

1. A frequency test method of an airflow machine for measuring flow data of an air flow meter, the frequency test method comprising the step of: choosing a sampling program or a comparison program;inputting a product information;starting sampling or comparison, wherein data of static frequency, accelerating curve, air charge temperature, thermistor, atmospheric pressure, flow curve, and frequency amplitude are measured or compared sequentially; andsaving and printing the data.

2. The frequency test method of the airflow machine according to claim 1, under the sampling program, after the inputting step further comprising the step of: setting multistage flow rate for measuring the data under different flow rate.

3. The frequency test method of the airflow machine according to claim 1, under the comparison program, further comprising the step of: choosing a test mode or a batch/rework mode according to the amount of the air flow meter under testing.

4. The frequency test method of the airflow machine according to claim 3, under the test mode, after the inputting step further comprising the step of: checking a measuring and comparison item;setting a parameter;calculating an error between a comparing data and a sampling data after the comparison step; andprinting a report.

5. The frequency test method of the airflow machine according to claim 3, under the batch/rework mode, after inputting step further comprising the step of: inputting a serial number of a batch;checking a measuring and comparison item;setting a parameter;calculating an error between a comparing data and a sampling data after the comparison step; andprinting a report.

6. The frequency test method of the airflow machine according to claim 5, under the batch/rework mode, further comprising the step of: processing statistics and analysis of the measured data of the air flow meter under each serial number;saving the statistics and analysis result after the processing step; andprinting a case report of the statistics and analysis result.

7. The frequency test method of an airflow machine according to claim 6, wherein each air flow meter comprises a QR code for reading the testing data of the air flow meter immediately.