JPH0679034B2 - Acceleration tester - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an acceleration tester used for testing an airbag sensor, for example.

[Conventional technology]

One of the acceleration testers for carrying out an operation confirmation test of an acceleration sensor for detecting the operation timing of an airbag in an airbag unit mounted in an automobile or the like and used for saving lives in the event of a vehicle collision. 2. Description of the Related Art There is an electromagnetic solenoid type in which a mover side having a test stand on which is mounted is rapidly driven by an electromagnetic force to obtain a desired collision acceleration for a test.

Figure 5 shows this electromagnetic solenoid type tester.
In the figure, reference numeral 1 is an E-shaped stator (field yoke), which is made of a magnetic material and to which a field coil (field coil) 2 is attached. A track 3 extends horizontally from a central leg 1A extending through the field coil 2, and the other end of the track 3 is supported by a receiving portion 4 located at a predetermined distance from the central leg 1A. Reference numeral 5 denotes a cylindrical air-core mover (aluminum armature coil) with openings at both ends, and free wheels are provided on the upper and lower inner circumferences on one end side.
6U and 6D are attached, and a test stand 7 for mounting a test piece (acceleration sensor) 8 and sensors extends from the other end, and a free wheel 6C is attached to the lower side of the test stand 7. It is worn.
The mover 5 is fitted onto the central leg 1A by engaging the free wheels 6U and 6D with the upper and lower surfaces of the central leg 1A, and the free wheel 6C of the test stand 7 engages with the upper surface of the track 3. Reference numeral 9 is a power supply device that supplies electric power to the field equator 2, 10 and 11 are power supply lines, and 12 is a field power supply.

In this configuration, when the test piece 8 is tested, a field current is passed through the field coil 2 and the power supply 9
Then, an acceleration command Pg as shown in FIG. 4 (a) is given to supply electric power whose envelope waveform is similar to the envelope waveform shown in FIG. As a result, a thrust force acting in the direction of the solid arrow in the figure acts on the mover 5. Upon receiving this thrust, the mover 5 is rapidly accelerated, travels on the center leg 1A and the track 3, and is accelerated to a predetermined test collision acceleration.

[Problems to be Solved by the Invention]

By the way, the tester has a fixed mechanical loss L _C due to the traveling friction of the mover 5 and a dynamic mechanical loss L _M (both are shown in FIG. 4 (a)) which is a speed function. Even if the acceleration command Pg is precisely calculated and given, the acceleration actually applied to the mover 5 is different from the acceleration command Pg. FIG. 4 (b) shows the speed of the mover 5, and the dynamic loss L _M is a function of this speed.

Therefore, the acceleration command Pg is given to drive the mover 5, and the actual acceleration actually used for the mover 5 is detected to calculate the acceleration command Pg.
Comparing with the above, a work such as correcting the acceleration command Pg is performed to create an optimum acceleration command. Six types of acceleration commands will be created as described above.

Anyone can think of using an acceleration sensor to detect the actual acceleration, but this acceleration sensor is expensive, and not only is it troublesome to install, but it also takes time and effort for adjustment. There is a problem that it takes time to prepare for the above-mentioned operation confirmation test.

The present invention has been made to solve the above problems,
An object of the present invention is to provide an acceleration tester capable of reducing the labor and time required for the pre-stage of the test specimen test as compared with the conventional one.

[Means for Solving the Problems]

In order to achieve the above object, the present invention has an arithmetic processing unit that calculates a sine-wave acceleration command based on various constants given through an input device, and a distance measuring device for detecting the actual acceleration of the mover. The processing device takes in the output of the distance measuring device corresponding to the transmitted acceleration command, calculates the actual acceleration of the mover from the output, and judges and corrects the appropriateness of the transmitted acceleration command based on this actual acceleration. It is configured to perform.

[Action]

In the present invention, instead of the acceleration sensor, a distance measuring device is used that does not substantially require manual adjustment after once disposing or attaching a magnet scale or encoder,
Since the actual acceleration of the mover is calculated from the output value, the labor and time required for the pre-stage of the test specimen test can be reduced.

〔Example〕

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

In FIG. 1, reference numeral 21 is an input device, 22 is an arithmetic processing unit (microcomputer CPU), and 23 is a memory serving as a commander, which has an output memory 23A and an input memory 23B.
Reference numeral 24 is a distance measuring device (in this example, a magnescale), and its distance output l _F is fed back to the input memory 23B. 25 is a power supply device (inverter of PWM control system). This power supply device 25 is a PWM-controlled inverter that functions as a power amplifier, and is composed of four power transistors T _R1 , T _R2 , T _R3 and T _R4 connected in a bridge as shown in FIG. A mover (armature coil) 5 is inserted between the AC output terminals A and B. D is a flywheel diede. 26 is an electrolytic capacitor, 27 is a rectifier, 28 is a controller of the inverter 25, 29 is a PWM signal generation circuit, 30 is a hase drive circuit, and 31 is a single-phase AC power supply.

The operator inputs to the input device 21 the number of patterns of the acceleration command, the test collision acceleration g, and the time width of the acceleration command.
The time width T _{2 of} T ₁ and the braking command (not shown) is keyed in. CPU22 acceleration command value acceleration command Pg ₁ for each sampling interval T _S for the first test step on the basis of this input, the acceleration command value for each sampling interval T _S of the acceleration command Pg ₁ for the second test step.. , Output memory 23A by calculating the acceleration command value of Pg _N for the Nth test step
To store. In this calculation, the fixed mechanical loss L _C described above is given as a preset value.

When the command waveform suitability test is started, the acceleration command values of the first test step acceleration command Pg _{1 in} the output memory 23A are sequentially read and sent to the PWM generating circuit 29 of the power supply device 25. The PWM signal generation circuit 29 compares this with a carrier wave (for example, carrier frequency 6 KHz) to create a PWM signal. The base drive circuit 30 generates a base drive signal based on this PWM signal and supplies it to the bases of the transistors _TR1 and _TR4 . As a result, both transistors T _R1 and T _R4 start the switching operation, and the envelope waveform is applied to the mover 5 by the acceleration command Pg.
A current with a waveform similar to the envelope waveform of ₁ (maximum value, for example, 300
Amperes) are supplied and the mover 5 is rapidly accelerated to reach a predetermined collision acceleration g. Then, the output l _F1 of the additional distance measuring device 24 corresponding to the acceleration command value of the acceleration command Pg ₁ for the first test step is sampled and input to the input memory 23B. When the reading of the acceleration command Pg ₁ for the first test step is completed and the mover 5 is returned to the original position and can be re-driven, the acceleration command values of the second acceleration command Pg ₁ in the output memory 23A are sequentially supplied to the power source. The output P _F g ₂ of the distance measuring device 24 corresponding to this acceleration command value is input to the input memory 23B, which is read out to the PWM generation circuit 29 of the device 25. Then, during this time, the CPU 22 causes the sampling value l of l _F1 to
Perform the following formula for _FS Determining a pass-fail acceleration command Pg ₁ is compared with the acceleration command value of the actual acceleration alpha _FS and acceleration command Pg _1, if the case is a failure indicated by the chain line in FIG. 5 (a) Then, the contents of the output memory 23A are rewritten with the corrected acceleration command value Pg ₁ . Acceleration command Pg ₂ of the operation for the second test step, the acceleration command Pg ₃ for the third test step
... is repeated for the acceleration command Pg _N for the N-th test step, and thus the output memory 23A stores various kinds of optimum acceleration commands, and in the operation confirmation test of the sample, the output memory 23A of this memory 23 is stored. Is used as a commander. The transistors T _R2 and T _R3 are driven ON / OFF when the mover 5 is braked, and supply a braking current to the mover 5.

As described above, in this embodiment, the moving distance l _F of the mover 5 is measured by the distance measuring device 24, and the actual acceleration is obtained by calculation. Since the distance measurement device 24 that does not require manual adjustment is used, the adjustment work such as in the case of using an acceleration sensor is unnecessary, and the preparatory industry before the main test such as the creation of an acceleration command is compared with the conventional one. It can be completed in a short time.

Incidentally, FIG. 3 shows another embodiment of the present invention.
Without using the memory 23, the acceleration command Pg
Is directly sent through the input / output interface 22A, and the arithmetic processing unit 22 directly takes in the output l _F of the distance measuring device 24 through the input / output interface 22A to calculate the actual acceleration. The difference from the embodiment of FIG. 1 is that the appropriateness determination and correction of the acceleration command are performed in time series.

Further, in each of the above embodiments, the magnescale is used as the distance measuring device, but the present invention is not limited to this, and the same effect can be obtained by using an encoder, for example.

〔The invention's effect〕

As described above, the present invention uses, instead of the acceleration sensor, a distance measuring device that does not substantially require manual adjustment after it has been installed or attached, and calculates the actual acceleration of the mover from its output value. Since it is sought, the labor and time required for the pre-stage of the specimen test can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram of a power supply device in the above embodiment, FIG. 3 is a block diagram showing another embodiment of the present invention, and FIG. FIG. 5 is a partial cross-sectional side view showing an example of the acceleration tester to which the above embodiment is applied. 1 …… stator, 5 …… mover, 21 …… input device, 22 ……
Processing unit, 22A ... Input / output interface, 23 ...
… Memory, 23A …… Output memory, 23 …… Input memory, 24
...... Distance measuring device, 25 …… Inverter which is the power supply device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page Examiner Katsumi Enari

Claims (2)

[Claims] 1. A stator equipped with a field coil, a mover which is an air-core coil, a test stand integrally provided on the mover, an acceleration command having a predetermined waveform is amplified and supplied to the mover. Which includes a power supply device, a calculation processing device that calculates a sine wave acceleration command based on various constants given through an input device, and a distance measuring device for detecting the actual acceleration of the mover. The output of the distance measuring device corresponding to the transmitted acceleration command is taken in, the actual acceleration of the mover is calculated from the output, and the propriety determination and correction of the transmitted acceleration command are performed based on this actual acceleration. Characteristic acceleration tester. 2. The power supply unit is a PWM for amplifying the power of the acceleration command.
The acceleration tester according to claim 1, wherein the acceleration tester is a control type single-phase inverter.