JPH0442031A - Minute-gap detecting apparatus - Google Patents

Abstract

PURPOSE:To make it possible to detect a minute gap with a simple constitution by arranging many minute-gap detecting pieces on a frame body having the shape along the periphery of a member to be inspected in an array pattern. CONSTITUTION:An ultrasonic-wave inspecting sound source part 13 which has at least one ultrasonic-wave piezoelectric transducer 24 as a pseudo point sound source and has the approximately uniform radiation characteristic is arranged in a tightly sealed space which is sealed with a door (an object to be inspected) 41. The ultrasonic waves which are transmitted into the tightly sealed space from the sound source part leaks to the outside through a minute gap when there is the minute gap at a part which is sealed with the door 41 of an automobile (an object to be inspected) 12. A plurality of minute-gap detecting pieces 43 of an ultrasonic wave sensor are provided in an ultrasonic-wave leakage detecting part 14 facing the sound source part along the sealing part at the outside convert the leaking ultrasonic waves into the detected signal. The distribution of the minute gaps generated in the peripheral part of the automobile 12 can be positively detected based on the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a micro-gap detection device, and is suitable for, for example, inspecting the sealing state of an exterior member of an automobile.

[Summary of the invention]

The present invention relates to a micro-gap detection device, and in particular, by forming an array of micro-gap detectors along the peripheral edge of a member to be inspected, it is possible to reliably detect the occurrence of micro-gaps and their distribution. can.

[Conventional technology]

For example, in a car 1 as shown in FIG. 13, a large number of exterior members constituting the vehicle body, such as doors 2 and a sunroof, are configured to be able to open and close individually relative to the vehicle body. When a member is locked in the closed state, if there is a gap around the member, external sounds may enter the vehicle interior.

In order to solve this problem, conventional automobiles employ a method in which a weather strip is inserted between each exterior member and the vehicle body, as shown in FIGS. 14 to 16.

That is, as shown in FIG. 14, for example, the window frame portion of the door 2 (line A-A in FIG. 13) constituting the exterior member of the automobile 1 has a rear inner side facing the vehicle body 3 of the window frame 2A. A weather strip 4 is attached to the end, and when the door 2 is locked, the weather strip 4 deforms and is strongly pressed against the vehicle body 3 to seal the space between the vehicle body 3 and the window frame 2A. being done.

In addition, as shown in FIG. 15, a weather strip 5 is attached to the rear side of the door 2 (line B-B in FIG. 13) at a position facing the vehicle body 3 at the rear inner end 2B of the door. When the door 2 is locked, the weather strip 5 deforms and strongly presses against the vehicle body 3, thereby sealing the space between the vehicle body 3 and the rear inside end 2B of the door.

In addition, on the lower side of the door 2 (line C-C in FIG. 13), as shown in FIG. When the weather strip 6 is attached and the door 2 is locked, the weather strip 6 deforms and presses against the vehicle body 3 strongly, thereby sealing the space between the vehicle body 3 and the lower end 2C of the door. .

Here, the weather strips 4.5 and 6 have a configuration in which a flexible material is molded into a tubular cross-section, and when the door 2 as an exterior member is locked in the sealing operation position, the weather strips 4.5 and 6 are deformed so as to crush the tubular portion. Accordingly, a sealed state between the vehicle body and the exterior member can be maintained using the elasticity of the weather strip.

[Problem to be solved by the invention]

In this way, the weather strip is arranged linearly so as to bend along the periphery of the exterior member to correspond to its three-dimensional shape, so if the weather strip does not contact the vehicle body or the exterior member sufficiently, a minute gap may be formed. This may cause wind noise.

As a means for detecting such minute gaps, a method has been proposed in the past in which the ultrasonic generation source and the detection device are moved along the periphery of the exterior member (Japanese Patent Laid-Open No. 63-88424). Publication No.).

However, according to this method, a large-scale moving device is actually required to move the ultrasonic wave source and the sound receiving element along the peripheral edge of the exterior member, and there is a problem that minute gaps cannot be easily detected.

The present invention has been made in consideration of the above points, and provides a minute gap detection device that can detect minute gaps with a significantly simpler configuration when inspecting the sealing state between an exterior member and a vehicle body. This is what I am trying to propose.

[Means for Solving the Problems] In order to solve the problems, the present invention provides an ultrasonic transducer that is arranged in a sealed space sealed by the object to be inspected 41, has at least one ultrasonic transducer, and emits substantially uniform radiation. An ultrasonic inspection sound source unit 13 that can be regarded as a pseudo point sound source by giving characteristics, and a plurality of ultrasonic sensors arranged along the sealed area of the inspection object 41 so as to face the sealed area from the outside. and an ultrasonic leak detection section 14 to detect the distribution of minute gaps occurring in the sealed portion based on the detection signal of the ultrasonic sensor.

[Effect]

When the ultrasonic waves sent into the sealed space from the ultrasonic inspection sound source section 13 reach a gap at the periphery of the object to be inspected 12, if there is a minute gap in the gap, the ultrasonic wave will leak to the outside through this minute gap and generate a minute amount. The gap detector 43 converts it into a detection signal Sll.

Thus, based on the detection signal Sll generated by the minute gap detector 43, it is possible to reliably determine the distribution of minute gaps occurring at the periphery of the object to be inspected 12.

〔Example〕

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

FIG. 1 shows a microgap detection device 11 according to the present invention used to detect whether or not a microgap exists in a sealed portion between an exterior member and a vehicle body of an automobile 12 (i.e., a sealed portion formed by a weather strip). The micro gap detection device 11 is composed of an ultrasonic inspection sound source section 13 and an ultrasonic leak detection section 14.

As shown in FIGS. 2 and 3, the ultrasonic inspection sound source section 13 is constructed by attaching a bottom surface 22 of a base 21 having an external shape of a regular dodecahedron (one side having a length of 45 [■]). An ultrasonic transducer 24 made of a ceramic piezoelectric element is attached to approximately the center position of the other 11 surface portions 23, and as a result, a practically omnidirectional ultrasonic inspection sound SON is generated from the 11 ultrasonic transducers 24. is generated, thereby forming a uniform sound field.

As shown in FIGS. 2 and 4, the ultrasonic transducer 24 receives a
(This power supply state is indicated by the power-on indicator lamp 28), and the drive power input S2 is connected to the drive signal oscillation circuit section 3.
0.

The drive signal oscillator circuit section 30 includes 11 white noise oscillators 31 that are provided corresponding to the 11 vibrators 24 and that oscillate independently of each other, and are set at a predetermined frequency, for example, 40 (kHz).
A white noise signal whose main component is the ultrasonic signal component of ing.

In this embodiment, the sound pressure of the ultrasonic test sound 5ONO generated from the vibrator 24 can be adjusted by a sound pressure adjustment volume 34 provided in the amplifier circuit section 32.

When the ultrasonic inspection sound source unit 13 having such a configuration is placed at an arbitrary position inside the automobile 12 (for example, on the dash board, on the seat, etc.) in which a minute gap is to be inspected, it can detect the exterior member to be scanned (for example, A substantially uniform ultrasonic sound field can be formed in the sealed space sealed by the door 41), that is, the interior space of the automobile 12.

As shown in FIG. 5, the ultrasonic leak detection unit 14 includes a frame body 42 having an inner surface 42A shaped along the outer periphery of a door 41, which is an exterior member in which minute gaps are to be detected, and conforms to the three-dimensional shape of the door 41. has.

In this way, when the frame 42 is applied along the outer periphery of the door 41 from the outside with the door 41 to be inspected in a locked state, the inner surface of the frame 42 comes into close contact with the outer periphery of the door 41. In this state, a plurality of micro gap detectors 43 are arranged in an array at positions facing the outer peripheral edge of the door 41 and scattered in a line at a predetermined interval. be done.

In this embodiment, the frame 42 includes, as shown in FIG.
A large number of through holes 45 are drilled at regular intervals across the thickness, and by inserting a micro gap detector 43 having a pen shape as a whole into each through hole 45, the micro gap detector 43 can be detected. It is designed so that it can be held on the frame 42 across its thickness.

As shown in FIGS. 7 to 10, the minute gap detector 43 is
An ultrasonic sensor 46 is attached to the inner end surface 43 IN, and a display element 47 made of, for example, a light emitting diode is attached to the outer end surface 43 OUT.

The microgap detector 43 has a cylindrical outer shape as a whole, and the diameter of the inner half 43A is tapered so that it becomes thinner as it approaches the inner end surface 431N. The through hole 45 of the body 42 (FIG. 6) is tapered so as to become narrower from the outer side surface 450UT to the inner side surface 451N.

Thus, when the minute gap detector 43 inserts its inner half 43A into the through hole 45 of the frame 42 from the outer side surface 450UT side, the tapered surface of the inner half 43A matches the tapered surface of the through hole 45. By being sandwiched between the two, the micro gap detector 43 is inserted and held in such a way that it does not easily fall off from the frame body 42.

In this way, the minute gap detector 43 is arranged with its inner half 43A inserted and held in the through hole 45 of the frame 42, and its outer half 43B protruding toward the outer end surface 450UT side of the frame 42. By doing so, the outer end surface 430U
The display elements 47 attached to the T are arranged in a line along the periphery of the door 41, so that an inspector outside the frame 42 can easily check whether the display elements 47 are lit or not. It is designed so that it can be visually confirmed.

As shown in FIG. 11, the minute gap detector 43 supplies the detection signal S11 obtained at the output terminal of the ultrasonic sensor 46 to the judgment display circuit 51, and detects the display element by the judgment output signal S12 obtained at the output terminal. 47 is driven to light up.

As shown in FIG.
The amplified output S21 is extracted by a bandpass filter circuit 53 to extract a signal component in a frequency band having a main component of 40 [k) tz), and the filter output S2
2 is detected in the detection circuit 54, and an evaluation output 324 indicating whether the signal level of the DC level detection output S23 exceeds the reference level is supplied to the display drive circuit 56 in the evaluation circuit 55. A display drive output S25 is supplied to the display element 47 such that the display element 47 is turned on when the value exceeds the value, whereas the display element 47 is turned off when the value is not exceeded.

In the case of this embodiment, the detection amplification circuit 52 is provided with a gain adjuster 57 for adjusting its amplification degree, and the adjustment hole 58 (seventh
By adjusting the gain adjuster 57 with an adjustment jig (for example, a driver) through the figure), by adjusting the signal level of the detection output S23 with respect to the evaluation level in the evaluation circuit 55, the standard for evaluating the presence or absence of a minute gap can be set. The level can be adjusted relatively.

Further, in the case of this embodiment, a pair of screws 61A and 61B constituting a power supply terminal are provided on the outer half 43B of the minute gap detector 43, and the minute gap detector 43 is connected to the through hole 45 of the frame 42. In the inserted state, the outer side surface 4 of the frame body 42
By protruding outward from the screws 61A and 62B from 50UT, power can be easily supplied to each minute gap detector 43 as needed.

In the above configuration, when inspecting whether or not there is a minute gap in the weather strip when the door 41 of the automobile 12 is locked, the ultrasonic inspection sound source section 13 is attached to a part of the interior of the automobile 12, for example, a dash board. At the same time, the ultrasonic leak detection section 14 is attached to the peripheral edge of the door 41.

In this state, the ultrasonic inspection sound source section 13 forms a substantially uniform sound field in the sealed space, that is, the interior of the automobile 12, using the ultrasonic waves generated from the 11 transducers 24, and therefore, the ultrasonic inspection sound source section 13 forms a substantially uniform sound field in the sealed space, that is, in the interior of the automobile 12. The weather strip inserted between the

If there is a minute gap between the weather strips 4 to 6 (FIGS. 14 to 16) attached to the door 41 and the vehicle body 3, the ultrasonic waves that have passed through the minute gap will detect the ultrasonic leak. 14, whereas the weather strips 4 to 6
If there are no micro gaps throughout the ultrasound inspection sound source section 13
The ultrasonic waves emitted from the sensor are blocked by the weather strips 4 to 6, so that they cannot reach the ultrasonic leak detector 14.

In this state, the through holes 45 arranged in an array on the inner surface of the ultrasonic leak detection unit 140 frame 42 are connected to the vehicle body 3.
They are arranged along the gap between the door 41 and the door 41.

Therefore, among the weatherstrips 4 to 6, ultrasonic waves leaking from a position where a minute gap is created in the weatherstrips 4 to 6 propagate to the through hole 45 facing the minute gap or the vicinity thereof and are inserted into the through hole 45. The detected signal is converted into a detection signal Sll by the ultrasonic sensor 46 of the small gap detector 43.

This detection signal Sll is subjected to judgment processing in the judgment display circuit 51, so that a judgment output signal S12 is obtained only for the minute gap detector 43 whose signal level is higher than the evaluation standard level set in the evaluation circuit 55. The display element 47 lights up.

Here, the signal level of the detection signal 311 corresponds to the intensity of the ultrasonic sound propagated to each through hole 45, and therefore corresponds to the distance between the minute gap created in the weather strips 4 to 6 and each through hole 45. Correspondingly, as a result, among the minute gap detectors 43 arranged in an array on the frame body 42, the display element 47 of the minute gap detectors 43 that are lit and the portion of the opposing weather strip are higher than the rating standard level of the rating circuit 55. This indicates that ultrasonic waves with the strength of sound are leaking out.

In this manner, the inspector can determine the distribution of micro gaps occurring at the peripheral edge of the door 41 by reading the distribution of the lit micro gap detectors 43 of the ultrasonic leak detector 14.

According to the above configuration, when the door as an exterior member is locked with respect to the vehicle body, whether or not a minute gap is generated at the peripheral edge thereof, and if so, the distribution state of the minute gap, such as the range thereof, can be determined. By visually checking the lighting state of the micro gap detector 43 of the ultrasonic leak detector 14, the inspector can easily and reliably read the information.

Accordingly, according to this embodiment, the ultrasonic examination sound source section 13 uses a predetermined frequency (that is, 40 (klh)).
By using white noise whose main component is ultrasonic waves, it is possible to effectively avoid the possibility of locally generating standing waves in the interior space of the automobile, and thus to further improve the accuracy of detecting minute gaps. I can do it.

Further, according to this embodiment, by driving the plurality of transducers 24 as the ultrasonic inspection sound source section 13 by independent drive systems, a more uniform ultrasonic sound field is formed in the interior space of the automobile 1. can do.

Furthermore, according to this embodiment, since the transducer 24 is disposed as the ultrasonic inspection sound source section 13 on the base 21 having a regular dodecahedral external shape, the ultrasonic sound can be more evenly distributed in the interior space of the vehicle. It is possible to create a field.

[2] Other embodiments (1) In the above embodiments, the ultrasonic examination sound source section 13
Although a regular dodecahedron base 21 was used as the
The shape of the base 21 is not limited to this, and various shapes can be applied.In short, a plurality of vibrations can be formed at a position where ultrasonic waves can be transmitted from the ultrasonic inspection sound source section 13 in a three-dimensionally uniform direction. All you need to do is make it possible to place children.

(2) In the above embodiment, a case was described in which the door 41 was attached as an exterior member to the main body of a car as a target for micro-gap detection, but it may also be applied to other exterior members, such as a sunroof, or It can be widely applied to detecting minute gaps in closed spaces.

〔Effect of the invention〕

As described above, according to the present invention, by arranging a large number of microgap detectors in an array in a frame having a shape that follows the periphery of the member to be inspected, Therefore, it is possible to easily realize a micro-gap detection device that can easily and reliably detect the distribution of micro-gap that may occur due to the occurrence of micro-gaps.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a microgap detection device according to the present invention, FIGS. 2 and 3 are a front view and a plan view showing an ultrasonic inspection sound source section, and FIG. 4 is an ultrasonic inspection sound source. FIG. 5 is a perspective view showing the configuration of the ultrasonic leak detection unit shown in FIG. 1, FIG. 6 is an enlarged perspective view showing the detailed configuration of FIG. 5, FIGS. Figures 8, 9 and 10
The figure shows a plan view, left side view, front view, and right side view of the minute gap detector 43 in FIG. 6, and FIG. 11 shows the minute gap detector 4.
12 is a block diagram showing the signal processing circuit of the minute gap detector, FIG. 13 is a perspective view of the route showing the automobile as the subject of minute gap inspection, and FIGS. 14 to 16. The figure is a cross-sectional view for explaining a minute gap to be detected in an automobile. 1...Car, 2.41...Door, 3
...Vehicle main body, 4-6...Weather strip, 11...Minute gap detection device, 12...
...Car, 13...Ultrasonic inspection sound source section,
14... Ultrasonic leak detection section, 42...
Frame body, 43... Micro gap detector, 46...
...Ultrasonic sensor, 47...Display element.

Claims (1)

[Claims] Disposed in a sealed space sealed by an object to be inspected,
An ultrasonic inspection sound source section that has at least one ultrasonic transducer and has almost uniform radiation characteristics so that it can be regarded as a pseudo point sound source, and an ultrasonic leak detection unit that arranges and holds a plurality of ultrasonic sensors so as to face the sealed area, and detects the distribution of minute gaps occurring in the sealed area based on the detection signals of the ultrasonic sensors. A micro gap detection device characterized by: