JPH028765A - Ultrasonic horn mounting structure - Google Patents

Abstract

PURPOSE:To prevent not only the promotion of reverberation but also erroneous detection by bringing the width of the protruding piece provided to the base part of a horn in a protruding state to be engaged with the opening edge part of a vibrator case to a part of the base part in the peripheral direction thereof. CONSTITUTION:An opening 4 for insertion of a base part 3a of a horn 3 is provided in the front surface plate part 2a of a vibrator case 2 receiving a vibrator 1 and a pair of engaging protruding pieces 6a, 6b in an opposed relation to each other so as to be mutually separated by the thickness of the front surface plate part 2a in the axial direction are provided to the base part 3a at a plurality of places. The widths of the protruding pieces 6a, 6b are the width of a part of the base part 3a in the peripheral direction. Notches 5 for inserting the protruding pieces 6a, 6b are provided to the edge part of the opening 4 and the protruding pieces 6b are matched with the notches 5 to insert the base part 3a of the horn 3 in the opening 4. Thereafter, by rotating the horn 3, the front surface plate part 2a is held between the protruding pieces 6a, 6b to mount the horn 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ultrasonic horn mounting structure for transmitting and receiving ultrasonic waves of 3 to 3 shades applied to an object detection device; i':/.

[1] (Next technology) Conventionally, as shown in Fig. 1t, the automatic door 51 has a human body 52
An ultrasonic transducer 53 is used to detect this.

The ultrasonic wave transmission/reception 2353 of the automatic door 51 requires detection areas of different sizes depending on the frontage of the door and the like. However, providing as many types of ultrasonic transducers 53 as f:u iff of the detection area is inefficient in manufacturing.

Therefore, we prepare many types of horns with different shapes, select them according to the site, combine them with the vibrator, and set the detection area.

FIG. 12 shows a conventional ultrasonic transducer for transmitting and receiving signals with a detachable horn. An opening 57 is provided in the front plate portion 55a of the vibrator case 55 housing the vibrator 54, and the base portion 56a of the horn 56 is inserted into the opening 57. The horn 56 is the base 56
A is provided with a brim-like protrusion 58 and an engaging protrusion 59 extending all around the circumference, and the engaging protrusion 59 is inserted from the notch fi O to form the pawn 56.
Rotate. Thereby, the transducer case 55 is attached with the front plate portion 55a sandwiched therebetween.

[Problem to be solved by the invention]

In the ultrasonic transducer described above, a human body is detected by transmitting an ultrasonic signal from the vibrator 54 and receiving a reflected wave from the human body within a certain period of time after the wave transmission.

At this time, the vibration of the vibrator 54 is transmitted to the vibrator case 55 and further transmitted to the horn 56. The horn 56 is the brim-like protrusion 5
However, since the flanged protrusion 58 is thin and continuous around the entire circumference and easily vibrates, the vibration of the vibrator 54 is transmitted to the horn 56 to a large extent.

When the horn 56 vibrates greatly, the reverberation of the horn 56 becomes large.

That is, even if the applied voltage that drives the vibrator 54 is removed, the horn 56 vibrates.

When the reverberation becomes large in this way, the reverberation remains even during the period when the reflected wave is received, and the reflected wave reflected by the human body and detected by the horn 56 cannot be distinguished from the reverberation, resulting in false detection.

Even if the transmitter and receiver are installed separately,
If they are attached to a common attachment member, vibrations will be transmitted through the attachment member, which will cause the same problem of false detection as described above.

An object of the present invention is to provide an ultrasonic horn mounting structure that allows the horn and the vibrator case to be coupled without promoting reverberation and prevents false detection.

[Means to solve the problem]

This invention provides an ultrasonic horn mounting structure in which an opening is provided in the front plate of a transducer case housing a transducer, and the horn is detachably attached by inserting the horn base into the opening. The width of the engaging protrusion that engages with the opening edge of the vibrator case is a part of the base in the circumferential direction. The vibrator and horn may be used for both transmitting and receiving waves, or may be used exclusively for transmitting waves.

[Effect]

According to the configuration of the present invention, since the width of the engaging protrusion of the horn that engages with the vibrator case is a part of the circumferential direction, the vibration of the vibrator case is difficult to be transmitted to the engaging protrusion, and the horn vibrates less. do not. Therefore, the reverberation does not become long.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS. 1 to 5. This embodiment is an example of a transmitting/receiving type.

On the front plate part 2a of the vibrator case 2 that houses the vibrator l,
An opening 4 into which the base 3a of the horn 3 is inserted is provided. base 3
A is a pair of engaging protrusions 6a facing each other and separated from each other in the axial direction by approximately the thickness of the front plate portion 2a.

6b are provided at multiple locations in the circumferential direction. Engagement protrusion 6a.

The width of 6b is a partial width of the base portion 3a in the circumferential direction.

At the edge of the opening 4 of the vibrator case 2, an engaging protrusion 6d6b is provided.
A notch 5 is provided for inserting the.

The engaging protrusion 6b and the notch 5 are aligned, and the base 3a of the horn 3 is inserted into the opening 4 of the vibrator case 2. After this, horn 3
By rotating the front plate part 2 of the vibrator case 2,
a is held between the engaging protrusions 6a and 6b, and the horn 3 is attached.

Figure 3 shows the electrical circuit. FIGS. 4(A) to 4(F) show signals a to r of each part in FIG. 3. FIGS. 5(A) and 5(B) are partially enlarged views of FIGS. 4(B) and (D), respectively.

The transmission signal a applied to the vibrator case l is obtained as follows. The integration circuit 11 starts integration at the same time as 'Q[ is turned on, and when the potential reaches a predetermined level, drives the monostable multi-bi break 12.

The monostable multi-by-break 12 receives the output signal of the integrating circuit 11 and applies an ON signal for a certain period of time to the gate 17 . Monostable multi-bi break 13 and switching circuit 1
Output to 6. The switching circuit 16 receives the signal from the monostable multi-by-break 12 and instantaneously discharges the charge stored in the integrating circuit 11. Monostable multivibrator 1
3 receives the signal from the monostable multi-bi break 12 and outputs the signal for a certain period of time. This signal determines the application time to be applied to the transducer l. Furthermore, the flipflop 22 is reset by this signal. The oscillation circuit 14 receives the signal from the monostable multi-high break 13 and outputs a high frequency signal only during the period of the signal.

This high frequency signal is amplified by the driver 15 and applied to the vibrator l. The transducer l transmits an ultrasonic signal and receives a reflected wave reflected by an object.

The weak transfer signal received by the vibrator 1 is amplified by the amplifier circuit 18, and the amplified output signal is sent to the detection circuit 19 manually. A detection circuit 19 removes high frequency components and extracts only the envelope.

The level detection circuit 20 determines whether or not the detected output C has reached a predetermined level, and continues to output a signal only while the detected output C has reached the predetermined level. The integration circuit 21 is the level detection circuit 2
It is determined whether the temporal width of the output of 0 is a predetermined width. In other words, if this time is shorter than the predetermined time, it is determined that the wave is electrical noise or the like and not a reflected wave from a sensing object. Further, the integration circuit 21 is applied with the gate signal d of the gate circuit 17, and also determines whether or not the delivery signal is within a predetermined period. The gate 17 receives the signal from the monostable multi-bibreak 12, outputs a signal after a certain period of time, and sends the signal to the integrating circuit 21. This is a so-called time gate that determines the detection distance.

, when the integrating circuit 21 determines that there is a predetermined time width and that it is within the gate period, the output is stored in the flip-flop 22. The flip-flop 22 is reset by the monostable multivibrator 13 when the next transmission signal is generated. The switching circuit 23 turns on the relay 24 while the output e of the flip-flop 22 is present.

The relay 24 outputs an output r that drives a drive source for other equipment, such as an automatic door.

The operation of the above configuration will be explained. The ultrasonic signal is transmitted from the transducer 1 by the transmission signal a (Fig. 4 (A)) outputted at a predetermined interval, and the ultrasound signal reaches a predetermined level within the gate time of the gate signal d (Fig. 4 (C)). If the reflected waves above and for a predetermined time width or more are received, it is determined that there is an object, and the relay 24 is driven.

The output b (Fig. 4 (B)) of the amplifier circuit 18 that increases the delivered signal of the transducer l (1) U includes not only the reflected wave component b1 but also the transmitted signal component b2. includes reverberation components. Therefore, if the reverberation component b3 remains long (as shown by the chain line in FIG. 5), it will take a long gate time and the reverberation component b3 will be mistakenly detected as the reflected wave component b1.

However, according to the ultrasonic horn mounting structure of this embodiment,
Engagement protrusions 6a, 6 of horn 3 that engage with vibrator case 2
Since the width b is a part of the circumferential direction, the vibration of the vibrator case 2 is difficult to be transmitted to the engaging protrusions 6a and 6b, and the horn 3 does not vibrate much. Therefore, reverberation does not remain for a long time, and there is no false detection due to reverberation, resulting in high reliability.

6 and 7 show a second embodiment, which includes:
Among the engagement protrusions 6a' and 6b' of the horn 3, the position of the engagement protrusion 6a' that engages with the front surface of the front plate portion 2a of the camera case 2, and the engagement protrusion that engages with the back surface. The position of 6b' is shifted in the circumferential direction. Even with this configuration, the same low acid reverberation effect as described above can be obtained.

8 to 10 show a third embodiment.

In this example, a transmitter 30 and a receiver 31 are provided separately, and the engaging protrusion of the first embodiment is attached to the part where the horn 3 of the transmitter 31 is attached to the vibrator case 2. The mounting structure according to 6a and 6b is applied.

The transmitter 30 and the receiver 31 are housed in a cover 32,
The vibrator case 2 is attached to the body 33. The cover 32 has a front surface formed of a net 34.

When the transmitter 30 and the receiver 31 are provided separately in this way, when the transmitter 30 transmits waves, the receiver 3! Although a transmission signal is not directly applied to the vibrator, the vibration of the transmitter 30 is transmitted to the receiver 31 via the body. If there is reverberation in the horn 3 of the transmitter 30, the reverberation will also be transmitted. However, in this embodiment, the reverberation of the vibrator l of the transmitter 30 is shortened, so that false detection is prevented.

〔Effect of the invention〕

In the ultrasonic horn mounting structure of the present invention, since the width of the engaging protrusion of the horn that engages with the transducer case is a part of the circumferential direction, the vibration of the transducer case is difficult to be transmitted to the engaging protrusion, and the horn does not vibrate much. Therefore, reverberation does not remain for a long time, and there is no false detection due to reverberation, resulting in high reliability.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of the first embodiment of the present invention, FIG. 2 is a sectional view thereof, FIG. 3 is a block diagram of the electric circuit, and FIG. 4 is an explanatory diagram of waveforms of each part. 5 is an enlarged view of a part of FIG. 4, FIG. 6 is an exploded perspective view of the second embodiment, FIG. 7 is a sectional view thereof, and FIG. 8 is a cutaway plan view of the third embodiment. Fig. 9 is a cutaway side view thereof, Fig. 10 is a perspective view thereof, Fig. 11 is an explanatory diagram of a conventional automatic door, and Fig. 1
FIG. 2 is an exploded perspective view of a conventional ultrasonic transducer. l... Vibrator, 2... Vibrator case, 2a... Front plate part, 3... Horn, 3a... Base, 4... Opening, 5... Notch, 6a, 6b ...Engaging protrusion 1 - Domukai (F) ↓136 Figure Figure Figure Figure

Claims (1)

[Claims] An opening into which the base of the horn is inserted is provided in the front plate of the vibrator case housing the vibrator, and a plurality of engaging protrusions that engage with the front and back surfaces of the edge of the opening are provided at the base of the horn. and an ultrasonic horn mounting structure in which these engaging protrusions have a partial width in the circumferential direction of the base.