JPH04238498A - Ultrasonic sensor - Google Patents

Abstract

PURPOSE:To prevent deterioration in the reverberation characteristic due to invasion of water so as to prevent a near distance range finding performance from being lost and to protect a radiation face of an ultrasonic vibrator so as to improve the reliability. CONSTITUTION:The ultrasonic sensor is realized by arranging a cushioning material 2 to surround an ultrasonic vibrator 1 and sending/receiving an ultrasonic wave via an opening 2a for ultrasonic wave transmission and reception of the cushioning material 2, and a seal layer 6 made of a thin rubber blocking the opening 2a to a radiation face of the ultrasonic vibrator 1 and the ultrasonic wave is sent/received via the seal layer 6. The seal layer prevents invasion of water to a gap between the ultrasonic vibrator and the buffer member.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor that transmits and receives ultrasonic waves to detect obstacles.

0002

2. Description of the Related Art Conventionally, this type of ultrasonic sensor for detecting obstacles by transmitting and receiving ultrasonic waves includes an ultrasonic transducer 1 and an ultrasonic transducer for transmitting and receiving ultrasonic waves, as shown in FIGS. 3 and 4. opening 2
a and a buffer member 2 that surrounds the ultrasonic transducer 1, and the ultrasonic transducer 1 transmits ultrasonic waves through an opening 2a and receives reflected waves from obstacles. was. In the figure, numeral 3 denotes a shield wire for inputting and outputting transmission signals and reception signals, and numeral 4 denotes a sound absorbing material that prevents sound from entering and exiting from the rear of the ultrasonic transducer 1.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, water may enter through the gap 5 formed between the ultrasonic transducer 1 and the buffer member 2. There was a problem that the reverberation characteristics deteriorated due to the intrusion. That is, when the ultrasonic transducer 1 is driven with a tone burst signal as shown in FIG. 5(a), the reverberation time t1 becomes unstable and becomes long as shown in FIG. 5(b), and this reverberation When there is sound, reflected waves from obstacles cannot be identified, so there is a problem in that short-range distance measurement performance is impaired. Note that FIG. 5(c)
This shows the reverberation characteristics when no water has entered.

[0004] The present invention aims to solve the above problems, and is capable of preventing deterioration of reverberation characteristics due to water intrusion and preventing short-range ranging performance from being impaired. The present invention aims to provide an ultrasonic sensor in which the radiation surface of an ultrasonic transducer is protected.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises an ultrasonic transducer and a buffer member surrounding the ultrasonic transducer and having an opening for transmitting and receiving ultrasonic waves. In an ultrasonic sensor that uses a sonic vibrator to transmit ultrasonic waves through an aperture and to receive reflected waves from obstacles, a sealing layer made of thin rubber or the like that closes the aperture is attached to the ultrasonic vibrator. The ultrasonic wave is transmitted and received through the sealing layer.

[0006]

[Operation] According to the above configuration, in the ultrasonic sensor in which the buffer member is arranged so as to surround the ultrasonic transducer and ultrasonic waves are transmitted and received through the opening for transmitting and receiving ultrasonic waves in the buffer member, the opening is A sealing layer made of thin rubber or the like is adhered to the radiation surface of the ultrasonic transducer, and ultrasonic waves are transmitted and received through the sealing layer, so that no water is present between the ultrasonic transducer and the buffer member. The sealing layer prevents the intrusion of water, prevents deterioration of reverberation characteristics due to water intrusion, and prevents short-range ranging performance from being impaired. can be protected.

[0007]

[Embodiment] Figs. 1 and 2 show an embodiment of the present invention, which is composed of an ultrasonic transducer 1 and a buffer member 2 surrounding the ultrasonic transducer 1 and having an opening 2a for transmitting and receiving ultrasonic waves. In an ultrasonic sensor similar to the conventional example in which the ultrasonic transducer 1 transmits ultrasonic waves through the aperture 2a and receives reflected waves from obstacles, a thin A sealing layer 6 made of rubber or the like is adhered to the radiation surface of the ultrasonic transducer 1, and ultrasonic waves are transmitted and received through the sealing layer 6.

In the present embodiment, a sealing layer 6 made of thin rubber or the like that closes the ultrasonic transmission/reception opening 2a of the buffer member 1 is adhered to the radiation surface of the ultrasonic transducer 1. The seal layer 6 can prevent water from entering the gap 6 formed between the ultrasonic transducer 1 and the buffer member 2, and can prevent deterioration of reverberation characteristics due to water entry. Therefore, the reverberation characteristics are always the same as in Figure 5 (c
), and the short-range distance measurement performance is not impaired. In addition, since the ultrasonic transducer 1 is surrounded by the buffer member 2 and the radiation surface of the ultrasonic transducer 1 is protected by the seal layer 6 that closes the opening 2a, damage caused by external factors can be prevented and reliability can be improved. It is possible to improve the In addition,
Since the seal layer 6 is made of thin rubber, it does not adversely affect the ultrasonic transmission/reception performance.

[0009]

[Effects of the Invention] The present invention is configured as described above,
In an ultrasonic sensor in which a buffer member is arranged to surround an ultrasonic transducer and ultrasonic waves are transmitted and received through an opening for transmitting and receiving ultrasonic waves in the buffer member, a seal made of thin rubber or the like that closes the opening is used. The layer is adhered to the radiation surface of the ultrasonic vibrator, and ultrasonic waves are transmitted and received through the sealing layer, so the sealing layer prevents water from entering between the ultrasonic vibrator and the buffer member. This has the effect of preventing deterioration of reverberation characteristics due to water intrusion, preventing loss of short-range distance measurement performance, and protecting the radiation surface of the ultrasonic transducer. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a front view of the same as above.

FIG. 3 is a sectional view of a conventional example.

FIG. 4 is a front view of the same as above.

FIG. 5 is an explanatory diagram of the conventional example and the operation of the present invention.

[Explanation of symbols]

1 Ultrasonic transducer 2 Buffer member 2a opening 6 Seal layer

Claims (1)

[Claims] Claim 1: Comprised of an ultrasonic transducer and a buffer member having an aperture for transmitting and receiving ultrasonic waves and surrounding the ultrasonic transducer, the ultrasonic transducer transmits ultrasonic waves through the aperture, and In an ultrasonic sensor that receives reflected waves from obstacles, a sealing layer made of thin rubber or the like that closes the opening is adhered to the radiation surface of the ultrasonic transducer, and ultrasonic waves are transmitted through the sealing layer. An ultrasonic sensor characterized by transmitting and receiving.