JPS61126487A - Ultrasonic sensor for vehicle - Google Patents

Abstract

PURPOSE:To eliminate the dead area of an ultrasonic sensor and to improve the safety by providing the cylindrical horn of an ultrasonic wave transmitter receiver mounted on a vehicle so that it projects from the fitting base of the vehicle, and forming an opening hole in the side wall of the horn. CONSTITUTION:Three ultrasonic wave transmitter receivers 2, 3, and 4 are fixed to the fitting base 1 such as the bumper of the vehicle at equal intervals. When the transmitter receivers 2... are formed, horns 7, etc., which contain microphones 6 through cushion bodies 5 for reverberation prevention are formed in a cylindrical elliptical shape whose tip is vertically long and fitted to housing parts 8 to prevent the wrong detection of the ground surface. Then, the horns 7 are projected from the fitting base 1 and opening holes 11 and 11 are bored laterally at both sides of the side wall of the horn 6 of the center transmitter receiver 3 to detect an obstacle G by the horn 7 and an obstacle H in the front.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an ultrasonic sensor that detects obstacles around a vehicle using an ultrasonic transducer.

r1) [Background technology] Generally, an ultrasonic sensor has a cylindrical horn attached to its tip in order to improve its directivity, and as a result, the detection area becomes narrower. It was difficult to detect a wide range of surrounding areas. In view of this,
For example, Tokukai Shofi? As shown in Publication No. 54878, there are some devices that use multiple ultrasonic sensors to widen the detection range, but the detection area of the ultrasonic sensor is narrow near the horn and gradually widens as you move away from the horn. Therefore, although it is possible to detect a wide range of obstacles at a distance from the horn, the area immediately next to the horn becomes a blind spot and obstacles cannot be detected, especially small obstacles such as children. In some cases, it was difficult for the driver to visually check the situation, and the weather was extremely poor.

[Object of the Invention] The present invention was made in view of the above-mentioned problems, and its purpose is to provide an ultrasonic sensor for a vehicle that eliminates the blind spot of the ultrasonic sensor and improves safety. be.

[Disclosure of the invention]

(Embodiment) An embodiment of the present invention will be described below based on drawings 1 to 3. l is a mounting base such as a bumper of a vehicle, and three ultrasonic transducers 2, 3.4 are connected to each other. Equal intervals (dimension e in the diagram)
Separated and fixed with screws.

The transducer 2, 3.4 includes a horn 7 in which a microphone 6 is housed at the base via a Kutschev body 5 for preventing reverberation, and a transparent body part 8 in which electric parts (not shown) such as a head amplifier are housed. The lead wire 9 has an oval tip to narrow the detection area in the vertical direction, and in order to avoid false detection of the ground, the 6 has openings 11 opening laterally on both sides of its side walls. As shown in FIG. I have to. Further, the aperture 11 is formed into an oval shape that is elongated in the axial direction of the horn 7, so that the detection area is shortened in the axial direction, thereby preventing false detection of the mounting base l.

(Operation) Next, the operation of the embodiment of the present invention will be explained based on FIGS. 1 and 4 to 7. The circuit is as shown in Figure 4, with the transmission interval set by the integrating circuit and the monostable multiplier of 1.
The waveform created by the oscillation circuit 14 based on the microphone drive time set in step 3 is shown in FIG. 5 (2A).
In (3A) and (4A), there is also a wrap-around component F of obstacles. The level detectors 18, 19, 20
The gate circuit detects the wrap-around component F, and if the wrap-around component F exceeds a certain level within the time set by the gate circuit, the waveform shaping circuit ρ, 23, 24
, and the AND circuit, a signal is input to the display through 2[i, and a buzzer, lamp, etc., indicates this.If this display is displayed, all ultrasonic sensors are operating normally. This shows that there are no failures such as disconnections.

In addition, as shown in FIG. 1, when an obstacle G exists within the detection area of the transducer 3, it is input to the AND circuit 31 via the horn and the waveform shaping circuit (supply), and as shown in FIG. (
Within the time set by the gate circuit blade shown in C),
In addition, if there is a reflected signal above a certain level, Fig. 6 (D)
A detection signal shown in is output from the AND circuit 31, and an indicator such as a buzzer or lamp indicates the presence of an obstacle.

Furthermore, as shown in FIG. 1, when an obstacle H exists, the output waveform from the amplifier 16 becomes as shown in FIG. time(
If there is a reflected signal of a certain level or higher within the time period 1) shown in Figure 7(C), the detection signal shown in Figure 7(D) is ANDed.
The signal is output from the circuit 31, and the presence of the obstacle is indicated on the display device.

〔Effect of the invention〕

As described above, according to the present invention, an ultrasonic transducer is attached to a vehicle to detect reflected waves from obstacles around the vehicle, and the perforation of the side wall of the horn is improved.

[Brief explanation of drawings]

Fig. 1 is a top view showing an embodiment of the present invention, Fig. 2 is an external perspective view of the above transducer, Fig. 3 is a sectional view of the above transducer, and Fig. 4 is a circuit block diagram of the above. , Figure 5 shows the output waveform diagram when there is no obstacle, 2A, 3A
, 4A is the output waveform diagram of each of the transducers 2 and 3.4, 2
B, 3B, and 4B are output waveform diagrams of the amplifiers 15, 16, and 17, respectively, FIGS. 6 and 7 are output waveform diagrams when an obstacle is present, and A is the output of the transducer 3. In the waveform diagrams, B is an output waveform diagram of the amplifier 16, C is an output waveform diagram of the gate circuit clearer, and D is an output waveform diagram of the AND circuit 31. 1... Mounting base, 2, 3.4... Transducer/receiver, 7...
・Horn, 11...Open hole, G, H...Obstacle.

Claims (1)

[Scope of Claims] 1) An ultrasonic sensor for a vehicle that detects reflected waves from obstacles around the vehicle by attaching an ultrasonic transducer to a vehicle, the ultrasonic transducer having a cylindrical shape. An ultrasonic sensor for a vehicle, characterized in that a horn is provided to protrude from a mounting base of a vehicle, and an opening is formed in a side wall of the horn. 2) The ultrasonic sensor for a vehicle according to claim 1, wherein openings are formed on both side walls of the horn. 3) The ultrasonic sensor according to claim 1, wherein the opening has an oval shape that is elongated in the axial direction of the horn.