CN220367419U

CN220367419U - Ultrasonic sensor

Info

Publication number: CN220367419U
Application number: CN202321516029.6U
Authority: CN
Inventors: 申桃; 曹淼; 旷栋升; 阴伏星; 李佳
Original assignee: Chengdu Huitong West Electronic Co ltd
Current assignee: Chengdu Huitong West Electronic Co ltd
Priority date: 2023-06-14
Filing date: 2023-06-14
Publication date: 2024-01-19
Anticipated expiration: 2033-06-14

Abstract

The utility model relates to the technical field of ultrasonic sensors, in particular to an ultrasonic sensor, which comprises a sensing device, wherein a shell is sleeved outside the sensing device, a matching layer, a piezoelectric ceramic plate and a PCB (printed Circuit Board) are arranged in the shell, the matching layer, the piezoelectric ceramic plate, the PCB and a terminal wire are sequentially connected to form the sensing device together, the piezoelectric ceramic plate is arranged at the lower end of the matching layer, the PCB is connected to the lower end of the piezoelectric ceramic plate, the terminal wire is connected to the lower end of the PCB, namely, the installation and the manufacturing are simple, the cost is reduced, the cost is saved, and the combined sensing device adopts an ultrasonic ToF technology, so that the sensing device is simple in manufacturing mode, low in cost and high in sensitivity.

Description

Ultrasonic sensor

Technical Field

The utility model relates to the technical field of ultrasonic sensors, in particular to an ultrasonic sensor.

Background

Currently, smart home has entered into thousands of households, and people's lifestyle has entered into an intelligent era. The robot sweeps floor as a popular intelligent house of masses, has liberated both hands, has greatly improved people's life convenience simultaneously, has also greatly improved people's satisfaction and happiness of life.

However, some sweeping robots have poor obstacle avoidance capability, which also brings bad experience to users, and causes the users to spit grooves with 'mental retardation but without obstacle avoidance'. At present, the main obstacle avoidance modes of the sweeping robot in the market are as follows: the first is mechanical obstacle avoidance, which monitors objects by collision, hits the obstacle and turns randomly until the next obstacle is hit. The method has the advantages of low cost, wide application and obvious defect of insufficient intelligence; the second type is laser radar obstacle avoidance, and the obstacle is judged by transmitting laser to receive reflected signals. The method has the advantages of quick response, good obstacle avoidance effect, occasional misjudgment, poor recognition of transparent and black objects; the third is that the infrared light source avoids the obstacle, utilize the principle of triangular ranging to judge the obstacle through transmitting and receiving infrared light, the advantage is with low costs, easy to realize, the disadvantage is that it is influenced by the color of the obstacle greatly, can be absorbed partial infrared ray to meet the dark thing, the degree of accuracy is reduced, and the stereoscopic profile recognition precision to the obstacle is not enough; the fourth is 3D ToF keeps away the barrier, through transmitting laser, analyze the obstacle and reflect laser intensity and time, calculate the degree of depth of object surface and discern the obstacle, the advantage of this kind of mode is that can discern the three-dimensional profile of obstacle, the precision is high, the interference killing feature is strong, the shortcoming is with high costs.

Disclosure of Invention

The utility model aims at: the photoelectric sensor in the prior art is influenced by transparent or dark obstacles, and has high cost; the ultrasonic sensor has the advantages of strong anti-interference capability and low cost.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

the utility model provides an ultrasonic sensor, includes the casing, be equipped with sensing device in the casing, sensing device including the matching layer that connects gradually piezoceramics, PCB board, specifically does:

the lower end of the matching layer is provided with the piezoelectric ceramic piece;

the lower end of the piezoelectric ceramic piece is connected with the PCB;

and the lower end of the PCB is connected with the terminal wire.

The utility model relates to an ultrasonic sensor, the lower end of a matching layer is connected with the upper end of a piezoelectric ceramic plate, the matching layer is used as an important component of an ultrasonic guided wave transducer through the matching of the matching layer and the piezoelectric ceramic plate, acoustic impedance matching can be realized, the lower end of the piezoelectric ceramic plate is also connected with a PCB (printed circuit board) and a terminal wire arranged at the lower end of the PCB, and the signal of the piezoelectric ceramic plate and the terminal wire are subjected to a transfer function through the PCB.

As a preferred scheme of the utility model, the sensing device adopts ultrasonic TOF technology (TOF technology is a technology for measuring the distance between an object and a camera, is totally called Time of flight. TOF technology, light waves are reflected back by the object to be measured and then collected by a sensor, the system calculates the distance between the object to be measured and the camera by calculating the pulse difference or the Time difference of the received light waves), and the sensing device adopts ultrasonic TOF technology, and judges an obstacle by calculating the Time difference of the emitted and reflected ultrasonic waves.

As a preferable scheme of the utility model, the shell body is a plastic shell, and the sensing device is fixed through the plastic shell.

As a preferable scheme of the utility model, the plastic shell is in a cylindrical ladder shape with a small upper part and a large lower part, a first through hole is axially formed in the plastic shell by taking a ladder part as a demarcation line, and a second through hole is axially formed in the lower end of the plastic shell, so that components in the sensing device can be completely placed in the plastic shell, and the plastic shell is in a ladder shape for being matched with the internally installed sensing device conveniently.

As a preferable scheme of the utility model, the diameter of the first through hole is smaller than that of the second through hole, the first through hole is communicated with the second through hole, an annular boss is arranged in the middle of the inner wall of the plastic shell and is positioned at the junction of the first through hole and the second through hole, and the annular boss is arranged on the inner wall of the plastic shell for stably placing the matching layer in the sensing device in the first through hole in the plastic shell and preventing the matching layer from falling or shaking.

As a preferable scheme of the utility model, the side surface of one end of the plastic shell with larger diameter is provided with the wire passing groove, and the wire passing groove is used for installing the terminal wire, so that the terminal wire cannot be bent during installation.

As a preferable scheme of the utility model, the whole matching layer is cylindrical in a ladder shape, the diameter of the upper end face is smaller than that of the lower end face, a pad table is arranged on the lower end face of the matching layer, and the pad table is equal to the diameter of an annular boss arranged on the inner wall of the plastic shell, so that the matching layer is in a ladder shape, and the measured distance is further.

As a preferable scheme of the utility model, at least one pair of lug-shaped mounting parts are arranged on the side surface of the plastic shell, mounting holes are formed in the lug-shaped mounting parts along the axial direction, and the mounting holes are in an hourglass shape with small middle and large two ends and are used for mounting and connecting the sensor.

Preferably, the mounting hole of one of the ear-shaped mounting portions has a constant original center position, and the mounting hole is offset to both sides with reference to the original center positionThis arrangement makes the sensor more convenient during installation.

As a preferable scheme of the utility model, the piezoelectric ceramic plate arranged in the sensing device is connected with the PCB through the backing adhesive, and the backing adhesive is used for absorbing the reflected echo at the rear end of the ceramic plate and playing a role in inhibiting residual vibration.

As the preferable scheme of the utility model, the front end face pouring sealant is filled above the annular boss arranged in the plastic shell, the matching layer is in sealing connection with the plastic shell by the front end face pouring sealant, the rear end face pouring sealant is filled in the area below the annular boss arranged in the plastic shell, one end of the terminal wire is fixed in the second through hole below the plastic shell by the rear end face pouring sealant, and the whole sensor is connected into a whole through the front end face pouring sealant and the rear end face pouring sealant.

In summary, due to the adoption of the technical scheme, the beneficial effects of the utility model are as follows:

1. the utility model relates to an ultrasonic sensor, the lower end of a matching layer is connected with the upper end of a piezoelectric ceramic plate, the matching layer is used as an important component of an ultrasonic guided wave transducer through the matching of the matching layer and the piezoelectric ceramic plate, acoustic impedance matching can be realized, the lower end of the piezoelectric ceramic plate is also connected with a PCB (printed Circuit Board) and a terminal wire arranged at the lower end of the PCB, and the signal of the piezoelectric ceramic plate and the terminal wire is subjected to a switching function through the PCBz＝Is combined intoThe sensing device adopts the ultrasonic TOF technology, and the obstacle is judged by calculating the time difference between the emitted ultrasonic wave and the reflected ultrasonic wave, so that the defect that the photoelectric signal easily penetrates through the transparent obstacle can be overcome, the sensing device is not influenced by the surface of the obstacle, the environmental interference is small, the cost is low, the manufacturing mode of the sensing device is simple, the cost is low, and the sensitivity is high.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic top view of the present utility model;

FIG. 3 is a schematic diagram of an exploded construction of the present utility model;

FIG. 4 is a schematic diagram of a matching layer structure of the present utility model;

FIG. 5 is a schematic diagram of the front view of the matching layer of the present utility model;

FIG. 6 is a schematic diagram of a cross-sectional configuration of a sensor of the present utility model;

FIG. 7 is a schematic view of the plastic housing structure of the present utility model;

FIG. 8 is a schematic cross-sectional view of a molded case of the present utility model;

FIG. 9 is a schematic diagram of the sensing device of the present utility model.

Icon: 1-pouring sealant on the front end surface; 2-matching layer; 3-piezoelectric ceramic plates; 4-molding; 5-backing adhesive; 6-a PCB board; 7-terminal wires; 8-pouring sealant on the rear end face; 9-a sensing device; 21-a pad table; 41-a first through hole; 42-a second through hole; 43-annular boss; 44-ear mount; 45-wire passing grooves; 441-mounting holes.

Detailed Description

The present utility model will be described in detail with reference to the accompanying drawings.

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

Example 1

The ultrasonic sensor as shown in fig. 1-3 and 9 comprises a matching layer 2, wherein a piezoelectric ceramic plate 3 is arranged at the lower end of the matching layer 2, a PCB 6 is arranged at the lower end of the piezoelectric ceramic plate 3, and a terminal wire 7 is also arranged at the lower end of the PCB 6;

the matching layer 2, the piezoelectric ceramic plate 3, the PCB 6 and the terminal wire 7 are sequentially connected to form the sensing device 9, the matching layer 2 and the piezoelectric ceramic plate 3 are connected and matched to enable the matching layer 2 to serve as a component part of an ultrasonic guided wave transducer, acoustic impedance matching can be achieved, namely acoustic impedance is enabled to be between the piezoelectric ceramic plate 3 and acoustic impedance of an object to be tested by utilizing the matching layer 2, reflection of acoustic waves at an interface of two media is reduced, transmission efficiency of acoustic energy is improved, measurement is achieved, the PCB 6 is arranged at the lower end of the piezoelectric ceramic plate 3, the terminal wire 7 is arranged at the lower end of the PCB 6, mechanical signals are converted into electric signals or the electric signals are converted into mechanical signals through the PCB, and signal conversion between the piezoelectric ceramic plate 3 and the terminal wire 7 is achieved;

further, the terminal wire 7 is a terminal wire with shielding function, the shielding layer at one end of the terminal wire 7 is processed in a suspending way, and the shielding layer at the other end is pressed into the terminal.

Optionally, the sensing device 9 further adopts the ToF technology, and the time difference between the emitted and reflected ultrasonic waves is calculated to further judge the obstacle, so that the defect that the photoelectric signal easily penetrates through the transparent obstacle can be overcome, the influence of the surface of the obstacle is avoided, the environmental interference is small, the cost is low, the manufacturing mode of the sensing device is simple, the cost is low, and the sensitivity is high.

The outer part of the sensing device 9 is provided with a plastic shell 4, the plastic shell 4 is in a stepped shape of a cylinder with a small upper part and a large lower part, the plastic shell 4 is further formed by splicing a cylinder with a small diameter and a cylinder with a large diameter, the cylinder with the small diameter is arranged above the plastic shell 4, the plastic shell 4 is in a stepped shape after the splicing is completed, the plastic shell is used for mounting a subsequent sensing device 9, the cylinder with the small diameter is axially provided with a first through hole 41, and the cylinder with the large diameter is axially provided with a second through hole 42, as shown in fig. 7.

The first through hole 41 arranged on the plastic shell 4 has a smaller diameter than the second through hole 42, and the two through holes are communicated, so that when the sensing device 9 is installed subsequently, the various components of the sensing device 9 can be ensured to be contacted and operated, as shown in fig. 7-8.

The middle part of the inner wall of the plastic shell 4 is provided with the annular boss 43, the outer diameter of the annular boss 43 is the same as the inner diameter of the first through hole 41, the annular boss 43 can be positioned at the junction of the first through hole 41 and the second through hole 42, the annular boss 43 can be further arranged at any position inside the plastic shell 4, and the purpose of the annular boss 43 is to ensure that the sensing device 9 cannot fall off in the axial direction after the sensing device 9 is installed in the plastic shell 4, as shown in fig. 7-8.

The side surface of the cylinder with the larger diameter in the plastic housing 4 is provided with the wire passing groove 45, the wire passing groove 45 penetrates through the side wall of the cylinder with the larger diameter, and the wire passing groove 45 is used for extending the terminal wire 7 into the plastic housing 4, so that the terminal wire 7 can be connected with the PCB 6, as shown in fig. 8.

Optionally, the opening size of the wire passing groove 45 needs to be larger than the outer diameter of the terminal wire 7, so that the terminal wire 7 cannot be damaged, and the wire passing groove 45 needs to ensure that one end of the terminal wire 7 enters the plastic shell 4.

The matching layer 2 is of a cylindrical structure with a chamfer on the upper end face, and the chamfer is arranged at the upper end of the matching layer 2, so that the diameter of the upper end face of the matching layer 2 is smaller than that of the lower end face, and the matching layer is further stepped, so that acoustic resistance of the matching layer 2 presents different values at different positions, gradient change of acoustic resistance is realized, and reflection of acoustic waves between the matching layer and an object to be measured is reduced;

further, the matching layer 2 can be made of a composite of epoxy resin and light material, and has a diameter of a small circle at the upper endLet the diameter of the big circle at the lower end be +.>The ratio of the small circle to the large circle is +.>As shown in fig. 4-5;

further describing the above ratio, when the sensor is tested at distances exceeding 1.5m, thenThe ratio cannot be 1.

Alternatively, the overall height D of the matching layer 2 is 2.7-3.5 mm, and the step height D of the matching layer 2 after chamfering is 0.8-1.5 mm, as shown in fig. 5.

The side wall of the plastic shell 4 is further provided with a plurality of ear-shaped mounting parts 44, and mounting holes 441 are formed in the middle of the ear-shaped mounting parts 44, so that the sensor can be mounted in an adapting manner with other devices through the arrangement of the ear-shaped mounting parts 44. As shown in fig. 1-2.

Alternatively, the mounting portion 11 may be in an hourglass shape.

Of the above-mentioned plurality of mounting holes 441, one of the mounting holes 441 has a constant original center position, and the mounting holes 441 are offset to both sides with reference to the original center positionThis allows for more flexibility in mounting when fitting with the rest of the device, as shown in fig. 8.

The piezoelectric ceramic plate 3 and the PCB 6 disposed in the above-mentioned sensing device 9 are connected by a backing adhesive 5, and the backing adhesive 5 is used for absorbing the reflected echo at the rear end of the piezoelectric ceramic plate 3, so as to play a role in suppressing residual vibration, as shown in fig. 3 and 6.

The front end face pouring sealant 1 is poured above the annular boss 43 arranged in the plastic shell 4, the front end face pouring sealant 1 is used for carrying out sealing connection between the matching layer 2 and the plastic shell 4, the rear end face pouring sealant 8 is poured in the area below the annular boss 43 arranged in the plastic shell 4, and one end of the terminal wire 7 is fixed in the second through hole 42 below the plastic shell 4 by the rear end face pouring sealant 8, as shown in fig. 3 and 6;

furthermore, the glue amount of the front end face pouring sealant 1 needs to be larger than that of the step surface of the matching layer 2 and smaller than that of the end face of the matching layer 2, namely the height of the front end face pouring sealant 1 beyond the step surface of the matching layer is d min < e < d max, the residual vibration and the sensitivity value of the ultrasonic sensor are a pair of contradictors, and if the front end face pouring sealant is lower than that of the step surface of the matching layer, the residual vibration is large, and the sensitivity value is high; if the front end surface pouring sealant exceeds the end surface of the matching layer, the residual vibration is small, and the sensitivity is low. This has the advantage of ensuring that both residual vibration and sensitivity values are within a suitable range, as shown in figure 6.

Example 2

A set of sensors was fabricated, and the sensors were driven with a 200kHz driving source, and echo values of distances 0.8m, 1m, 1.2m, 1.5m, and 2m were sequentially tested, to obtain a reception waveform as shown in fig. 6. The specific results are shown in Table 1 below:

table 1 sensor echo sensitivity reception data

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The utility model provides an ultrasonic sensor, includes the casing, its characterized in that, be equipped with sensing device (9) in the casing, sensing device (9) are including matching layer (2), piezoceramics piece (3), PCB board (6) that connect gradually, specifically:

the piezoelectric ceramic piece (3) is arranged at the lower end of the matching layer (2);

the piezoelectric ceramic piece (3), the lower end of the piezoelectric ceramic piece (3) is connected with the PCB (6);

the PCB (6), PCB (6) lower extreme is connected with terminal line (7).

2. An ultrasonic sensor according to claim 1, wherein the housing body is a plastic housing (4).

3. An ultrasonic sensor according to claim 2, wherein the plastic housing (4) is in a cylindrical step shape with a smaller upper part and a larger lower part, a first through hole (41) is axially formed at the upper end of the plastic housing (4) taking a step part as a boundary line, and a second through hole (42) is axially formed at the lower end of the plastic housing (4).

4. An ultrasonic sensor according to claim 3, characterized in that the first through hole (41) has a smaller diameter than the second through hole (42), and that the first through hole (41) communicates with the second through hole (42); an annular boss (43) is arranged in the middle of the inner wall of the plastic shell (4), and the annular boss (43) is located at the junction of the first through hole (41) and the second through hole (42).

5. An ultrasonic sensor according to claim 2, characterized in that the side of the larger diameter end of the plastic housing (4) is provided with a wire-passing groove (45), said wire-passing groove (45) being used for the mounting of the terminal wire (7).

6. An ultrasonic sensor according to any one of claims 2-5, wherein the matching layer (2) is integrally cylindrical and stepped, and the diameter of the upper end face is smaller than that of the lower end face, a pad (21) is arranged on the lower end face of the matching layer (2), and the diameter of the pad (21) is equal to that of an annular boss (43) arranged on the inner wall of the plastic shell (4).

7. An ultrasonic sensor according to claim 2, wherein the side surface of the plastic housing (4) is provided with at least a pair of ear-shaped mounting parts (44), the ear-shaped mounting parts (44) are axially provided with mounting holes (441), and the mounting holes (441) are in an hourglass shape with small middle and large two ends.

8. An ultrasonic sensor according to claim 7, characterized in that the in-situ position of one of the mounting holes (441) of the ear-shaped mounting portion (44) is unchanged and the mounting hole (441) is in-situOffset to both sides with reference to position

f: offset distance.

9. An ultrasonic sensor according to claim 1, characterized in that the piezoelectric ceramic plate (3) provided in the sensing device (9) is connected to the PCB board (6) by a backing glue (5).

10. An ultrasonic sensor according to any one of claims 7-8, wherein a front end face pouring sealant (1) is poured above an annular boss (43) arranged in the plastic housing (4), the front end face pouring sealant (1) is used for sealing connection between the matching layer (2) and the plastic housing (4), a rear end face pouring sealant (8) is poured in a region below the annular boss (43) arranged in the plastic housing (4), and one end of the terminal wire (7) is fixed inside a second through hole (42) below the plastic housing (4) by the rear end face pouring sealant (8).