Ultrasonic detector and detection device

1. An ultrasonic detector, comprising:

a detection area; and

a cover body, comprising at least two cavities, a plurality of fluid inlets and a plurality of fluid outlets which are communicated in sequence from inside to outside, wherein each of the plurality of fluid inlets and each of the plurality of fluid outlets are configured to allow fluid to flow into and flow out of a respective one of the at least two cavities;

wherein, the plurality of fluid inlets, the plurality of fluid outlets and the at least two cavities are in fluid communication to form a fluid channel, the fluid channel is configured to guide the fluid to flow along at least one bent path, and the detection area is located in an innermost one of the at least two cavities,

each of the at least two cavities is provided with a fluid inlet and a fluid outlet, so that when the fluid flows into the outermost one of the at least two cavities from the fluid inlet of the outermost one of the at least two cavities, part of the fluid can flow into the detection area and part of the fluid can carry air bubbles in the fluid to flow only along the outermost one of the at least two cavities and then be discharged from the fluid outlet of the outermost one of the at least two cavities so as to prevent the air bubbles in the fluid from entering the detection area, and

the each of the plurality of fluid inlets is located on a bottom surface of the respective one of the at least two cavities, the each of the plurality of fluid outlets is located on an upper surface of the respective one of the at least two cavities, the fluid inlet of the outermost one of the at least two cavities is lower than the fluid inlet of the innermost one of the at least two cavities, and the fluid outlet of the innermost one of the at least two cavities is lower than the fluid outlet of the outermost one of the at least two cavities.

2. The ultrasonic detector according to claim 1 , wherein the at least two cavities comprise an inner cavity and an outer cavity, a fluid inlet of the outer cavity is smaller than a fluid inlet of the inner cavity, so that the fluid in the outer cavity merges at the fluid inlet of the inner cavity.

3. The ultrasonic detector according to claim 1 , wherein the at least two cavities comprise an inner cavity and an outer cavity, a fluid inlet of the inner cavity is smaller than a fluid inlet of the outer cavity, so that the fluid in the outer cavity is diverted to flow into the inner cavity.

4. The ultrasonic detector according to claim 1 , wherein the at least two cavities comprise an inner cavity and an outer cavity, a fluid inlet of the inner cavity and a fluid inlet of the outer cavity are misaligned, and a fluid outlet of the inner cavity and a fluid outlet of the outer cavity are misaligned.

5. The ultrasonic detector according to claim 4 , wherein the fluid inlet of the inner cavity and the fluid outlet of the inner cavity are misaligned, and the fluid inlet of the outer cavity and the fluid outlet of the outer cavity are misaligned.

6. The ultrasonic detector according to claim 2 , wherein the fluid outlet of the inner cavity is smaller than the fluid inlet of the inner cavity, so that the fluid in the inner cavity is diverted at the fluid outlet of the inner cavity.

7. The ultrasonic detector according to claim 3 , wherein the fluid outlet of the inner cavity is larger than the fluid inlet of the inner cavity, so that the fluid in the inner cavity merges at the fluid outlet of the inner cavity.

8. The ultrasonic detector according to claim 2 , wherein the cover body comprises an inner case and an outer case sleeved outside the inner case, the inner cavity is formed inside the inner case, and the outer cavity is formed between the inner case and the outer case.

9. The ultrasonic detector according to claim 8 , wherein a first side of the inner cavity is provided with a first hole disposed on the inner case and a second hole disposed on the outer case; and a second side of the inner cavity is provided with a third hole disposed on the inner case and a fourth hole disposed on the outer case.

10. The ultrasonic detector according to claim 9 , wherein at least two first holes and at least two third holes are provided, and one second hole and one fourth hole are provided.

11. The ultrasonic detector according to claim 9 , wherein a first side of the outer case is provided with a fifth hole, the fifth hole and the second hole are convective, and the fifth hole and the first hole are misaligned.

12. A detection device, comprising an ultrasonic detector, the ultrasonic detector comprising:

a detection area; and

a cover body, comprising at least two cavities, a plurality of fluid inlets and a plurality of fluid outlets which are communicated in sequence from inside to outside, wherein each of the plurality of fluid inlets and each of the plurality of fluid outlets are configured to allow fluid to flow into and flow out of a respective one of the at least two cavities;

wherein, the plurality of fluid inlets, the plurality of fluid outlets and the at least two cavities are in fluid communication to form a fluid channel, the fluid channel is configured to guide the fluid to flow along at least one bent path, and the detection area is located in an innermost one of the at least two cavities,

each of the at least two cavities is provided with a fluid inlet and a fluid outlet, so that when the fluid flows into the outermost one of the at least two cavities from the fluid inlet of the outermost one of the at least two cavities, part of the fluid can flow into the detection area and part of the fluid can carry air bubbles in the fluid to flow only along the outermost one of the at least two cavities and then be discharged from the fluid outlet of the outermost one of the at least two cavities so as to prevent the air bubbles in the fluid from entering the detection area, and

the each of the plurality of fluid inlets is located on a bottom surface of the respective one of the at least two cavities, the each of the plurality of fluid outlets is located on an upper surface of the respective one of the at least two cavities, the fluid inlet of the outermost one of the at least two cavities is lower than the fluid inlet of the innermost one of the at least two cavities, and the fluid outlet of the innermost one of the at least two cavities is lower than the fluid outlet of the outermost one of the at least two cavities.

13. The detection device according to claim 12 , further comprising a control box, a liquid level detection pipe, a fluid pipe and a flange, wherein

the fluid pipe is configured for transporting fluid;

the liquid level detection pipe is configured to detect a liquid level of fluid in a tank;

the flange is configured to seal the fluid in the tank; and

the control box is configured to provide electric connection of the liquid level detection pipe and an external electronic device, and electric connection of the ultrasonic detector and the external electronic device.

14. The detection device according to claim 13 , further comprising a heater circuit, wherein the heater circuit is configured to heat the fluid to prevent the fluid from being solidified.

15. The detection device according to claim 12 , wherein the at least two cavities comprise an inner cavity and an outer cavity, a fluid inlet of the outer cavity is smaller than a fluid inlet of the inner cavity, so that the fluid in the outer cavity merges at the fluid inlet of the inner cavity.

16. The detection device according to claim 12 , wherein the at least two cavities comprise an inner cavity and an outer cavity, a fluid inlet of the inner cavity is smaller than a fluid inlet of the outer cavity, so that the fluid in the outer cavity is diverted to flow into the inner cavity.

17. The detection device according to claim 12 , wherein the at least two cavities comprise an inner cavity and an outer cavity, a fluid inlet of the inner cavity and a fluid inlet of the outer cavity are misaligned, and a fluid outlet of the inner cavity and a fluid outlet of the outer cavity are misaligned.

18. The ultrasonic detector according to claim 4 , wherein the fluid outlet of the inner cavity is smaller than the fluid inlet of the inner cavity, so that the fluid in the inner cavity is diverted at the fluid outlet of the inner cavity.

19. The ultrasonic detector according to claim 4 , wherein the fluid outlet of the inner cavity is larger than the fluid inlet of the inner cavity, so that the fluid in the inner cavity merges at the fluid outlet of the inner cavity.

20. The ultrasonic detector according to claim 3 , wherein the cover body comprises an inner case and an outer case sleeved outside the inner case, the inner cavity is formed inside the inner case, and the outer cavity is formed between the inner case and the outer case.