An ultrasonic gas sensor

Abstract

The present invention provides an ultrasonic gas sensor, comprising a shell and a first ultrasonic transducer and a second ultrasonic transducer respectively arranged at the top of the inner cavity of the shell, wherein the first ultrasonic transducer and the second ultrasonic transducer form a V-shaped ultrasonic transmission path in the shell, and an air inlet channel and an air outlet channel are arranged in the shell, wherein the air outlet upper end of the air inlet channel is close to the first ultrasonic transducer, and the upper end of the air outlet channel is close to the second ultrasonic transducer, so that the measured airflow entering the bypass pipe can pass through the detection area of ​​the first and second ultrasonic transducers, and the lower ends of the air inlet channel and the air outlet channel are both connected to the gas sensor mounting seat. The present invention does not require additional connecting pipes, can directly replace traditional electrochemical gas sensors, and has the advantages of long life, fast response speed, low cost, no need for manual calibration, compact structure, and easy installation.

Description

Technical Field

[0001] The present invention relates to the technical field of gas sensor equipment, and in particular to an ultrasonic gas sensor. Background Art

[0002] In medical equipment such as ventilators and anesthesia machines, gas sensors are needed to monitor the concentrations of oxygen, anesthetic gas, hydrogen and other gases in the delivered mixed gas. The gas sensors transmit the detected gas concentration data to the control unit of the ventilator and anesthesia machine. The control unit processes the detection data and adjusts the flow of the corresponding gas branch according to the detection results.

[0003] Traditional gas sensors use electrochemical principles for detection. For example, patent document CN102441213B discloses an anesthesia machine using an electrochemical oxygen sensor. The oxygen concentration is measured based on the mechanism that oxygen molecules react with specific chemical substances inside the oxygen sensor to generate current. The oxygen concentration is linearly related to the magnitude of the generated current, and the oxygen concentration is measured based on the magnitude of the generated current. However, as the use time increases, the form of the chemical substances inside the oxygen sensor will change, and the corresponding relationship between the oxygen concentration and the current will change. Therefore, the oxygen sensor needs to be calibrated or even replaced. The current electrochemical oxygen sensors are all installed in the mounting base of the ventilator or anesthesia machine. The calibration operation requires manual intervention, which is complicated and time-consuming. This leads to high cost and short life of the gas sensor.

[0004] In order to extend the service life of the gas sensor and reduce the cost of the gas sensor, there is a technical solution in the prior art that uses ultrasonic detection technology to detect the airflow entering the sensor and obtain the concentration of the measured gas in the airflow. Patent document CN106248148B discloses a technical solution that uses ultrasonic detection technology to detect the airflow entering the sensor and obtain the oxygen concentration in the airflow. It discloses a counter-type ultrasonic gas sensor, and patent document CN103201599B discloses a V-type ultrasonic flow sensor. The gas measuring devices of the two structures disclosed above have their air inlet and air outlet located at both ends of the measuring air chamber, respectively, and need to be connected to the oxygen gas measuring pipe section. For the current mainstream ventilators and anesthesia machines, the measuring pipe section usually only has fixed mounting holes for installing oxygen sensors, and there is no additional connecting pipe. Therefore, the existing ultrasonic sensor and the oxygen sensor mounting seat cannot directly form an airflow channel and cannot be directly matched and installed. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides an ultrasonic gas sensor, which, on the one hand, can replace the existing electrochemical gas sensor, has a long service life, and does not require manual intervention; on the other hand, it can match the gas sensor mounting holes on current mainstream ventilators, anesthesia machines and other equipment, overcoming the defect that the current traditional through-beam and V-type ultrasonic gas sensors need to add additional measuring pipe sections for matching installation.

[0006] An embodiment of the present invention provides an ultrasonic gas sensor, comprising a shell and a first ultrasonic transducer and a second ultrasonic transducer respectively arranged at the top end of the inner cavity of the shell, the first ultrasonic transducer and the second ultrasonic transducer form a V-shaped ultrasonic transmission path in the shell, the shell is sealed by a bottom plate at the bottom of the shell, an air inlet channel and an air outlet channel are provided at the bottom of the shell, the upper end of the air inlet channel extends into the left side of the ultrasonic transmission path, and the upper end of the air outlet channel extends into the right side of the ultrasonic transmission path, the lower end of the air inlet channel and the lower end of the air outlet channel are aggregated on the lower side of the shell bottom plate and are separated by a baffle protruding from the lower side of the shell bottom plate, and the lower end of the air inlet channel and the lower end of the air outlet channel are both connected to the gas sensor mounting seat.

[0007] The upper end of the air inlet channel is close to the first ultrasonic transducer, and the upper end of the air outlet channel is close to the second ultrasonic transducer, so that the measured airflow entering the inner cavity of the shell can pass through the detection areas of the first and second ultrasonic transducers.

[0008] The inner cavity of the shell is a bilaterally symmetrical V-shaped structure. The shell is sealed and communicated with the gas sensor mounting seat through an air inlet channel and an air outlet channel. The air inlet channel and the air outlet channel are both in the shape of circular holes.

[0009] The baffle plate extends downward into the gas sensor mounting seat, and the lower end of the baffle plate does not contact the bottom of the gas sensor mounting seat, and a flow splitting gap exists between the two.

[0010] The baffle plate extends downward into the gas sensor mounting seat, and the lower end of the baffle plate contacts the bottom of the gas sensor mounting seat.

[0011] A connection portion extending downward is provided at the lower end of the shell, and the shell is connected to the sensor mounting seat through the connection portion. The interior of the connection portion is hollow and communicates with the air inlet channel and the air outlet channel.

[0012] The length L1 of the baffle extending downward is greater than or equal to the length L2 of the connecting portion extending downward.

[0013] The lower end of the shell is threadedly connected or snap-fitted to the gas sensor mounting seat.

[0014] A temperature sensor is arranged in the middle of the ultrasonic channel.

[0015] The upper end of the shell is provided with a first mounting groove and a second mounting groove, and the first mounting groove and the second mounting groove are used for mounting the first ultrasonic transducer and the second ultrasonic transducer respectively.

[0016] The technical solution provided by the embodiment of the present invention has the following beneficial effects:

[0017] The conventional square measuring chamber is abandoned, and a V-shaped chamber is adopted to make the ultrasonic signal transmission path consistent with the shape of the inner cavity of the measuring chamber, which can reduce the volume of the sensor. The air inlet and outlet channels are designed to be separated from each other at the upper end and aggregated at the lower end, so that it can be directly matched with the traditional gas sensor base.

[0018] No additional connecting pipes are required. The latest ultrasonic technology is used to directly replace the traditional electrochemical gas sensor. It has the advantages of long life, low cost, no need for manual calibration, compact structure, easy installation and fast response. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an exploded view of an ultrasonic gas sensor and a gas sensor base adapted to be installed with each other according to the present invention;

[0020] Figure 2 yes Figure 1 A top view of the middle housing 1;

[0021] Figure 3 yes Figure 2 AA section diagram in;

[0022] Figure 4 yes Figure 1 A bottom view of the middle housing 1;

[0023] Figure 5 yes Figure 1 A schematic diagram of the middle base 10.

[0024] In the figure: 1-shell, 2-ultrasonic transmission path, 3-bottom plate, 4-first mounting groove, 5-second mounting groove, 6-air inlet channel, 6a-upper end of air inlet channel, 6b-lower end of air inlet channel, 7-air outlet channel, 7a-upper end of air outlet channel, 7b-lower end of air outlet channel, 8-connecting part, 9-baffle, 10-gas sensor mounting seat, 11-air inlet connector, 12-air outlet connector. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0026] Please refer to Figure 1 The embodiment of the present invention provides an ultrasonic gas sensor, which is used to measure the concentration of gases such as oxygen, anesthetic gas, and hydrogen. In this embodiment, only oxygen measurement is used as an example, but this is not limited to this. The ultrasonic gas sensor includes a housing 1 and a pair of ultrasonic transducers, namely a first ultrasonic transducer and a second ultrasonic transducer.

[0027] Please refer to Figure 2 , 3 and 4, the inner cavity of the shell 1 is a bilaterally symmetrical V-shaped structure, the first ultrasonic transducer and the second ultrasonic transducer are both located at the top of the shell 1, and a V-shaped ultrasonic transmission path 2 is formed between the first ultrasonic transducer and the second ultrasonic transducer. Specifically, the first ultrasonic transducer is installed in the first installation groove 4, and the second ultrasonic transducer is installed in the second installation groove 5. The first ultrasonic transducer transmits an ultrasonic signal along the V-shaped ultrasonic transmission path 2, and the ultrasonic signal is reflected by the bottom plate 3 at the bottom of the shell 1. The reflected ultrasonic signal continues to propagate along the V-shaped ultrasonic transmission path 2 to the second ultrasonic transducer and is received by the second ultrasonic transducer.

[0028] Please refer to Figure 2 and 3 The shell 1 is also provided with an air inlet channel 6 and an air outlet channel 7, wherein the air inlet channel 6 and the air outlet channel 7 are both cylindrical holes, the upper end 6a of the air inlet channel 6 is close to the first ultrasonic transducer, and the upper end 7a of the air outlet channel 7 is close to the second ultrasonic transducer, so that the measured airflow entering the inner cavity of the shell 1 can pass through the detection area of ​​the first and second ultrasonic transducers, reducing the "dead zone" of ultrasonic detection, the lower end 6b of the air inlet channel 6 and the lower end 7b of the air outlet channel 7 are aggregated on the lower side of the bottom plate 3 at the bottom of the shell 1 and are separated by a baffle 9 protruding from the lower side of the bottom plate 3 of the shell 1, and the lower end 6b of the air inlet channel 6 and the lower end 7b of the air outlet channel 7 are both connected to the gas sensor mounting seat 10.

[0029] Please refer to Figure 1 and 5 In order to improve the response speed of the sensor, a baffle 9 is provided between the lower end 6b of the air inlet channel 6 and the lower end 7b of the air outlet channel 7. The baffle 9 extends downward from the lower end of the housing 1 and extends into the gas sensor mounting seat 10.

[0030] In this embodiment, a connected air inlet connector 11 and an air outlet connector 12 are provided at both ends of the gas sensor mounting base 10. The gas sensor mounting base 10 is a rectangular block, and the air inlet connector 11 and the air outlet connector 12 are both tubular connectors, which are respectively provided on opposite side surfaces of the gas sensor mounting base 10. However, in fact, there is no restriction on the structure of the gas sensor mounting base 10, so the setting of the baffle 9 can promote more measured gas entering from the air inlet connector 11 to enter the V-shaped ultrasonic transmission path 2 through the air inlet channel 6, and flow out of the V-shaped ultrasonic transmission path 2 through the air outlet channel 7. Thereby, the circulation speed of the measured gas between the first ultrasonic transducer and the second ultrasonic transducer is accelerated, and the response speed of the oxygen concentration measurement is accelerated.

[0031] A connection portion 8 extending downward is provided at the lower end of the housing 1, and the housing 1 is connected to the gas sensor mounting seat 10 via the connection portion 8. The connection portion 8 is hollow inside and communicates with the air inlet passage 6 and the air outlet passage 7. The length L1 of the baffle 9 extending downward is greater than or equal to the length L2 of the connection portion extending downward.

[0032] When the oxygen flow rate in the measuring pipe section is small, the lower end of the baffle 9 is made to contact the bottom of the gas sensor mounting base 10, so that all the airflow entering from the air intake connector 11 enters the air intake channel 6 after being blocked by the baffle 9, thereby ensuring the airflow velocity entering the ultrasonic channel.

[0033] In addition, when the oxygen flow rate in the measuring pipe section is large, the lower end of the baffle 9 does not contact the bottom of the gas sensor mounting base 10, and there is a diversion gap between the two. In this way, a part of the airflow entering from the air inlet connector 11 passes through the baffle 9 to enter the air inlet channel 6 after being blocked, and the other part of the airflow directly flows from the diversion gap to the air outlet connector 12. Under the premise of ensuring the airflow velocity entering the ultrasonic channel, the influence of oxygen detection on the oxygen supply of the ventilator and the anesthesia machine is reduced, and the influence of airflow instability on the accuracy of oxygen concentration measurement is eliminated.

[0034] In order to accurately measure the temperature of the gas in real time, a temperature sensor is arranged in the middle of the ultrasonic channel.

[0035] When in use, the ultrasonic gas sensor of the present invention is used in conjunction with an external PCBA, which connects the first ultrasonic transducer, the second ultrasonic transducer and the temperature sensor to achieve real-time measurement of gas concentration.

[0036] In this embodiment, only the ultrasonic gas sensor is used in the gas sensor mounting seat on medical equipment such as ventilators and oxygen generators for illustration, but in fact it can also be applied to other occasions that use a gas sensor mounting seat similar to that used in this embodiment to form a detection path, and this is not limited to this. In this article, the front, back, top, bottom and other directional words involved are defined by the positions of the parts in the drawings and the positions of the parts relative to each other, just for the clarity and convenience of expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection requested by this application.

[0037] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultrasonic gas sensor, characterized in that: It includes a shell and a first ultrasonic transducer and a second ultrasonic transducer respectively arranged at the top end of the inner cavity of the shell, the first ultrasonic transducer and the second ultrasonic transducer form a V-shaped ultrasonic transmission path in the shell, the shell is sealed by a bottom plate at the bottom of the shell, and an air inlet channel and an air outlet channel are provided at the bottom of the shell, the upper end of the air inlet channel extends into the left side of the ultrasonic transmission path, and the upper end of the air outlet channel extends into the right side of the ultrasonic transmission path, so that the measured gas enters the ultrasonic transmission path through the air inlet channel and flows out of the ultrasonic transmission path through the air outlet channel; the lower end of the air inlet channel and the lower end of the air outlet channel are aggregated on the lower side of the shell bottom plate and separated by a baffle protruding from the lower side of the shell bottom plate, and the lower end of the air inlet channel and the lower end of the air outlet channel are both connected to the gas sensor mounting seat.

2. The ultrasonic gas sensor according to claim 1, characterized in that: The upper end of the air inlet channel is close to the first ultrasonic transducer, and the upper end of the air outlet channel is close to the second ultrasonic transducer, so that the measured airflow entering the inner cavity of the shell can pass through the detection areas of the first and second ultrasonic transducers.

3. The ultrasonic gas sensor according to claim 1, characterized in that: The inner cavity of the shell is a bilaterally symmetrical V-shaped structure. The shell is sealed and communicated with the gas sensor mounting seat through an air inlet channel and an air outlet channel. The air inlet channel and the air outlet channel are both in the shape of circular holes.

4. The ultrasonic gas sensor according to claim 3, characterized in that: The baffle plate extends downward into the gas sensor mounting seat, and the lower end of the baffle plate does not contact the bottom of the gas sensor mounting seat, and a flow splitting gap exists between the two.

5. The ultrasonic gas sensor according to claim 3, characterized in that: The baffle plate extends downward into the gas sensor mounting seat, and the lower end of the baffle plate contacts the bottom of the gas sensor mounting seat.

6. The ultrasonic gas sensor according to claim 3, characterized in that: A connection portion extending downward is provided at the lower end of the shell, and the shell is connected to the sensor mounting seat through the connection portion. The interior of the connection portion is hollow and communicates with the air inlet channel and the air outlet channel.

7. The ultrasonic gas sensor according to claim 6, characterized in that: The length L1 of the baffle extending downward is greater than or equal to the length L2 of the connecting portion extending downward.

8. The ultrasonic gas sensor according to claim 6, characterized in that: The lower end of the shell is threadedly connected or snap-fitted to the gas sensor mounting seat.

9. The ultrasonic gas sensor according to claim 1, wherein: A temperature sensor is provided in the middle of the ultrasonic transmission path.

10. The ultrasonic gas sensor according to claim 1, wherein: The upper end of the shell is provided with a first mounting groove and a second mounting groove, and the first mounting groove and the second mounting groove are used for mounting the first ultrasonic transducer and the second ultrasonic transducer respectively.

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