Sensor for urea solution detection

Abstract

The invention particularly relates to a sensor for urea solution detection. The sensor comprises a base, a cover shell and a sensing module, wherein the cover shell surrounds the base to form a hollow mounting cavity, and the sensing module is accommodated in the mounting cavity; the base comprises a mounting seat and a medium introduction channel penetrating through the mounting seat, one end of the medium introduction channel is communicated with an external to-be-tested sample, and the other end of the medium introduction channel is plugged in the sensing module; wherein the inlet end of the medium introduction channel is arranged to be an annular flow channel which spirally ascends. The centrifugal force is provided for the to-be-measured sample through the spirally rising annular flow channel, so that the to-be-measured sample achieves the purpose of bubble elimination under the centrifugal effect, and the technical problem that the urea measurement precision is influenced by bubble interference is solved.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle urea filling, and in particular to a sensor for detecting urea solution. Background Art

[0002] The concentration standard of automotive urea solution (National VI) is 32.5% ± 1.5%, and the quality of automotive urea in vehicles filled with urea needs to be tested. In response to the high requirements of the National VI emission standard, urea quality sensors are currently used in the market to measure the concentration of urea solution and feed it back to the ECU for urea quality monitoring.

[0003] For example, the prior art CN117627764A provides an ECU diagnostic method for preventing urea bubbles. In the background technology, it points out that after a new car is filled with urea, the urea solution will produce a large number of bubbles, and the bubbles will adhere to the surface of the sensor probe, causing the sensor detection value to be distorted. In order to ensure the accuracy of urea detection, it adopts an ECU diagnostic method to eliminate the influence of bubbles. However, this method has great limitations. It is only used for off-line detection of new cars and cannot be universally applied to urea detection during urea filling. In addition, its detection method requires multiple shielding opening and closing processes, and requires the engine to be in the starting state, which has great restrictions on use.

[0004] Another example is the prior art CN218546640U, which provides an anti-interference urea concentration sensor packaging device, which uses an inner and outer shell to package the sensor in a shell, and a medium flow channel is set in the shell to eliminate the influence of bubbles. Although it uses physical means to make the anti-bubble interference universal, its structure is too large relative to the sensor, which is not conducive to the miniaturization of the sensor, and the use of external devices will inevitably lead to compatibility issues with the sensor. Therefore, the setting of the above device affects its large-scale application. Summary of the invention

[0005] The present invention aims at the technical problem of bubble influence in urea filling detection in the prior art and provides a sensor for urea solution detection to solve the pain points of limited application scenarios, difficult to ensure accuracy or large device size. The sensor has at least the advantages of small structure, basically no bubble interference and reliable detection.

[0006] The present invention provides a sensor for detecting urea solution, comprising:

[0007] A base, a cover shell enclosing the base to form a mounting cavity, and a sensor module accommodated in the mounting cavity;

[0008] The base includes a mounting seat and a medium introduction channel penetrating the mounting seat, one end of the medium introduction channel is connected to the external sample to be tested, and the other end is blocked by the sensor module;

[0009] Wherein, the inlet of the medium introduction channel is arranged as a spirally ascending annular flow channel.

[0010] Specifically, one of the main concepts of the present invention is to provide centrifugal force for the sample to be tested through a spirally ascending annular flow channel, so that the sample to be tested can achieve the purpose of eliminating bubbles under the centrifugal action, thereby solving the technical problem of bubble interference affecting the accuracy of urea determination.

[0011] Furthermore, the inlet end of the annular flow channel is constructed to be open from large to small and faces the inflow direction of the medium.

[0012] Specifically, the present invention constructs the inlet section of the annular flow channel into an open trumpet shape, so that the sample to be tested has a variable diameter structure in the annular flow channel, forming a jet structure with a wide inlet and a narrow channel. The flow rate of the sample to be tested in the annular flow channel is accelerated by changing the tube diameter, thereby enhancing the centrifugal effect of the sample to be tested.

[0013] Furthermore, a spoiler layer is provided at the outlet end of the annular flow channel. The present invention uses the spoiler layer to make the centrifuged sample turbulent, thereby preventing the sample from forming a reinforced vortex after passing through the annular flow channel and causing impact on the sensor component, thereby improving the structural stability and reliability of the present invention.

[0014] Optionally, the spoiler layer is a multi-layer hole structure or a twisted channel structure.

[0015] Optionally, the medium introduction channel further includes a sampling channel, and the sampling channel is gradually expanded from small to large in the direction from the spoiler layer toward the sensor module.

[0016] Specifically, the inlet end of the annular flow channel, the flow channel and the sampling channel form a large-small-large variable diameter structure, which enhances the jet effect of the sample to be tested in the annular flow channel.

[0017] Furthermore, the base is provided with a medium outlet channel, one end of the medium outlet channel is connected to the sampling channel, and the other end thereof faces the backflow direction of the medium.

[0018] Specifically, the medium outlet channel corresponds to the medium inlet channel, so that the sample to be tested can enter and exit the sensor. In addition, the medium inlet channel and the medium outlet channel are oriented in two directions, namely, the flow direction and the back flow direction, so that the medium to be tested forms a negative pressure at the back flow, thereby accelerating the flow of the sample to be tested in the annular flow channel through the driving of positive and negative pressures.

[0019] Optionally, the sensor module includes a substrate and a sensor element disposed on the substrate;

[0020] The substrate is provided with a through sensing channel, and one end of the sensing channel is blocked by the sensing element.

[0021] Furthermore, the sensing channel also includes a defoaming net;

[0022] The defoaming net is arranged on the substrate and is close to the sensing element.

[0023] Furthermore, the defoaming net is made of metal and is attached to the sensor element.

[0024] Specifically, another concept of the present invention is to utilize a defoaming net with a mesh structure to filter and eliminate the bubbles remaining after centrifugal crushing, and utilize its metal properties combined with the heat generated by the sensor element during operation to increase the temperature of the defoaming net, and utilize high temperature combined with the characteristics of mesh filtration to achieve the purpose of eliminating residual bubbles, so that the sensor provided by the present invention is basically not affected by bubbles in the urea solution.

[0025] Further, the sensor module includes a processing circuit;

[0026] The processing circuit is arranged on the substrate and is electrically connected to the sensor element.

[0027] In summary, the present invention provides a sensor for urea solution detection, which has at least the following advantages:

[0028] 1. The present invention provides centrifugal force for the sample to be tested through a spirally ascending annular flow channel, so that the sample to be tested can achieve the purpose of eliminating bubbles under the centrifugal action, thereby solving the technical problem that the bubble interference affects the accuracy of urea determination;

[0029] 2. The present invention also structures the inlet section of the annular flow channel into an open trumpet shape, so that the sample to be tested has a variable diameter structure in the annular flow channel, forming a jet structure with a wide inlet and a narrow channel. The flow rate of the sample to be tested in the annular flow channel is accelerated by the change in tube diameter, thereby enhancing the centrifugal effect of the sample to be tested;

[0030] 3. The present invention utilizes a defoaming net with a mesh structure to filter and eliminate the bubbles remaining after centrifugal crushing, and utilizes its metal properties combined with the heat generated by the sensor element during operation to increase the temperature of the defoaming net. The high temperature combined with the characteristics of mesh filtration is utilized to achieve the purpose of eliminating residual bubbles, so that the sensor provided by the present invention is basically not affected by the bubbles in the urea solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be used as a limitation on the scope of the present invention. In addition, unless otherwise specified, the drawings are only schematically representing the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0032] Figure 1 A front cross-sectional view of a sensor for urea solution detection provided by one embodiment of the present invention;

[0033] 1. Base; 2. Cover shell; 3. Installation cavity; 4. Sensor module; 11. Mounting seat; 12. Medium introduction channel; 13. Medium outlet channel; 21. Probe; 41. Substrate; 42. Sensor element; 43. Processing circuit; 44. Wiring terminal; 45. Sealant; 121. Annular flow channel; 122. Turbine layer; 123. Sampling channel; 411. Sensor channel; 121a. Inlet end; 121b. Outlet end; 411a. Defoaming net. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1 , the present invention is described in detail.

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The main idea of ​​the present invention is to eliminate the foam of the sample to be tested after passing through the medium introduction channel 12 through the structural design of the medium introduction channel 12 in the sensor, thereby avoiding the interference of bubbles on the sensor and achieving the purpose of improving the measurement accuracy of the urea solution.

[0037] For further explanation of the technical concept of the present invention, please refer to Figure 1 The figure shows a front cross-sectional view of a sensor for urea solution detection provided by one embodiment of the present invention.

[0038] Specifically, the sensor provided by the present invention includes four parts: a cover shell 2, a base 1, a mounting cavity 3 and a sensor module 4. Among them, the mounting cavity 3 is surrounded by the cover shell 2 and the base 1, and the sensor module 4 is arranged in the mounting cavity 3. The sensor module 4 is the core component of the sensor, which is used to measure various parameters in the urea solution, and can be any known type of sensor, such as a temperature sensor, a pressure sensor, and a component sensor. On the one hand, the base 1 is used for installing the sensor module 4, and on the other hand, it is used to be installed on a detection carrier and applied to the measurement of urea solution. The cover shell 2 is a packaging component of the sensor module 4, which is used to package the sensor module 4 and the base 1 as a whole to form a sensor. It is worth noting that the mounting cavity 3 is surrounded by the cover shell 2 and the base 1, and is intended to provide an installation space for the sensor module 4.

[0039] Furthermore, the base 1 includes a medium introduction channel 12 for introducing the sample to be tested for detection and analysis by the sensor module 4. The sample to be tested is a urea solution. The inlet end 121a of the medium introduction channel 12 is set as a spiraling annular flow channel 121. The main concept of the present invention is to make the sample to be tested form a centrifugal motion through the action of the annular flow channel 121, and then eliminate the bubbles through the centrifugal action. Finally, after the sample to be tested flows through the annular flow channel 121, a urea solution with bubbles eliminated is obtained for detection by the sensor module 4. The above-mentioned structural design relies on the structure of the sensor itself, and has the advantages of strong fit, small sensor, and detection results not being interfered by bubbles.

[0040] Furthermore, the medium introduction channel 12 at least includes an annular flow channel 121, a spoiler layer 122 and a sampling channel 123, and the sample to be tested at least passes through the annular flow channel 121, the spoiler layer 122 and the sampling channel 123 in sequence. Among them, the spoiler layer 122 is a multi-layer hollow structure or a twisted channel structure; the sampling channel 123 is a gradually expanding shape from small to large. It is worth explaining that although the sample to be tested has completed the elimination of bubbles through the annular flow channel 121, it is also easy to generate eddy currents and centrifugal shocks due to the centrifugal effect, which will easily cause damage to the sensor module 4. The spoiler layer 122 arranged at the outlet end 121b of the annular flow channel 121 breaks up the centrifugal force of the sample to be tested passing through the annular flow channel 121 through its spoiler effect, so that its flow returns to stability.

[0041] Furthermore, the inlet end 121a of the annular flow channel 121 is shaped like a trumpet that gradually decreases in size, so that the pipe diameter at any point of the inlet end 121a is larger than the pipe at any point of the annular flow channel 121, and then cooperates with the gradually expanding sampling channel 123 to make the annular flow channel 121 the thinnest point of the medium introduction channel 12, so that the sample to be tested generates a jet in the annular flow channel 121, thereby accelerating its flow rate in the annular flow channel 121, thereby enhancing the centrifugal effect.

[0042] Furthermore, the base 1 is also provided with a medium outlet channel 13, which is used to allow the sample to be tested to flow in through the medium introduction channel 12 and then flow out through the medium outlet channel 13. In addition, the medium introduction channel 12 is arranged in a front flow direction and the medium outlet channel 13 is arranged in a back flow direction, so that the sample to be tested generates a negative pressure at the outlet of the medium outlet channel 13, thereby assisting the flow of the sample to be tested in the base 1. It is worth explaining that the flow rate of the fluid to be tested can be provided by the outside world or by the rotation of the sensor.

[0043] Furthermore, the sensor module 4 includes a substrate 41, a sensor element 42, a processing circuit 43, a wiring terminal 44, a sealant 45 and other structures. Among them, the substrate 41 is a common chip board, which is used to power the sensor element 42 and the processing circuit 43. It is connected to the probe 21 on the cover shell 2 through the wiring terminal 44, and draws electricity from the outside through the probe 21. The sensor element 42 is used to convert signals, converting the information to be tested of the urea solution into electrical signals, and the processing circuit 43 processes the electrical signals so that the information to be tested of the urea solution is characterized. In addition, the sealant 45 is used to seal between the substrate 41 and the mounting seat 11 to prevent the sample to be tested from entering the mounting cavity 3 through the gap between the substrate 41 and the mounting seat 11. Among them, the mounting seat 11 is a seat structure in the base 1, which is used to support the substrate 41.

[0044] Furthermore, the substrate 41 includes a sensing channel 411 , and the sensing channel 411 is used for the sample to be tested to contact the sensing element 42 .

[0045] Furthermore, the substrate 41 is provided with a defoaming net 411 a, and the defoaming net 411 a is arranged close to the sensing element 42 for filtering the bubbles.

[0046] Optionally, the defoaming net 411a is a grid-like filtering structure, the pore size of which is determined according to the size of the bubbles, and is used to completely eliminate residual bubbles.

[0047] Optionally, the defoaming net 411a is a heat-conducting metal and is arranged in close contact with the sensor element 42. Since the sensor element 42 will dissipate heat during operation, and the heat can be used by the defoaming net 411a, the temperature of the defoaming net 411a after heat exchange is significantly higher than that of the sample to be tested, thereby eliminating the residual bubbles by high temperature. The present invention uses multi-level defoaming means to ensure that the sensor element 42 is basically not disturbed by bubbles, thereby ensuring the detection accuracy of the sensor.

[0048] The present invention is described in detail above. The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A sensor for detecting urea solution, characterized in that: include: A base (1), a cover shell (2) enclosing the base (1) to form a mounting cavity (3), and a sensor module (4) accommodated in the mounting cavity (3); The base (1) comprises a mounting seat (11) and a medium introduction channel (12) penetrating the mounting seat (11); one end of the medium introduction channel (12) is connected to an external sample to be tested, and the other end is blocked by the sensor module (4); Wherein, the inlet of the medium introduction channel (12) is arranged as a spirally ascending annular flow channel (121).

2. A sensor for detecting urea solution according to claim 1, characterized in that: The inlet end (121a) of the annular flow channel (121) is constructed in an open shape that gradually decreases in size and faces the inflow direction of the medium.

3. A sensor for detecting urea solution according to claim 2, characterized in that: The outlet end (121b) of the annular flow channel (121) is provided with a spoiler layer (122).

4. A sensor for detecting urea solution as claimed in claim 3, characterized in that: The spoiler layer (122) is a multi-layer hole structure or a twisted channel structure.

5. A sensor for detecting urea solution as claimed in claim 3, characterized in that: The medium introduction channel (12) further comprises a sampling channel (123), and the sampling channel (123) is in a gradually expanding shape from small to large in the direction from the spoiler layer (122) toward the sensor module (4).

6. A sensor for detecting urea solution according to claim 5, characterized in that: The base (1) is provided with a medium outlet channel (13), one end of the medium outlet channel (13) is connected to the sampling channel (123), and the other end faces the backflow direction of the medium.

7. A sensor for detecting urea solution according to claim 1, characterized in that: The sensor module (4) comprises a substrate (41) and a sensor element (42) arranged on the substrate (41); The substrate (41) is provided with a through sensing channel (411), and one end of the sensing channel (411) is blocked by the sensing element (42).

8. A sensor for detecting urea solution according to claim 7, characterized in that: The sensing channel (411) further comprises a defoaming net (411a); The defoaming net (411a) is arranged on the substrate (41) and is close to the sensing element (42).

9. A sensor for detecting urea solution according to claim 8, characterized in that: The defoaming net (411a) is made of metal.

10. A sensor for detecting urea solution according to claim 7, characterized in that: The sensor module (4) comprises a processing circuit (43); The processing circuit (43) is disposed on the substrate (41) and is electrically connected to the sensor element (42).

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