High-precision temperature and pressure integrated sensor

Abstract

The invention provides a high-precision temperature and pressure integrated sensor, and relates to the technical field of sensors, and the high-precision temperature and pressure integrated sensor comprises a connecting piece; the shell is provided with an inner cavity, the opening end of the inner cavity of the shell is connected with the connecting piece, the other end, away from the opening end of the inner cavity, of the shell is provided with a first channel and a second channel which are communicated with the inner cavity and are independent of each other, the bottom of the inner cavity is provided with a groove, and the top of the groove is provided with a sealing table; the temperature and pressure integrated sensor effectively improves the precision and reliability of a product.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a high-precision temperature and pressure integrated sensor. Background Art

[0002] With the continuous development of the automotive industry and industrial technology, people's demand for system stability and safety is increasing. High-precision, long-term reliability, and low-cost sensors are becoming increasingly important. In the vehicle control system, sensors collect temperature and pressure data from the monitoring area and feed it back to the processing unit. The data processing unit processes the collected data and issues instructions to the actuator to achieve the requirements of stable operation of the vehicle control system. Current integrated temperature and pressure sensors have the following problems:

[0003] The temperature sensors commonly used in the prior art are mostly thermistors, while the pressure sensors are ceramic capacitors. The temperature and pressure sensors use thermistors and ceramic capacitors to integrate the temperature and pressure acquisition functions. At the same time, the two functional areas need to be independently distinguished in the sensor structure, and corresponding sealing functions are required. In order to achieve this function, the current temperature and pressure sensors have added a temperature sensor base to increase the internal space to achieve the relative independence of the two functional areas. The current temperature sensor resistor base and sealing ring are mostly made of plastic material. This material is very sensitive to temperature. After expansion and contraction due to heat and cold, it has a great impact on the pressure data acquisition area, seriously affecting the accuracy of the product. The addition of the temperature sensor base will also bring about a series of problems such as increased costs and increased sealing links. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of existing technologies by providing a high-precision integrated temperature and pressure sensor that ensures the relative independence of temperature and pressure zones while significantly increasing product stability and achieving low-cost production. By removing the temperature sensor base and designing a novel metal sealing solution, the product achieves improved pressure accuracy and leak-free operation.

[0005] In order to achieve the above and other purposes, the present invention proposes, based on the existing technology, the idea of ​​removing the temperature sensor base and the plastic sealing ring, and realizes the requirements of sensor sealing and functional area independence by optimizing the structure of the pressure sensor and adding an independent load-bearing channel for the temperature sensor.

[0006] The present invention is achieved by including the following technical solutions: The present invention provides a high-precision temperature and pressure integrated sensor, the high-precision temperature and pressure integrated sensor comprising: a connecting piece; a shell having an inner cavity, the inner cavity opening end of the shell being connected to the connecting piece, the shell being provided with a first channel and a second channel communicating with the inner cavity and being independent of each other at the other end away from the inner cavity opening end, the inner cavity bottom having a groove, the groove top edge having a sealing platform, the sealing platform comprising a sealing belt at the top and a first arc surface and a second arc surface provided on both sides of the sealing belt, the sealing belt having a width of 0.01-0.1 mm; a protective tube, one end of the protective tube being located in the first channel, the other end of the protective tube extending out of the first channel; a pressure sensing element being placed in the inner cavity, the pressure sensing element being communicated with the second channel, a through hole being provided on the pressure sensing element, the pressure sensing element and the sealing belt being crimped;

[0007] a temperature sensing element, one end of which is located in the protective tube and the other end of which passes through the through hole via the first channel; and a circuit board, which is placed in the inner cavity and located on the pressure sensing element, one end of the circuit board is electrically connected to the connector, and the other end of the circuit board is electrically connected to the temperature sensing element and the pressure sensing element.

[0008] In one embodiment, the first arc surface is located close to the groove, the second arc surface is located away from the groove, and the first arc surface and the second arc surface are tangentially transitioned to the sealing band.

[0009] In one embodiment, the arc radius of the first arc surface is r1, the arc radius of the second arc surface is r2, and the distance between the first arc surface and the second arc surface is d, where d≥r1+r2.

[0010] In one embodiment, the arc radius r1 of the first arc surface is ≤0.2 mm, and the arc radius r2 of the second arc surface is ≤0.2 mm.

[0011] In one embodiment, the height between the sealing band and the bottom surface of the inner cavity is h, and the value of h is 0.2-0.3 mm.

[0012] In one embodiment, the through hole is an eccentrically arranged waist-shaped hole or a round hole.

[0013] In one embodiment, the circuit board has a first connecting hole that matches the circular hole, and the diameter of the first connecting hole is smaller than the diameter of the circular hole.

[0014] In one embodiment, the edge of the pressure sensing element has a positioning surface, and the bottom of the inner cavity has a positioning platform matching the positioning surface.

[0015] In one embodiment, a positioning hole is provided on the pressure sensing element, and a positioning pin matching the positioning hole is provided on the bottom of the inner cavity.

[0016] In one embodiment, the connector includes a connector body and a conductive member located in the connector body. The connector body has a pressure ring at its bottom, the pressure ring is pressed onto the pressure sensor, and the pressure ring has a cavity inside.

[0017] The present invention has the following beneficial effects:

[0018] 1. The present invention forms a pressure sensing area by directly contacting the pressure sensor and the housing. It does not use the temperature sensor base commonly provided in the inner cavity of the prior art. This can avoid the problem of deformation of the base due to temperature influence. Eliminating this part not only saves costs but also greatly improves the stability of product quality control and reduces quality risks.

[0019] 2. The existing technology, when using a temperature sensor base, inevitably requires sealing between the temperature sensor base and the pressure sensor, as well as sealing between the temperature sensor base and the housing. By removing the temperature sensor base and placing the pressure sensor in direct contact with the housing, sealing only needs to be performed between the pressure sensor and the housing. This reduces the number of sealing steps, significantly reducing the risk of seal failure, saving on sealing ring costs, and improving production cycle time. This reduced sealing risk also significantly improves the stability of product pressure data collection.

[0020] 3. The sealed cavity in the pressure acquisition area of ​​the existing structure is formed by the temperature sensor base, the pressure sensor and the shell. Due to the characteristics of the temperature sensor base material that expands when heated and contracts when cooled, the actual pressure sensing area of ​​the pressure area is constantly changing, which seriously affects the accuracy and reliability of pressure data acquisition. By eliminating the temperature sensor base and allowing the pressure sensor to directly form a pressure sensing cavity with the shell, the accuracy and reliability of the product are effectively improved.

[0021] 4. In the prior art, the temperature sensor must be soldered to the temperature sensor base and then connected to the circuit board through the temperature sensor base. In the structure of the present invention, the pressure sensor provides a dedicated channel for the temperature sensor through a separate through-hole, allowing the temperature sensor and the circuit board to be directly connected. This reduces the number of soldering steps in product production and assembly from two to one, greatly improving product cycle time and circuit power stability.

[0022] 5. Based on the existing structure, a mechanical metal structure seal is used to replace the rubber ring sealing solution, and the sealing of the sensor and the independence of the functional areas are achieved by optimizing the structure of the pressure sensor and adding an independent load-bearing channel for the temperature sensor.

[0023] 6. A metal sealing platform structure is used instead of a rubber ring sealing method. Compared with rubber, metal is less affected by temperature, and the pressure-sensing cavity is much more stable than the existing structure, thereby improving the accuracy of pressure data collection. To ensure the stability and effectiveness of the sealing effect, the connector uses a metal pressure ring to effectively transmit the axial force through the metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shown is a schematic structural diagram of a high-precision temperature and pressure integrated sensor according to an embodiment of the present invention;

[0025] Figure 2 Shown is a cross-sectional view of a high-precision integrated temperature and pressure sensor according to an embodiment of the present invention;

[0026] Figure 3 Shown is a cross-sectional view of a high-precision integrated temperature and pressure sensor according to an embodiment of the present invention;

[0027] Figure 4 Shown is an exploded view of a high-precision integrated temperature and pressure sensor according to an embodiment of the present invention;

[0028] Figure 5 Shown is a top view of a housing in one embodiment of the present invention;

[0029] Figure 6 Shown is a cross-sectional view of a high-precision integrated temperature and pressure sensor according to another embodiment of the present invention;

[0030] Figure 7 Shown is a top view of a pressure sensing element according to one embodiment of the present invention;

[0031] Figure 8 Shown is a schematic structural diagram of a circuit board and a pressure sensor in one embodiment of the present invention;

[0032] Figure 9 Shown is a top view of a housing in yet another embodiment of the present invention;

[0033] Figure 10 Shown is a cross-sectional view of the housing of the present invention;

[0034] Figure 11 Shown as the present invention Figure 10 Enlarged view of point A in the middle;

[0035] Figure 12 Shown is a partially enlarged cross-sectional view of the sealing platform of the present invention;

[0036] Numbers in the figure: 1-connector, 11-connector body, 11a-cavity, 11b-pressure ring, 12-conducting member, 2-shell, 21-inner cavity, 22-first channel, 22a-step notch, 23-second channel, 24-groove, 25-positioning platform, 3-protective tube, 31-convex edge, 4-temperature sensor, 5-sealing platform, 51-sealing belt, 52-first arc surface, 53-second arc surface, 6-pressure sensor, 61-diaphragm, 62-substrate, 63-through hole, 64-positioning surface, 65-positioning hole, 7-circuit board, 71-first connecting hole, 72-second connecting hole, 8-positioning pin, 9-elastic member, 100-sealant, 200-sealing ring. DETAILED DESCRIPTION

[0037] See also Figures 1 to 12 The following describes the embodiments of the present invention through specific examples.

[0038] like Figure 1 As shown, the present invention provides a high-precision integrated temperature and pressure sensor, which includes a connector 1. The connector 1 can electrically connect the signal of the sensor to a monitoring and reading device such as a computer.

[0039] like Figure 4 As shown, in some embodiments, the connector 1 includes a connector body 11 and a conductive member 12 located in the connector body 11 .

[0040] like Figure 2 and Figure 4 As shown, the high-precision integrated temperature and pressure sensor includes a housing 2, which can be a metal housing. The housing 2 defines an inner cavity 21. The open end of the inner cavity 21 can be connected to one end of the connector 1. The housing 2 is provided with a first channel 22 and a second channel 23 at the other end away from the open end, which communicate with the inner cavity 21. The first channel 22 is a temperature sensing channel, and the second channel 23 is a pressure sensing channel.

[0041] like Figure 2 and Figure 4 As shown, a protective tube 3 is provided at one end of the first channel 22 away from the inner cavity 21. One end of the protective tube 3 is provided in the first channel 22, and the other end of the protective tube 3 extends a certain distance out of the first channel 22. The protective tube 3 can be made of stainless steel.

[0042] like Figure 2As shown, the high-precision integrated temperature and pressure sensor includes a temperature sensing element 4, one end of which is disposed within the protective tube 3, and the other end of which passes through the first channel 22. The temperature sensing element 4 may be an NTC thermistor, and thermally conductive adhesive is disposed between the temperature sensing element 4 and the protective tube 3.

[0043] like Figure 2 and Figure 4 As shown, a groove 24 is provided at the bottom of the inner cavity 21, and the groove 24 is communicated with the second channel 23. The groove 24 is located on one side of the first channel 22. A sealing platform 5 is provided at the top edge of the groove 24. The sealing platform 5 is also made of metal. The sealing platform 5, the pressure sensor 6 and the groove 24 can be combined to form a pressure sensing cavity.

[0044] like Figure 11 and Figure 12 As shown, the sealing platform 5 includes a first arc surface 52 close to the groove 24 and a second arc surface 53 away from the groove 24. A sealing strip 51 is provided between the first arc surface 52 and the second arc surface 53. The sealing strip 51 is a very narrow sealing plane. The width of the sealing strip 51 can be 0.01-0.1 mm. The central angles of the arcs on the first arc surface 52 and the second arc surface 53 are acute angles.

[0045] The first arc surface 52 and the second arc surface 53 can be distributed on both sides of the sealing belt 51 , for example, symmetrically distributed on both sides of the sealing belt 51 , and the first arc surface 52 and the second arc surface 53 transition tangentially with the sealing belt 51 .

[0046] The present invention provides a very small sealing strip 51 , which can form a line contact with the pressure sensing element 6 , and the arc surfaces on both sides can form an auxiliary sealing area with slight deformation under pressure.

[0047] like Figure 11 As shown, the arc radius of the first arc surface 52 is r1, and the arc radius of the second arc surface 53 is r2. In one embodiment, r1=r2, the distance between the first arc surface 52 and the second arc surface 53 is d, and the height between the sealing belt 51 and the bottom surface of the inner cavity 21 is h, which can be between 0.2 and 0.3 mm.

[0048] In some embodiments, d≥r1+r2.

[0049] In one embodiment, r1≤0.2mm, r2≤0.2mm, so as to avoid the formation of sharp edges and prevent scratches on the product.

[0050] In some embodiments, d=0.4 mm, h=0.3 mm.

[0051] The present invention adopts a line seal, and the contact area between the sealing platform 5 and the pressure sensor 6 is very small. The pressure transmitted by the pressure sensor 6 can cause the first arc surface 52 and the second arc surface 53 to have a slight deformation. The slight deformation can also cover the uneven area, and will not cause the problem of sealing failure. Compared with the surface seal, it has a better fault tolerance rate and improves the reliability of the seal. h is limited to the range of 0.2~0.3mm, which can avoid the hidden danger of slight tilt of the upper pressure sensor 6 due to being too high.

[0052] like Figure 6 As shown, the bottom end of the first channel 22 is provided with a stepped groove 22a that matches the protection tube 3, and the outer wall of the protection tube 3 is provided with a convex edge 31. The convex edge 31 and the stepped groove 22a form a sealing surface through interference extrusion.

[0053] like Figure 2 As shown, a pressure sensing element 6 is further provided in the inner cavity 21 . The pressure sensing element 6 may be a ceramic pressure-sensitive core, such as a ceramic capacitor, and further a circular ceramic capacitor.

[0054] like Figure 3 As shown, the bottom of the connector 1 can be mounted on and supported by the pressure sensor 6. The connector 1 has a pressure ring 11b at its bottom, with a cavity 11a defined within the pressure ring 11b. The circuit board 7 can be positioned within the cavity 11a. The pressure ring 11b allows the riveting force of the housing 2 to be transmitted to the pressure sensor 6 during assembly, thereby forming a seal with the sealing platform 5. The pressure ring 11b can be made of metal.

[0055] like Figure 4 As shown, in one embodiment, the pressure sensor 6 includes a substrate 62 and a diaphragm 61. The diaphragm 61 can be an elastic diaphragm, which can generate different deformations by being squeezed by the medium to be measured, thereby converting the pressure into an electrical signal.

[0056] like Figure 2 and Figure 7 As shown, a through hole 63 is provided at a non-axial position of the pressure sensor 6 , and the top of the temperature sensor 4 can pass through the through hole 63 to achieve electrical connection with the circuit board 7 .

[0057] like Figure 2As shown, a circuit board 7 is further disposed in the inner cavity 21. The circuit board 7 is disposed on the pressure sensor 6. One end of the circuit board 7 can be electrically connected to the output end of the pressure sensor 6 and the top of the temperature sensor 4. The other end of the circuit board 7 can be electrically connected to the conductive member 12 in the connector 1.

[0058] The circuit board 7 can be any one of a flexible circuit board and a rigid circuit board.

[0059] like Figure 2 As shown, when a flexible circuit board is used, the circuit board 7 can be welded to the conductive member 12 .

[0060] like Figure 6 As shown, when a hard circuit board is used, the circuit board 7 and the conductive member 12 can be connected by an elastic member 9, and the elastic member 9 can be a spring.

[0061] like Figure 5 and Figure 7 As shown, in one embodiment, the circuit board 7 is a flexible circuit board. In this case, the through hole 63 in the pressure sensor 6 can be a waist-shaped hole. This waist-shaped hole allows the temperature sensor 4 to be soldered and integrated onto the flexible circuit board, while providing sufficient positioning tolerance, greatly enhancing the high requirements for product quality precision and product quality stability. One end edge of the pressure sensor 6 can be provided with a positioning surface 64, and the bottom of the inner cavity 21 is provided with a positioning platform 25 that mates with the positioning surface 64. Using a pressure sensor 6 with a special-shaped structure having a positioning surface 64 to mate with the housing 2 can effectively prevent misalignment caused by radial rotation of the pressure sensor 6.

[0062] like Figure 6 and Figure 8 As shown, in one embodiment, the circuit board 7 is a rigid circuit board. In this case, the through hole 63 on the pressure sensor 6 can be a double-hole structure. In this case, the circuit board 7 has a first connection hole 71 that matches the through hole 63, and the aperture of the through hole 63 is larger than the aperture of the first connection hole 71. In the rigid circuit board solution, the through hole 63 on the pressure sensor 6 is a double-hole structure, and there are two first connection holes 71 on the circuit board 7. The aperture of the through hole 63 is larger than the aperture of the first connection hole 71. The difference in aperture between the two forms a conical pagoda guide mechanism, which can quickly and effectively guide the top pin of the temperature sensor 4, realize a fast welding process, and save installation time. The pressure sensor 6 is provided with a positioning hole 65 on one side of the through hole 63, and the positioning hole 65 can accommodate the positioning pin 8.

[0063] like Figure 8 and Figure 9As shown, the positioning pin 8 can be disposed in the inner cavity 21. The circuit board 7 has a second connection hole 72 disposed on one side of the first connection hole 71. The second connection hole 72 can be connected to the electrical signal output terminal of the pressure sensor 6. The use of the positioning pin 8 to mate with the housing 2 can effectively prevent radial rotation of the pressure sensor 6 and misalignment.

[0064] like Figure 2 As shown, the assembly process for the sensor of the present invention using a flexible circuit board is exemplified below. During assembly, the circuit board 7, pressure sensor 6, and conductive element 12 are connected together by soldering to form a data transmission circuit. The pressure sensor 6 is in direct contact with the housing 2, and its positioning surface 64 is aligned with the positioning platform 25 within the housing 2 for positioning. A sealed pressure-sensing chamber is formed by the sealing platform 5. The temperature sensor 4 enters through the first channel 22 and through-hole 63 on the housing 2 and is then soldered to the circuit board 7 to form a temperature-sensitive heat collection unit. The protective tube 3 is filled with thermally conductive adhesive and press-fitted to the bottom of the first channel 22. After the top of the shell 2 is curled, it is fixed to the connector 1 by riveting, and the metal pressure ring 11b of the connector is used to ensure that the pressure sensor 6 and the sealing platform 5 form an effective and stable seal. The sealing failure will not occur due to the temperature sensitivity disadvantage of the connector body 11 made of plastic material in conventional technology. By coating the connection edge with sealant 100, it is isolated from the external environment. The sealing ring 200 of the sensor installed on the client and the installation body that needs to detect temperature and pressure, such as a pipeline, form a sealing area to prevent leakage of the medium to be measured.

[0065] The integrated pressure sensor of the present invention has an average leakage rate of less than 2.6×10⁻ during helium sealing test. 7 mbar·L / s.

[0066] Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial value. The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by persons of ordinary skill in the art without departing from the spirit and technical concepts disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A high-precision integrated temperature and pressure sensor, characterized by: The high-precision temperature and pressure integrated sensor includes: Connectors; A housing having an inner cavity, wherein an open end of the inner cavity of the housing is connected to the connector, and the housing is provided with a first channel and a second channel that are independent of each other and communicate with the inner cavity at the other end away from the open end of the inner cavity, the bottom of the inner cavity having a groove, the top edge of the groove having a sealing platform, the sealing platform including a sealing strip at the top and a first curved surface and a second curved surface provided on both sides of the sealing strip, the width of the sealing strip being 0.01 to 0.1 mm; a protective tube, one end of which is located in the first channel and the other end of which extends out of the first channel; a pressure sensing element disposed in the inner cavity, the pressure sensing element being in communication with the second channel, the pressure sensing element being provided with a through hole, and the pressure sensing element being press-connected with the sealing tape; a temperature sensing element, one end of the temperature sensing element being located in the protection tube, and the other end of the temperature sensing element passing through the first channel and the through hole; and a circuit board placed in the inner cavity and located on the pressure sensing element, one end of the circuit board being electrically connected to the connecting element, and the other end of the circuit board being electrically connected to the temperature sensing element and the pressure sensing element.

2. The high-precision integrated temperature and pressure sensor according to claim 1, characterized in that: The first arc surface is located on a side close to the groove, and the second arc surface is located on a side away from the groove. The first arc surface and the second arc surface transition tangentially with the sealing belt.

3. The high-precision integrated temperature and pressure sensor according to claim 1, characterized in that: The arc radius of the first arc surface is r1, the arc radius of the second arc surface is r2, and the distance between two sides of the first arc surface and the second arc surface is d, where d≥r1+r2.

4. The high-precision integrated temperature and pressure sensor according to claim 3, characterized in that: The arc radius r1 of the first arc surface is ≤0.2 mm, and the arc radius r2 of the second arc surface is ≤0.2 mm.

5. The high-precision integrated temperature and pressure sensor according to claim 3, characterized in that: The height between the sealing belt and the bottom surface of the inner cavity is h, and the value of h is 0.2-0.3 mm.

6. The high-precision integrated temperature and pressure sensor according to claim 1, characterized in that: The through hole is an eccentrically arranged waist-shaped hole or a round hole.

7. The high-precision integrated temperature and pressure sensor according to claim 6, characterized in that: The circuit board is provided with a first connecting hole matched with the circular hole, and the aperture of the first connecting hole is smaller than the aperture of the circular hole.

8. The high-precision integrated temperature and pressure sensor according to claim 1, characterized in that: The edge of the pressure sensor is provided with a positioning surface, and the bottom of the inner cavity is provided with a positioning platform matching the positioning surface.

9. The high-precision integrated temperature and pressure sensor according to claim 1, characterized in that: The pressure sensor is provided with a positioning hole, and the bottom of the inner cavity is provided with a positioning pin matching the positioning hole.

10. The high-precision integrated temperature and pressure sensor according to claim 1, characterized in that: The connector includes a connector body and a conductive member located in the connector body. The bottom of the connector body is provided with a pressure ring, the pressure ring is press-connected to the pressure sensor, and the inner side of the pressure ring is provided with a cavity.

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