Built-in pressure and temperature and humidity integrated sensor

Abstract

The invention relates to the technical field of sensors, in particular to a built-in pressure and temperature and humidity integrated sensor which comprises a pressure detection unit and a temperature and humidity detection unit, the pressure detection unit comprises an elastic base body, a strain gauge and a pressure circuit board, and a detection flow channel extending in the axial direction of the elastic base body is formed in the elastic base body; a temperature and humidity detection hole communicated with the detection flow channel is formed in the closed end of the elastic base body, the temperature and humidity detection unit is installed in the temperature and humidity detection hole and comprises a temperature and humidity sensing module and a temperature and humidity circuit board, and the pressure circuit board and the temperature and humidity circuit board are arranged in a spaced mode; the temperature and humidity detection unit is arranged in the pressure detection unit, the environment temperature and humidity are detected while the pressure is detected, the appearance structure of the sensor is not changed, meanwhile, the temperature and humidity detection unit and the pressure detection unit are mutually independent physically, the pressure detection unit is not impacted by air pressure, but the temperature and humidity detection unit and the pressure detection unit are mutually connected on the signal transmission layer. And stable and reliable signal transmission is ensured.

Description

Technical Field

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

[0002] With the development of automobile electrification, more and more mid-to-high-end models are equipped with air suspension systems to improve the comfort of the car. Passenger car air suspension systems can be divided into open and closed types according to the air circuit form. Whether it is an open system or a closed system, it needs to be supplemented with air from the outside. However, the outside air contains more or less water vapor. If it is not properly controlled, it will cause a lot of trouble to the air suspension, such as: water freezing at low temperatures will block the air circuit and make it impossible to lift and lower. Water will accelerate the corrosion of internal parts of the valve pump, and even cause the air pump to stall, affecting the function of the double-chamber air spring stiffness valve, etc. Although there is a dryer in the air suspension system, it is impossible to detect the temperature and humidity status inside the system. Adding a temperature and humidity sensor alone will cost customers a lot of money to modify the air suspension system. Therefore, how to add temperature and humidity detection with minimal changes has become a problem that more and more customers are concerned about. Summary of the invention

[0003] The technical problem to be solved by the present invention is: in order to solve the problem that the air suspension system in the prior art cannot detect temperature and humidity and the installation of temperature and humidity sensors will lead to major changes and high costs in the air suspension system, a built-in pressure and temperature and humidity integrated sensor is now provided.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: a built-in pressure and temperature and humidity integrated sensor, comprising: The pressure detection unit comprises an elastic substrate, a strain gauge and a pressure circuit board, wherein a detection channel extending along the axial direction is formed inside the elastic substrate, and the detection channel passes through one end of the elastic substrate in the axial direction to form an open end, and the other end is a closed end, the strain gauge is attached to the outer side wall of the elastic substrate near the closed end, and a temperature and humidity detection hole connected to the detection channel is opened on the closed end of the elastic substrate; And a temperature and humidity detection unit, which is installed in the temperature and humidity detection hole and seals it, including a temperature and humidity sensing module and a temperature and humidity circuit board. The pressure circuit board and the temperature and humidity circuit board are arranged axially with respect to the elastic substrate, and the strain gauge and the pressure circuit board are electrically connected to the temperature and humidity circuit board.

[0005] Furthermore, one side of the elastic matrix is ​​formed into a planar structure extending along its axial direction, the outer plane of the planar structure is a sensing surface for the strain gauge to be attached, and a thin wall is formed between the outer plane and the inner plane.

[0006] Furthermore, the outer peripheral wall of the temperature and humidity sensing module and the hole wall of the temperature and humidity detection hole are glued and sealed.

[0007] Furthermore, a buffer gasket for buffering fluid impact force is provided between the elastic substrate and the temperature and humidity circuit board.

[0008] Furthermore, the temperature and humidity detection hole is expanded on one side away from the opening end of the elastic base to form a receiving groove for accommodating a buffer gasket, and a portion of the temperature and humidity circuit board is located in the receiving groove, while the other portion extends out of the receiving groove and a binding wire is provided between its side and the strain gauge.

[0009] Furthermore, the sensor also includes a support ring for supporting the pressure circuit board and a cap disposed above the pressure circuit board to limit its position.

[0010] Furthermore, the support ring includes a supporting portion, a first limiting protrusion protruding from the supporting portion, and a first limiting groove recessed in the supporting portion, and the cover cap includes a cover portion, a second limiting protrusion protruding from the cover portion, and a second limiting groove recessed in the cover portion, the first limiting protrusion is plugged into the second limiting groove, and the second limiting protrusion is a hook, which extends into the first limiting groove and is hooked with the pressure circuit board.

[0011] Furthermore, the outer cover of the support ring is provided with an outer shell, one end of the outer shell is welded to the elastic base, and the other end is bent inwardly to form an inner flange for abutting against the cover cap.

[0012] Furthermore, the outer peripheral wall of the elastic base is formed with a first limiting step for abutting against the outer shell and a second limiting step for abutting against the support ring.

[0013] Furthermore, the sensor also includes a connecting element installed in the cap, one end of the connecting element is connected to the pressure circuit board, and the other end extends out of the cap.

[0014] Beneficial effects of the present invention: The present invention arranges the temperature and humidity detection unit in the pressure detection unit, detects the ambient temperature and humidity while detecting the pressure, and does not change the appearance structure of the sensor. At the same time, the temperature and humidity detection unit and the pressure detection unit are physically independent of each other, and the pressure detection unit is not affected by air pressure shock, but the two are interconnected at the signal transmission level to ensure stable and reliable signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 is a three-dimensional schematic diagram of the present invention; Figure 2 It is a front view of the present invention; Figure 3is a cross-sectional view of the present invention; Figure 4 is a three-dimensional schematic diagram of the present invention after removing the outer shell; Figure 5 is a three-dimensional schematic diagram of a pressure detection unit of the present invention; Figure 6 is an exploded view of the present invention; Figure 7 is a three-dimensional schematic diagram of the elastic matrix; In the figure: 1. Elastic substrate; 101. Detection channel; 102. Open end; 103. Closed end; 104. Temperature and humidity detection hole; 105. Sensing surface; 106. Accommodation groove; 107. First limiting step; 108. Second limiting step; 2. Strain gauge; 3. Pressure circuit board; 4. Temperature and humidity sensor module; 5. Temperature and humidity circuit board; 6. Buffer gasket; 7. Bind wire; 8. Support ring; 801. Support portion; 802. First limiting protrusion; 803. First limiting groove; 9. Cover cap; 901. Covering portion; 902. Second limiting protrusion; 903. Second limiting groove; 10. Shell; 1001. Inner flange; 11. Connecting elements; 12. Soft flat cable. DETAILED DESCRIPTION

[0017] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner only, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0018] like Figure 1-Figure 3 As shown, a built-in integrated pressure, temperature and humidity sensor comprises: The pressure detection unit includes an elastic substrate 1, a strain gauge 2 and a pressure circuit board 3. A detection channel 101 extending along the axial direction is formed inside the elastic substrate 1, and the detection channel 101 passes through one end of the elastic substrate 1 in the axial direction to form an open end 102, and the other end is a closed end 103. The strain gauge 2 is attached to the outer wall of the elastic substrate 1 near the closed end 103, which is a half-bridge structure or a full-bridge structure, and a temperature and humidity detection hole 104 connected to the detection channel 101 is opened on the closed end 103 of the elastic substrate 1; And a temperature and humidity detection unit is installed in the temperature and humidity detection hole 104 and blocks it to achieve a sealing setting of the closed end 103 to avoid pressure changes caused by fluid leakage; the temperature and humidity detection unit includes a temperature and humidity sensor module 4 and a temperature and humidity circuit board 5. The temperature and humidity sensor module 4 is opposite to the fluid to sense the temperature and humidity changes of the fluid. The cross-sectional area of ​​the detection channel 101 is large, thereby increasing the force area and reducing the impact on the temperature and humidity detection unit, thereby improving the accuracy of temperature and humidity detection.

[0019] The pressure circuit board 3 and the temperature and humidity circuit board 5 are arranged axially at intervals along the elastic matrix 1, and the pressure circuit board 3 is located above the temperature and humidity circuit board 5. During detection, the fluid enters the elastic matrix 1, and the pressure circuit board 3 arranged above the temperature and humidity circuit board 5 will not be impacted by the fluid and can work normally. The strain gauge 2 and the pressure circuit board 3 are both electrically connected to the temperature and humidity circuit board 5. The temperature and humidity circuit board 5 and the strain gauge 2 are connected by a binding wire 7, and the binding wire 7 can be but is not limited to an aluminum wire. The pressure circuit board 3 and the temperature and humidity circuit board 5 are connected by a soft flat cable 12, that is, the temperature and humidity circuit board 5 serves as a transmission board for temperature and humidity signals, and also collects the resistance change of the strain gauge 2 and transmits it to the pressure circuit board 3 through the soft flat cable 12.

[0020] During detection, the fluid enters from the open end 102 of the elastic matrix 1 and flows to the closed end 103. During the flow of the fluid, pressure is generated on the elastic matrix 1, and the elastic matrix 1 is deformed under the force, and the resistance of the strain gauge 2 attached thereto changes. At the same time, the temperature and humidity sensing module 4 senses the changes in temperature and humidity of the fluid, generates a temperature and humidity signal, and transmits it to the temperature and humidity circuit board 5 for signal conditioning to complete the monitoring of temperature and humidity. At the same time, the temperature and humidity circuit board 5 can collect the resistance change of the strain gauge 2, and transmit it to the pressure circuit board 3 through the flexible cable 12 for pressure signal conditioning to complete high-precision pressure monitoring.

[0021] In some examples, such as Figure 3 and Figure 7As shown, one side of the elastic matrix 1 is formed into a planar structure extending along its axial direction. The planar structure can be regarded as formed by cutting off part of the elastic matrix 1 along the axial direction. The elastic matrix 1 is roughly D-shaped. The outer plane of the planar structure is the sensing surface 105 for the strain gauge 2 to be attached, and the inner plane is the flow channel wall on one side of the detection flow channel 101. There is a thin wall between the outer plane and the inner plane, that is, the wall thickness of the planar structure is less than the wall thickness of the rest of the elastic matrix 1. Attaching the strain gauge 2 at this position can improve the sensing accuracy of the strain gauge 2.

[0022] In some examples, such as Figure 3 As shown, the outer wall of the temperature and humidity sensing module 4 is adhesively sealed to the hole wall of the temperature and humidity detection hole 104, and one end of the temperature and humidity sensing module 4 is a sensing end that contacts the fluid to sense changes in the temperature and humidity of the fluid, and the other end protrudes radially to form a blocking end to block the temperature and humidity detection hole 104, a sealing surface is formed between the sensing end and the blocking end, and the sealing surface and the hole wall of the temperature and humidity detection hole 104 are filled with sealant.

[0023] In some examples, such as Figure 3 and Figure 6 As shown, a buffer gasket 6 for buffering the impact force of the fluid is provided between the elastic matrix 1 and the temperature and humidity circuit board 5. After the fluid enters the elastic matrix 1, it will impact the elastic matrix 1 and the temperature and humidity detection unit. The elastic matrix 1 will be elastically deformed under the force, and the resistance of the strain gauge 2 attached thereon will change to realize pressure detection. However, the working environment of the temperature and humidity circuit board 5 needs to be relatively stable. Therefore, the present application adopts an anti-vibration design. A buffer gasket 6 is provided between the elastic matrix 1 and the temperature and humidity circuit board 5 to buffer the impact force of the fluid and eliminate the influence of air pressure shock on the reliability and stability of the binding wire 7.

[0024] In some examples, such as Figure 3 and Figure 7 As shown, the temperature and humidity detection hole 104 is expanded on one side away from the open end 102 of the elastic base 1 to form a receiving groove 106 for accommodating the buffer gasket 6. The receiving groove 106 and the temperature and humidity detection hole 104 form a stepped hole that is larger at the top and smaller at the bottom. The buffer gasket 6 is placed on the stepped surface, and a through hole for the temperature and humidity sensor module 4 to pass through is opened in the center of the buffer gasket 6. A part of the temperature and humidity circuit board 5 is located in the receiving groove 106, and the other part extends out of the receiving groove 106 and a binding wire 7 is provided between its side and the strain gauge 2. In this embodiment, the thickness of the temperature and humidity circuit board 5 is correspondingly thickened to further prevent shock, and a solder pad is designed on the side so that the solder pad and the strain gauge 2 are arranged in the same direction, and the two are connected by the binding wire 7, thereby reducing the length of the binding wire 7 and simplifying the internal wiring of the sensor.

[0025] In some examples, such as Figure 1-Figure 3As shown, the sensor further comprises a support ring 8 for supporting the pressure circuit board 3 and a cover cap 9 which is arranged above the pressure circuit board 3 to limit its position, and the pressure circuit board 3 is installed between the two.

[0026] In some examples, such as Figure 3 and Figure 6 As shown, the support ring 8 includes a support portion 801, a first limiting protrusion 802 protruding from the support portion 801, and a first limiting groove 803 recessed in the support portion 801, and the three are arranged alternately, and the cover cap 9 includes a cover portion 901, a second limiting protrusion 902 protruding from the cover portion 901, and a second limiting groove 903 recessed in the cover portion 901, and the three are arranged alternately. The first limiting protrusion 802 is plug-fitted with the second limiting groove 903, and the second limiting protrusion 902 is a hook, which extends into the first limiting groove 803 and is hooked with the pressure circuit board 3, and the pressure circuit board 3 is provided with a slot for the second limiting protrusion 902 to be inserted.

[0027] In some examples, such as Figure 3 and Figure 6 As shown, the outer cover of the support ring 8 is provided with a shell 10, one end of the shell 10 is welded to the elastic base 1, and the other end is bent inward to form an inner flange 1001 for abutting against the cap 9. The cap 9 forms a limiting step, and the inner flange 1001 abuts against the limiting step to limit the freedom of the cap 9 to move upward, and the support ring 8 limits the freedom of the cap 9 to move downward.

[0028] In some examples, such as Figure 5 As shown, the outer peripheral wall of the elastic base 1 is formed with a first limiting step 107 for abutting against the outer shell 10 and a second limiting step 108 for abutting against the support ring 8. The outer shell 10 is limited by the first limiting step 107 and then welded to it, and the support ring 8 is limited by the second limiting step 108 and then welded to it.

[0029] In some examples, such as Figure 1-Figure 3 As shown, the sensor also includes a connecting element 11 installed in the cap 9, one end of the connecting element 11 is connected to the pressure circuit board 3, and the other end extends out of the cap 9. The connecting element 11 is a variable diameter spring with a small top and a large bottom. The cap 9 has an installation groove for installing the connecting element 11. The installation groove is a stepped groove with a small top and a large bottom for limiting the variable diameter spring.

[0030] Working principle: During detection, the fluid enters from the open end 102 of the elastic substrate 1 and flows to the closed end 103. During the flow of the fluid, pressure is generated on the elastic substrate 1, and the elastic substrate 1 is deformed by the force, and the resistance of the strain gauge 2 attached thereto changes. At the same time, the temperature and humidity sensing module 4 senses the temperature and humidity changes of the fluid, generates a temperature and humidity signal, and transmits it to the temperature and humidity circuit board 5 for signal conditioning to complete the temperature and humidity monitoring. At the same time, the temperature and humidity circuit board 5 can collect the resistance change of the strain gauge 2, and transmit it to the pressure circuit board 3 through the flexible cable 12 for pressure signal conditioning, thereby completing high-precision pressure monitoring. The application integrates the strain gauge 2 and the temperature and humidity detection unit on the same elastic substrate 1. On the basis of not changing the appearance structure of the air-suspended pressure sensor, the sensor size is only slightly increased (14mm→18mm), and without affecting the pressure output, the pressure, temperature and humidity detection are innovatively integrated into one sensor. The lower part of the sensor is pressed into the customer's hydraulic block through a conventional press-fit structure, and the middle part adopts a split-board design to connect the temperature, humidity and pressure signals. The upper part is connected to the host computer MCU through a connecting element 11, so as to detect the ambient temperature and humidity while detecting the pressure.

[0031] Process and assembly process: 1. The sensing surface 105 of the elastic substrate 1 is pasted with glass glue by silk-screen printing; 2. The strain gauge 2 is pasted on the melted glass glue, and then the glass glue is sintered in a special high-temperature tunnel furnace to sinter the strain gauge 2 and the elastic matrix 1 into one; 3. Place the buffer gasket 6 into the receiving groove 106 at the top of the elastic base 1; 4. Place the temperature and humidity detection unit on the buffer gasket 6, and seal the temperature and humidity sensor module 4 and the elastic base 1 by coating the surface with glue; 5. Connect the strain gauge 2 and the pad on the temperature and humidity circuit board 5 through the binding wire 7; 6. Weld the support ring 8 to the elastic base 1; 7. Place the pressure circuit board 3 on the support ring 8; 8. Connect the connecting element 11 to the pressure circuit board 3; 9. Put the cap 9 in from the top and fix the pressure circuit board 3 through the second limiting protrusion 902; 10. Insert the outer shell 10 from the top and connect it to the elastic base 1 by welding.

[0032] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A built-in integrated pressure, temperature and humidity sensor, characterized in that: include: A pressure detection unit, comprising an elastic substrate (1), a strain gauge (2) and a pressure circuit board (3), wherein the elastic substrate (1) has a detection channel (101) formed inside thereof and extending along its axial direction, and the detection channel (101) penetrates through one end of the elastic substrate (1) in the axial direction to form an open end (102), and the other end is a closed end (103), the strain gauge (2) is attached to the outer wall of the elastic substrate (1) near the closed end (103), and a temperature and humidity detection hole (104) connected to the detection channel (101) is provided on the closed end (103) of the elastic substrate (1); and a temperature and humidity detection unit, which is installed in the temperature and humidity detection hole (104) and seals the same, and comprises a temperature and humidity sensing module (4) and a temperature and humidity circuit board (5), wherein the pressure circuit board (3) and the temperature and humidity circuit board (5) are arranged axially spaced from each other along the elastic base (1), and the strain gauge (2) and the pressure circuit board (3) are both electrically connected to the temperature and humidity circuit board (5).

2. The built-in integrated pressure and temperature and humidity sensor according to claim 1, characterized in that: One side of the elastic base (1) is formed into a planar structure extending along its axial direction, the outer plane of the planar structure is a sensing surface (105) for the strain gauge (2) to be attached, and a thin wall is formed between the outer plane and the inner plane.

3. The built-in integrated pressure and temperature and humidity sensor according to claim 1, characterized in that: The outer peripheral wall of the temperature and humidity sensing module (4) and the hole wall of the temperature and humidity detection hole (104) are glued and sealed.

4. The built-in integrated pressure, temperature and humidity sensor according to claim 1, characterized in that: A buffer gasket (6) for buffering the impact force of the fluid is provided between the elastic base (1) and the temperature and humidity circuit board (5).

5. The built-in integrated pressure and temperature and humidity sensor according to claim 4, characterized in that: A side of the temperature and humidity detection hole (104) facing away from the open end (102) of the elastic base (1) is expanded to form a receiving groove (106) for receiving the buffer gasket (6); a portion of the temperature and humidity circuit board (5) is located in the receiving groove (106), and another portion extends out of the receiving groove (106) and a binding wire (7) is provided between the side surface of the temperature and humidity circuit board and the strain gauge (2).

6. The built-in integrated pressure, temperature and humidity sensor according to claim 1, characterized in that: The sensor further comprises a support ring (8) for supporting the pressure circuit board (3) and a cover cap (9) which is arranged above the pressure circuit board (3) to limit its position.

7. The built-in integrated pressure, temperature and humidity sensor according to claim 6, characterized in that: The support ring (8) comprises a support portion (801), a first limiting protrusion (802) protruding from the support portion (801), and a first limiting groove (803) recessed in the support portion (801); the cover cap (9) comprises a cover portion (901), a second limiting protrusion (902) protruding from the cover portion (901), and a second limiting groove (903) recessed in the cover portion (901); the first limiting protrusion (802) and the second limiting groove (903) are plug-fitted together; the second limiting protrusion (902) is a hook, which extends into the first limiting groove (803) and is hooked to the pressure circuit board (3).

8. The built-in integrated pressure, temperature and humidity sensor according to claim 6, characterized in that: The support ring (8) is covered externally with an outer shell (10), one end of the outer shell (10) is welded to the elastic base (1), and the other end is bent inwardly to form an inner flange (1001) for abutting against the cover cap (9).

9. The built-in integrated pressure, temperature and humidity sensor according to claim 8, characterized in that: The outer peripheral wall of the elastic base (1) is formed with a first limiting step (107) for abutting against the outer shell (10) and a second limiting step (108) for abutting against the support ring (8).

10. The built-in integrated pressure, temperature and humidity sensor according to claim 6, characterized in that: The sensor further comprises a connecting element (11) installed in the cover cap (9); one end of the connecting element (11) is connected to the pressure circuit board (3) and the other end extends out of the cover cap (9).

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