Pressure sensor

Abstract

The invention discloses a pressure sensor, and the sensor comprises a housing which comprises a metal pressure joint and a metal cylindrical shell; a metal substrate; a pressure sensitive element; the metal corrugated sheet is arranged between the pressure joint and the substrate; a circle of first crimping part formed at the edge of the barrel shell presses the edge of the corrugated sheet against the pressure joint, and the first crimping part, the corrugated sheet and the pressure joint are welded together in a circumferential sealing manner through a circle of first welding seam; the first crimping part is matched with the first welding seam, so that the cylindrical shell, the pressure joint and the corrugated sheet can be conveniently sealed and fixed, the structural strength of the pressure sensor can be improved, and the sealing performance of the joint of the cylindrical shell, the pressure joint and the corrugated sheet can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure detection, and in particular relates to a pressure sensor. Background Art

[0002] Pressure sensors are sensors used to measure the pressure of the environment or medium. Currently, they are mostly implemented through MEMS (micro-electromechanical systems), that is, the pressure is measured through the piezoresistive effect of semiconductor silicon. Among them, the middle part of the silicon core is set to be a diaphragm. The pressure applied to the silicon diaphragm on both sides causes the resistance value of the doped resistor on the silicon diaphragm to change. The current or voltage signal output by the measurement circuit composed of several resistors can be further processed by the conditioning circuit and then output the measurement result to the outside. When a vacuum cavity is set on one side of the diaphragm in the silicon chip, the measured pressure is the pressure applied on the other side relative to the vacuum pressure, that is, the absolute pressure; when atmospheric pressure is introduced on one side of the diaphragm, the measured pressure is the pressure relative to the atmosphere, that is, the gauge pressure; when other pressures are introduced on both sides of the diaphragm, the measured pressure is the difference between the pressures on both sides, that is, the differential pressure. In some other sensors, temperature sensitive elements can also be integrated to measure the pressure and temperature of the medium at the same time.

[0003] A Chinese utility model patent with publication number CN219104249U discloses a pressure sensor, which includes: a pressure connector, in which a longitudinally extending pressure channel is provided; a pressure sensitive head, a longitudinal distal end of which is recessed inward to form a connecting tube with a sensing cavity facing the distal end, and a longitudinal proximal end of which forms an elastic diaphragm accordingly, a surface of the longitudinal proximal end of the elastic diaphragm is provided with a pressure measuring circuit, the proximal end of the connecting tube is sealedly connected to the pressure connector to connect the proximal end of the pressure channel to the sensing cavity; a terminal and a shell that together with the pressure connector enclose a mounting cavity, the proximal and distal ends of the shell are sealedly connected to the terminal and the pressure connector in a one-to-one correspondence; a support seat and a signal processing component arranged in the mounting cavity, the signal processing component having a circuit board snapped onto the proximal end of the support seat, the circuit board being electrically connected to the pressure measuring circuit; and a plurality of electrical connectors that are electrically connected to the circuit board after passing through the terminal.

[0004] The pressure sensitive element of this pressure sensor can directly contact with the pressure medium and is easily corroded when the pressure medium is corrosive. Summary of the invention

[0005] An object of the present invention is to provide a pressure sensor to solve at least one of the above technical problems.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A pressure sensor, comprising:

[0008] A housing, comprising a metal pressure joint and a metal shell, wherein the top of the pressure joint is fixed to the bottom of the shell by welding, a pressure introduction channel for introducing a medium to be measured is formed in the pressure joint, and the top of the pressure joint forms a flat surface;

[0009] A metal substrate located in the housing and fixed to the top surface of the pressure joint, on which a processing circuit is provided, and a detection hole connected to the pressure introduction channel is opened on the substrate;

[0010] A pressure sensitive element is arranged on the substrate, which is sealed at the top opening of the detection hole to receive the pressure of the pressure medium to be measured and convert the pressure into an electrical signal. The pressure sensitive element is electrically connected to the processing circuit and is used to process the electrical signal through the processing circuit.

[0011] A metal corrugated sheet is arranged between the pressure joint and the substrate, the top surface of the pressure joint is recessed to form a first avoidance cavity for avoiding the corrugated sheet, the substrate protrudes toward a side away from the corrugated sheet, and its bottom forms a second avoidance cavity for avoiding the corrugated sheet, the corrugated sheet closes the second avoidance cavity from the top side, and closes the first avoidance cavity from the bottom side; a circle of first crimping parts formed on the edge of the cylinder shell presses the edge of the corrugated sheet against the flat surface, the first crimping part, the corrugated sheet and the flat surface are circumferentially sealed and welded together by a circle of first welds, the second avoidance cavity and the detection hole are filled with a pressure-conducting medium, and the first crimping part is arranged to cooperate with the first weld to facilitate the sealing and fixing of the cylinder shell, the pressure joint and the corrugated sheet.

[0012] The present invention isolates the external pressure medium from the pressure sensitive element by arranging a corrugated sheet between the pressure joint and the substrate, thereby preventing the pressure medium from corroding the pressure sensitive element, and then transmits the pressure to the pressure sensitive element through the arranged pressure-conducting medium, so that the pressure sensitive element can receive the pressure of the pressure medium to be measured and convert the pressure into an electrical signal; the arranged flat surface facilitates welding the pressure joint, the corrugated sheet and the substrate together; the pressure sensitive element is arranged on the upper side surface of the substrate, and a detection hole is opened to enable the pressure sensitive element to receive the pressure to be measured.

[0013] Furthermore, a circle of second crimping portions formed on the cylindrical shell is pressed downward and is sealingly welded to the top side of the edge of the substrate through a second weld, and the second crimping portion is located on the inner side of the first crimping portion. The second crimping portion and the second weld are provided to facilitate the sealing welding of the substrate and the cylindrical shell together, thereby enhancing the structural strength of the pressure sensor and the sealing of the connection between the substrate and the cylindrical shell.

[0014] Furthermore, the edge of the base plate extends horizontally and presses downward against the adjacent edge of the corrugated sheet to facilitate fixing the corrugated sheet.

[0015] Furthermore, the edge of the substrate is welded to the flat surface, thereby increasing the structural strength of the pressure sensor and improving the sealing between the substrate and the flat surface.

[0016] Further, the edge of the substrate is welded to the flat surface through the first weld.

[0017] Furthermore, the edge of the flat surface protrudes upward to form a positioning flange surrounding the first crimping portion, which is used for positioning the first crimping portion to facilitate assembly of the cylinder shell.

[0018] Furthermore, a circuit board is provided on the substrate, and the processing circuit is arranged on the circuit board, and the circuit board is arranged for arranging the processing circuit.

[0019] Furthermore, the shell body also includes an end button, and the top of the cylindrical shell is gathered inward to form a circle of pressing edge, and the pressing edge is pressed tightly on the end button to press the end button and the substrate onto the pressure joint.

[0020] Furthermore, a sealing ring is provided between the pressing edge and the end button to improve the sealing performance of the connection between the cylinder shell and the end button.

[0021] Furthermore, a terminal is provided on the terminal button, one end of the terminal is located outside the terminal button, and the other end is located inside the terminal button and electrically connected to the processing circuit. The terminal is provided to connect an external device to the pressure sensor.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention isolates the external pressure medium from the pressure sensitive element by setting a corrugated sheet between the pressure joint and the substrate to prevent the pressure medium from corroding the pressure sensitive element. The pressure is then transmitted to the pressure sensitive element through the set pressure-conducting medium, so that the pressure sensitive element can receive the pressure of the pressure medium to be measured and convert the pressure into an electrical signal.

[0024] (2) The first crimping portion is provided in combination with the first weld to facilitate sealing and fixing the shell, the pressure joint and the corrugated sheet, which is beneficial to improving the structural strength of the pressure sensor and improving the sealing of the joints among the shell, the pressure joint and the corrugated sheet.

[0025] (3) The second crimping portion and the second welding seam facilitate the sealing welding of the substrate and the cylindrical shell together, which can further enhance the structural strength of the pressure sensor and the sealing of the connection between the substrate and the cylindrical shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the pressure sensor in this embodiment;

[0027] Figure 2 This is a diagram showing the relationship between the first weld, the pressure joint and the substrate in this embodiment;

[0028] Figure 3 This is a diagram showing the relationship between the first weld, the pressure joint and another position of the substrate in this embodiment;

[0029] In the figure: 1. shell; 101. pressure joint; 102. cylinder shell; 103. terminal button; 104. pressure introduction channel; 105. flat surface; 2. substrate; 201. processing circuit; 202. detection hole; 203. circuit board; 3. pressure sensitive element; 4. corrugated sheet; 5. first avoidance cavity; 6. second avoidance cavity; 7. first crimping part; 8. first weld; 9. pressure-conducting medium; 10. second crimping part; 11. second weld; 12. positioning flange; 13. pressing edge; 14. sealing ring; 15. terminal. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, this embodiment provides a pressure sensor, including a housing 1 , a metal substrate 2 , a pressure sensitive element 3 and a metal corrugated sheet 4 .

[0032] The housing 1 includes a metal pressure joint 101 and a metal cylinder shell 102. The top of the pressure joint 101 and the bottom of the cylinder shell 102 are fixed by welding. A pressure introduction channel 104 for introducing the medium to be measured is formed in the pressure joint 101, and a flat surface 105 is formed on the top of the pressure joint 101. The housing 1 may also include a terminal 103 connected to the upper end of the metal cylinder shell 102. The top of the cylinder shell 102 is gathered inward to form a circle of pressing edge 13. The pressing edge 13 is pressed tightly on the terminal 103 to press the terminal 103 and the substrate 2 on the pressure joint 101. Preferably, a sealing ring 14 may be provided between the pressing edge 13 and the terminal 103 to improve the sealing of the connection between the cylinder shell 102 and the terminal 103. Furthermore, a terminal 15 is provided on the terminal 103. One end of the terminal 15 is located outside the terminal 103 to connect to an external device, and the other end is located inside the terminal 103. The terminal 15 is provided to connect an external device to the pressure sensor.

[0033] The metal substrate 2 is located in the shell 1 and fixed to the top surface of the pressure joint 101. A processing circuit 201 is provided on it. The processing circuit 201 is electrically connected to one end of the terminal 15 located in the terminal button 103. A detection hole 202 connected to the pressure introduction channel 104 is opened on the substrate 2.

[0034] The pressure sensitive element 3 is arranged on the substrate 2, and is sealed at the top opening of the detection hole 202 to receive the pressure of the pressure medium to be measured and convert the pressure into an electrical signal. The pressure sensitive element 3 is electrically connected to the processing circuit 201, and is used to process the electrical signal through the processing circuit 201. Preferably, a circuit board 203 may also be provided on the substrate 2, the processing circuit 201 is provided on the circuit board 203, the pressure sensitive element 3 is also provided on the circuit board 203, and a hole is provided on the circuit board 203 for the pressure sensitive element 3 to receive the pressure to be measured.

[0035] A metal corrugated sheet 4 is arranged between the substrate 2 and the pressure connector 101. The edge of the substrate 2 extends horizontally and presses downward against the adjacent edge of the corrugated sheet 4 to facilitate fixing the corrugated sheet 4. The edge of the substrate 2 is welded to the flat surface 105 to increase the structural strength of the pressure sensor and improve the sealing between the substrate 2 and the flat surface 105. The top surface of the pressure connector 101 is concave to form a first avoidance cavity 5 to avoid the corrugated sheet 4. The substrate 2 protrudes toward the side away from the corrugated sheet 4, and its bottom forms a second avoidance cavity 6 to avoid the corrugated sheet 4. The corrugated sheet 4 closes the second avoidance cavity 6 from the top side and closes the first avoidance cavity 5 from the bottom side.

[0036] The first crimping portion 7 formed on the edge of the shell 102 presses the edge of the corrugated sheet 4 against the flat surface 105. Preferably, the edge of the flat surface 105 can protrude upward to form a positioning flange 12 surrounding the first crimping portion 7, which is used to position the first crimping portion 7 and facilitates the assembly of the shell 102. Figure 2 As shown, the first crimping portion 7, the corrugated sheet 4 and the flat surface 105 are circumferentially sealed and welded together by a circle of first weld seams 8. Preferably, the edge of the substrate 2 can also be sealed by Figure 3 The first weld 8 shown is welded to the flat surface 105. The second avoidance cavity 6 and the detection hole 202 are filled with a pressure-conducting medium 9. The first crimping portion 7 provided cooperates with the first weld 8 to facilitate the sealing and fixing of the cylindrical shell 102, the pressure connector 101 and the corrugated sheet 4. Preferably, a circle of second crimping portions 10 can also be formed on the cylindrical shell 102. The second crimping portion 10 presses downward and is sealed and welded to the top side of the edge of the substrate 2 through a second weld 11. The second crimping portion 10 is located on the inner side of the first crimping portion 7. The second crimping portion 10 and the second weld 11 are provided to facilitate the sealing welding of the substrate 2 and the cylindrical shell 102 together, which can enhance the structural strength of the pressure sensor and enhance the sealing of the connection between the substrate 2 and the cylindrical shell 102.

[0037] The present invention sets a corrugated sheet 4 between the pressure joint 101 and the substrate 2 to isolate the external pressure medium from the pressure sensitive element 3, thereby preventing the pressure medium from corroding the pressure sensitive element 3, and then transmits the pressure to the pressure sensitive element 3 through the set pressure-conducting medium 9, so that the pressure sensitive element 3 can receive the pressure of the pressure medium to be measured and convert the pressure into an electrical signal; the set flat surface 105 facilitates the welding of the pressure joint 101, the corrugated sheet 4 and the substrate 2; the pressure sensitive element 3 is set on the upper side surface of the substrate 2, and a detection hole 202 is opened to enable the pressure sensitive element 3 to receive the pressure to be measured.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure sensor, characterized in that: include: A housing, comprising a metal pressure joint and a metal shell, wherein the top of the pressure joint is fixed to the bottom of the shell by welding, a pressure introduction channel for introducing a medium to be measured is formed in the pressure joint, and the top of the pressure joint forms a flat surface; A metal substrate located in the housing and fixed to the top surface of the pressure joint, on which a processing circuit is provided, and a detection hole connected to the pressure introduction channel is opened on the substrate; A pressure sensitive element disposed on the substrate, which is sealed at the top opening of the detection hole to receive the pressure of the pressure medium to be measured and convert the pressure into an electrical signal, and the pressure sensitive element is electrically connected to the processing circuit; A metal corrugated sheet is arranged between the pressure joint and the substrate, the top surface of the pressure joint is recessed to form a first avoidance cavity for avoiding the corrugated sheet, the substrate protrudes toward a side away from the corrugated sheet, and its bottom forms a second avoidance cavity for avoiding the corrugated sheet, the corrugated sheet closes the second avoidance cavity from the top side, and closes the first avoidance cavity from the bottom side; a circle of first crimping parts formed on the edge of the cylinder shell presses the edge of the corrugated sheet against the flat surface, the first crimping part, the corrugated sheet and the flat surface are circumferentially sealed and welded together by a circle of first welds, and the second avoidance cavity and the detection hole are filled with a pressure-conducting medium.

2. The pressure sensor according to claim 1, characterized in that: A circle of second crimping portions formed on the cylinder shell presses downward and is sealedly welded to the top side of the edge of the base plate through a second weld, and the second crimping portion is located on the inner side of the first crimping portion.

3. The pressure sensor according to claim 2, characterized in that: The edge of the base plate extends horizontally and presses downward against the adjacent edge of the corrugated sheet.

4. The pressure sensor according to claim 1, characterized in that: The edge of the base plate is welded to the planar surface.

5. The pressure sensor according to claim 4, characterized in that: The edge of the base plate is welded to the planar surface by the first weld.

6. The pressure sensor according to claim 1, characterized in that: The edge of the flat surface protrudes upward to form a positioning flange surrounding the first crimping portion.

7. The pressure sensor according to claim 1, characterized in that: A circuit board is arranged on the substrate, and the processing circuit is arranged on the circuit board.

8. The pressure sensor according to claim 1, characterized in that: The shell also includes an end button, and the top of the cylindrical shell is gathered inward to form a circle of pressing edge, and the pressing edge is pressed tightly on the end button to press the end button and the substrate onto the pressure joint.

9. The pressure sensor according to claim 8, characterized in that: A sealing ring is provided between the pressing edge and the end button.

10. The pressure sensor according to claim 8, characterized in that: The terminal button is provided with a terminal, one end of the terminal is located outside the terminal button, and the other end of the terminal is located inside the terminal button and is electrically connected to the processing circuit.

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