Pressure sensor

Abstract

A pressure sensor comprises: a housing defining a mounting cavity, the housing being provided with a pressure introduction channel of which one end of the inner side is communicated to the mounting cavity; the pressure sensitive element is positioned in the mounting cavity and is hermetically fixed at one end of the inner side of the pressure introduction channel; the supporting seat is located in the mounting cavity, the lower end of the supporting seat is fixed to the inner side of the shell, and a containing hole for containing the pressure sensitive element is formed in the supporting seat; the first circuit board is fixed on the upper side of the supporting seat and is electrically connected to the pressure sensitive element; the second circuit board is fixed on the lower side of the supporting seat and is provided with a via hole allowing the pressure sensitive element to pass up and down; the upper ends and the lower ends of the electric contact springs are electrically contacted with the first circuit board and the second circuit board in a one-to-one correspondence mode, and the electric contact springs are kept on the supporting seat. According to the pressure sensor, the two circuit boards are respectively arranged on the upper side and the lower side of the supporting seat and are electrically connected through the electric contact spring, so that the cost is reduced, and the assembly is also facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of sensors, and particularly to a pressure sensor. Background Art

[0002] In a pressure sensor for measuring hydraulic pressure, usually a double circuit board is provided to maintain a small size (especially the lateral size). Among them, the first circuit board is connected to the pressure-sensitive element, and the other circuit board is electrically connected to the first circuit board through a flexible circuit board and needs to be mechanically fixed to the terminal in advance. Therefore, the flexible circuit board raises the overall cost of the product due to its high price, and it is also not conducive to assembly. For example, the movement and assembly of the terminal are restricted by the length of the flexible board. Utility Model Content

[0003] Aiming at the deficiencies of the prior art, the present application provides a pressure sensor to solve at least one of the above problems.

[0004] To achieve the above object, the present application provides the following technical solution: A pressure sensor, comprising:

[0005] A housing that encloses an installation cavity, and is provided with a pressure introduction channel whose inner side at one end communicates with the installation cavity;

[0006] A pressure-sensitive element located in the installation cavity and hermetically fixed to the inner side at one end of the pressure introduction channel;

[0007] A support seat located in the installation cavity and fixed to the inner side of the housing at the lower end, and is provided with a receiving hole for receiving the pressure-sensitive element;

[0008] A first circuit board fixed to the upper side of the support seat and electrically connected to the pressure-sensitive element;

[0009] A second circuit board fixed to the lower side of the support seat and provided with a through hole allowing the pressure-sensitive element to pass through up and down;

[0010] A plurality of electrical contact springs whose upper and lower ends are in one-to-one electrical contact with the first circuit board and the second circuit board respectively, and are held on the support seat.

[0011] The above pressure sensor electrically connects the two circuit boards by respectively arranging them on the upper and lower sides of the support seat and using electrical contact springs, which reduces the cost and is also conducive to assembly.

[0012] In order not to interfere with the connection to the housing and to maintain an appropriate height between the two circuit boards, preferably, the support base includes a holding portion, an upper support portion provided at the upper end of the holding portion, and a lower support portion formed by protruding downward from the edge of the holding portion. A concave cavity is defined between the lower side surface of the holding portion and the inner wall of the lower support portion, and the second circuit board is fixed in the concave cavity.

[0013] Preferably, the second circuit board is bonded to the lower side surface of the holding portion.

[0014] Alternatively, preferably, the edge of the second circuit board is snap - connected to the inner wall of the lower support portion.

[0015] In order to facilitate the assembly of the first circuit board, preferably, the first circuit board is snap - connected to the upper side of the support base.

[0016] In order to facilitate the assembly of the first circuit board, preferably, the upper support portion is provided at the upper end edge of the holding portion and a plurality of buckles are formed thereon, and the first circuit board is fixed to the upper side surface of the holding portion by the buckles.

[0017] Preferably, a plurality of first holding holes penetrating up and down are provided on the holding portion to hold the electrical contact spring in a vertical posture.

[0018] Preferably, the housing includes a metal cylindrical shell, a terminal button connected to the upper end of the cylindrical shell, and a metal pressure port connected to the lower end of the cylindrical shell; the lower support portion is snap - connected to the pressure port; the lower end of the cylindrical shell is welded to the pressure port, and the upper end presses the terminal button downward against the upper support portion.

[0019] Preferably, the pressure sensor further includes a terminal, the upper end of the terminal extends to the outside of the housing, and the lower end of the terminal extends into the housing and is electrically connected to the first circuit board.

[0020] Preferably, a plurality of second holding holes penetrating up and down are provided on the terminal button, the terminal includes a stepped spring, and the stepped spring is held in the second holding holes; the upper end of the stepped spring extends outward to the outside of the housing and the lower end electrically contacts the first electrical contact portion provided on the upper side surface of the first circuit board. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of a pressure sensor of a preferred embodiment.

[0022] Figure 2 It is a schematic structural diagram of a pressure sensor of another preferred embodiment.

[0023] Description of reference numerals: 10, pressure introduction channel; 11a, enlarged diameter portion; 11b, groove; 11, protruding portion; 1, pressure port; 2, cylindrical shell; 31, support portion; 32, membrane; 33, pressure measurement circuit; 34, thickened portion; 3, pressure sensitive element; 42, lower support portion; 43a, buckle; 43, upper support portion; 44a, upper side surface; 44b, lower side surface; 44, holding portion; 45, hemming; 49a, first holding hole; 49, electrical contact spring; 4a, receiving hole; 4, support base; 5a, through hole; 5, second circuit board; 61, electronic component; 62, lead; 6a, through hole; 6, first circuit board; 71, lower end; 7a, step surface; 7b, second holding hole; 7c, sealing ring; 7, terminal; 8, terminal. Detailed implementation manners

[0024] The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and cannot be construed as a limitation to the present application. In the following description, the same reference numerals are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0025] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present application is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present application.

[0026] In addition, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0027] It should also be further understood that the term "and / or" used in the specification and corresponding claims of the present application refers to any combination of one or more of the listed items and all possible combinations.

[0028] Such as Figure 1As shown in the figure, a pressure sensor according to a preferred embodiment of the present invention includes a housing and a pressure sensitive element 3, a support base 4, a second circuit board 5, and a first circuit board 6 disposed in an installation cavity (not marked) surrounded by the housing. Among them, the housing has a pressure introduction channel 10 for introducing a pressure medium to be measured into the installation cavity. The inner end of the pressure introduction channel 10 communicates with the installation cavity. The pressure sensitive element 3 may include a horizontally extending metal film 32, and a pressure measurement circuit 33 is provided on the upper side surface of the film 32, such as a Wheatstone bridge composed of a plurality of piezoresistors; the edge of the film 32 extends downward to form a surrounding support portion 31, and the lower end of the support portion 31 can be hermetically fixedly connected to the pressure port 1. In some other embodiments, the pressure sensitive element 3 may also be some other types of pressure sensitive elements, such as a capacitive pressure sensitive element, and may also be a semiconductor pressure sensitive element in terms of material.

[0029] Only by way of example, the housing includes a metal cylindrical shell 2, a terminal button 7 connected to the upper end of the cylindrical shell 2, and a metal pressure port 1 connected to the lower end of the cylindrical shell 2. Among them, the pressure port 1 is preferably made of metal, so that it can be welded to the lower end of the support portion 31. Exemplarily, the upper end of the pressure introduction channel 10 is defined by a tubular protrusion 11 protruding upward from the upper end of the pressure port 1. The middle part of the outer wall of the protrusion 11 can be expanded outward to form a surrounding diameter-expanded portion 11a. The lower end of the support portion 31 can be supported and welded to the diameter-expanded portion 11a. Correspondingly, a surrounding groove 11b is formed between the diameter-expanded portion 11a and the upper side surface of the pressure port 1 to reduce the influence of the installation stress of the pressure port 1 on the pressure sensitive element 3.

[0030] The support base 4 is fixed in the installation cavity and includes a holding portion 44, an upper support portion 43 provided at the upper end of the holding portion 44, and a lower support portion 42 protruding downward from the edge of the holding portion. A concave cavity (not marked) is formed between the lower side surface 44b of the holding portion 44 and the inner wall of the lower support portion 42. The second circuit board 5 is fixed in the concave cavity. Specifically, the second circuit board 5 is adhered to the lower side surface 44b of the holding portion 44, or the edge of the second circuit board 5 is tightly fitted to the inner wall of the lower support portion 42 or snapped to the inner wall of the lower support portion 42. The first circuit board 6 can be adhered to the upper side surface 44a of the holding portion 44 and can be additionally snap-fixed by a plurality of buckles 43a formed on the upper support portion 43.

[0031] Among them, the lower support portion 42 can be snap-fitted to an inner annular positioning step formed on the pressure port 1. The lower end of the cylinder shell 2 is welded to an outer annular positioning step formed on the pressure port 1. The upper end of the cylinder shell 2 can be rolled inward to form a crimping edge 45. The crimping edge 45 is pressed downward against an upward step surface 7a formed on the outer wall of the terminal button 7, so that the lower end 71 of the terminal button 7 is pressed against the upper support portion 43. A sealing ring 7c can be provided between the crimping edge 45 and the step surface 7a. Sealant can also be additionally applied to the gap between the crimping edge 45 and the outer wall of the terminal button 7.

[0032] To facilitate the electrical connection between the pressure-sensitive element 3 and the first circuit board 6, a receiving hole 4a for receiving the pressure-sensitive element 3 is provided on the holding portion 44, and the receiving hole 4a penetrates the holding portion 44 vertically. The pressure measurement circuit 33 of the pressure-sensitive element 3 is electrically connected to a processing circuit including a plurality of electronic components 61 provided on the upper side surface of the first circuit board 6. A via hole 6a allowing the lead wire 62 to pass through vertically can be provided on the first circuit board 6. A via hole 5a allowing the protruding portion 11 to pass through vertically is also provided on the second circuit board 5. A plurality of vertically penetrating first holding holes 49a are formed in the holding portion 44, and the electrical contact spring 49 is disposed in the first holding hole 49a and held in a vertical posture. The upper and lower ends of the electrical contact spring 49 are electrically contacted to the first circuit board 6 and the second circuit board 5 respectively. Among them, during assembly, the second circuit board 5 can be temporarily placed on the upper side surface of the pressure port 1 first, then the pressure-sensitive element 3 is welded to the protruding portion 11, and then the second circuit board 5 is lifted (without detaching from the pressure-sensitive element 3, and the outer diameter of the pressure-sensitive element 3 is preferably larger than the inner diameter of the second via hole 5a to increase the available area of the second circuit board 5) and installed on the support base 4.

[0033] Among them, the upper end of the support portion 31 can be expanded outward to form a thickened portion, thereby increasing the rigidity of the edge of the film 32. At the same time, it also requires a correspondingly larger receiving hole 4a, but also correspondingly limits the assembly method of the second circuit board 5.

[0034] In some other embodiments, the pressure sensor further includes a plurality of terminals 8. The upper ends of the terminals 8 extend to the outside of the housing. The lower ends of the terminals 8 extend into the housing and are electrically connected to the first circuit board 6. Preferably, a plurality of vertically penetrating second holding holes 7b are provided on the terminal button 7. The terminal 8 includes a stepped spring. The stepped spring is held in the second holding hole 7b. The upper end of the stepped spring extends outward to the outside of the housing and the lower end is electrically contacted to a first electrical contact portion provided on the upper side surface of the first circuit board 6.

[0035] Please refer to Figure 2。In another preferred embodiment, preferably, the lower surface of the second circuit board 5 can also be directly bonded to the upper surface of the pressure port 1. At this time, when assembling the pressure sensor, the second circuit board 5 can be first bonded to the upper surface of the pressure port 1, and then the pressure sensitive element 3 can be welded to the protrusion 11. Subsequently, the support base 4 and the first circuit board 6 are assembled onto the pressure port 1.

[0036] The scope of the present disclosure is not limited by the detailed description, but is defined by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are construed as being included in the present disclosure.

Claims

1. A pressure sensor, characterized in that: include: A housing enclosing a mounting cavity, wherein a pressure introduction channel (10) is provided on the housing, one inner end of the pressure introduction channel being connected to the mounting cavity; A pressure sensitive element (3) located in the installation cavity and sealed and fixed to one end of the inner side of the pressure introduction channel (10); A support seat (4) located in the installation cavity and having its lower end fixed to the inner side of the housing, and having a receiving hole (4a) for receiving the pressure sensitive element (3); A first circuit board (6) fixed to the upper side of the support seat (4) and electrically connected to the pressure sensitive element (3); A second circuit board (5) fixed to the lower side of the support seat (4), provided with a through hole (5a) for allowing the pressure sensitive element (3) to pass up and down; A plurality of electrical contact springs (49) are electrically contacted to the first circuit board (6) and the second circuit board (5) in a one-to-one correspondence at the upper and lower ends and are held on the support seat (4).

2. The pressure sensor according to claim 1, characterized in that: The support seat (4) comprises a retaining portion (44), an upper support portion (43) arranged at the upper end of the retaining portion (44), and a lower support portion (42) formed by the edge of the retaining portion protruding downward, a concave cavity is formed between the lower side surface (44b) of the retaining portion (44) and the inner wall of the lower support portion (42), and the second circuit board (5) is fixed in the concave cavity.

3. The pressure sensor according to claim 2, characterized in that: The second circuit board (5) is bonded to the lower surface (44b) of the holding portion (44).

4. The pressure sensor according to claim 2, characterized in that: The edge of the second circuit board (5) is clamped onto the inner wall of the lower support portion (42).

5. The pressure sensor according to claim 2, characterized in that: The first circuit board (6) is clamped on the upper side of the support seat (4).

6. The pressure sensor according to claim 3, characterized in that: The upper support portion (43) is arranged at the upper end edge of the retaining portion (44) and has a plurality of buckles (43a) formed thereon, and the first circuit board (6) is fixed to the upper side surface (44a) of the retaining portion (44) by the buckles (43a).

7. The pressure sensor according to claim 2, characterized in that: The holding portion (44) is provided with a plurality of first holding holes (49a) penetrating vertically and holding the electric contact spring (49) in a vertical position.

8. The pressure sensor according to any one of claims 2 to 7, characterized in that The outer shell comprises a metal cylinder shell (2), a terminal button (7) connected to the upper end of the cylinder shell (2), and a metal pressure port (1) connected to the lower end of the cylinder shell (2); the lower support portion (42) is snap-connected to the pressure port (1); the lower end of the cylinder shell (2) is welded to the pressure port (1), and the upper end is downwardly pressed to tighten the terminal button (7) to the upper support portion (43).

9. The pressure sensor according to claim 8, characterized in that: It also comprises a terminal, wherein the upper end of the terminal (8) extends to the outside of the housing, and the lower end of the terminal (8) extends into the interior of the housing to be electrically connected to the first circuit board (6).

10. The pressure sensor according to claim 9, characterized in that: The terminal button (7) is provided with a plurality of second retaining holes (7b) extending vertically therethrough, and the terminal comprises a stepped spring, which is retained in the second retaining hole (7b); the upper end of the stepped spring extends outward to the outside of the housing and the lower end electrically contacts a first electrical contact portion provided on the upper surface of the first circuit board (6).

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