Pressure sensor

Abstract

The invention provides a pressure sensor, which comprises a shell defining a mounting cavity and comprising an end button and a pressure interface which are arranged at two longitudinal ends, and a metal cylindrical shell longitudinally connecting the end button and the pressure interface; the pressure interface is provided with a pressure introduction channel for introducing a to-be-measured pressure medium into the mounting cavity; the pressure measuring element is arranged in the mounting cavity and is hermetically connected to one end of the inner side of the pressure introduction channel; the electronic module assembly is arranged in the mounting cavity and is electrically connected to the pressure measuring element; wherein the top of the cylindrical shell extends inwards in the radial direction and is molded in the end button, and a first retaining hole used for retaining a grounding spring is formed in the end button; the ground spring extends substantially longitudinally and has one end in electrical contact with the top and the other end in electrical contact with the electronics module assembly. According to the pressure sensor, the electric connection between the electronic module assembly and the metal cylinder shell has high reliability.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a pressure sensor. Background Art

[0002] In a type of pressure sensor with a metal cylinder, a flexible circuit board connected to the circuit board is usually extended outward to form a spring with a conductive part. During installation, the inner side of the metal cylinder is assembled downward to form an electrical contact with the spring, thereby forming an electromagnetic shield for the electronic module assembly inside the pressure sensor through the metal cylinder. The reliability of this grounded electrical connection structure has room for further improvement. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present application provides a pressure sensor, which makes the electrical connection between the pressure sensor and the metal cylinder shell more reliable.

[0004] The present invention provides a pressure sensor, comprising:

[0005] A housing enclosing an installation cavity comprises terminals and pressure interfaces arranged at both ends in the longitudinal direction, and a metal cylindrical shell longitudinally connecting the terminals and the pressure interfaces; the pressure interface has a pressure introduction channel for introducing a pressure medium to be measured into the installation cavity;

[0006] A pressure measuring element disposed in the installation cavity and sealed to one end of the inner side of the pressure introduction channel;

[0007] an electronic module assembly disposed in the mounting cavity and electrically connected to the pressure measuring element;

[0008] The top of the cylindrical shell extends radially inward and is molded in the end button, and a first retaining hole for retaining a grounding spring is formed in the end button; the grounding spring extends generally longitudinally, and one end thereof is electrically contacted to the top, and the other end is electrically contacted to the electronic module assembly.

[0009] Preferably, a plurality of first retaining holes for retaining spiral elastic terminals are formed in the terminal button. The elastic terminal generally extends longitudinally, and one end thereof is electrically contacted to the electronic module assembly, and the other end extends outward to the outside of the shell.

[0010] Preferably, the elastic terminal is a coil spring, comprising:

[0011] A first portion disposed longitudinally along the central axis and sparsely coiled;

[0012] A second portion having a central axis disposed longitudinally and a bottom end connected to a top end of the first portion, comprising a tightly coiled portion and a sparsely coiled portion having a bottom end connected to the tightly coiled portion;

[0013] and a transition portion connecting the top of the first portion and the bottom of the second portion, comprising at least one tapered portion, wherein the outer diameter of the bottom of the tapered portion is greater than the outer diameter of the top.

[0014] Preferably, the top end of the sparsely coiled portion has a lateral portion.

[0015] Preferably, the elastic terminal further comprises a tapered tail portion with a gradually decreasing outer diameter connected to the bottom of the first portion.

[0016] . According to any one of claims 1 to 2, the pressure sensor, wherein the central axis of the first part and the central axis of the second part are collinearly arranged, and the maximum outer diameter of the second part is smaller than the outer diameter of the first part.

[0017] . According to any one of claims 1 to 2, the pressure sensor, wherein the central axis of the first part and the central axis of the second part are offset by a certain distance in the lateral direction.

[0018] Preferably, projections of outer contours of the tapered portion and the first portion on the transverse plane partially overlap.

[0019] Preferably, it also includes a generally cylindrical supporting element for supporting the electronic module assembly; an inner end of the pressure interface longitudinally extends into the interior of the supporting element and is provided with at least one positioning groove on its periphery, and an inner wall of the supporting element protrudes radially inward to form a positioning portion that cooperates with the positioning groove; an inner end of the pressure introduction channel longitudinally extends inward to form a connecting tube, and a middle part of the connecting tube extends outward to form a disk body; the pressure measuring element includes a metal diaphragm, which is sealingly connected to a side of the disk body away from the pressure interface; an edge of the disk body forms a first guide groove for longitudinally giving way to the positioning portion, one end of the positioning portion is supported on the pressure interface, and the other end extends radially inward to cross the first guide groove.

[0020] Preferably, the other end of the positioning portion is close to the disk body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional diagram of the elastic terminal of the first embodiment;

[0022] Figure 2 A front view of the elastic terminal of the first embodiment;

[0023] Figure 3 is a three-dimensional diagram of the pressure sensor of the first embodiment;

[0024] Figure 4 is a top view of the pressure sensor of the first embodiment;

[0025] Figure 5 The pressure sensor of the first embodiment is Figure 4 A cross-sectional view of AA shown in FIG;

[0026] Figure 6 The pressure sensor of the first embodiment is Figure 4 A cross-sectional view of BB shown in ;

[0027] Figure 7 A front view of the elastic terminal of the second embodiment;

[0028] Explanation of reference numerals: 100, pressure sensor; 101a, tail; 101, first part; 102a, tightly coiled part; 102b, sparsely coiled part; 102c, lateral part; 102, second part; 103, transition part; 104, extension part; 105, tapered part; 10, elastic terminal; 110, pressure introduction channel; 11, pressure interface; 120, top; 12, shell; 130, second holding hole; 133, pressing surface; 13, terminal; 1, shell; 20, diaphragm; 21, pressure measurement circuit; 2, pressure measurement element; 5, external Equipment; 111, disk; 112, connecting pipe; 113, positioning groove; 11a, stress isolation groove; 11b, first guide groove; 131, leg; 134, first retaining hole; 20a, second guide groove; 22, extension; 23, flexible circuit board; 24, circuit board; 25, processing electronic components; 26, other electronic components; 27, thickening portion; 313, anti-slip portion; 314, positioning portion; 31a, first yielding portion; 31b, window; 31, barrel; 32a, yielding groove; 32b, second yielding portion; 32, connecting portion; 3, supporting element; 6, grounding spring; DETAILED DESCRIPTION

[0029] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application. In the following description, the same symbols are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0030] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the products of the present application are usually placed when in use, or the directions or positional relationships usually understood by those skilled in the art, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the equipment or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limitations on the present application. In addition, the prepositive terms "first", "second", "third", etc. are only used to distinguish the modified objects, and cannot be understood as indicating or implying relative importance.

[0031] In addition, the terms "installed", "connected" and "connected" 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 a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] It should be further understood that the term “and / or” used in the specification and corresponding claims of this application refers to any and all possible combinations of one or more of the listed items.

[0033] like Figure 1 , Figure 2 As shown. The elastic terminal 10 of the first embodiment is a spiral spring, which includes a first part 101 whose central axis is arranged along the longitudinal direction, and a second part 102 whose central axis is arranged along the longitudinal direction, and the central axis of the second part 102 is arranged colinearly with the central axis of the first part 101. The top end of the first part 101 and the bottom end of the second part 102 are integrally connected through a transition part 103. Among them, the outer diameter of the first part 101 is greater than the maximum outer diameter of the second part 102. The transition part 103 includes a tightly wound conical part 105 (not marked), the top end outer diameter of the conical part 105 is smaller than the bottom end outer diameter, the top end of the conical part 105 is integrally transitioned to the top end of the first part 101, and the bottom end of the conical part 105 is integrally transitioned to the bottom end of the second part 102. The conical part 105 is preferably tightly wound and has a strong rigidity, so as to be pressed toward the bottom side by other components. In some other schemes, the conical part 105 can also be sparsely wound.

[0034] The second portion 102 includes a tightly coiled portion 102a at the bottom and a sparsely coiled portion 102b at the top. The outer diameter of the sparsely coiled portion 102b may be smaller than or equal to the outer diameter of the tightly coiled portion 102a. The sparsely coiled portion 102b may be connected to an external device (in Figure 3 The tightly coiled portion 102a can increase the lateral stiffness when in contact with an external device, thereby suppressing the lateral displacement of the second portion 102 when making electrical contact with the external device.

[0035] Preferably, the top of the sparsely coiled portion 102b forms a lateral portion 102c extending in the transverse direction, and the lateral portion 102c can provide a larger contact area when making electrical contact with the external device 5 (which can be a circuit board or an electrical contact component) to avoid the second portion 102 only forming point contact when making longitudinal contact with the external device due to the existence of the spiral inclination angle.

[0036] Please refer to Figure 3 to Figure 6 . Figure 3 to Figure 6 A pressure sensor 100 including the above-mentioned multiple elastic terminals 10 is shown. The pressure sensor 100 includes a shell 1 that encloses an installation cavity, an electronic module assembly (not marked) disposed in the installation cavity, and at least one pressure measuring element 2. The pressure measuring elements 2 are each connected to the pressure medium to be measured through a pressure introduction channel 110 to obtain the pressure of the medium to be measured. The pressure measuring element 2 converts the above-mentioned pressure into an electrical signal and transmits it to the electronic module assembly. The shell 1 may include a metal cylindrical shell 12 extending generally longitudinally, a terminal button 13 fixed to the top end of the cylindrical shell 12, and a pressure interface 11 fixed to the bottom end of the cylindrical shell 12. The pressure introduction channel 110 may be disposed in the pressure interface 11. In some other schemes, the pressure introduction channel is not necessary, for example, one side of the pressure measuring element 2 may be directly exposed to the pressure medium to be measured.

[0037] The pressure measuring element 2 is disposed in the mounting cavity and is sealedly connected to one end of the inner side of the pressure introduction channel 110 , and is electrically connected to the electronic module assembly.

[0038] The top 120 of the cylindrical shell 12 extends radially inward and is molded in the terminal button 13. A first holding hole 134 for holding a grounding spring 6 is formed in the terminal button 13. The grounding spring 6 extends substantially longitudinally, and its upper end is electrically in contact with the top 120, and its lower end is electrically in contact with the electronic module assembly.

[0039] The end button 13 may be formed with a second retaining hole 130, and the tapered portion 105 of the transition portion 103 is retained in the second retaining hole 130. Preferably, the second retaining hole 130 may be a stepped hole, which includes a first hole portion on the bottom side and a second hole portion on the top side, and a pressing surface 133 forms a transition between the first hole portion and the second hole portion, and the pressing surface 133 presses downward onto the tapered portion 105 of the transition portion 103. The pressing surface 133 is preferably a tapered surface, and preferably matches the outer shape of the tapered portion 105 of the transition portion 103.

[0040] At least a portion of the bottom of the tightly coiled portion 102a is held in the second holding hole 130, so that the side wall of the second hole portion forms a lateral support for the tightly coiled portion 102a to increase the lateral rigidity of the second portion 102. Preferably, the top end of the tightly coiled portion 102a extends to the outside of the second holding hole 130.

[0041] In which, the electronic module assembly may include a circuit board 24, on which a first electrical contact portion (not shown) is provided, and the pressing surface 133 presses downward onto the conical portion 105 of the transition portion 103, so that the bottom end of the first portion 101 is elastically electrically contacted to the above-mentioned first electrical contact portion.

[0042] Exemplarily, the pressure measuring element 2 may include a diaphragm 20 that generates surface strain under the above-mentioned pressure, and a pressure measuring circuit 21 is provided on a surface of the diaphragm 20 that is away from the pressure interface 11, and generates a corresponding electrical signal according to the above-mentioned strain. The above-mentioned pressure measuring circuit 21 is electrically connected to the circuit board 24. For example, the pressure measuring circuit 21 may be electrically connected to the circuit board 24 via a flexible circuit board 23.

[0043] A substantially cylindrical support element 3 may also be provided inside the housing 1, and the circuit board 24 may be fixed on the support element 3, and the bottom of the support element 3 may be supported on the pressure interface 11. One end of the inner side of the pressure interface 11 extends longitudinally into the interior of the support element 3 and is provided with at least one positioning groove 113 on its periphery. The inner wall of the support element 3 protrudes radially inward to form a positioning portion 314 that cooperates with the positioning groove 113. One end of the inner side of the pressure introduction channel 110 extends longitudinally inward to form a connecting pipe 112. The middle part of the connecting pipe 112 extends outward to form a disk body 111, and a stress isolation groove 11a is left between the disk body 111 and the main body of the pressure interface 11. The diaphragm 20 is sealedly connected to the side of the disk body 111 away from the pressure interface 11. The edge of the disk body 111 forms a first guide groove 11b that longitudinally gives way to the positioning portion 314. One end of the positioning portion 314 is supported on the pressure interface 11. The other end extends radially inward to form an anti-slip portion 313 that passes over the first guide groove 11b. The other end of the positioning portion 314 is close to the disk body 111. Among them, the edge of the diaphragm 20 can extend downward to form a cylindrical extension portion 22, and the lower end of the extension portion 22 can be welded to the disk body 111. The edge of the diaphragm 20 can also expand radially outward to form a thickened portion 27, thereby increasing the rigidity of the edge of the diaphragm 20. A second guide groove 20a corresponding to the positioning portion 314 can be provided on the circumference of the diaphragm 20. Accordingly, in order to facilitate the circumferential positioning of the diaphragm 20 and the pressure interface 11 by other equipment, a window 31b corresponding to the circumference of the second guide groove 20a can be provided on the support element 3.

[0044] The bottom end of the shell 12 can be welded to the pressure interface 11. In some other solutions, the top 120 of the shell 12 can also be fixed to the terminal button 13 by riveting, and the support element 3 can provide support for the terminal button 13.

[0045] The support element 3 may include a cylindrical portion 31 extending up and down and a plate-shaped connecting portion 32 integrally connected to the proximal end of the upper end of the cylindrical portion 31 from the outer circumference. The diaphragm 20 may be enclosed inside the cylindrical portion 31, and the support element 3 may form a first notch-shaped or window-shaped ditching portion 31a in the circumferential direction to allow the flexible circuit board 23 to pass through. A second notch-shaped or window-shaped ditching portion 32b may also be provided on the connecting portion 32 to make way for the flexible circuit board 23. Preferably, the first ditching portion 31a is notch-shaped and extends longitudinally, and the terminal 13 extends downward to form a leg 131, and the leg 131 is inserted downward into the first ditching portion 31a in a cooperative manner, so that the terminal 13 is circumferentially positioned relative to the support element 3. The top of the support element 3 is supported upward on the edge of the circuit board 24.

[0046] The circuit board 24 may be a double-sided circuit board, and a processing electronic component 25 (such as an ASIC chip) may be disposed on its lower surface, and other electronic components 26 may be disposed on its upper surface. A recess 32a may be disposed on the upper side of the connecting portion 32 to make way for the processing electronic component 25. The connecting portion 32 may protrude upward to form a plurality of heat rivet columns 32c, and the circuit board 24 may be fixed to the top of the supporting element 3 through the heat rivet columns 32c.

[0047] It should be emphasized that the elastic terminal 10 of the present invention is not only applicable to Figure 3 The specific pressure sensor shown is also applicable to many known types of pressure sensors. The pressure sensor is particularly suitable for pressure sensors built into a specific installation space in the automotive field to save installation space, such as a pressure sensor built into an EBS (Electronic Brake System) to obtain the pressure of the brake medium.

[0048] See also Figure 7 . On the basis of the first embodiment, the central axis of the second part 102 and the first part 101 of the elastic terminal 10 may not be colinear, for example, the central axis of the first part 101 and the second part 102 are laterally offset by a certain distance. In addition to the tapered part 105, the transition part 103 also includes an extension part 104 whose two ends are respectively connected to the bottom end of the transition part 103 and the top end of the first part 101. The above-mentioned lateral offset distance is mainly provided by the extension part 104. The advantage of doing so is that when the area of ​​the terminal button 13 that can be used to install the elastic terminal 10 is usually significantly smaller than the lateral area of ​​the circuit board 24, it can facilitate the arrangement of the electrical contact part.

[0049] At this time, the outer diameter of the top end of the tapered portion 105 only needs to be smaller than the outer diameter of the bottom end, and the outer diameter of the first portion 101 does not need to be larger than the maximum outer diameter of the second portion 102. At least a portion of the second portion 102 may be retained by a third retaining hole (not shown) on an additional retaining element (not shown) to prevent it from lateral displacement. The additional retaining element may be fixed to the bottom end of the terminal button, or to the top end of the supporting element. Preferably, the tapered portion 105 partially overlaps with the first portion 101 in the lateral direction, that is, the projections of the outer contours of the two on the lateral plane partially overlap, so that when the tapered portion 105 is pressed with the pressed surface facing downward, the first portion can be effectively compressed to elastically electrically contact the circuit board 24.

[0050] In the above embodiments, the elastic terminal 10 may further include a tapered tail portion 101 a connected to the bottom of the first portion 101 and having a gradually decreasing outer diameter.

[0051] The scope of the disclosure is defined not by the detailed description but 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 disclosure.

Claims

1. A pressure sensor, characterized in that: include: A housing enclosing an installation cavity comprises terminal buttons (13) and a pressure interface (11) arranged at both ends in the longitudinal direction, and a metal cylindrical shell (12) longitudinally connecting the terminal buttons (13) and the pressure interface (11); the pressure interface (11) has a pressure introduction channel (110) for introducing a pressure medium to be measured into the installation cavity; A pressure measuring element disposed in the installation cavity and sealed to an inner end of the pressure introduction channel (110); an electronic module assembly disposed in the mounting cavity and electrically connected to the pressure measuring element; The top (120) of the cylindrical shell (12) extends radially inward and is molded in the end button (13), and a first retaining hole (134) for retaining a grounding spring (6) is formed in the end button (13); the grounding spring (6) extends generally longitudinally, and one end thereof is electrically in contact with the top (120), and the other end is electrically in contact with the electronic module assembly.

2. The pressure sensor according to claim 1, characterized in that: A plurality of first retaining holes (130) for retaining the spiral elastic terminal (10) are formed in the terminal button (13); the elastic terminal (10) generally extends longitudinally, and one end thereof is electrically contacted to the electronic module assembly, and the other end thereof extends outward to the outside of the housing.

3. The pressure sensor according to claim 2, characterized in that: The elastic terminal is a coil spring, comprising: A first portion disposed longitudinally along the central axis and sparsely coiled; A second portion having a central axis disposed longitudinally and a bottom end connected to a top end of the first portion, comprising a tightly coiled portion and a sparsely coiled portion having a bottom end connected to the tightly coiled portion; and a transition portion connecting the top of the first portion and the bottom of the second portion, comprising at least one tapered portion, wherein the outer diameter of the bottom of the tapered portion is greater than the outer diameter of the top.

4. The pressure sensor according to claim 3, characterized in that: The top end of the sparsely coiled portion has a lateral portion.

5. The pressure sensor according to claim 4, characterized in that: The elastic terminal also includes a tapered tail portion with a gradually decreasing outer diameter connected to the bottom of the first portion.

6. The pressure sensor according to any one of claims 3 to 5, characterized in that: The central axis of the first part and the central axis of the second part are collinearly arranged, and the maximum outer diameter of the second part is smaller than the outer diameter of the first part.

7. The pressure sensor according to any one of claims 3 to 5, characterized in that: The central axis of the first part and the central axis of the second part are offset by a certain distance in the transverse direction.

8. The pressure sensor according to claim 7, characterized in that: The projections of the outer contours of the tapered portion and the first portion on the transverse plane partially overlap.

9. The pressure sensor according to claim 1, characterized in that: The electronic module assembly also includes a substantially cylindrical support element (3) for supporting the electronic module assembly; an inner end of the pressure interface (11) extends longitudinally into the interior of the support element (3) and is provided with at least one positioning groove (113) on its periphery; an inner wall of the support element (3) protrudes radially inward to form a positioning portion (314) that cooperates with the positioning groove (113); an inner end of the pressure introduction channel (110) extends longitudinally inward to form a connecting pipe (112); and the connecting pipe (112) is provided with a plurality of connecting pipes (112) and a plurality of connecting pipes (112) disposed on the inner wall of the pressure interface (111). The middle portion extends outward to form a disk body (111); the pressure measuring element (2) includes a metal diaphragm (20), and the diaphragm (20) is sealingly connected to a side of the disk body (111) away from the pressure interface (11); the edge of the disk body (111) forms a first guide groove (11b) for longitudinally giving way to the positioning portion (314), one end of the positioning portion (314) is supported on the pressure interface (11), and the other end extends radially inward to cross the first guide groove (11b).

10. The pressure sensor according to claim 9, characterized in that: The other end of the positioning portion (314) is close to the disk body (111).

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