Tension sensor

Abstract

A tension sensor low in manufacturing cost comprises a metal element which comprises a diaphragm extending transversely and a seat body integrally connected with the diaphragm upwards, the upper side surface of the diaphragm is provided with a pressure measuring circuit, and the seat body is used for receiving a downward first tension; the shell covers the diaphragm downwards, and the lower end of the shell is connected to the seat body; an electronic module assembly disposed inside the housing and electrically connected to the pressure measurement circuit; and the pull rod is formed by integrally extending the middle part of the upper end of the diaphragm upwards, and the pull rod upwards penetrates through the shell to receive an upward second pulling force.

Description

Technical Field

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

[0002] Tension sensors can be used in automobile braking or parking systems to measure the magnitude of force. For example, in a sensor of this type shown in CN118641073A, the circuit board is directly bonded to the surface of the metal diaphragm, which will interfere with the measurement circuit composed of the varistor on the surface of the diaphragm to a certain extent. On the other hand, since the pull rod is located at the lower end, a ring groove needs to be left between it and the main part of the metal diaphragm, which is difficult to machine and has a high cost. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present application provides a tension sensor to reduce stress interference on a metal diaphragm.

[0004] To achieve the above objectives, the present application provides the following technical solution: a tension sensor, comprising:

[0005] A metal element, comprising a diaphragm extending laterally and a seat integrally connected to the edge of the diaphragm upward, a pressure measuring circuit being arranged on the upper surface of the diaphragm, and the seat being used to receive a first upward pulling force;

[0006] A housing is disposed downwardly outside the diaphragm and connected at its lower end to the housing of the seat;

[0007] An electronic module assembly disposed inside the housing and electrically connected to the pressure measurement circuit via leads;

[0008] and a pull rod integrally extended downward from the middle portion of the lower end of the diaphragm, which is used to receive a second downward pulling force.

[0009] Preferably, it further comprises a supporting element arranged inside the housing, the electronic module assembly is fixed to the upper end of the supporting element, and the lower end of the supporting element is fixed to the base.

[0010] Preferably, a first step is formed on the outer circumference of the seat body, and the lower end of the support element is clamped to the outer circumferential wall of the first step.

[0011] Preferably, the supporting element comprises a longitudinally extending cylindrical portion, the edge of a supporting plate is integrally connected to the upper portion of the cylindrical portion, a circuit board which is at least a part of the electronic module assembly is fixed to the upper surface of the supporting plate; and a yield portion is provided on the supporting plate to allow the lead to pass through.

[0012] Preferably, the upper end of the barrel protrudes upward to the upper side of the support plate to form a groove with the support plate, and the circuit board is arranged in the groove and is fitted and fixed to the upper surface of the support plate.

[0013] Preferably, the edge of the diaphragm is integrally connected to the upper end of the seat body through a cylindrical integral connection portion, and the outer wall of the integral connection portion shrinks radially inward to form an annular groove between the outer periphery of the diaphragm and the outer periphery of the seat body.

[0014] Preferably, the housing further comprises a longitudinally extending cylinder, the lower end of which is sealingly fixed to a second step on the seat.

[0015] Preferably, the housing further comprises a connector mounting portion integrally connected to the upper end of the cylinder, the connector mounting portion is provided with an electrical connector, and the electrical connector is electrically connected to the electronic module assembly.

[0016] Preferably, it also includes a cable which is inserted into the cylinder and then electrically connected to the electronic module assembly, and the housing also includes a cover which is combinedly covered on the upper end of the cylinder.

[0017] Preferably, the inner diameter of the upper end of the integral connection portion is smaller than the outer diameter of the lower end of the pull rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a tension sensor according to a first embodiment;

[0019] Figure 2 is a structural schematic diagram of a tension sensor according to a second embodiment;

[0020] Figure 3 is a schematic structural diagram of a tension sensor according to a first embodiment;

[0021] Figure 4 is a schematic structural diagram of a tension sensor according to a fourth embodiment;

[0022] Figure 5 is a structural schematic diagram of a tension sensor according to a fifth embodiment;

[0023] Description of reference numerals: 101, lead wire; 10, varistor; 11, diaphragm; 120, force-bearing flange; 12a, step; 12b, step; 12, seat; 13a, ring groove; 13, integrated connection portion; 1, metal element; 200, tension sensor; 211, support portion; 21a, lower end opening; 21, cylinder; 221a, connection hole; 221, connector mounting portion; 222a, upper end opening; 222, pull rod connection portion; 223a, first portion; 223b, second portion; 223c, third part; 223, radial connection part; 22, cover body; 2, housing; 301, electrical contact part; 30, terminal; 31a, retaining hole; 31, retaining part; 3, electrical connector; 41a, hole; 41, mechanical connection part; 4, pull rod; 5a, yielding part; 5, circuit board; 6a, electrical connector; 6b, electrical connector; 71, barrel; 72a, yielding part; 72, support plate; 73, buckle; 7a, groove; 7, support element; 8a, wiring harness; 8, cable; 9, sealing plug. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] See also Figure 1 The tension sensor 100 of this embodiment includes a metal element 1 and a housing 2. The metal element 1 includes a diaphragm 11 extending transversely (i.e., the horizontal direction in the figure) and a seat 12 integrally connected to the edge of the diaphragm 11 upward. The seat 12 is used to receive a first upward tension F1 applied to the seat 12 by a first external device. Specifically, the first tension F1 can be applied to a force-bearing flange 120 formed by protruding outward from the lower end of the seat 12. Preferably, a positioning step 1b is formed at the lower end of the force-bearing flange 120. The housing 2 is downwardly covered on the outside of the diaphragm 11 and the lower end is connected to the seat 12. For example, the housing 2 may include a cylinder 21 extending longitudinally (i.e., the up-down direction in the figure), and the lower end opening 21a of the cylinder 21 is welded and fixed to a step 12a on the seat 12 (the upward supporting surface or the lower part of the step 12a is connected to the outer peripheral wall of the supporting surface).

[0029] The tension sensor 100 further includes a pull rod 4 integrally extending downward from the middle of the lower end of the diaphragm 11, which receives the second downward tension F2. For example, the upper end of the pull rod 4 may be provided with a mechanical connection portion 41 for a second external device to apply the second tension F2 to the pull rod 4. Thus, under the action of the first tension F1 and the second tension F2, the upper surface of the diaphragm 11 generates corresponding stress. The mechanical connection portion 41 may be provided with a laterally extending hole 41a.

[0030] Among them, a pressure measurement circuit is provided on the upper surface of the diaphragm 11 to measure the above-mentioned stress. For example, the pressure measurement circuit may include at least one varistor 10 fixedly attached to the upper surface of the metal element 1. The varistor 10 senses the stress at its location and generates a corresponding resistance change. The varistor 10 and other fixed resistors form at least a part of the measurement circuit that can output an electrical signal accordingly when an external power supply is provided. Preferably, the above-mentioned measuring bridge is a Wheatstone bridge, for example, it may include two varistors 10 and two fixed resistors. In some other schemes, the above-mentioned Wheatstone bridge may include two pairs of four varistors 10, and each pair of varistors 10 includes two varistors 10 that generate corresponding resistance changes at different stress distribution positions.

[0031] Preferably, the edge of the diaphragm 11 is integrally connected to the upper end of the seat body 12 through a cylindrical integral connection portion 13. The inner diameter of the upper end of the integral connection portion 13 is smaller than the outer diameter of the lower end of the tie rod 4. Accordingly, an annular groove 1a with an opening facing downward is left between the outer wall of the tie rod 4 and the inner wall of the integral connection portion 13. In this way, a relatively small annular portion is formed within the annular region S1 of the diaphragm 11, thereby generating a larger stress (compressive stress is generated on the upper surface of the diaphragm 11 here). When the above-mentioned varistor 10 is attached to the upper surface of the above-mentioned annular region S1 of the diaphragm 11, the measurement accuracy can be improved. Preferably, the outer wall of the integral connection portion 13 shrinks radially inward to form an annular groove 13a between the outer periphery of the diaphragm 11 and the outer periphery of the seat body 12.

[0032] The tension sensor 100 further includes an electronic module assembly (not labeled), which is disposed inside the housing 2. The electronic module assembly may include a circuit board 5, and the circuit board 5 is electrically connected to the pressure measurement circuit through the lead 101. The circuit board 5 may be directly bonded to the upper surface of the diaphragm 11. A clearance portion 5a is provided on the circuit board 5 for the lead 101 to pass through up and down.

[0033] In some other schemes, preferably, the tension sensor 100 may further include a support element 7 for supporting the circuit board 5, and the lower end of the support element 7 is fixed to the base 12. The circuit board 5 may be clamped or bonded to the upper end of the support element 7, and a gap is left between it and the upper surface of the diaphragm 11, so as not to contact the upper surface of the diaphragm 11. In this way, the interference of the circuit board 5 on the diaphragm 11 can be avoided. Among them, the support element 7 can be a plastic part, and a step 12b can be formed on the outer periphery of the base 12. A plurality of buckles 73 may be formed at the lower end of the support element 7, and the lower end of the buckle 73 may be clamped to the outer peripheral wall of the step 12b. The support element 7 may include a longitudinally extending barrel 71. The edge of a support plate 72 is integrally connected to the upper part of the barrel 71, and the circuit board 5 is fixed to the upper surface of the support plate 72. The support plate 72 may be provided with a clearance portion 72a for allowing the lead 101 to pass through. The support plate 72 may be annular, and the clearance portion 72a may be defined by at least a portion of the inner peripheral wall of the support plate 72. Preferably, the upper end of the barrel portion 71 protrudes upward to the upper side of the support plate 72 to form a groove 7a with the support plate 72. The circuit board 5 is positioned in the groove 7a and is bonded to the upper surface of the support plate 72.

[0034] The housing 2 may further include a connector mounting portion 221 integrally connected to the upper end of the barrel 21. An electrical connector 3 is provided on the connector mounting portion 221. A connecting hole 221a is provided on the connector mounting portion 221, and the electrical connector 3 may include a main body (not marked) made of an insulating material, and the main body is molded on the connecting hole 221a. The electrical connector 3 also includes a plurality of terminals 30 passing through the connecting hole 221a inside and outside, and one end of the inner side of the terminal 30 may be electrically connected to the circuit board 5 through the electrical connector 6b. The electrical connector 6b may be a flexible circuit board.

[0035] See also Figure 2 . On the basis of the first embodiment, the tension sensor 200 of the second embodiment may be modified as follows: the tension sensor 200 does not include the above-mentioned electrical connector 3, but includes a plurality of wire harnesses 8a that are electrically connected (for example, welded) to the circuit board 5 after passing through a threading hole (not marked) provided on the cylinder 21 inwardly. The threading hole and the cable 8 composed of the plurality of wire harnesses 8a may be sealed by a sealing plug 9. After the wire harness 8a is welded to the circuit board 5, the cover body 22 that is independent of the cylinder 21 may be combined and covered on the upper end of the cylinder 21 by bonding or the like. The upper portion of the cylinder 21 may protrude inwardly to form a plate-shaped support portion 211 for supporting and positioning the cover body 22. The support portion 211 is preferably an annular plate having a center hole for welding operations.

[0036] See also Figure 3 The tension sensor 300 of the third embodiment includes a metal element 1 and a housing 2. The metal element 1 includes a diaphragm 11 extending transversely (i.e., the horizontal direction in the figure) and a seat 12 integrally connected to the edge of the diaphragm 11 upward. The seat 12 is used to receive a first downward tension F3 applied to the seat 12 by a first external device. Specifically, the first tension F1 can be applied to a force-bearing flange 120 formed by the lower end of the seat 12 protruding outward. The housing 2 is downwardly covered on the outside of the diaphragm 11 and the lower end is connected to the seat 12. For example, the housing 2 may include a cylinder 21 extending longitudinally (i.e., the up and down direction in the figure), and the lower end opening 21a of the cylinder 21 is welded and fixed to a step 12a on the seat 12 (the upward supporting surface or the lower part of the step 12a is connected to the outer peripheral wall of the supporting surface).

[0037] The tension sensor 300 further includes a pull rod 4 integrally extending upward from the middle of the upper end of the diaphragm 11, and the pull rod 4 passes upward through the upper end opening 222a of the housing 2. The pull rod 4 is used to receive the second upward tension F4 and apply it to the middle of the diaphragm 11. For example, a mechanical connection portion 41 may be provided at the upper end of the pull rod 4 for a second external device to apply the second tension F4 to the pull rod 4. Thus, under the action of the first tension F3 and the second tension F4, the upper surface of the diaphragm 11 generates corresponding stress. The mechanical connection portion 41 may be provided with a laterally extending hole 41a.

[0038] Among them, a pressure measurement circuit is provided on the upper surface of the diaphragm 11 to measure the above-mentioned stress. For example, the pressure measurement circuit may include at least one varistor 10 fixedly attached to the upper surface of the metal element 1. The varistor 10 senses the stress at its location and generates a corresponding resistance change. The varistor 10 and other fixed resistors form at least a part of the measurement circuit that can output an electrical signal accordingly when an external power supply is provided. Preferably, the above-mentioned measuring bridge is a Wheatstone bridge, for example, it may include two varistors 10 and two fixed resistors. In some other schemes, the above-mentioned Wheatstone bridge may include two pairs of four varistors 10, and each pair of varistors 10 includes two varistors 10 that generate corresponding resistance changes at different stress distribution positions.

[0039] Preferably, the edge of the diaphragm 11 is integrally connected to the upper end of the seat body 12 through a cylindrical integral connection portion 13. The inner diameter of the upper end of the integral connection portion 13 is smaller than the outer diameter of the lower end of the tie rod 4. Accordingly, an annular groove 1a with an opening facing downward is left between the outer wall of the tie rod 4 and the inner wall of the integral connection portion 13. In this way, a relatively small annular portion is formed within the annular region S2 of the diaphragm 11, thereby generating a larger stress (here, tensile stress is generated on the upper surface of the diaphragm 11). When the above-mentioned varistor 10 is attached to the upper side surface of the above-mentioned annular region S2 of the diaphragm 11, the measurement accuracy can be improved. Preferably, the outer wall of the integral connection portion 13 shrinks radially inward to form an annular groove 13a between the outer periphery of the diaphragm 11 and the outer periphery of the seat body 12.

[0040] The tension sensor 300 further includes an electronic module assembly (not labeled), which is disposed inside the housing 2. The electronic module assembly may include a circuit board 5, and the circuit board 5 is electrically connected to the pressure measurement circuit through the lead 101. The circuit board 5 may be directly bonded to the upper surface of the diaphragm 11. A clearance portion 5a is provided on the circuit board 5 for the lead 101 to pass through up and down.

[0041] The housing 2 may include a circle of tie rod connection parts 222 sealed and welded to the outer wall of the tie rod 4, and the upper end opening 222a is defined by the inner peripheral wall of the tie rod connection part 222. The housing 2 may also include a cylinder 21 extending longitudinally and an intermediate connection part integrally connected to the upper edge of the cylinder 21 and the lower edge of the tie rod connection part 222. In this way, since the tie rod connection part 222 and the cylinder 21 are located on circumferences with different radii, when the tie rod 4 is stretched upward, the intermediate part can provide a certain degree of axial deformation, thereby reducing the risk of the tie rod 4 and the tie rod connection part 222, and the cylinder 21 and the seat 12 being detached, especially when the housing 2 as a whole is a thin shell-like element obtained by press forming.

[0042] Preferably, the intermediate connection portion may include a connector mounting portion 221 extending laterally on the upper side of the diaphragm 11. The tension sensor 300 may include an electrical connector 3 that passes through the connector mounting portion 221 in a sealed manner. The electrical connector 3 is electrically connected to the electronic module assembly. A connection hole 221a is provided on the connector mounting portion 221, and the electrical connector 3 may include a main body (not marked) made of an insulating material and molded on the connection hole 221a. The electrical connector 3 also includes a plurality of terminals 30 that pass through the connection holes 221a in and out, and the inner end of the terminal 30 may be electrically connected to the circuit board 5 through a plurality of electrical connectors 6a. Preferably, the electrical connector 6a may be a spring, such as a coil spring, in which case an electrical contact portion 301 for forming electrical contact with the upper end of the coil spring may be formed on the inner end of the terminal 30, and the lower end of the coil spring may be electrically contacted to the circuit board 5; a retaining portion 31 may be correspondingly formed on the main body of the electrical connector 3, and a retaining hole 31a for retaining the coil spring may be provided on the retaining portion 31. The connector mounting portion 221 may be rectangular or any other shape sufficient to mount the electrical connector 3. The connector mounting portion 221 is preferably annular, and its outer edge may be integrally connected to the upper end of the barrel 21. The intermediate connection portion may also include a circle of radial connection portions 223 integrally connected to the radial inner edge of the connector mounting portion 221. In some other schemes, the radial inner and outer sides of the connector mounting portion 221 and the radial connection portion 223 may be interchanged in order, that is, the housing 2 includes the rod connection portion 222, the connector mounting portion 221, the radial connection portion 223 and the barrel 21 in sequence from the inside to the outside in the radial direction. In this case, the radial connection portion 223 may also be integrally connected to the radial outer edge of the connector mounting portion 221, and the radial outer edge of the radial connection portion 223 is integrally connected to the upper end of the barrel 21; the inner edge of the connector mounting portion 221 is integrally connected to the rod connection portion 222.

[0043] In other implementations of this embodiment, the tension sensor 300 may also include a support element whose lower end is fixed to the base body 12 as in the first or second embodiment. The circuit board may be clamped or bonded to the upper end of the support element, leaving a gap between it and the upper surface of the diaphragm so as not to contact the upper surface of the diaphragm. This can avoid interference of the circuit board with the diaphragm. Among them, the support element may be a plastic part, and a step may be formed on the outer periphery of the base. Several buckles may be formed at the lower end of the support element, and the lower ends of the buckles may be clamped to the outer peripheral wall of the step. The support element may include a longitudinally extending barrel. The edge of a support plate is integrally connected to the upper part of the barrel, and the circuit board is fixed to the upper surface of the support plate. A clearance portion for allowing the lead to pass may be provided on the support plate. The support plate may be annular, and the clearance portion may be defined by at least a portion of the inner peripheral wall of the support plate. Preferably, the upper end of the barrel protrudes upward to the upper side of the support plate to form a groove with the support plate. The circuit board is positioned in the groove a and is bonded to the upper surface of the support plate.

[0044] Figure 4 The structure diagram of the tension sensor 400 of the fourth embodiment is shown. Compared with the tension sensor 300 of the third embodiment, the tension sensor 400 of this embodiment has a radial connection portion 223 that is wavy. For example, the radial connection portion 223 includes a first portion 223a, a third portion 223c, and a second portion 223b that are sequentially connected from the inside to the outside in the radial direction. From the axial section, the first portion 223a, the third portion 223c, and the second portion 223b are wavy, that is, the first portion 223a and the second portion 223 are bent relative to the third portion 223c.

[0045] Figure 5 FIG. 5 is a schematic diagram of the structure of a tension sensor 500 of the fifth embodiment. Compared with the tension sensor 400 of the fourth embodiment, the tension sensor 500 of this embodiment has a radially outer edge of the third portion 223c located above its radially inner edge, that is, a circle of recessed portions is formed on the radial connecting portion 223, which can increase the axial deformation capacity of the housing 2, thereby further reducing the risk of the housing 2 being pulled off when the housing 2 is axially stretched to the same extent.

[0046] 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 tension sensor, characterized in that: include: A metal element (1) comprising a transversely extending diaphragm (11) and a seat (12) integrally connected to the edge of the diaphragm (11) facing upward, a pressure measuring circuit being arranged on the upper surface of the diaphragm (11), and the seat (12) being used for receiving a first upward pulling force (F1); A housing (2) which is disposed downwardly on the outside of the diaphragm (11) and has a lower end connected to the seat (12); An electronic module assembly disposed inside the housing (2) and electrically connected to the pressure measurement circuit via a lead (101); and a pull rod (4) integrally extending downward from the middle portion of the lower end of the diaphragm (11), which is used to receive a second downward pulling force (F2).

2. The tension sensor according to claim 1, characterized in that: It also includes a supporting element (7) arranged inside the housing (2), the electronic module assembly is fixed to the upper end of the supporting element (7), and the lower end of the supporting element (7) is fixed to the base (12).

3. The tension sensor according to claim 2, characterized in that: A first step (12b) is formed on the outer periphery of the seat body (12), and the lower end of the support element (7) is clamped to the outer peripheral wall of the first step (12b).

4. The tension sensor according to claim 2, characterized in that: The support element (7) includes a longitudinally extending cylindrical portion (71), the edge of a support plate (72) is integrally connected to the upper portion of the cylindrical portion (71), a circuit board (5) as at least a part of the electronic module assembly is fixed to the upper surface of the support plate (72); the support plate (72) is provided with a clearance portion (72a) for allowing the lead wire (101) to pass through.

5. The tension sensor according to claim 4, characterized in that: The upper end of the barrel (71) protrudes upward to the upper side of the support plate (72) to form a groove (7a) with the support plate (72); the circuit board (5) is arranged in the groove (7a) and is fitted and fixed to the upper surface of the support plate (72).

6. The tension sensor according to claim 1, characterized in that: The edge of the diaphragm (11) is integrally connected to the upper end of the seat body (12) via a cylindrical integral connecting portion (13), and the outer wall of the integral connecting portion (13) shrinks radially inward to form an annular groove (13a) between the outer periphery of the diaphragm (11) and the outer periphery of the seat body (12).

7. The tension sensor according to claim 1, characterized in that: The housing (2) further comprises a longitudinally extending cylinder (21), the lower end of the cylinder (21) being sealed and fixed to a second step (12a) on the seat (12).

8. The tension sensor according to claim 7, characterized in that: The housing (2) further comprises a connector mounting portion (221) integrally connected to the upper end of the cylinder (21), and an electrical connector (3) is arranged on the connector mounting portion (221), and the electrical connector (3) is electrically connected to the electronic module assembly.

9. The tension sensor according to claim 7, characterized in that: It also includes a cable (8) which is inserted inwardly through the cylinder (21) and then electrically connected to the electronic module assembly. The housing (2) also includes a cover (22) which is assembled and covers the upper end of the cylinder (21).

10. The tension sensor according to any one of claims 1 to 9, characterized in that: The inner diameter of the upper end of the integral connection portion (13) is smaller than the outer diameter of the lower end of the pull rod (4).

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