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 automotive braking or parking systems to measure force. One such sensor, such as that shown in CN118641073A, has a circuit board directly bonded to the surface of a metal diaphragm, which can interfere with the measurement circuitry comprised of piezoresistors and other components on the diaphragm's surface. Furthermore, because the pull rod is located at the lower end, a ring groove is required between it and the main body of the metal diaphragm. This ring groove is difficult and expensive to machine. Utility Model Content

[0003] In view of the deficiencies of the prior art, the present application provides a tension sensor to reduce stress interference on the 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 transversely extending diaphragm and a seat integrally connected upward to an edge of the diaphragm, wherein a pressure measuring circuit is provided on an upper surface of the diaphragm, and the seat is configured to receive a first upward pulling force;

[0006] A downward cover is arranged outside the diaphragm and has a lower end connected to the outer shell 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 periphery of the base body, and the lower end of the support element is clamped to the outer peripheral wall of the first step.

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

[0012] Preferably, the upper end of the cylinder portion protrudes upwardly to the upper side of the support plate to form a recess with the support plate, and the circuit board is arranged in the recess and is fixedly attached to the upper side surface of the support plate.

[0013] Preferably, the edge of the diaphragm is integrally connected to the upper end of the seat body by a cylindrical integral connecting portion, and the outer wall of the integral connecting portion is contracted toward the inner side in the radial direction 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 cylinder portion extending longitudinally, and the lower end of the cylinder portion is sealingly fixed to a second step on the seat body.

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

[0016] Preferably, a cable is further arranged to be electrically connected to the electronic module assembly by penetrating the cylinder portion inwardly, and the housing further comprises a cover body which is combined to cover the upper end of the cylinder portion.

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

[0018] Figure 1 Structure diagram of a tension sensor of a first embodiment;

[0019] Figure 2 Structure diagram of a tension sensor of a second embodiment;

[0020] Figure 3 Structure diagram of a tension sensor of a first embodiment;

[0021] Figure 4 Structure diagram of a tension sensor of a fourth embodiment;

[0022] Figure 5 Structure diagram of a tension sensor of a fifth embodiment;

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

[0024] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. The following examples are exemplary and are used only to explain the present application, and cannot be interpreted as a limitation on the present application. In the following description, the same reference signs are used to represent the same or equivalent elements, and repetitive descriptions are omitted.

[0025] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the prepositions "first", "second", "third", etc. are only used for the purpose of distinguishing the objects being modified, and cannot be understood as indicating or implying relative importance.

[0026] In addition, the terms "mounting", "connecting", and "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

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

[0028] Referring to Figure 1 The tension sensor 100 of the present embodiment comprises a metal element 1 and a housing 2. The metal element 1 comprises a diaphragm 11 extending in a transverse direction (i.e. horizontally in the figure) and a seat 12 integrally connected to the edge of the diaphragm 11 upwardly. The seat 12 is configured to receive a first upward tension F1 applied by a first external device to the seat 12, in particular, the first upward tension F1 can be applied to a force receiving flange 120 protruding outwardly from the lower end of the seat 12, preferably, the lower end of the force receiving flange 120 is formed with a positioning step 1b. The housing 2 is configured to cover the diaphragm 11 downwardly and is connected to the seat 12 at the lower end, for example, the housing 2 can comprise a cylinder 21 extending in a longitudinal direction (i.e. vertically in the figure), and the lower end opening 21a of the cylinder 21 is welded to a step 12a (the upward supporting surface of the step 12a or the outer peripheral wall connected to the supporting surface) of the seat 12.

[0029] The tension sensor 100 further comprises a tension rod 4 integrally extending downwardly from the middle of the lower end of the diaphragm 11, which is configured to receive a second downward tension F2, for example, the upper end of the tension rod 4 can be provided with a mechanical connecting portion 41 for a second external device to apply the second tension F2 to the tension rod 4. Thus, under the action of the pair of tensions F1 and F2, the upper surface of the diaphragm 11 generates a corresponding stress. The mechanical connecting portion 41 can be provided with a transversely extending hole 41a.

[0030] The upper surface of the diaphragm 11 is provided with a pressure measuring circuit to measure the stress, for example, the pressure measuring circuit can comprise at least one piezoresistor 10 fixedly attached to the upper surface of the metal element 1, the piezoresistor 10 generates a corresponding resistance change in response to the stress at its location. The piezoresistor 10 and other fixed resistors form at least part of a measuring circuit that can output an electrical signal in response to an external power supply. Preferably, the above-mentioned measuring bridge is a Wheatstone bridge, which can comprise two piezoresistors 10 and two fixed resistors. In other embodiments, the above-mentioned Wheatstone bridge can comprise two pairs of four piezoresistors 10, each pair of piezoresistors 10 comprising two piezoresistors 10 generating 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 housing 12 by a cylindrical integral connecting portion 13. The upper end of the integral connecting portion 13 has an inner diameter smaller than the outer diameter of the lower end of the pull rod 4, and correspondingly, the outer wall of the pull rod 4 and the inner wall of the integral connecting portion 13 leave a downwardly open annular groove la, so that the diaphragm 11 forms a relatively thin annular portion within the annular region SI in the drawing, thereby generating a relatively large stress (a compressive stress is generated on the upper side surface of the diaphragm 11), and when the above-mentioned pressure-sensitive resistor 10 is attached to the upper side surface of the diaphragm 11 within the above-mentioned annular region SI, the measurement accuracy can be improved. Preferably, the outer wall of the integral connecting portion 13 is contracted toward the inner side in the radial direction to form an annular groove 13a between the outer periphery of the diaphragm 11 and the outer periphery of the housing 12.

[0032] The tension sensor 100 further comprises an electronic module assembly (not labeled) disposed inside the housing 2. The electronic module assembly can comprise a circuit board 5 electrically connected to the pressure measurement circuit by lead wires 101. The circuit board 5 can be directly bonded to the upper side surface of the diaphragm 11. The circuit board 5 is provided with a clearance 5a for the lead wires 101 to pass through.

[0033] In other embodiments, the tension sensor 100 can further comprise a support element 7 for supporting the circuit board 5, the lower end of the support element 7 being fixed to the housing 12. The circuit board 5 can be clamped or bonded to the upper end of the support element 7, leaving a gap between the upper side surface of the support element 7 and the upper side surface of the diaphragm 11, so as not to contact the upper side surface of the diaphragm 11. In this way, the interference of the circuit board 5 on the diaphragm 11 can be avoided. The support element 7 can be a plastic piece, and the outer periphery of the housing 12 can be formed with a step 12b. The lower end of the support element 7 can be formed with a plurality of buckles 73, the lower end of the buckles 73 being clamped to the outer periphery wall of the step 12b. The support element 7 can comprise 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, and the circuit board 5 is fixed to the upper side surface of the support plate 72. The support plate 72 can be provided with a clearance 72a for the lead wires 101 to pass through. The support plate 72 can be annular, and the clearance 72a can be defined by at least a portion of the inner periphery wall of the support plate 72. Preferably, the upper end of the cylindrical portion 71 protrudes upwardly 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 within the groove 7a and is adhesively bonded to the upper side surface of the support plate 72.

[0034] The shell 2 can further include a connector mounting portion 221 integrally connected to the upper end of the barrel 21. An electrical connector 3 is disposed on the connector mounting portion 221. The connector mounting portion 221 is provided with a connecting hole 221a, and the electrical connector 3 can include a main body portion (not labeled) made of insulating material, which is molded on the connecting hole 221a. The electrical connector 3 further includes a plurality of terminals 30 that pass through the connecting hole 221a, and the inner end of the terminal 30 can be electrically connected to the circuit board 5 through an electrical connecting member 6b. The electrical connecting member 6b can be a flexible circuit board.

[0035] Referring to Figure 2 On the basis of the first embodiment, the tension sensor 200 of the second embodiment can be changed as follows: the tension sensor 200 does not include the electrical connector 3 described above, but includes a plurality of wire harnesses 8a that pass through a wire passing hole (not labeled) provided on the barrel 21 and are electrically connected (e.g., welded) to the circuit board 5. The wire passing hole and the cable 8 composed of the plurality of wire harnesses 8a can be sealed by a sealing plug 9. After the wire harnesses 8a are welded to the circuit board 5, a cover 22 separate from the barrel 21 can be combined and attached to the upper end of the barrel 21 by adhesion or the like. The upper portion of the barrel 21 can be inwardly protruded to form a plate-shaped support portion 211 for supporting and positioning the cover 22, and the support portion 211 is preferably an annular plate having a central hole for welding operation.

[0036] Referring to Figure 3 The tension sensor 300 of the third embodiment includes the metal element 1 and the shell 2. The metal element 1 includes a diaphragm 11 extending in the transverse direction (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 tension F3 applied by a first external device to the seat 12 downward, and specifically, the first tension F1 can be applied to a force receiving flange 120 outwardly protruded at the lower end of the seat 12. The shell 2 is downwardly covered on the outside of the diaphragm 11 and connected to the seat 12 at the lower end, for example, the shell 2 can include a barrel 21 extending in the longitudinal direction (i.e., the up-down direction in the figure), and the lower end opening 21a of the barrel 21 is welded and fixed to a step 12a (the upward supporting surface of the step 12a or the outer peripheral wall connected to the lower part of the supporting surface) on the seat 12.

[0037] The tension sensor 300 further includes a tension rod 4 integrally extended upward from the middle of the upper end of the diaphragm 11, and the tension rod 4 passes through the upper end opening 222a of the shell 2 upward. The tension rod 4 is used to receive a second tension F4 applied by a second external device to the middle of the diaphragm 11 upward, and for example, the upper end of the tension rod 4 can be provided with a mechanical connecting portion 41 for the second external device to apply the second tension F4 to the tension rod 4. Thus, under the action of the pair of tensions F3 and F4, the upper surface of the diaphragm 11 generates corresponding stress. The mechanical connecting portion 41 can be provided with a transversely extending hole 41a.

[0038] The upper surface of the diaphragm 11 is provided with a pressure measurement circuit for measuring the above-mentioned stress. For example, the pressure measurement circuit can include at least one piezoresistor 10 fixedly attached to the upper surface of the metal element 1. The piezoresistor 10 senses the stress at its location and generates a corresponding resistance change. The piezoresistor 10 and other fixed resistors form at least part of a measurement circuit that can output an electrical signal in response to an external power supply. Preferably, the above-mentioned measurement bridge is a Wheatstone bridge, which can include two piezoresistors 10 and two fixed resistors. In other embodiments, the Wheatstone bridge can include two pairs of piezoresistors 10, i.e. a total of four piezoresistors 10, each pair of piezoresistors 10 including two piezoresistors 10 that generate corresponding resistance changes at different stress distribution locations.

[0039] Preferably, the edge of the diaphragm 11 is integrally connected to the upper end of the seat 12 by a cylindrical integral connecting portion 13. The inner diameter of the upper end of the integral connecting portion 13 is smaller than the outer diameter of the lower end of the pull rod 4, and correspondingly, an annular groove la is formed between the outer wall of the pull rod 4 and the inner wall of the integral connecting portion 13, which is open downward. In this way, the diaphragm 11 forms an annular portion with relatively small thickness within the annular region S2 in the figure, thereby generating a larger stress (here, the upper surface of the diaphragm 11 is in tension), which can improve the measurement accuracy when the piezoresistor 10 is attached to the upper surface of the diaphragm 11 within the above-mentioned annular region S2. Preferably, the outer wall of the integral connecting portion 13 is tapered inward in the radial direction to form an annular groove 13a between the outer periphery of the diaphragm 11 and the outer periphery of the seat 12.

[0040] The tension sensor 300 further includes an electronic module assembly (not labeled) disposed inside the housing 2. The electronic module assembly can include a circuit board 5 electrically connected to the pressure measurement circuit by lead wires 101. The circuit board 5 can be directly bonded to the upper surface of the diaphragm 11. The circuit board 5 is provided with a clearance 5a for the lead wires 101 to pass through.

[0041] The housing 2 can include a pull rod connecting portion 222 sealingly welded to the outer wall of the pull rod 4, and an upper opening 222a defined by the inner peripheral wall of the pull rod connecting portion 222. The housing 2 can further include a cylindrical body 21 extending longitudinally, and an intermediate connecting portion integrally connected to the upper edge of the cylindrical body 21 and the lower edge of the pull rod connecting portion 222. In this way, since the pull rod connecting portion 222 and the cylindrical body 21 are located on circumferences with different radii, the intermediate connecting portion can provide a certain degree of axial deformation when the pull rod 4 is stretched upward, thereby reducing the risk of the pull rod 4 and the pull rod connecting portion 222, the cylindrical body 21 and the seat 12 being disconnected, especially when the housing 2 is a thin shell element obtained by compression molding.

[0042] Preferably, the intermediate connecting portion can include a transversely extending connector mounting portion 221 on the upper side of the diaphragm 11. The tension sensor 300 can include an electrical connector 3 sealingly passing through the connector mounting portion 221. The electrical connector 3 is electrically connected to the electronic module assembly. The connector mounting portion 221 is provided with a connecting hole 221a, and the electrical connector 3 can include a main body portion (not labeled) made of an insulating material and molded on the connecting hole 221a. The electrical connector 3 further includes a plurality of terminals 30 passing through the connecting hole 221a, and an inner end of the terminal 30 can be electrically connected to the circuit board 5 through a plurality of electrical connectors 6a. Preferably, the electrical connectors 6a can be springs, such as coil springs, and in this case, the inner end of the terminal 30 can form an electrical contact portion 301 for electrical contact with an upper end of the coil spring, and a lower end of the coil spring is electrically connected to the circuit board 5; the main body portion of the electrical connector 3 can be correspondingly provided with a retaining portion 31 provided with a retaining hole 31a for retaining the coil spring. The connector mounting portion 221 can be rectangular or any other shape sufficient to mount the electrical connector 3. Preferably, the connector mounting portion 221 is annular, and an outer edge thereof can be integrally connected to an upper end of the barrel 21. The intermediate connecting portion can further include a plurality of radial connecting portions 223 integrally connected to a radially inner edge of the connector mounting portion 221. In other embodiments, the radial inner and outer sides of the connector mounting portion 221 and the radial connecting portion 223 can be exchanged, i.e., the housing 2 radially includes the pull rod connecting portion 222, the connector mounting portion 221, the radial connecting portion 223, and the barrel 21 in sequence from the inside to the outside, and in this case, the radial connecting portion 223 can be integrally connected to a radially outer edge of the connector mounting portion 221, and the radially outer edge of the radial connecting portion 223 is integrally connected to an upper end of the barrel 21; and the inner edge of the connector mounting portion 221 is integrally connected to the pull rod connecting portion 222.

[0043] In other embodiments of the present embodiment, the tension sensor 300 can also include a support element whose lower end is fixed to the seat body 12 as in the first or second embodiments. The circuit board can be clamped or adhered to the upper end of the support element, leaving a gap between the upper side surface of the diaphragm and the circuit board so as not to contact the upper side surface of the diaphragm. In this way, the interference of the circuit board with the diaphragm can be avoided. The support element can be a plastic member, and a step can be formed on the outer periphery of the seat body. The lower end of the support element can be formed with a plurality of clamps, and the lower end of the clamps can be clamped to the outer peripheral wall of the step. The support element can include a longitudinally extending cylindrical portion. An edge of a support plate is integrally connected to the upper portion of the cylindrical portion, and the circuit board is fixed to the upper side surface of the support plate. The support plate can be provided with a clearance portion that allows the lead wires to pass through. The support plate can be annular, and the clearance portion can be defined by at least a portion of the inner peripheral wall of the support plate. Preferably, the upper end of the cylindrical portion 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 adhered to the upper side surface of the support plate.

[0044] Figure 4 A structural diagram of a tension sensor 400 of a fourth embodiment is shown. The tension sensor 400 of the present embodiment is compared with the tension sensor 300 of the third embodiment, and the radial connecting portion 223 is wavy, for example, the radial connecting portion 223 includes a first portion 223a, a third portion 223c and a second portion 223b integrally connected in the radial direction from inside to outside in order, and the first portion 223a, the third portion 223c and the second portion 223b are wavy from the axial cross-section, that is, the first portion 223a and the second portion 223 are bent relative to the third portion 223c.

[0045] Figure 5 A structural diagram of a tension sensor 500 of a fifth embodiment is shown. The tension sensor 500 of the present embodiment is compared with the tension sensor 400 of the fourth embodiment, and the radial outer edge of the third portion 223c is located on the upper side of the radial inner edge, that is, a ring of recesses is formed on the radial connecting portion 223, which can improve the axial deformation ability of the housing 2, so as to further reduce 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 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 interpreted to be included in the disclosure.

Claims

1. A tension sensor characterized by, The application relates to a metal element (1) comprising a transversely extending diaphragm (11) provided with a pressure measuring circuit on the upper side surface of the diaphragm (11) and a seat body (12) integrally connected to the edge of the diaphragm (11) on the upper side, the seat body (12) being used for receiving a first pulling force (F1) in the upward direction; a shell (2) covering the diaphragm (11) on the outside and connected to the seat body (12) on the lower end; an electronic module assembly arranged in the shell (2) and electrically connected to the pressure measuring circuit through a lead wire (101); and a pull rod (4) integrally extended downward from the middle of the lower end of the diaphragm (11) and used for receiving a second pulling force (F2) in the downward direction. The application further comprises a supporting element (7) arranged in the shell (2), the electronic module assembly being fixed to the upper end of the supporting element (7), and the lower end of the supporting element (7) being fixed to the seat body (12). The seat body (12) is provided with a first step (12b) on the outer periphery, and the lower end of the supporting element (7) is clamped to the outer wall of the first step (12b). The supporting element (7) comprises a longitudinally extending cylinder portion (71), the edge of a supporting plate (72) is integrally connected to the upper portion of the cylinder portion (71), and a circuit board (5) as at least a part of the electronic module assembly is fixed to the upper side surface of the supporting plate (72); the supporting plate (72) is provided with a clearance (72a) allowing the lead wire (101) to pass through. The upper end of the cylinder portion (71) protrudes upward to the upper side of the supporting plate (72) to form a groove (7a) together with the supporting plate (72), and the circuit board (5) is arranged in the groove (7a) and fixed to the upper side surface of the supporting plate (72).

2. 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) through a ring-shaped integral connecting portion (13), the outer wall of the integral connecting portion (13) is contracted to the inner side in the radial direction to form an annular groove (13a) between the outer periphery of the diaphragm (11) and the outer periphery of the seat body (12).

3. The tension sensor of claim 2, wherein The shell (2) further comprises a cylinder body (21) extending in the longitudinal direction, and the lower end of the cylinder body (21) is sealingly fixed to a second step (12a) on the seat body (12).

4. The tension sensor of claim 2, wherein The shell (2) further comprises a connector mounting portion (221) integrally connected to the upper end of the cylinder body (21), and an electric connector (3) is arranged on the connector mounting portion (221) and electrically connected to the electronic module assembly.

5. The tension sensor of claim 4, wherein, The application further comprises a cable (8) electrically connected to the electronic module assembly by penetrating the cylinder body (21) in the inward direction, and the shell (2) further comprises a cover body (22) combinedly covering the upper end of the cylinder body (21).

6. The tension sensor of claim 1, wherein, The upper end inner diameter of the integral connecting portion (13) is smaller than the lower end outer diameter of the pull rod (4).

7. The tension sensor of claim 1, wherein ​ 8. The tension sensor of claim 7, wherein, ​ 9. The tension sensor of claim 7, wherein, ​ 10. The tension sensor according to any one of claims 1 to 9, characterized in that, ​

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