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 technical field of sensors, in particular to a tension sensor. BACKGROUND

[0002] The tension sensor can be used in the automobile brake or parking system to measure the force. As shown in CN118641073A, the circuit board of one such sensor is directly bonded to the surface of the metal diaphragm, which will interfere with the measurement circuit composed of pressure-sensitive resistors on the diaphragm surface to some 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 metal diaphragm body part, which is difficult to machine and has high cost. CONTENT OF THE UTILITY MODEL

[0003] In view of the deficiencies of the prior art, the present application provides a tension sensor to reduce its manufacturing cost.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a tension sensor, comprising:

[0005] a metal element comprising a diaphragm extending transversely and a seat body integrally connected to the diaphragm upwardly, a pressure measurement circuit being arranged on the upper surface of the diaphragm, the seat body being used for receiving a first tension downwardly;

[0006] an outer shell covering the diaphragm externally and connected to the seat body at the lower end;

[0007] an electronic module assembly arranged inside the outer shell and electrically connected to the pressure measurement circuit;

[0008] and a pull rod integrally extending upwardly from the middle part of the upper end of the diaphragm, which passes through the outer shell upwardly to receive a second tension upwardly.

[0009] Preferably, the outer shell comprises a pull rod connecting part sealingly connected to the outer wall of the pull rod.

[0010] Preferably, the outer shell further comprises a cylinder extending longitudinally and an intermediate connecting part integrally connected to the upper edge of the cylinder and the lower edge of the pull rod connecting part; the lower end of the cylinder is sealingly fixed to a step on the seat body.

[0011] Preferably, the intermediate connecting part comprises a transversely extending part on the upper side of the diaphragm; the tension sensor further comprises an electric connector sealingly passing through the transversely extending part internally and externally, which is electrically connected to the electronic module assembly.

[0012] Preferably, the transversely extending part is annular.

[0013] Preferably, the intermediate connecting portion further comprises a ring of radial connecting portions integrally connected to the radially inner or radially outer edge of the transversely extending portion.

[0014] Preferably, the radial connecting portions are wavy.

[0015] Preferably, the radial connecting portions comprise at least a third portion, the radially outer edge of which is located above the radially inner edge.

[0016] Preferably, the edges of the diaphragm are integrally connected to the upper end of the seat body by a ring of cylindrical integral connecting portions, the upper end of which has an inner diameter smaller than the outer diameter of the lower end of the pull rod.

[0017] Preferably, the outer shell is thin-walled and obtained by press molding. 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 third 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] BRIEF DESCRIPTION OF DRAWINGS: 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, cylindrical body; 221a, connecting hole; 221, transversely extending 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, outer shell; 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 member; 6b, electrical connecting member; 71, cylindrical 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 in combination with the drawings. The following examples are exemplary and are used to explain the present application, but 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 repeated description is omitted.

[0025] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate 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 do not indicate or imply 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", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of 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" used in the specification and corresponding claims means any combination of one or more of the listed items and all possible combinations.

[0028] Please refer to Figure 1 The tension sensor 100 of the present embodiment includes a metal element 1 and a housing 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 body 12 integrally connected to the edge of the diaphragm 11 upward. The seat body 12 is used to receive a first upward tension F1 applied by a first external device to the seat body 12, specifically, the first tension F1 can be applied to a force receiving flange 120 protruding outwardly formed at the lower end of the seat body 12, preferably, the lower end of the force receiving flange 120 is formed with a positioning step 1b. The housing 2 is covered downwardly outside the diaphragm 11 and connected to the seat body 12 at the lower end, for example, the housing 2 can include a cylinder 21 extending in the longitudinal direction (i.e. the up-down direction in the figure), the lower end opening 21a of the cylinder 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 body 12.

[0029] The tension sensor 100 further comprises a pull rod 4 integrally extended 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 can be provided with a mechanical connecting portion 41 for the second external device to exert the second tension F2 on the pull rod 4. Thus, the upper surface of the diaphragm 11 generates corresponding stress under the action of the pair of tensions F1 and F2. 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 measurement circuit to measure the 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, which generates corresponding resistance changes in response to the stress at its location. The piezoresistor 10 and other fixed resistors form at least part of the measurement circuit that can output corresponding electrical signals with 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 four piezoresistors 10, each pair of piezoresistors 10 including two piezoresistors 10 that generate corresponding resistance changes at different stress distribution locations.

[0031] Preferably, the edge of the diaphragm 11 is integrally connected to the upper end of the seat body 12 by a ring-shaped 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, the outer wall of the pull rod 4 and the inner wall of the integral connecting portion 13 leave an open downward annular groove 1a, so that the diaphragm 11 forms a relatively thin annular portion within the annular region S1 in the figure, thereby generating a larger stress (where the upper surface of the diaphragm 11 generates compressive stress), which can improve the measurement accuracy when the above-mentioned piezoresistor 10 is attached to the upper surface of the diaphragm 11 within the annular region S1. Preferably, the outer wall of the integral connecting portion 13 is contracted 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 comprises an electronic module assembly (not labeled) arranged inside the housing 2. The electronic module assembly can include a circuit board 5 electrically connected to the pressure measurement circuit through a lead 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 101 to pass through.

[0033] In some other embodiments, the tension sensor 100 preferably further comprises a support member 7 for supporting the circuit board 5, the lower end of the support member 7 being fixed to the housing 12. The circuit board 5 can be clamped or adhered to the upper end of the support member 7, leaving a gap between the upper side of the support member 7 and the upper side of the diaphragm 11 so as not to contact the upper side of the diaphragm 11. In this way, the circuit board 5 can be prevented from interfering with the diaphragm 11. The support member 7 can be made of plastic, and a step 12b can be formed on the outer periphery of the housing 12. The lower end of the support member 7 can be formed with a plurality of clamping portions 73, the lower ends of the clamping portions 73 being clamped to the outer periphery of the step 12b. The support member 7 can comprise a longitudinally extending cylindrical portion 71. An edge of a support plate 72 is integrally connected to the upper end of the cylindrical portion 71, and the circuit board 5 is fixed to the upper side of the support plate 72. The support plate 72 can be provided with a clearance 72a for allowing the lead 101 to pass therethrough. The support plate 72 can be annular, and the clearance 72a can be defined by at least a portion of the inner periphery of the support plate 72. Preferably, the upper end of the cylindrical portion 71 protrudes upwardly beyond the upper side of the support plate 72 to define a recess 7a with the support plate 72. The circuit board 5 is positioned in the recess 7a and adhered to the upper side of the support plate 72.

[0034] The housing 2 can further comprise a transversely extending portion 221 integrally connected to the upper end of the cylindrical portion 21. The transversely extending portion 221 is provided with the electrical connector 3. The transversely extending portion 221 is provided with a connecting hole 221a, and the electrical connector 3 can comprise a main body portion (not labeled) made of insulating material, the main body portion being molded to the connecting hole 221a. The electrical connector 3 further comprises a plurality of terminals 30 extending through the connecting hole 221a, the inner ends of the terminals 30 being electrically connected to the circuit board 5 via the electrical connecting member 6b. The electrical connecting member 6b can be a flexible printed circuit board.

[0035] Referring to Figure 2 On the basis of the first embodiment, the tension sensor 200 of the second embodiment can be modified as follows: instead of the electrical connector 3, the tension sensor 200 comprises a plurality of wire harnesses 8a extending through a wire passing hole (not labeled) provided in the cylindrical portion 21 and electrically connected (e.g. soldered) to the circuit board 5. The wire passing hole and the cable 8 formed by the plurality of wire harnesses 8a can be sealed by a sealing plug 9. After the wire harnesses 8a are soldered to the circuit board 5, a cover 22 separate from the cylindrical portion 21 can be assembled to the upper end of the cylindrical portion 21 by means of adhesion or the like. The upper end of the cylindrical portion 21 can be formed with a plate-shaped support portion 211 for supporting and positioning the cover 22, the support portion 211 being preferably an annular plate having a central hole for soldering operation.

[0036] Referring to Figure 3The tension sensor 300 of the third 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 an edge of the diaphragm 11 upwardly. The seat 12 is configured to receive a first tension F3 applied downwardly by a first external device to the seat 12, in particular, the first tension F3 can be applied to a force receiving flange 120 formed outwardly at a lower end of the seat 12. The housing 2 is configured to cover the diaphragm 11 outwardly and is connected to the seat 12 downwardly, for example, the housing 2 can comprise a cylinder 21 extending in a longitudinal direction (i.e. vertically in the figure), and a lower end opening 21a of the cylinder 21 is welded to a step 12a (a support surface upwardly of the step 12a or an outer wall connected to the support surface downwardly) of the seat 12.

[0037] The tension sensor 300 further comprises a tension rod 4 integrally extending upwardly from a middle portion of an upper end of the diaphragm 11, and the tension rod 4 passes through an upper end opening 222a of the housing 2 upwardly. The tension rod 4 is configured to receive a second tension F4 applied upwardly and apply the second tension F4 to a middle portion of the diaphragm 11, for example, an upper end of the tension rod 4 can be provided with a mechanical connection portion 41 for a 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, a corresponding stress is generated on an upper side surface of the diaphragm 11. The mechanical connection portion 41 can be provided with a hole 41a extending in a transverse direction.

[0038] The upper side surface of the diaphragm 11 is provided with a pressure measurement circuit for measuring the stress, for example, the pressure measurement circuit can comprise at least one piezoresistor 10 fixedly attached to the upper side surface of the metal element 1, and the piezoresistor 10 generates a corresponding resistance change in response to the stress at the position where the piezoresistor 10 is located. The piezoresistor 10 and other fixed resistors form at least a 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, for example, it can comprise two piezoresistors 10 and two fixed resistors. In other embodiments, the above-mentioned Wheatstone bridge can comprise two pairs of piezoresistors 10, i.e. a total of four piezoresistors 10, each pair of piezoresistors 10 comprises two piezoresistors 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 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 are spaced apart to define a downwardly open annular groove la, so that the diaphragm 11 has a relatively small annular portion in the annular region S2 in the drawing, thereby generating a relatively large stress (tensile stress on the upper surface of the diaphragm 11), which can improve the measurement accuracy when the above-mentioned pressure-sensitive resistor 10 is attached to the upper surface of the diaphragm 11 in the above-mentioned annular region S2. Preferably, the outer wall of the integral connecting portion 13 is inwardly tapered to define 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 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 the 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 therethrough.

[0041] The housing 2 can comprise a pull rod connecting portion 222 sealingly welded to the outer wall of the pull rod 4, and the upper opening 222a is defined by the inner peripheral wall of the pull rod connecting portion 222. The housing 2 can further comprise 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. Thus, since the pull rod connecting portion 222 and the cylindrical body 21 are located on circumferences with different radii, the intermediate 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 separated, especially when the housing 2 is a thin shell-like element obtained by compression molding.

[0042] Preferably, the intermediate connecting portion can include a lateral extension 221 on the upper side of the diaphragm 11. The tension sensor 300 can include an electrical connector 3 sealingly passing through the lateral extension 221. The electrical connector 3 is electrically connected to the electronic module assembly. The lateral extension 221 is provided with a connecting hole 221a. The electrical connector 3 can include a body portion (not labeled) made of 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. 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. In this case, the inner end of the terminal 30 can form an electrical contact portion 301 for electrically contacting an upper end of the coil spring. A lower end of the coil spring is electrically connected to the circuit board 5. A retaining portion 31 can be formed on the body portion of the electrical connector 3. The retaining portion 31 is provided with a retaining hole 31a for retaining the coil spring. The lateral extension 221 can be rectangular or any other shape sufficient for mounting the electrical connector 3. Preferably, the lateral extension 221 is annular. An outer edge of the lateral extension 221 can be integrally connected to an upper end of the cylindrical body 21. The intermediate connecting portion can further include a plurality of radial connecting portions 223 integrally connected to a radially inner edge of the lateral extension 221. In other embodiments, the radial inner and outer sides of the lateral extension 221 and the radial connecting portions 223 can be exchanged. In this case, the housing 2 includes the tension rod connecting portion 222, the lateral extension 221, the radial connecting portions 223 and the cylindrical body 21 in sequence from the inner side to the outer side in the radial direction. The radial connecting portions 223 can be integrally connected to a radially outer edge of the lateral extension 221. The radially outer edge of the radial connecting portions 223 is integrally connected to the upper end of the cylindrical body 21. The radially inner edge of the lateral extension 221 is integrally connected to the tension rod connecting portion 222.

[0043] In other embodiments of the present embodiment, the tension sensor 300 can also include a support element having a lower end fixed to the seat body 12 as in the first or second embodiment. The circuit board can be clamped or adhered to an upper end of the support element with a gap between the upper side surface of the support element and the upper side surface of the diaphragm so as not to contact the upper side surface of the diaphragm. In this way, the circuit board can avoid interfering with the diaphragm. The support element can be a plastic member. The seat body can be provided with a step on the outer periphery. The lower end of the support element can be provided with a plurality of clamping portions. The lower end of the clamping portions 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 an upper portion of the cylindrical portion. The circuit board is fixed to the upper side surface of the support plate. The support plate can be provided with a clearance portion allowing the lead wires to pass through. The support plate can be annular. 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 upwardly to the upper side of the support plate to form a recess with the support plate. The circuit board is positioned in the recess a and adhered to the upper side surface of the support plate.

[0044] Figure 4 A structural diagram of the tension sensor 400 of the fourth embodiment is shown. The tension sensor 400 of the fourth 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 the first portion 223a, the third portion 223c and the second portion 223b which are 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 section, that is, the first portion 223a and the second portion 223 are both bent relative to the third portion 223c.

[0045] Figure 5 A structural diagram of the tension sensor 500 of the fifth embodiment is shown. The tension sensor 500 of the fifth 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 circle of recesses is formed on the radial connecting portion 223, so that the axial deformation ability of the outer shell 2 can be improved, so that the risk of the outer shell 2 being pulled off can be further reduced when the outer shell 2 is axially stretched to the same extent.

[0046] The scope of the disclosure is not limited by the detailed description, but is instead defined by the claims, with equivalents of the claims to be included within the scope of the claims. All modifications equivalent that are within the scope of the claims are to be interpreted as included in the disclosure.

Claims

1. A tension sensor characterized by, The utility model relates to a metal element (1) comprising a transversely extending diaphragm (11) and a seat (12) integrally connected to the diaphragm (11) on the upper side, the diaphragm (11) being provided with a pressure measuring circuit on the upper side surface, the seat (12) being used for receiving a first pulling force (F3) downwardly; an outer shell (2) is covered downwardly on the outside of the diaphragm (11) and is connected to the seat (12) at the lower end; an electronic module assembly is arranged in the outer shell (2) and is electrically connected to the pressure measuring circuit; and a pull rod (4) integrally extends upwardly from the middle of the upper end of the diaphragm (11), passes through the outer shell (2) upwardly and is used for receiving a second pulling force (F4) upwardly. The outer shell (2) comprises a pull rod connecting portion (222) sealingly connected to the outer wall of the pull rod (4). The outer shell (2) further comprises a longitudinally extending cylinder (21) and an intermediate connecting portion integrally connected to the upper edge of the cylinder (21) and the lower edge of the pull rod connecting portion (222); the lower end of the cylinder (21) is sealingly fixed to a step (12a) on the seat (12). The intermediate connecting portion comprises a transversely extending portion (221) on the upper side of the diaphragm (11); the pull rod further comprises an electric connector (3) sealingly passing through the transversely extending portion (221) from the inside to the outside, and the electric connector (3) is electrically connected to the electronic module assembly. The transversely extending portion (221) is annular.

2. The tension sensor according to claim 1, characterized in that The intermediate connecting portion further comprises a radial connecting portion (223) integrally connected to the radially inner side edge or the radially outer side edge of the transversely extending portion (221).

3. The tension sensor of claim 2, wherein The radial connecting portion (223) is wavy.

4. The tension sensor of claim 3, wherein The radial connecting portion (223) comprises at least one third portion (223c); the radially outer side edge of the third portion (223c) is located on the upper side of the radially inner side edge.

5. The tension sensor of claim 4, wherein, The edges of the diaphragm (11) are integrally connected to the upper end of the seat (12) through a cylindrical integral connecting portion (13), and the upper end inner diameter of the integral connecting portion (13) is smaller than the lower end outer diameter of the pull rod (4).

6. The tension sensor of claim 5, wherein, The outer shell (2) is thin-shell-shaped and is obtained by press forming.

7. The tension sensor of claim 6, wherein ​ 8. The tension sensor of claim 6, wherein, ​ 9. The tension sensor of claim 1, wherein, ​ 10. The tension sensor according to any one of claims 1 to 9, characterized in that, ​

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