Nut with pretightening force measuring function and pretightening force measuring method

Abstract

The invention discloses a nut with a pre-tightening force measuring function and a pre-tightening force measuring method, the nut is used for sleeving the periphery of a stud, the stud is used for being connected with the nut to clamp a connected piece, the nut comprises a nut base body, and the bottom of the nut base body is provided with an annular boss used for abutting against a test tool; the periphery of the annular boss is sleeved with a resistance wire assembly and a signal processing assembly installed on the side wall of the annular boss, the resistance wire assembly is electrically connected with the signal processing assembly, and the resistance wire assembly can be stretched or shortened along with radial deformation of the annular boss so as to change the resistance value of the resistance wire assembly. The signal processing assembly is used for receiving the resistance value of the resistance wire assembly, processing the resistance value and outputting a pre-tightening force signal borne by the nut base body. By means of the arrangement, the nut can accurately measure the pretightening force of the installed stud and the alternating stress of the stud subjected to the external load, the method is not affected by stress unbalance loading of the nut, the measurement precision is high, and installation and maintenance of the nut on site are not affected.

Description

Technical Field

[0001] The invention relates to the field of detection technology, and in particular to a nut with a preload measurement function and a preload measurement method. Background Art

[0002] There are a large number of studs installed by hydraulic tensioning on wind turbines. High-strength studs above M30 are key components for connecting the foundation, tower, nacelle, hub, and blades of wind turbines. There are thousands of bolts or studs above M30 on a single unit, especially the blade root studs, pitch bearing studs, and main shaft and hub connection studs of the wind rotor system. They are subject to the complex alternating loads of the wind rotor rotation, which can easily lead to the loosening of the studs and the loss of preload, thus causing problems such as stud fatigue fracture, which directly affects the safe operation of the unit. At the same time, the blade root studs and main shaft and hub connection studs are all assembled by the installation company during on-site hoisting. The on-site construction environment is relatively harsh, the hydraulic tensioner is used frequently, the equipment is easily worn out, and the factors of environment, people, and equipment bring great uncertainty to the accuracy of the stud preload.

[0003] The existing technology often uses a washer-type sensor with a resistance strain gauge to measure the stud preload or ultrasonic measurement. The main problems of installing a washer-type sensor are: 1. The washer-type sensor is expensive; 2. The washer-type sensor adopts a Wheatstone bridge structure, and the circumferential force is uneven, which can easily lead to large measurement errors; 3. The on-site construction is relatively rough, and the washer-type sensor is easily damaged by the nut torsion and clamping force; 4. The washer-type sensor increases the clamping thickness and changes the original connection design type. There is a risk of creep causing the bolt pair to change its force. The main problems of ultrasonic method for measuring bolt preload are: 1. The test stud needs to be processed separately; 2. Real-time monitoring is not possible.

[0004] Therefore, how to provide a nut that can accurately measure the preload force of the stud installed by the hydraulic stretching method without affecting on-site construction is a technical problem that technical personnel in this field currently need to solve. Summary of the invention

[0005] The invention aims to provide a nut which can accurately measure the pre-tightening force of a stud installed by a hydraulic stretching method and does not affect on-site construction.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A nut with a preload measurement function, used for sleeved on the outer periphery of a stud, the stud is used to connect with the nut to clamp the connected parts, comprising:

[0008] A nut base, the bottom of which is provided with an annular boss for pressing the connected member;

[0009] A resistance wire assembly and a signal processing assembly installed on the side wall of the annular boss are sleeved on the outer periphery of the annular boss. The resistance wire assembly and the signal processing assembly are electrically connected. The resistance wire assembly can stretch or shorten with the radial deformation of the annular boss to change the resistance value of the resistance wire assembly. The signal processing assembly is used to receive the resistance value of the resistance wire assembly for processing and output the preload force signal of the nut base.

[0010] Preferably, the side wall of the annular boss is provided with an annular groove, the axis of the annular groove coincides with the axis of the nut base, and the resistance wire assembly is wound around the inner wall of the annular groove.

[0011] Preferably, the inner wall of the annular groove is provided with a rough surface so that the resistance wire assembly is tightly attached to the inner wall of the annular groove.

[0012] Preferably, the inner wall of the annular groove is coated with glue to bond the resistance wire assembly.

[0013] Preferably, the resistance wire assembly is an insulated thin copper resistance wire wound in several turns.

[0014] Preferably, the side wall of the annular boss is also provided with a receiving groove for installing a signal processing component, and the signal processing component includes: a signal adjustment and processing circuit, a chip, a battery and a wireless signal transmitter, and the four are electrically connected. The chip is connected to the resistance wire component through the signal adjustment and processing circuit, and the chip is used to convert the resistance value change of the resistance wire component into a current or voltage signal. The wireless signal transmitter is connected to the chip, and the chip is used to transmit the current signal or voltage signal converted by the chip to the outside, and the battery is used to provide the signal adjustment and processing circuit, the chip and the wireless signal transmitter with the energy required for their operation.

[0015] Preferably, it further comprises a signal receiver, which is used to receive the signal transmitted by the signal transmitter and convert the signal into a preload force.

[0016] Preferably, an annular sealing cover is arranged on the outer periphery of the annular groove, and a groove for mounting the annular sealing cover is arranged on the outer periphery of the annular boss, and the depth of the groove is the same as the thickness of the annular sealing cover.

[0017] Preferably, the annular sealing cover is made of a transparent material.

[0018] This article also provides a preload force measurement method, which is applicable to the nut with preload force measurement function mentioned above, including:

[0019] An annular groove is provided in the circumferential direction of the side wall of the annular boss of the nut, and the bottom surface of the annular groove is roughened;

[0020] The resistance wire assembly is bonded and wound on the wall surface of the annular groove;

[0021] A cylindrical receiving groove is provided at a position of the annular boss close to the annular groove, and a signal processing component is installed in the receiving groove, and the signal processing component is connected to the resistance wire component;

[0022] Install the nut at the position to be tested and apply a pre-tightening force to the nut;

[0023] When the radial dimension of the annular boss increases, the resistance wire component is elongated and its resistance value increases, the current or voltage of the signal processing component increases, and the pre-tightening force on the stud on which the nut is sleeved increases;

[0024] When the radial dimension of the annular boss becomes smaller, the resistance wire component is shortened and its resistance value becomes smaller, the current or voltage of the signal processing component becomes smaller, and the pre-tightening force of the stud on which the nut is mounted becomes smaller.

[0025] Compared with the above-mentioned background technology, the present invention provides a nut with a preload measurement function, which is used to be sleeved on the outer periphery of a stud, and the stud is used to be connected to the nut to clamp the connected part, comprising: a nut base, and the bottom of the nut base is provided with an annular boss for pressing the connected part; a resistance wire assembly and a signal processing assembly installed on the side wall of the annular boss are sleeved on the outer periphery of the annular boss, the resistance wire assembly and the signal processing assembly are electrically connected, the resistance wire assembly can be stretched or shortened with the radial deformation of the annular boss to change the resistance value of the resistance wire assembly, and the signal processing assembly is used to receive the resistance value of the resistance wire assembly for processing and output the preload signal of the nut base.

[0026] Specifically, the nut provided in this embodiment cooperates with the stud to connect two connected parts through a hydraulic tensioner; the nut includes a nut base and an annular boss arranged at the bottom, the nut base is screwed to the outer periphery of the stud, and the annular boss is pressed against the upper surface of the connected part, at this time there will be a pre-tightening force between the nut and the stud, when the stud is subjected to axially staggered axial forces, the pre-tightening force between the nut and the stud will increase or decrease; at the same time, a resistance wire assembly is sleeved on the outer periphery of the nut base, and the resistance wire assembly can change with the radial change of the annular boss. That is, when the annular boss is compressed by pressure, its radial direction becomes thicker and the resistance wire assembly becomes longer. When the pressure on the annular boss is reduced, the nut will restore its original length, that is, it is stretched relative to the initial state, and its radial direction becomes thinner, and the resistance wire assembly will become shorter. When the length of the resistance wire assembly changes, its resistance value will also change. The signal processing component can measure the size of the preload force on the stud according to the change in its resistance value. Moreover, since the nut structure is the same as that of an ordinary nut, a hydraulic tensioner can also be used to perform initial preload on the stud. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 A schematic diagram of a nut structure with a preload measurement function provided by an embodiment of the present invention;

[0029] Figure 2 for Figure 1 A cross-sectional view of

[0030] Figure 3 for Figure 2 A partial enlarged view of

[0031] Figure 4 A schematic diagram of the structure of the nut in use state provided by an embodiment of the present invention;

[0032] Figure 5 A top view of a nut provided by an embodiment of the present invention;

[0033] Figure 6 A cross-sectional view of a nut provided by an embodiment of the present invention;

[0034] Figure 7 This is a table of different specifications and sizes of nuts provided in the embodiments of the present invention.

[0035] in:

[0036] 01-nut, 02-stud, 03-connected part;

[0037] 100-nut base, 110-annular boss, 111-annular groove;

[0038] 200-resistance wire assembly;

[0039] 300-signal processing component, 310-accommodation slot;

[0040] 400- annular sealing cover, 410- groove. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0043] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “backward”, “left” and “right” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the positions or elements referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limitations of the present invention.

[0044] The invention aims to provide a nut which can accurately measure the pre-tightening force of a stud installed by a hydraulic stretching method and does not affect on-site construction.

[0045] To achieve the above object, the present invention provides the following technical solutions:

[0046] See also Figures 1 to 7 The present embodiment provides a nut 01 with a preload measurement function, which is used to be sleeved on the outer periphery of a stud 02. The stud 02 is used to be connected to the nut 01 to clamp a connected part 03, and includes: a nut base 100, and a ring-shaped boss 110 is provided at the bottom of the nut base 100 for pressing the connected part 03; a resistance wire assembly 200 and a signal processing assembly 300 installed on the side wall of the ring-shaped boss 110 are sleeved on the outer periphery of the ring-shaped boss 110, and the resistance wire assembly 200 and the signal processing assembly 300 are electrically connected. The resistance wire assembly 200 can be stretched or shortened with the radial deformation of the ring-shaped boss 110 to change the resistance value of the resistance wire assembly 200, and the signal processing assembly 300 is used to receive the resistance value of the resistance wire assembly 200 for processing and output the preload signal of the nut base 100.

[0047] Specifically, the nut 01 provided in this embodiment cooperates with the stud 02 to connect two connected parts 03 through a hydraulic tensioner, that is, the nut 01 with a preload measurement function provided in this embodiment will replace the common ordinary nut to preload the stud 02; the nut 01 includes a nut base 100 and an annular boss 110 arranged at the bottom, and the overall shape is similar to that of an ordinary nut structure; the nut base 100 is provided with an external thread inside, which can be screwed to the outer periphery of the stud 02, and the annular boss 110 is pressed against the upper surface of the connected part 03 surface; the setting of the annular boss 110 can increase the supporting area of ​​the nut 01, so that the gasket with small hardness and poor flatness can be omitted, the tensile "rebound" can be reduced, the average value and uniformity of the pre-tightening force of the stud 02 can be increased, and the alternating load on the stud 02 can be reduced; when the nut 01, the stud 02 and the connected part 03 are installed, there will be a pre-tightening force between the nut 01 and the stud 02, and the annular boss 110 of the nut 01 will have a certain deformation, that is, the diameter becomes thicker. When the stud 02 is subjected to the axially staggered axial force, the nut 0 When the pre-tightening force increases, the diameter of the annular boss 110 will continue to increase, and when the pre-tightening force decreases, the diameter of the annular boss 110 will become thinner relative to the initial diameter during installation; at the same time, a resistance wire assembly 200 is sleeved on the outer periphery of the nut base 100, and the resistance wire assembly 200 can change with the radial change of the annular boss 110, that is, when the annular boss 110 is compressed by pressure, its radial direction becomes thicker, and the resistance wire assembly 200 will also become longer. When the pressure is reduced, the nut 01 becomes thinner relative to the initial state during installation, that is, it is stretched relative to the initial state, and its radial direction becomes thinner, and the resistance wire assembly 200 will also become thinner as a whole, that is, the overall length becomes shorter. When the length of the resistance wire assembly 200 changes, its resistance value will also change. The signal processing component 300 can measure the size of the pre-tightening force on the stud 02 according to the change of its resistance value; and because the structure of the nut 01 is the same as that of an ordinary nut, it can also use a hydraulic tensioner to initially pre-tighten the stud 02. With this arrangement, a nut 01 that does not affect on-site construction and can detect the pre-tightening force on the stud 02 can be provided.

[0048] Preferably, an annular groove 111 is provided on the side wall of the annular boss 110 , the axis of the annular groove 111 coincides with the axis of the nut base 100 , and the resistance wire assembly 200 is wound around the inner wall of the annular groove 111 .

[0049] Specifically, Figure 2 and Figure 3As shown, in order to better accommodate the resistance wire assembly 200, the circumferential side wall of the annular boss 110 provided in this embodiment is provided with a circle of annular grooves 111, and the plane where the annular grooves 111 are located is perpendicular to the axis of the nut base 100, and the resistance wire assembly 200 is tightly wound to the inner wall of the annular groove 111, so that the resistance wire assembly 200 can better lengthen or shorten with the change of the diameter of the annular boss 110.

[0050] In addition, providing an annular groove 111 on the circumference of the annular boss 110 can also increase the deformation of the nut 01 under the preload, which is also beneficial for the resistance wire assembly 200 to sense the change in its diameter, and then detect the change in the preload, thereby improving the sensitivity of the nut 01 in detecting the preload; and by providing the annular groove 111 and installing the resistance wire assembly 200 into the annular groove 111, the influence on the shape of the nut 01 can be reduced, so that the nut 01 provided in this embodiment can be used normally at the construction site; finally, the resistance wire assembly 200 is wound around the inner wall of the annular groove 111, so that the resistance wire assembly 200 can be subjected to uniform circumferential force, which is beneficial to improving the accuracy of the detection of the nut 01 with a preload measurement function.

[0051] Preferably, the inner wall of the annular groove 111 is provided with a rough surface so that the resistance wire assembly 200 is tightly attached to the inner wall of the annular groove 111 .

[0052] In this embodiment, the inner wall surface of the annular groove 111 is roughened, that is, the inner wall surface is set to a rough surface. This setting allows the resistance wire assembly 200 to be stably wound around the inner wall of the annular groove 111 without the resistance wire assembly 200 sliding easily; in this way, when the diameter of the annular boss 110 increases or decreases, the resistance wire assembly 200 can stably change with it.

[0053] Preferably, the inner wall of the annular groove 111 is coated with glue to bond the resistance wire assembly 200 .

[0054] It is understandable that applying glue on the inner wall of the annular groove 111 can make the connection between the resistance wire assembly 200 and the inner wall of the annular groove 111 more stable, further enhancing the accuracy of the nut 01 with preload measurement function during detection. The required glue can be selected according to actual conditions, and this article does not make specific restrictions.

[0055] Preferably, the resistance wire assembly 200 is an insulated thin copper resistance wire wound in several turns.

[0056] In this embodiment, the resistance wire assembly 200 is preferably an insulated thin copper resistance wire, such that the material has good ductility, and its resistance value can change sensitively with its length, and the insulated thin copper resistance wire has a low cost, which can reduce the overall manufacturing cost of the nut 01 and the cost required for testing.

[0057] It should be noted that in order to ensure the accuracy and sensitivity of the nut 01 in detecting the pre-tightening force, the insulated thin copper resistance wire covers the entire inner wall of the annular groove 111 to form a resistance wire assembly 200 .

[0058] Preferably, the side wall of the annular boss 110 is also provided with a receiving groove 310 for installing the signal processing component 300. The signal processing component 300 includes: a signal adjustment processing circuit, a chip, a battery and a wireless signal transmitter. The four are electrically connected. The chip is connected to the resistance wire component 200 through the signal adjustment processing circuit. The chip is used to convert the resistance value change of the resistance wire component 200 into a current or voltage signal. The wireless signal transmitter is connected to the chip. The chip is used to transmit the current signal or voltage signal converted by the chip to the outside. The battery is used to provide the signal adjustment processing circuit, the chip and the wireless signal transmitter with the energy required for their operation.

[0059] In this embodiment, if Figures 1 to 3 As shown, an inwardly recessed receiving groove 310 is provided on the circumferential side wall of the annular boss 110, and the receiving groove 310 can be installed with an integrated signal processing component 300, and the signal processing component 300 includes a signal adjustment processing circuit, a chip, a battery and a wireless signal transmitter; the signal adjustment processing circuit cooperates with the chip to receive currents or voltages of different sizes through changes in the resistance value of the resistance wire component 200, and transmit the signal to the outside through the wireless signal transmitter; in this way, the signal processing component 300 can detect changes in the preload force on the nut 01 in real time through the resistance wire component 200.

[0060] Preferably, it further comprises a signal receiver, which is used to receive the signal transmitted by the signal transmitter and convert the signal into a preload force.

[0061] It can be understood that in order to enable the operator to understand the status of the nut 01 in real time, a signal receiver is also provided. The signal receiver can wirelessly transmit signals to and from the wireless signal transmitter, and the signal receiver can receive the signal transmitted by the wireless signal transmitter and convert the signal into the magnitude of the preload force on the nut 01.

[0062] In this embodiment, the nut 01 with preload measurement function needs to collect the relationship between the current or voltage signal and the preload through an ultrasonic preload tester and calibration equipment before installation, so that the chip or signal receiver can directly obtain the size of the preload according to the current or voltage signal.

[0063] In this embodiment, different specifications of studs 02 use nuts 01 of different specifications. The sizes of the various positions corresponding to the nuts 01 of different specifications are as follows: Figures 5 to 7 shown.

[0064] In addition, in this embodiment, the signal receiver can be a handheld receiver, which can facilitate the staff to inspect the site where the nut 01 is used to detect whether the pre-tightening force applied to the nut 01 is within a normal range.

[0065] In addition, in another embodiment, a wireless signal transmitter is not provided in the signal processing component 300. In this embodiment, the signal processing component 300 of each nut 01 can be connected to an external signal collector via a cable. It should be noted that each signal collector can be connected to several different nuts 01 via cables at the same time. The signal collector can detect the pre-tightening force applied to these nuts 01 in real time, and transmit this data information to the computer or mobile phone of the staff, so as to facilitate the staff to make a clear judgment on the pre-tightening force applied to the nut 01 in real time.

[0066] Preferably, an annular sealing cover 400 is disposed on the outer periphery of the annular groove 111 , and a groove 410 for mounting the annular sealing cover 400 is disposed on the outer periphery of the annular boss 110 , and the depth of the groove 410 is the same as the thickness of the annular sealing cover 400 .

[0067] In this embodiment, in order to protect the resistance wire assembly 200 in the annular groove 111 from being damaged during the use of the nut 01, a circle of annular sealing cover 400 is provided on the side wall of the annular groove 111. The annular sealing cover 400 can completely wrap the opening of the annular groove 111, and at the same time partially expose the signal processing assembly 300 to facilitate the operator to replace the battery; further, in order to ensure that the overall structure of the nut 01 is the same as that of the ordinary nut 01, a circle of grooves 410 is provided on the annular boss 110 corresponding to the upper side of the annular groove 111, and the annular sealing ring can be installed inside the groove 410, and the depth of the groove 410 is set to be the same as the depth of the annular sealing cover 400.

[0068] Preferably, the annular sealing cover 400 is made of a transparent material.

[0069] In this embodiment, the annular sealing cover 400 is preferably made of a transparent material. This arrangement allows the condition of the resistance wire assembly 200 in the annular groove 111 to be observed, thereby preventing the resistance wire assembly 200 from being damaged or its position changed during use without the operator being aware of the change, resulting in inaccurate detection of the preload force.

[0070] This article also provides a preload force measurement method, which is applicable to the nut 01 with preload force measurement function mentioned above, including:

[0071] An annular groove 111 is formed in the circumferential direction of the side wall of the annular boss 110 of the nut 01, and the bottom surface of the annular groove 111 is roughened;

[0072] The resistance wire assembly 200 is bonded and wound on the wall surface of the annular groove 111;

[0073] A cylindrical receiving groove 310 is provided at a position of the annular boss 110 close to the annular groove 111, and a signal processing component 300 is installed in the receiving groove 310 to connect the signal processing component 300 and the resistance wire component 200;

[0074] Install nut 01 at the position to be tested and apply pre-tightening force to nut 01;

[0075] When the radial dimension of the annular boss 110 increases, the resistance wire assembly 200 is elongated and its resistance value increases, the current or voltage of the signal processing assembly 300 increases, and the pre-tightening force on the stud 02 on which the nut 01 is sleeved increases;

[0076] When the radial dimension of the annular boss 110 becomes smaller, the resistance wire assembly 200 is shortened and its resistance value becomes smaller, the current or voltage of the signal processing assembly 300 becomes smaller, and the pre-tightening force on the stud 02 on which the nut 01 is mounted becomes smaller.

[0077] It can be understood that after the initial installation of the nut 01 with a preload measurement function, a preload will be generated between it and the stud 02, and the preload will cause the nut 01 to deform; and when the stud 02 is subjected to staggered axial forces, the preload between the nut 01 and the stud 02 will decrease or increase, and the annular boss 110 of the nut 01 will become thicker or thinner relative to the initial state; and in the present application, the change in the preload of the nut 01 can be detected by the change in the diameter of the annular boss 110, and specifically, the resistance wire assembly 200 performs real-time detection, and transmits different current or voltage signals by changing its own resistance value, thereby completing the detection of the preload.

[0078] In summary, this article provides a nut 01 with a preload measurement function and a preload measurement method. An annular boss 110 is arranged at the bottom of the nut 01. An annular groove 111 is circumferentially opened on the side wall of the annular boss 110. The bottom surface of the groove is roughened, and then a certain length of insulated thin copper resistance wire is glued and wound on the wall of the annular groove 111 to form a resistance wire assembly 200. A cylindrical receiving groove 310 is opened near the annular groove 111 on the annular boss 110. A signal conditioning and processing circuit is installed in the receiving groove 310. A chip battery and a wireless signal transmitter can also be installed. The resistance value change of the insulated thin copper resistance wire can be converted into a current or voltage signal, which is further converted into a preload size and transmitted to a receiving device through a signal line or a wireless signal transmitting device. The outer side of the annular groove 111 is sealed with an annular sealing cover 400 and sealed with glue. When the nut 01 is subjected to the alternating axial force generated by the clamping of the stud 02, the radial deformation of the bottom cylindrical surface of the annular groove 111 on the lower side of the nut 01 and the inner cylindrical surface of the nut 01 will drive the insulated thin copper resistance wire bonded and wound with the bottom wall of the annular groove 111 to extend or shorten together, the clamping force of the stud 02 increases, the bottom cylindrical surface of the annular groove 111 on the lower side of the nut 01 radially increases, the insulated thin copper resistance wire becomes longer, the resistance value increases, the converted current or voltage signal increases, and the preload force of the test stud 02 increases; the clamping force of the stud 02 decreases, the bottom cylindrical surface of the annular groove 111 on the lower side of the nut 01 radially decreases, the insulated thin copper resistance wire becomes shorter, the resistance value decreases, the converted current or voltage signal decreases, and the preload force of the test stud 02 decreases. This measurement method is less affected by the uneven circumferential force of the nut 01, and after being calibrated by the nut 01 preload force calibration device, the alternating stress of the stud 02 can be accurately measured.

[0079] It should be noted that, in this specification, relational terms such as first and second are only used to distinguish one entity from other entities, and do not necessarily require or imply any actual relationship or order between these entities. In this specification, various embodiments are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between various embodiments can be referred to each other.

[0080] The embodiments provided by the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A nut (01) with a preload measurement function, used to be sleeved onto the outer circumference of a stud (02), the stud (02) being used to be connected to the nut (01) to clamp a connected part (03), characterized in that: include: A nut base (100), the bottom of which is provided with an annular boss (110) for pressing the connected member (03); The annular boss (110) is sleeved with a resistance wire assembly (200) and a signal processing assembly (300) mounted on the side wall of the annular boss (110); the resistance wire assembly (200) and the signal processing assembly (300) are electrically connected; the resistance wire assembly (200) can be stretched or shortened with radial deformation of the annular boss (110) to change the resistance value of the resistance wire assembly (200); the signal processing assembly (300) is used to receive the resistance value of the resistance wire assembly (200), process it, and output a pre-tightening force signal applied to the nut base (100).

2. The nut (01) with preload force measurement function according to claim 1, characterized in that: The side wall of the annular boss (110) is provided with an annular groove (111), the axis of the annular groove (111) coincides with the axis of the nut base (100), and the resistance wire assembly (200) is wound around the inner wall of the annular groove (111).

3. The nut (01) with preload force measurement function according to claim 2, characterized in that: The inner wall of the annular groove (111) is provided with a rough surface so that the resistance wire assembly (200) is tightly attached to the inner wall of the annular groove (111).

4. The nut (01) with preload force measurement function according to claim 3, characterized in that: The inner wall of the annular groove (111) is coated with glue to bond the resistance wire assembly (200).

5. The nut (01) with preload force measurement function according to claim 1, characterized in that: The resistance wire assembly (200) is an insulated thin copper resistance wire wound in a plurality of turns.

6. The nut (01) with preload force measurement function according to claim 1, characterized in that: The side wall of the annular boss (110) is also provided with a receiving groove (310) for installing the signal processing component (300), the signal processing component (300) comprising: a signal conditioning processing circuit, a chip, a battery and a wireless signal transmitter, the four being electrically connected, the chip being connected to the resistance wire component (200) via the signal conditioning processing circuit, the chip being used to convert the resistance value change of the resistance wire component (200) into a current or voltage signal, the wireless signal transmitter being connected to the chip, the chip being used to transmit the current signal or voltage signal converted by the chip outwardly, and the battery being used to provide the signal conditioning processing circuit, the chip and the wireless signal transmitter with energy required for their operation.

7. The nut (01) with preload force measurement function according to claim 6, characterized in that: It also includes a signal receiver, which is used to receive the signal transmitted by the signal transmitter and convert the signal into a preload force.

8. The nut (01) with preload force measurement function according to claim 3, characterized in that: An annular sealing cover (400) is arranged on the outer periphery of the annular groove (111), and a groove (410) for mounting the annular sealing cover (400) is arranged on the outer periphery of the annular boss (110), wherein the depth of the groove (410) is the same as the thickness of the annular sealing cover (400).

9. The nut (01) with preload force measurement function according to claim 8, characterized in that: The annular sealing cover (400) is made of a transparent material.

10. A preload force measurement method, applicable to a nut (01) with a preload force measurement function as claimed in any one of claims 1 to 9, characterized in that: include: An annular groove (111) is provided in the circumferential direction of the side wall of the annular boss (110) of the nut (01), and the bottom surface of the annular groove (111) is roughened; A resistance wire assembly (200) is bonded and wound on the wall surface of the annular groove (111); A cylindrical receiving groove (310) is provided at a position of the annular boss (110) close to the annular groove (111), and a signal processing component (300) is installed in the receiving groove (310), and the signal processing component (300) is connected to the resistance wire component (200); Installing the nut (01) at the position to be tested, and applying a pre-tightening force to the nut (01); When the radial dimension of the annular boss (110) increases, the resistance wire assembly (200) is elongated and its resistance value increases, the current or voltage of the signal processing assembly (300) increases, and the pre-tightening force on the stud (02) on which the nut is sleeved increases; When the radial dimension of the annular boss (110) decreases, the resistance wire assembly (200) is shortened and its resistance value decreases, the current or voltage of the signal processing assembly (300) decreases, and the pre-tightening force on the stud (02) on which the nut is sleeved decreases.

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