Bolt pretightening force monitoring assembly and displacement sensing device

Abstract

The utility model relates to a bolt pre-tightening force monitoring assembly and a displacement sensing device. The bolt pretightening force monitoring assembly comprises a positioning rod which is arranged in a detection hole in a bolt, the first end of the positioning rod is arranged to be fixedly connected with the bolt, and the second end of the positioning rod is a free end; the shell is arranged to be fixed on the bolt; the trace deformation transmitter is arranged on the shell; and the micro-deformation transmission piece is arranged in the shell and between the micro-deformation transmitter and the positioning rod, and the micro-deformation transmission piece is arranged to transmit the movement of the positioning rod to the micro-deformation transmitter. In addition, the utility model also provides a displacement sensing device. According to the bolt pre-tightening force monitoring assembly or the displacement sensing device in some embodiments, the force borne by the bolt in the using process can be converted into the electric signal, the stress condition change of the bolt can be obtained through the change of the electric signal, and then the bolt pre-tightening force can be monitored in real time.

Description

Technical Field

[0001] The present disclosure relates to the technical field of detection equipment, and in particular to a bolt preload monitoring assembly and a displacement sensing device. Background Art

[0002] When a bolt is stressed to its limit, the material will yield and fracture. Preload design is crucial for extending the life of the bolt within its effective elastic curve. Preload varies with different materials and specifications, and large preload errors can occur depending on the application and tooling. Monitoring is generally not performed in conventional applications. However, when applied to high-value projects or equipment, the preload of fasteners, in particular, becomes a key area that designers must control, and there are numerous methods for monitoring this preload.

[0003] During conventional installation, a device with a fixed preload can be used. After the preload is set, the device is installed. When the preload is reached, the device will automatically slide relative to the bolt. However, in subsequent use projects, the force applied to the bolt will change. For example, when applied to the fracture safety monitoring of infrastructure bolts, if there is an obvious design defect between the probe and the shell, when the diameter of the probe is large, the circumference of the side of the probe connected to the shell will be larger, and its sealing cannot adapt to the outdoor environment. If the probe is sealed, it will cause damping, affecting the reading during measurement, and also causing safety hazards due to the delay in knowing the bolt preload. Therefore, the problem of the existing technology is how to effectively monitor the bolt preload or further improve the effect of monitoring the bolt preload. Utility Model Content

[0004] The present disclosure provides a bolt preload monitoring assembly, which can convert the force applied to the bolt during use into an electrical signal, and the change in the force applied to the bolt can be obtained through the change in the electrical signal.

[0005] The above-mentioned objectives of the present disclosure are achieved through the following technical solutions:

[0006] The present disclosure provides a bolt preload monitoring assembly, which includes:

[0007] A positioning rod is disposed in the detection hole in the bolt, wherein the first end of the positioning rod is configured to be fixedly connected to the bolt, and the second end of the positioning rod is a free end;

[0008] a housing configured to be fixed to the bolts;

[0009] The micro deformation transmitter is arranged on the housing;

[0010] The micro-deformation transmission member is arranged in the housing and between the micro-deformation transmitter and the positioning rod. The micro-deformation transmission member is configured to transmit the movement of the positioning rod to the micro-deformation transmitter.

[0011] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0012] The outer wall of the positioning rod is arranged to have a gap with the inner wall of the detection hole in the bolt.

[0013] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0014] The width of the above-mentioned gap is set to 0.1mm-0.5mm.

[0015] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0016] Micro deformation transmission components include:

[0017] a transmitting rod configured to be slidably connected to the housing;

[0018] A first transmitting element is provided on the transmitting rod, and a magnet is provided on the first transmitting element;

[0019] A second transmitting member is configured to be slidably connected to the first transmitting member;

[0020] A return spring, wherein the first end of the return spring is arranged in a hole in the second transmitting member, and the second end of the return spring is arranged to abut against the first transmitting member.

[0021] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0022] Micro deformation transmitter includes:

[0023] A detection circuit board is disposed in the cavity within the housing and is configured to be connected to the micro-deformation transmission member;

[0024] The connecting plug is provided on the housing and is configured to be electrically connected to the detection circuit board.

[0025] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0026] The test circuit board includes:

[0027] A first detection circuit board is configured to be fixedly connected to the second transmission component;

[0028] a second detection circuit board, configured to be fixedly connected to the first detection circuit board and configured to be electrically connected to the connection plug;

[0029] The second detection circuit board is further configured to be electrically connected to the first detection circuit board.

[0030] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0031] The second transmitting component is further provided with a partition plate, which is provided between the first detection circuit board and the second transmitting component.

[0032] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0033] The transmitting rod is arranged so that there is a gap between the transmitting rod and the positioning rod.

[0034] Furthermore, in the above embodiment of the bolt preload monitoring assembly,

[0035] The transmitting rod is arranged to abut against the positioning rod.

[0036] In a second aspect of the present disclosure, a displacement sensing device is provided, comprising:

[0037] The bolt preload monitoring assembly of any one of the above embodiments.

[0038] Therefore, various embodiments of the present disclosure provide the following beneficial effects, for example:

[0039] By setting a positioning rod in the bolt preload monitoring assembly and setting it in the detection hole in the bolt, the first end of the positioning rod is set to be fixedly connected to the bolt, and the second end of the positioning rod is set to be free, so that the positioning rod becomes a scale for monitoring the bolt preload; then, a micro-deformation transmission member is set in the housing and is set between the micro-deformation transmitter and the positioning rod, so that the micro-deformation transmission member transmits the movement of the positioning rod to the micro-deformation transmitter, thereby converting the bolt preload deformation into a measurable relative displacement with the positioning rod, thereby being able to quantitatively output preload strain information. In addition, by setting a gap between the outer wall of the positioning rod and the inner wall of the detection hole in the bolt, better fit between the parts is achieved. In addition, since the first end of the positioning rod is threadedly connected to the inside of the bolt, compared with other application solutions on the market, the threaded fixing type in the present disclosure is equivalent to the positioning rod and the bolt forming an integral whole, and its measurement accuracy and sensitivity are better than those where the positioning rod is not fixedly connected or directly penetrates into the bolt. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings, in which:

[0041] Figure 1 This is a deployment diagram of a bolt preload monitoring assembly provided by the present disclosure.

[0042] Figure 2 This is a schematic diagram of opening a hole in a bolt provided by the present disclosure.

[0043] Figure 3 It is a structural schematic diagram of a bolt preload monitoring assembly provided by the present disclosure.

[0044] In each of the accompanying drawings, the same or corresponding reference numerals represent the same or corresponding parts; the reference numerals are: 1. positioning rod, 2. housing, 3. micro-deformation transmitter, 4. micro-deformation transmission component, 31. detection circuit board, 32. connecting plug, 41. transmitting rod, 42. first transmitting component, 43. magnet, 44. second transmitting component, 45. reset spring, 311. first detection circuit board, 312. second detection circuit board, 431. partition, 101. blind hole, 102. threaded hole. DETAILED DESCRIPTION

[0045] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure.

[0046] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to." The term "based on" should be understood as "based at least in part on." The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment." The terms "first," "second," etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0047] The present disclosure discloses a bolt preload monitoring assembly. In some examples, see Figure 1 The present disclosure discloses a bolt preload monitoring assembly including a positioning rod 1, a housing 2, a micro-deformation transmitter 3, and a micro-deformation transmission member 4. The present disclosure will be further introduced below in conjunction with a specific installation.

[0048] The bolt preload monitoring assembly disclosed in the present disclosure is installed on the bolt. First, a blind hole 101 is opened on one end of the bolt, and a threaded hole 102 is opened on the bottom surface of the blind hole 101. Figure 2 As shown, for the purpose of unified description below, the blind hole 101 is referred to as a detection hole.

[0049] The positioning rod 1 is set in the detection hole in the bolt. The first end of the positioning rod 1 is fixedly connected to the bolt, and the second end of the positioning rod 1 is a free end. In combination with the above, the connection between the first end of the positioning rod 1 and the bolt is a threaded connection. Furthermore, in some embodiments, for applications in different working conditions, the threaded connection between the first end of the positioning rod 1 and the bolt is also provided with a thread sealant to strengthen the connection relationship between them. It should be understood that thread sealant has a wide range of applications in many fields due to its unique anoxic adhesive curing characteristics, such as: locking and anti-loosening: metal screws are easily loosened or offline due to impact and vibration. Traditional mechanical locking methods are not ideal, while chemical locking methods are cheap and effective. If the screws are coated with anaerobic adhesive and assembled, a strong plastic film will be formed in the thread gap after curing, so that the screws will be locked and will not loosen. Sealing and leak prevention: It is impossible for any plane to be in completely tight contact, and a leak-proof seal is required. Using thread sealant instead of solid gaskets can achieve tight contact after curing, making the sealing more durable. Thread sealant is used for sealing threaded pipe joints and threaded plugs, sealing flange mating surfaces, and sealing mechanical box joints, and has an excellent leak-proof effect. Retention and positioning: Cylindrical components such as bearings and shafts, pulleys and shafts, gears and shafts, and other hole-shaft assembly accessories can be filled with thread sealant. After curing, it is strong, durable, stable and reliable. Filling and plugging leaks: For castings, die-castings, powder metallurgy parts, and welded parts with micropores, low-viscosity anaerobic adhesive can be applied to the defects, allowing the adhesive to penetrate the micropores. It will cure at room temperature in the absence of oxygen, filling the pores and achieving a sealing effect.

[0050] It should be noted that the connection between the first end of the positioning rod 1 and the bolt is a threaded connection, and the first end of the positioning rod 1 is threadedly connected to the inside of the bolt. Compared with other application solutions on the market, such as some that are not fixedly connected, such as directly positioning the rod deep into the bolt; then this method is not as good as the threaded fixing method in some embodiments of the present disclosure. The threaded fixing method in the present disclosure is equivalent to the positioning rod 1 and the bolt forming a whole, and the measurement accuracy and sensitivity will be better than the effect of not having a fixed connection or directly positioning the rod deep into the bolt.

[0051] The housing 2 is configured to be fixed on a bolt, the micro-deformation transmitter 3 is installed on the housing 2, the micro-deformation transmission component 4 is installed inside the housing 2 and is arranged between the micro-deformation transmitter 3 and the positioning rod 1, and the micro-deformation transmission component 4 is configured to transmit the movement of the positioning rod 1 to the micro-deformation transmitter 3.

[0052] The movement of the positioning rod 1 means that the force on the bolt changes. At this time, the screw rod deforms, driving the positioning rod 1 to move. The movement of the positioning rod 1 is transmitted to the micro-deformation transmitter 3 through the micro-deformation transmission component 4, and the micro-deformation transmitter 3 converts the micro-deformation into an electrical signal.

[0053] In the time dimension, the electrical signal (micro-deformation) is a curve, and the points on the curve (vertical coordinate) represent the size of the deformation.

[0054] In some examples, there is a gap between the outer wall of the positioning rod 1 and the inner wall of the detection hole in the bolt. The purpose is to achieve measurement accuracy because the gap can prevent the positioning rod 1 from deforming with the bolt.

[0055] In some possible implementations, the gap width is 0.1 mm-0.5 mm.

[0056] For some examples, see Figure 3 The micro-deformation transmission component 4 includes a transmission rod 41, a first transmission component 42, a magnet 43, a second transmission component 44 and a reset spring 45. The transmission rod 41 is slidingly connected to the housing 2, the first transmission component 42 is fixed on the transmission rod 41, and the magnet 43 is fixed on the first transmission component 42.

[0057] In some possible implementations, the magnet 43 is disposed in a groove on the first transmitting component 42 .

[0058] The second transmitting member 44 is slidably connected to the first transmitting member 42 . The first end of the return spring 45 is disposed in a hole in the second transmitting member 44 , and the second end abuts against the first transmitting member 42 .

[0059] When the transmission rod 41 moves, it can drive the first transmission component 42 and the magnet 43 to move. At this time, the distance between the magnet 43 and the micro-deformation transmitter 3 changes, and the electrical signal output by the micro-deformation transmitter 3 also changes synchronously.

[0060] The micro-deformation transmitter 3 consists of a detection circuit board 31 and a connecting plug 32. The detection circuit board 31 is arranged in the cavity inside the shell 2 and connected to the micro-deformation transmission component 4. The connecting plug 32 is installed on the shell 2 and electrically connected to the detection circuit board 31.

[0061] The detection circuit board 31 consists of a first detection circuit board 311 and a second detection circuit board 312 . The first detection circuit board 311 is fixedly connected to the second transmitter 44 . The second detection circuit board 312 is fixedly connected to the first detection circuit board 311 and electrically connected to the connection plug 32 .

[0062] The first detection circuit board 311 and the second detection circuit board 312 are connected electrically.

[0063] As can be seen in the figure, the second detection circuit board 312 is arranged between the first detection circuit board 311 and the magnet 43. When the magnet 43 moves, the distance between the magnet 43 and the second detection circuit board 312 changes. The detection component on the second detection circuit board 312 is a Hall sensor.

[0064] The working principle of the Hall sensor is as follows:

[0065] The principle of the Hall effect is to feedback the size of the magnetic field through the output Hall voltage value. The movement of the magnet 43 will cause the magnetic field strength around the Hall sensor on the second detection circuit board 312 to change, and the output Hall voltage value will change synchronously.

[0066] The first detection circuit board 311 is installed with a related detection circuit for obtaining the Hall voltage value output by the Hall sensor. The detection circuit includes a protection resistor, a voltage sensor and a circuit. The protection resistor and the Hall sensor are in the same loop. The voltage sensor detects the voltage on both sides of the protection resistor. Of course, a current sensor can also be used to detect the current in the loop.

[0067] The detection data of the voltage sensor or current sensor is output through the connecting plug 32. The connecting plug 32 is connected to the programmable logic controller, industrial computer or control terminal through a data line. The programmable logic controller, industrial computer or control terminal stores the received data and alarms when the data exceeds a threshold.

[0068] In some examples, a partition 431 is further provided on the second transmitting element 44 . The partition 431 is provided between the first detection circuit board 311 and the second transmitting element 44 . One function of the partition 431 is to prevent direct contact between the second detection circuit board 312 and the magnet 43 .

[0069] In some possible implementations, the partition 431 has a certain degree of softness.

[0070] In addition, the cover 431 can also prevent the magnet 43 from being too close to the first detection circuit board 311 to avoid generating a large current during the detection process, which may cause damage to the first detection circuit board 311 and the second detection circuit board 312.

[0071] In some examples, there is a gap between the transmitting rod 41 and the positioning rod 1. Of course, the transmitting rod 41 also abuts against the positioning rod 1. This mainly depends on the initial setting. For example, the bolt will be compressed when it is subjected to force. At this time, it is selected that there is a gap between the transmitting rod 41 and the positioning rod 1. For another example, the bolt will be stretched when it is subjected to force, then it is selected that the transmitting rod 41 also abuts against the positioning rod 1.

[0072] In addition, in some embodiments, a displacement sensing device is also provided, which includes the above-mentioned bolt preload monitoring assembly.

[0073] Furthermore, to facilitate understanding by those skilled in the art, the bolt preload monitoring assembly or displacement sensing device based on the above-mentioned embodiments is introduced in more detail below. For example, in some of the above-mentioned embodiments, the bolt is under static load and dynamic load; it should be understood that when the bolt is applied under static load, what is generally monitored is the looseness of the nut and bolt in a natural environment. Assuming that the preload of a 12.9-grade bolt and nut connection pair is approximately 2600 Nm, and the preload error is ±5%, the preload force causes the bolt body material to stretch, while the intermediate rod installed in the bolt hole does not contact the bolt and does not deform. At this time, the tensile variable measured by the monitoring assembly is used to analyze whether the bolt pair is loose through long-term data recording and data comparison. When the monitoring component is used for dynamic loads, the monitored data will fluctuate depending on the situation. The monitoring component needs to cooperate with the host computer unit to filter and analyze the data signal to find the actual variables for monitoring. For example, when monitoring the bolts at the mouth of a large pressure vessel, the bolt pair must not only bear the preload of the static load in advance, but also need to bear the additional tensile force when the tank body is under pressure. When the tank body pressure drops, the material stretches and resets, and the reciprocating action forms a dynamic load force on the bolt pair. At this time, by collecting and filtering the working condition information, the operating health status of the fastener thread pair can be monitored in real time. It should be understood that in some embodiments, the monitoring component can output RS485 digital signals, Bluetooth signals, and wireless remote transmission according to different application conditions.

[0074] It should be understood that the above embodiments of the present disclosure are aimed at monitoring fastener bolts used in situations with pre-tightening force, and are not aimed at situations without pre-tightening force. Therefore, they cannot monitor situations without pre-tightening force.

[0075] It should be understood that in more preferred embodiments, for the preload monitoring components or displacement sensing devices in various embodiments of the present disclosure, there is mostly a certain amount of mechanical vibration in the application scenarios, and the corresponding preload monitoring components or displacement sensing devices themselves need to relax while monitoring looseness.

[0076] Therefore, in a further embodiment, in order to resist the possible loosening problem of the tightening force monitoring component or the displacement sensing device itself during vibration, for the above-mentioned pre-tightening force monitoring component or displacement sensing device, each connecting part (or "connecting part") therein, in addition to the original threaded connection, will also be fixed by thread glue to enhance its fixing effect, especially the loosening effect during vibration. It should be understood that in non-vibration scenarios, no additional thread glue fixation is required.

[0077] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between the various embodiments can be referred to in detail. The terminology used herein is selected to best explain the principles, practical applications, or technological improvements of each embodiment in the market, or to enable other persons of ordinary skill in the art to understand the various embodiments disclosed herein.

[0078] The foregoing description is merely an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that the present disclosure is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A bolt preload monitoring assembly, characterized in that: include: A positioning rod (1) is arranged in a detection hole in the bolt, a first end of the positioning rod (1) is arranged to be fixedly connected to the bolt, and a second end of the positioning rod (1) is a free end; a housing (2) configured to be fixed on the bolt; A micro-deformation transmitter (3) is provided on the housing (2); The micro-deformation transmission member (4) is arranged in the housing (2) and between the micro-deformation transmitter (3) and the positioning rod (1). The micro-deformation transmission member (4) is configured to transmit the movement of the positioning rod (1) to the micro-deformation transmitter (3).

2. The bolt preload monitoring assembly according to claim 1, characterized in that: The outer wall of the positioning rod (1) is arranged so that a gap exists between the outer wall and the inner wall of the detection hole in the bolt.

3. The bolt preload monitoring assembly according to claim 2, characterized in that: The width of the gap is set to 0.1 mm-0.5 mm.

4. The bolt preload monitoring assembly according to claim 1, characterized in that: The micro deformation transmission member (4) comprises: A transmission rod (41) is configured to be slidably connected to the housing (2); A first transmission member (42) is provided on the transmission rod (41), and a magnet (43) is provided on the first transmission member (42); A second transmission member (44) is configured to be slidably connected to the first transmission member (42); A return spring (45), wherein the first end of the return spring (45) is arranged in a hole in the second transmitting member (44), and the second end of the return spring (45) is arranged to abut against the first transmitting member (42).

5. The bolt preload monitoring assembly according to claim 1 or 4, characterized in that: The micro deformation transmitter (3) comprises: A detection circuit board (31) is disposed in the cavity within the housing (2) and is configured to be connected to the micro-deformation transmission member (4); A connecting plug (32) is provided on the housing (2) and is configured to be electrically connected to the detection circuit board (31).

6. The bolt preload monitoring assembly according to claim 5, characterized in that: The detection circuit board (31) comprises: A first detection circuit board (311) is configured to be fixedly connected to the second transmission element (44); A second detection circuit board (312) is configured to be fixedly connected to the first detection circuit board (311) and to be electrically connected to the connection plug (32); The second detection circuit board (312) is further configured to be electrically connected to the first detection circuit board (311).

7. The bolt preload monitoring assembly according to claim 6, characterized in that: A partition (431) is also provided on the second transmitting element (44), and the partition (431) is provided between the first detection circuit board (311) and the second transmitting element (44).

8. The bolt preload monitoring assembly according to claim 4, characterized in that: The transmitting rod (41) is arranged so that there is a gap between the transmitting rod (41) and the positioning rod (1).

9. The bolt preload monitoring assembly according to claim 4, characterized in that: The transmitting rod (41) is arranged to abut against the positioning rod (1).

10. A displacement sensing device, characterized in that: include: A bolt preload monitoring assembly according to any one of claims 1 to 9.

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