Bolt preload monitoring assembly and displacement sensing device

Abstract

A bolt preload monitoring assembly, comprising: a positioning rod (1) arranged in a detection hole in a bolt, wherein a first end of the positioning rod (1) is configured 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 to the bolt; a micro-deformation transmitter (3) arranged on the housing (2); and a micro-deformation transmission member (4) arranged in the housing (2) and between the micro-deformation transmitter (3) and the positioning rod (1), wherein the micro-deformation transmission member (4) is configured to transmit the movement of the positioning rod (1) to the micro-deformation transmitter (3). Further provided is a displacement sensing device.

Description

Bolt pre-tightening force monitoring assembly and displacement sensing device TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of detection equipment, in particular to a bolt pre-tightening force monitoring assembly and a displacement sensing device. BACKGROUND

[0002] When the bolt is stressed to the limit, the material will yield and break, and how to apply within the effective elastic curve of the material to extend the service life needs to be designed. For different materials and specifications, the pre-tightening force is not the same, the application occasion and tool are not the same, and a relatively large pre-tightening force error will be generated. In conventional occasions, relevant monitoring is generally not done. However, when applied to high-value engineering or equipment, especially the pre-tightening force of the fastener is the place that the designer needs to control, and how to monitor the pre-tightening force is also of many types.

[0003] When installed conventionally, a pre-tightening force device can be used, and after the pre-tightening force is set, the installation is performed. After the pre-tightening force is reached, the device will automatically slide relative to the bolt. However, in the subsequent use engineering, the force received by the bolt will change. For example, when applied to the fracture safety monitoring of the infrastructure bolt, if there is a obvious design defect between the measuring head and the shell, when the diameter of the measuring head is large, the circumference of the side of the measuring head connected with the shell is larger, and the sealing performance cannot adapt to the outdoor environment. If the measuring head is sealed, the damping will be caused, the reading during the measurement will be affected, and the safety hazard is caused due to the delay in knowing the pre-tightening force of the bolt. Therefore, the problem of the prior art is how to effectively monitor the pre-tightening force of the bolt or further improve the effect of monitoring the pre-tightening force of the bolt.

[0004] Practical new type content

[0005] The present disclosure provides a bolt pre-tightening force monitoring assembly, which can convert the force received by the bolt during use into an electrical signal, and the force change of the bolt can be obtained through the change of the electrical signal.

[0006] The above object of the present disclosure is achieved by the following technical scheme:

[0007] The present disclosure provides a bolt pre-tightening force monitoring assembly, which comprises:

[0008] A positioning rod is arranged in a detection hole in the bolt, a first end of the positioning rod is arranged in fixed connection with the bolt, and a second end of the positioning rod is a free end;

[0009] An outer shell is arranged to be fixed on the bolt;

[0010] A micro-deformation transmitter is arranged on the outer shell;

[0011] The micro-deformation transmission member is arranged in the shell and between the micro-deformation transmitter and the positioning rod, and is arranged to transmit the movement of the positioning rod to the micro-deformation transmitter.

[0012] Further, in the above-mentioned embodiment of the bolt pre-tightening force monitoring assembly,

[0013] The outer wall of the positioning rod is arranged to have a gap with the inner wall of the bolt inner detection hole.

[0014] Further, in the above-mentioned embodiment of the bolt pre-tightening force monitoring assembly,

[0015] The width of the gap is arranged to be 0.1mm-0.5mm.

[0016] Further, in the above-mentioned embodiment of the bolt pre-tightening force monitoring assembly,

[0017] The micro-deformation transmission member comprises:

[0018] The transmission rod is arranged in sliding connection with the shell;

[0019] The first transmission member is arranged on the transmission rod, and the magnet is arranged on the first transmission member;

[0020] The second transmission member is arranged in sliding connection with the first transmission member;

[0021] The reset spring has a first end arranged in a hole in the second transmission member and a second end arranged to abut on the first transmission member.

[0022] Further, in the above-mentioned embodiment of the bolt pre-tightening force monitoring assembly,

[0023] The micro-deformation transmitter comprises:

[0024] The detection circuit board is arranged in the cavity in the shell and is arranged in connection with the micro-deformation transmission member;

[0025] The connection plug is arranged on the shell and is arranged in electrical connection with the detection circuit board.

[0026] Further, in the above-mentioned embodiment of the bolt pre-tightening force monitoring assembly,

[0027] The detection circuit board comprises:

[0028] The first detection circuit board is arranged in fixed connection with the second transmission member;

[0029] The second detection circuit board is arranged in fixed connection with the first detection circuit board and is arranged in electrical connection with the connection plug;

[0030] The second detection circuit board is further electrically connected with the first detection circuit board.

[0031] Further, in the above-mentioned embodiments of the bolt pre-tightening force monitoring assembly,

[0032] The second transmission member is further provided with a partition plate arranged between the first detection circuit board and the second transmission member.

[0033] Further, in the above-mentioned embodiments of the bolt pre-tightening force monitoring assembly,

[0034] The transmission rod is arranged to have a gap with the positioning rod.

[0035] Further, in the above-mentioned embodiments of the bolt pre-tightening force monitoring assembly,

[0036] The transmission rod is arranged to abut against the positioning rod.

[0037] In a second aspect of the present disclosure, a displacement sensing device is provided, comprising:

[0038] The bolt pre-tightening force monitoring assembly of any one of the above-mentioned embodiments.

[0039] Therefore, in various embodiments of the present disclosure, the following beneficial effects are provided, for example:

[0040] By arranging the positioning rod in the bolt pre-tightening force monitoring assembly and arranging it in the detection hole in the 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, so that the positioning rod becomes a ruler for monitoring the bolt pre-tightening force; then the trace deformation transmitter arranged in the housing is arranged between the trace deformation transmitter and the positioning rod, so that the trace deformation transmitter transmits the movement of the positioning rod to the trace deformation transmitter, thereby converting the bolt pre-tightening force deformation into a measurable relative displacement of the positioning rod, so as to quantitatively output the pre-tightening force strain information. In addition, by arranging the gap between the outer wall of the positioning rod and the inner wall of the detection hole in the bolt, the cooperation between the parts is better. In addition, since the first end of the positioning rod is threadedly connected with the inside of the bolt, compared with other application schemes in the market, the threaded fixed type in the present disclosure is equivalent to that the positioning rod and the bolt form an integral whole, and compared with the case that the positioning rod is not fixedly connected or directly inserted into the bolt, the measurement accuracy and sensitivity are better. BRIEF DESCRIPTION OF DRAWINGS

[0041] The above and other features, advantages, and aspects of embodiments of the present disclosure will become more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which:

[0042] FIG. 1 is a deployment schematic diagram of a bolt pre-tightening force monitoring assembly provided by the present disclosure.

[0043] Fig. 2 is a schematic view of a hole drilled on a bolt according to the present disclosure.

[0044] Fig. 3 is a structural schematic view of a bolt pre-tightening force monitoring assembly according to the present disclosure.

[0045] In the various drawings, the same or corresponding reference numerals represent the same or corresponding parts; wherein the reference numerals are: 1, positioning rod, 2, housing, 3, micro-deformation transmitter, 4, micro-deformation transmission member, 31, detection circuit board, 32, connecting plug, 41, transmission rod, 42, first transmission member, 43, magnet, 44, second transmission member, 45, reset spring, 311, first detection circuit board, 312, second detection circuit board, 431, partition plate, 101, blind hole, 102, threaded hole. DETAILED DESCRIPTION

[0046] Embodiments of the present disclosure will be described in more detail with reference to the drawings. Although certain embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly and completely understood. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0047] In the description of embodiments of the present disclosure, the term "comprising" and its conjugations should be understood to encompass open-ended inclusion, i.e., "comprising 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. can refer to different or the same objects. Other explicit and implicit definitions can also be included below.

[0048] The present disclosure discloses a bolt pre-tightening force monitoring assembly, in some examples, referring to Fig. 1, the present disclosure discloses a bolt pre-tightening force monitoring assembly comprising 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 described in combination with a specific installation.

[0049] The bolt pre-tightening force monitoring assembly disclosed by the present disclosure is installed on a bolt, and a blind hole 101 needs to be drilled on one end of the bolt first. A threaded hole 102 is drilled on the bottom surface of the blind hole 101, as shown in Fig. 2. In order to unify the description below, the blind hole 101 is referred to as a detection hole.

[0050] The positioning rod 1 is arranged in a detection hole in the bolt, the first end of the positioning rod 1 is fixedly connected with the bolt, and the second end of the positioning rod 1 is a free end. In combination with the foregoing, the first end of the positioning rod 1 is connected with the bolt in a threaded connection. Further, in some embodiments, the threaded connection between the first end of the positioning rod 1 and the bolt is also provided with thread glue for application in different working conditions, so as to strengthen the connection relationship therebetween. It should be understood that the thread glue has a wide range of applications in many fields due to its unique anaerobic glue curing characteristics, for example: locking and preventing loosening: metal screws are prone to loosening or falling off under the action of impact and vibration, and traditional mechanical locking methods are not ideal, while chemical locking methods are inexpensive and effective. If the screws are assembled after being coated with anaerobic glue, a strong and flexible plastic film is formed in the thread gap after curing, so that the screws are locked and cannot loosen. Sealing and preventing leakage: any plane cannot be completely tightly contacted and needs to be sealed to prevent leakage. The thread glue is used to replace the solid gasket, and after curing, the tight contact can be achieved, so that the sealing is more durable. The thread glue is used for sealing of threaded pipe joints and threaded plugs, sealing of flange plate mating surfaces, sealing of mechanical box body joint surfaces, and the like, and has good leakage prevention effect. Holding and positioning: cylindrical components such as bearing and shaft, belt pulley and shaft, gear and shaft, and the like, the thread glue can be used to fill the fitting gap, and after curing, it is firm, durable, stable and reliable. Filling and plugging: for castings, die castings, powder metallurgy parts and welded parts with micropores, low-viscosity anaerobic glue can be coated on the defects, so that the glue seeps into the micropores, and the curing is completed in the case of room temperature isolation of oxygen, so as to fill the pores and achieve the sealing effect.

[0051] It should be noted that the first end of the positioning rod 1 is connected with the bolt in a threaded connection, and the first end of the positioning rod 1 is threadedly connected with the inside of the bolt, which is better than other application schemes in the market, for example, some are not fixedly connected, such as directly positioning the rod into the bolt. Then the way is not as good as the threaded fixed type in some embodiments of the present disclosure. The threaded fixed type in the present disclosure is equivalent to the positioning rod 1 and the bolt forming a whole, and the measurement accuracy and sensitivity are better than the effect of not fixedly connecting or directly positioning the rod into the bolt.

[0052] The shell 2 is arranged to be fixed on the bolt, the micro deformation transmitter 3 is installed on the shell 2, and the micro deformation transmitter 4 is installed inside the shell 2 and arranged between the micro deformation transmitter 3 and the positioning rod 1. The micro deformation transmitter 4 is arranged to transmit the movement of the positioning rod 1 to the micro deformation transmitter 3.

[0053] The movement of the positioning rod 1 means that the force acting on the bolt changes, at this time the screw rod deforms and drives 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 transmitter 4, and the micro deformation transmitter 3 converts the micro deformation into an electric signal.

[0054] In the time dimension, the electrical signal (micro-deformation) is a curve, and the point (ordinate) on the curve represents the deformation size.

[0055] 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, which is used to improve the accuracy of the measurement, because the gap can avoid the deformation of the positioning rod 1 with the bolt.

[0056] In some possible implementations, the gap width is 0.1-0.5 mm.

[0057] In some examples, referring to FIG. 3, the micro-deformation transmitter 4 includes a transmission rod 41, a first transmission member 42, a magnet 43, a second transmission member 44, and a reset spring 45. The transmission rod 41 is in sliding connection with the shell 2, the first transmission member 42 is fixed on the transmission rod 41, and the magnet 43 is fixed on the first transmission member 42.

[0058] In some possible implementations, the magnet 43 is arranged in a groove on the first transmission member 42.

[0059] The second transmission member 44 is in sliding connection with the first transmission member 42, the first end of the reset spring 45 is arranged in a hole in the second transmission member 44, and the second end is in abutment against the first transmission member 42.

[0060] When the transmission rod 41 moves, the first transmission member 42 and the magnet 43 are driven to move, at which 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.

[0061] The micro-deformation transmitter 3 is composed of a detection circuit board 31 and a connecting plug 32. The detection circuit board 31 is arranged in a cavity in the shell 2 and is connected with the micro-deformation transmitter 4, and the connecting plug 32 is mounted on the shell 2 and is electrically connected with the detection circuit board 31.

[0062] The detection circuit board 31 is composed of a first detection circuit board 311 and a second detection circuit board 312. The first detection circuit board 311 is fixedly connected with the second transmission member 44, and the second detection circuit board 312 is fixedly connected with the first detection circuit board 311 and is electrically connected with the connecting plug 32.

[0063] The connection between the first detection circuit board 311 and the second detection circuit board 312 is electrical connection.

[0064] 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, and 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.

[0065] The working principle of the Hall sensor is as follows:

[0066] The principle of the Hall effect is to feedback the size of the magnetic field through the output Hall voltage value, and 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, at which time the output Hall voltage value will change synchronously.

[0067] The first detection circuit board 311 is installed with a related detection circuit that obtains the Hall voltage value output by the Hall sensor, and the detection circuit includes a protection resistor, a voltage sensor, and a circuit, the protection resistor is in the same loop as the Hall sensor, and the voltage sensor detects the voltage on both sides of the protection resistor, and of course, a current sensor can also be used to detect the current in the loop.

[0068] The detection data of the voltage sensor or the current sensor is output through the connection plug 32. The connection plug 32 is connected with a programmable logic controller, an industrial computer, or a control terminal through a data line, and the programmable logic controller, the industrial computer, or the control terminal stores the received data and alarms when the data exceeds the threshold value.

[0069] In some examples, the second transmitting member 44 is further provided with a partition plate 431, which is arranged between the first detection circuit board 311 and the second transmitting member 44. One function of the partition plate 431 is to avoid direct contact between the second detection circuit board 312 and the magnet 43.

[0070] In some possible implementations, the partition plate 431 has a certain softness.

[0071] In addition, the partition plate 431 can also limit the magnet 43 from being too close to the first detection circuit board 311 to avoid generating a large current during detection, which causes damage to the first detection circuit board 311 and the second detection circuit board 312.

[0072] In some examples, there is a gap between the transmitting rod 41 and the positioning rod 1, and of course, the transmitting rod 41 also abuts against the positioning rod 1, which mainly depends on the initial setting. For example, when the bolt is compressed under stress, a gap is selected between the transmitting rod 41 and the positioning rod 1, and for another example, when the bolt is stretched under stress, the transmitting rod 41 abuts against the positioning rod 1.

[0073] In addition, in some embodiments, a displacement sensing device is also provided, which includes the bolt pre-tightening force monitoring assembly described above.

[0074] Further, for the convenience of those skilled in the art to understand, the following will be introduced in more detail based on the bolt pre-tightening force monitoring assembly or displacement sensing device in the above embodiments, for example, in some of the above embodiments, the bolt is under static load and dynamic load; it should be understood that when the bolt is applied under static load, generally the loosening of the nut and bolt in the natural environment is monitored, assuming that the pre-tightening force of a certain 12.9 grade bolt and nut connection pair is about 2600 Nm, the pre-tightening error is ± 5%, the pre-tightening force stretches the bolt body material, and the intermediate rod installed in the hole of the bolt does not contact and does not deform, at this time, the monitoring assembly measures the stretching variable, through long-term data recording and data comparison, whether the bolt pair is loosened is analyzed. When the monitoring assembly is used for dynamic load, the monitoring data will jump due to different occasions, and the monitoring assembly needs to cooperate with the upper computer unit to filter and analyze the data signal and find out the actual variable for monitoring. Assuming that the monitoring of the tank opening bolt of a certain large pressure vessel is carried out, at this time, the bolt pair not only needs to bear the pre-tightening force of the static load, but also needs to bear the stretching force when the tank body has pressure, and when the tank body pressure decreases, the material stretching resets, and reciprocating action forms dynamic load stress on the bolt pair. At this time, by collecting and filtering the working condition information, the running health status of the fastener thread pair is monitored in real time. It should be understood that in some embodiments, the monitoring assembly can output RS485 digital signal, Bluetooth signal output, and wireless remote output according to different application conditions.

[0075] It should be understood that the above embodiments of the present disclosure are intended for monitoring of fastener bolts in pre-tightening force situations, and are not intended for situations without pre-tightening force, which cannot monitor situations without pre-tightening force.

[0076] It should be understood that in more optional embodiments, the pre-tightening force monitoring assembly or displacement sensing device in each embodiment of the present disclosure is mostly subjected to certain mechanical vibration in the application situation, and accordingly the pre-tightening force monitoring assembly or displacement sensing device itself needs to be loosened while monitoring loosening.

[0077] Therefore, in further embodiments, in order to resist the possible loosening problem of the tight force monitoring assembly or displacement sensing device itself in vibration, for the above pre-tightening force monitoring assembly or displacement sensing device, each coupling (or "connecting piece") therein will be fixed by thread glue in addition to the original thread connection, in order to strengthen its fixing effect, especially the loosening effect in vibration. It should be understood that in non-vibration scenarios, additional thread glue fixing is not required.

[0078] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The terminology used herein is chosen to best explain the principles, practical applications, or technological improvements to the embodiments in the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

[0079] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A bolt pre-load monitoring assembly, characterized by, The bolt pre-tightening force monitoring assembly comprises a positioning rod (1) arranged in a detection hole in the bolt, a first end of the positioning rod (1) being arranged in fixed connection with the bolt, and a second end of the positioning rod (1) being a free end; a shell (2) arranged to be fixed on the bolt; a micro-deformation transducer (3) arranged on the shell (2); and a micro-deformation transmission member (4) arranged in the shell (2) and arranged between the micro-deformation transducer (3) and the positioning rod (1), the micro-deformation transmission member (4) being arranged to transmit the movement of the positioning rod (1) to the micro-deformation transducer (3).

2. The bolt pre-tightening force monitoring assembly according to claim 1, wherein a gap is arranged between the outer wall of the positioning rod (1) and the inner wall of the detection hole in the bolt.

3. The bolt pre-tightening force monitoring assembly according to claim 2, wherein the width of the gap is arranged to be 0.1mm-0.5mm.

4. The bolt pre-tightening force monitoring assembly according to claim 1, wherein the micro-deformation transmission member (4) comprises: a transducer rod (41) arranged in sliding connection with the shell (2); a first transducer member (42) arranged on the transducer rod (41), a magnet (43) being arranged on the first transducer member (42); a second transducer member (44) arranged in sliding connection with the first transducer member (42); and a reset spring (45), a first end of the reset spring (45) being arranged in a hole in the second transducer member (44), and a second end of the reset spring (45) being arranged to abut against the first transducer member (42).

5. The bolt pre-tightening force monitoring assembly according to claim 1 or 4, wherein the micro-deformation transducer (3) comprises: a detection circuit board (31) arranged in a cavity in the shell (2) and arranged in connection with the micro-deformation transmission member (4); and a connection plug (32) arranged on the shell (2) and arranged in electrical connection with the detection circuit board (31).

6. The bolt pre-tightening force monitoring assembly according to claim 5, wherein the detection circuit board (31) comprises: a first detection circuit board (311) arranged in fixed connection with the second transducer member (44); and a second detection circuit board (312) arranged in fixed connection with the first detection circuit board (311) and arranged in electrical connection with the connection plug (32); wherein the second detection circuit board (312) is further arranged in electrical connection with the first detection circuit board (311).

7. The bolt pre-tightening force monitoring assembly according to claim 6, wherein a partition plate (431) is further arranged on the second transducer member (44), the partition plate (431) being arranged between the first detection circuit board (311) and the second transducer member (44).

8. The bolt pre-tightening force monitoring assembly according to claim 4, wherein a gap is arranged between the transducer rod (41) and the positioning rod (1).

9. The bolt pre-tightening force monitoring assembly according to claim 4, wherein the transducer rod (41) is arranged to abut against the positioning rod (1). The bolt pre-tightening force monitoring assembly comprises a positioning rod (1) arranged in a detection hole in the bolt, a first end of the positioning rod (1) being arranged in fixed connection with the bolt, and a second end of the positioning rod (1) being a free end; a shell (2) arranged to be fixed on the bolt; a micro-deformation transducer (3) arranged on the shell (2); and a micro-deformation transmission member (4) arranged in the shell (2) and arranged between the micro-deformation transducer (3) and the positioning rod (1), the micro-deformation transmission member (4) being arranged to transmit the movement of the positioning rod (1) to the micro-deformation transducer (3). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10. A displacement sensing device, characterized by, ​ A bolt pre-load monitoring assembly as claimed in any one of claims 1 to 9.

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