Passive wireless bolt axial force measuring method and measuring equipment

Abstract

The invention discloses a passive wireless bolt axial force measuring method and equipment, the bolt axial force measuring equipment comprises a pulse transmitting unit, a transmitting end transmitting coil, a transmitting end receiving coil, an electric signal detection unit, a receiving end coil, a piezoelectric sensor and an ultrasonic probe, the pulse transmitting unit can generate an electric pulse signal with the pulse width of 100-0.01 us, and the receiving end coil can generate an electric pulse signal with the pulse width of 100-0.01 us; the electric pulse signal is received by the transmitting end transmitting coil to generate an induction pulse electromagnetic field, the induction pulse electromagnetic field is received by the receiving end coil to be transmitted to the piezoelectric sensor, the piezoelectric sensor generates ultrasonic waves, the ultrasonic waves act on the bolt and then are reflected, and the reflected ultrasonic signal outputs an electric signal through the piezoelectric sensor; after the electric signal detection unit receives the electric signal through the transmitting end receiving coil, the bolt axial force is calculated based on the ultrasonic propagation sound time when the ultrasonic propagation sound time is measured.

Description

Technical Field

[0001] The present invention relates to the technical field of bolt axial force detection, and more specifically, to a passive wireless bolt axial force measurement method and measurement device. Background Art

[0002] As an important connecting component, the axial force of a bolt is a key factor for evaluating the connection performance and directly affects the safety and stability of the structure. Therefore, accurately measuring the axial force of a bolt is crucial for ensuring the installation quality, preventing structural failure, and performing maintenance and repair. Currently, the measurement techniques for bolt axial force mainly include ultrasonic detection method, torque method, rotation angle method, strain gauge method, etc. Among them, the ultrasonic detection method has become one of the mainstream methods due to its non-destructive detection characteristics. This method is based on the acoustoelastic effect, that is, the velocity of elastic waves in a solid structure changes with the change of stress, and the axial force of the bolt is calculated by measuring the propagation velocity of ultrasonic waves in the bolt. This method can not only achieve online monitoring, but also is easy to install and is applicable to the bolt axial force detection in various complex environments.

[0003] However, since many bolts are installed at high altitudes or other positions that are difficult for personnel to reach, and it is necessary to dynamically master the bolt axial force state, it is very necessary to monitor the bolt axial force. Since the current monitoring devices require power supply, acquisition circuit, control circuit, wireless communication circuit, etc., the cost of the monitoring devices is high. In addition, it is limited by the battery service life and cannot be used for a long period, thus restricting the effective monitoring of bolt axial force.

[0004] In view of this, there is an urgent need in the art for a low-cost and battery-free axial force monitoring method and device to solve the problems existing in the prior art. Summary of the Invention

[0005] To solve the above problems, the object of the present invention is to provide a passive wireless bolt axial force measurement method and measurement device, which measures the axial force by using an unmanned aerial vehicle (UAV) to carry an ultrasonic detection probe, so as to realize low-cost, long-cycle, and ultrasonic axial force detection without position alignment. The service life of this device is close to that of the bolt, and the problem caused by position alignment is avoided.

[0006] To achieve the above object, the present invention provides a passive wireless bolt axial force measurement device, which includes: an external transmitting and measuring machine, a passive wireless axial force sensor, an ultrasonic probe, and a bolt:

[0007] The external transmitting and measuring machine includes:

[0008] A pulse transmitting unit, which is capable of generating one or more electrical pulse signals with a pulse width of 100 us to 0.01 us;

[0009] A transmitting-end transmitting coil, to which the electric pulse signal generated by the pulse transmitting unit is applied to generate an induced pulse electromagnetic field;

[0010] A transmitting-end receiving coil, which receives the induced pulse electromagnetic field emitted by the passive wireless axial force sensor; and

[0011] An electric signal detection unit, which receives the electric signal transmitted by the transmitting-end receiving coil;

[0012] The transmitting-end receiving coil and the transmitting-end transmitting coil are the same coil or two different coils;

[0013] The passive wireless axial force sensor includes:

[0014] A receiving-end coil, to which the induced pulse electromagnetic field emitted by the transmitting-end transmitting coil is applied to generate an induced electric pulse signal; and

[0015] A piezoelectric sensor, to which the induced electric pulse signal emitted by the receiving-end coil is applied to generate ultrasonic waves. The ultrasonic waves enter the bolt and are reflected at the bolt end face. The reflected ultrasonic waves are applied to the piezoelectric sensor, and the piezoelectric sensor outputs an electric signal, which is applied to the receiving-end coil;

[0016] The passive wireless axial force sensor is connected to the bolt through the ultrasonic probe.

[0017] In an embodiment of the present invention, the ultrasonic probe is a longitudinal and transverse wave integrated probe, which includes a first piezoelectric wafer, a second piezoelectric wafer and a trapezoidal wedge block. The first piezoelectric wafer is connected to the bolt through the parallel surface of the trapezoidal wedge block, and the second piezoelectric wafer is connected to the bolt after the inclined surface of the trapezoidal wedge block. The longitudinal and transverse wave integrated probe can transmit and receive ultrasonic waves. At this time, the ultrasonic waves generated by the piezoelectric sensor are a combination of ultrasonic longitudinal waves and ultrasonic transverse waves.

[0018] In an embodiment of the present invention, the ultrasonic probe is a longitudinal and transverse wave integrated probe, which includes a first piezoelectric wafer, a second piezoelectric wafer and a wedge block. The first piezoelectric wafer is directly connected to the bolt, and the second piezoelectric wafer is connected to the bolt through the wedge block. The longitudinal and transverse wave integrated probe can transmit and receive ultrasonic waves. At this time, the ultrasonic waves generated by the piezoelectric sensor are a combination of ultrasonic longitudinal waves and ultrasonic transverse waves.

[0019] In an embodiment of the present invention, the ultrasonic probe is a longitudinal wave probe, which includes a first piezoelectric wafer and a vertical wedge. The first piezoelectric wafer is connected to a bolt through the vertical wedge. The longitudinal wave probe can transmit and receive ultrasonic waves. At this time, the ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave.

[0020] In an embodiment of the present invention, the ultrasonic probe is a longitudinal wave probe, which includes a first piezoelectric wafer directly connected to a bolt. The longitudinal wave probe can transmit and receive ultrasonic waves. At this time, the ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave.

[0021] To achieve the above object, the present invention provides a passive wireless bolt axial force measurement method, which includes the following steps:

[0022] S1: The pulse emission unit generates one or more electrical pulse signals with a pulse width of 100 us to 0.01 us and applies them to the transmitting end transmitting coil. The transmitting end transmitting coil generates an induced pulse electromagnetic field due to the electromagnetic induction phenomenon;

[0023] S2: The induced pulse electromagnetic field is applied to the receiving end coil to generate an induced electrical pulse signal, and the induced electrical pulse signal is applied to the piezoelectric sensor to generate ultrasonic waves;

[0024] S3: When a combination of ultrasonic longitudinal waves and ultrasonic transverse waves is generated, the first piezoelectric wafer and the second piezoelectric wafer are in a parallel state. Among them, the ultrasonic longitudinal wave is coupled into the bolt through the first piezoelectric wafer to generate a longitudinal wave, and the ultrasonic transverse wave is coupled into the bolt through the second piezoelectric wafer to generate a transverse wave;

[0025] S4: The transverse wave and the longitudinal wave are reflected at the bolt end face, generating a longitudinal wave echo and a transverse wave echo. After being received by the longitudinal and transverse wave integrated probe, the longitudinal wave echo and the transverse wave echo generate two electrical signals through the piezoelectric sensor respectively;

[0026] S5: The two electrical signals generated by the piezoelectric sensor are respectively loaded into the receiving end coil at different times and then coupled to the transmitting end receiving coil. Two signals output at different times can be detected on the transmitting end receiving coil. The two signals are received by the electrical signal detection unit, and the electrical signal detection unit outputs two waveforms. By analyzing the two waveforms, the propagation time of the ultrasonic longitudinal wave and the propagation time of the ultrasonic transverse wave are measured. In an embodiment of the present invention, when a combination of ultrasonic transverse waves and ultrasonic longitudinal waves is generated, the propagation time T of the ultrasonic longitudinal wave in the bolt after the bolt is subjected to the axial force is measured _L 、the propagation time T of the ultrasonic transverse wave in the bolt after the bolt is subjected to the axial force is measured _S 、the propagation time T of the ultrasonic longitudinal wave in the stress-free state is measured _LO, measure the propagation time T of the ultrasonic shear wave in the stress-free state _SO , and combine the longitudinal wave stress coefficient K _L of the bolt material and the shear wave stress coefficient K _S , and calculate the axial force σ of the bolt according to the formula:

[0027]

[0028] To achieve the above object, the present invention also provides a passive wireless bolt axial force measurement method, which includes the following steps:

[0029] S1: The pulse transmitting unit generates one or more electrical pulse signals with a pulse width of 100 us to 0.01 us and applies them to the transmitting end transmitting coil, and the transmitting end transmitting coil generates an induced pulse electromagnetic field due to the electromagnetic induction phenomenon;

[0030] S2: The induced pulse electromagnetic field is applied to the receiving end coil to generate an induced electrical pulse signal, and the induced electrical pulse signal is applied to the piezoelectric sensor to generate ultrasonic waves;

[0031] S3: When a single ultrasonic longitudinal wave is generated, the single ultrasonic longitudinal wave is coupled into the bolt through the first piezoelectric wafer and then generates a single longitudinal wave;

[0032] S4: The longitudinal wave is reflected at the bolt end face, and only one longitudinal wave echo is generated. After the longitudinal wave echo is received by the longitudinal wave probe, a unique electrical signal is generated through the piezoelectric sensor.

[0033] S5: The single electrical signal generated by the piezoelectric sensor is loaded into the receiving end coil and then coupled to the transmitting end receiving coil to generate a single signal. A single signal can be detected on the transmitting end receiving coil, and the single signal is received by the electrical signal detection unit. The electrical signal detection unit outputs a waveform, analyzes the waveform, and measures the propagation time of the ultrasonic longitudinal wave.

[0034] In an embodiment of the present invention, when only one ultrasonic longitudinal wave is generated, measure the propagation time T' of the ultrasonic longitudinal wave after the bolt is subjected to the axial force _L , measure the propagation time T' of the ultrasonic longitudinal wave in the stress-free state _LO and combine the stress coefficient K' of the longitudinal wave of the bolt material _L , and calculate the axial force μ of the bolt according to the formula:

[0035]

[0036] The passive wireless bolt axial force measurement method and measurement device provided by the present invention, compared with the prior art, adopt a passive wireless ultrasonic detection method. Compared with regular manual detection, it eliminates the errors caused by position alignment, coupling, and manual operation of existing measurement devices. Compared with on-line monitoring, it eliminates the power supply module, acquisition module, and communication module, reduces the cost of a single sensor, and at the same time reduces the maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0038] Figure 1 Structural schematic diagram of a passive wireless bolt axial force measurement device according to an embodiment of the present invention;

[0039] Figure 2 Structural schematic of a longitudinal and transverse wave integrated probe according to an embodiment of the present invention Figure 1 ;

[0040] Figure 3 Structural schematic of a longitudinal and transverse wave integrated probe according to an embodiment of the present invention Figure 2 ;

[0041] Figure 4 Structural schematic of a longitudinal wave probe according to an embodiment of the present invention Figure 1 ;

[0042] Figure 5 Structural schematic of a longitudinal wave probe according to an embodiment of the present invention Figure 2 。

[0043] Description of reference numerals: 100 - external emission measurement machine; 101 - pulse emission unit; 102 - emission end emission coil; 103 - emission end receiving coil; 104 - electrical signal detection unit; 200 - passive wireless axial force sensor; 201 - receiving end coil; 202 - piezoelectric sensor; 401 - electrical pulse signal; 402 - induced pulsed electromagnetic field; 403 - induced electrical pulse signal; 404 - ultrasonic wave; 501 - longitudinal wave; 502 - longitudinal wave echo; 601 - transverse wave; 602 - transverse wave echo; 701 - electrical signal; 702 - electrical signal; 801 - electrical signal; 802 - electrical signal; 301 - bolt. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] Figure 1 It is a schematic structural diagram of a passive wireless bolt axial force measuring device according to an embodiment of the present invention. As Figure 1 shown, this embodiment provides a passive wireless bolt axial force measuring device, which includes an external transmitting and measuring machine 100, a passive wireless axial force sensor 200, an ultrasonic probe, and a bolt 301;

[0046] The external transmitting and measuring machine 100 includes:

[0047] A pulse transmitting unit 101, the pulse wave transmitting unit can generate one or more electrical pulse signals 401 with a pulse width of 100 us to 0.01 us. There are various forms of the electrical pulse signals, such as: sine wave, square wave, triangular wave, etc. The present invention does not limit the style of the pulse signal;

[0048] A transmitting end transmitting coil 102, the electrical pulse signal 401 is applied to the transmitting end transmitting coil to generate an induced pulse electromagnetic field 402;

[0049] A transmitting end receiving coil 103, the transmitting end receiving coil receives the induced pulse electromagnetic field emitted by the passive wireless axial force sensor;

[0050] The transmitting end transmitting coil 102 and the transmitting end receiving coil 103 are the same coil or two different coils;

[0051] An electrical signal detection unit 104, the electrical signal detection unit receives the electrical signal transmitted by the transmitting end receiving coil.

[0052] The passive wireless axial force sensor 200 includes:

[0053] A receiving end coil 201, the induced pulse electromagnetic field 402 is applied to the receiving end coil to generate an induced electrical pulse signal 403;

[0054] A piezoelectric sensor 202, when the induced electrical pulse signal 403 is applied to the piezoelectric sensor, ultrasonic waves 404 will be generated. The ultrasonic waves generated by the piezoelectric sensor are single ultrasonic longitudinal waves, or a combination of ultrasonic longitudinal waves and ultrasonic transverse waves. The ultrasonic waves enter the bolt and are reflected at the bolt end face. The reflected ultrasonic waves are applied to the piezoelectric sensor, and the piezoelectric sensor outputs an electrical signal. The electrical signal is applied to the receiving end coil 201, and the receiving end coil generates an induced pulse electromagnetic field;

[0055] The wireless axial force sensor is connected to the bolt through an ultrasonic probe, and the ultrasonic probe structure can transmit and receive ultrasonic waves.

[0056] Figure 2 Schematic diagram of the longitudinal and transverse wave integrated probe structure of an embodiment of the present invention Figure 1 , as Figure 2 shown, this embodiment provides an ultrasonic probe structure. The ultrasonic probe is a longitudinal and transverse wave integrated probe, and the longitudinal and transverse wave integrated probe can transmit and receive ultrasonic waves. It includes a first piezoelectric wafer, a second piezoelectric wafer, and a trapezoidal wedge. Among them, the first piezoelectric wafer is connected to the bolt through the parallel plane of the trapezoidal wedge, and the second piezoelectric wafer is connected to the bolt after passing through the inclined plane of the trapezoidal wedge. At this time, the ultrasonic waves generated by the piezoelectric sensor are a combination of ultrasonic longitudinal waves and ultrasonic transverse waves;

[0057] Figure 3 Schematic diagram of the longitudinal and transverse wave integrated probe structure of an embodiment of the present invention Figure 2 , as Figure 3 shown, this embodiment provides an ultrasonic probe structure. The ultrasonic probe is a longitudinal and transverse wave integrated probe, and the longitudinal and transverse wave integrated probe can transmit and receive ultrasonic waves. It includes a first piezoelectric wafer, a second piezoelectric wafer, and an inclined wedge. Among them, the first piezoelectric wafer is directly connected to the bolt, and the second piezoelectric wafer is connected to the bolt through the inclined wedge. At this time, the ultrasonic waves generated by the piezoelectric sensor are a combination of ultrasonic longitudinal waves and ultrasonic transverse waves;

[0058] Embodiment 1:

[0059] This embodiment uses Figure 1 , Figure 2 to constitute a device to provide a passive wireless bolt axial force measurement method, which includes the following steps:

[0060] S1: The pulse transmitting unit 101 generates one or more electrical pulse signals 401 with a pulse width of 100 us to 0.01 us and applies them to the transmitting end transmitting coil 102. The transmitting end transmitting coil generates an induced pulse electromagnetic field 402 due to the electromagnetic induction phenomenon;

[0061] S2: The induced pulsed electromagnetic field is applied to the receiving coil 201 to generate an induced electrical pulse signal 403, and the induced electrical pulse signal is applied to the piezoelectric sensor 202 to generate ultrasonic waves 404;

[0062] S3: When a combination of ultrasonic longitudinal waves and ultrasonic transverse waves is generated, the first piezoelectric wafer and the second piezoelectric wafer are in a parallel state. Among them, the ultrasonic longitudinal waves pass through the first piezoelectric wafer and the trapezoidal wedge plane and are coupled into the bolt 301 to generate longitudinal waves 501, and the ultrasonic transverse waves pass through the second piezoelectric wafer and the trapezoidal wedge inclined plane and are coupled into the bolt to generate transverse waves 601;

[0063] S4: The transverse waves and the longitudinal waves are reflected at the bolt end face, generating longitudinal wave echoes 502 and transverse wave echoes 602. After being received by the longitudinal and transverse wave integrated probe, the longitudinal wave echoes and the transverse wave echoes generate two electrical signals (electrical signal 701, electrical signal 702) through the piezoelectric sensor respectively;

[0064] S5: The two electrical signals generated by the piezoelectric sensor in S4 will be respectively loaded into the receiving coil at different times to generate two induced pulsed electromagnetic field signals. The two induced pulsed electromagnetic field signals are coupled to the transmitting end receiving coil 103 and output two signals (electrical signal 801, electrical signal 802) at different times. Two signals output at different times can be detected on the transmitting end receiving coil. The two signals are received by the electrical signal detection unit 104, and the electrical signal detection unit outputs two waveforms. By analyzing the two waveforms, the propagation time of the ultrasonic longitudinal wave and the propagation time of the ultrasonic transverse wave are measured.

[0065] In this embodiment, when a combination of ultrasonic transverse waves and ultrasonic longitudinal waves is generated, the propagation time T of the ultrasonic longitudinal wave in the bolt after the bolt is subjected to axial force is measured _L 、the propagation time T of the ultrasonic transverse wave in the bolt after the bolt is subjected to axial force is measured _S 、the propagation time T of the ultrasonic longitudinal wave in the stress-free state is measured _LO 、the propagation time T of the ultrasonic transverse wave in the stress-free state is measured _SO , and combined with the longitudinal wave stress coefficient K _L and the transverse wave stress coefficient K _S of the bolt material, the axial force σ of the bolt is calculated. The calculation formula is as follows:

[0066]

[0067] Measuring T _L and T _S under different known axial tensile force states can calibrate K _L 、K _S . The axial tensile force is measured by using commercially available products, and the present invention does not limit it

[0068] Embodiment 2:

[0069] This embodiment uses Figure 1 and Figure 3 The device composed of provides a passive wireless bolt axial force measurement method, which includes the following steps:

[0070] S1: The pulse transmitting unit 101 generates one or more electrical pulse signals 401 with a pulse width of 100 us to 0.01 us and applies them to the transmitting end transmitting coil 102. The transmitting end transmitting coil generates an induced pulse electromagnetic field 402 due to the electromagnetic induction phenomenon;

[0071] S2: The induced pulse electromagnetic field is applied to the receiving end coil 201 to generate an induced electrical pulse signal 403, and the induced electrical pulse signal is applied to the piezoelectric sensor 202 to generate ultrasonic waves 404;

[0072] S3: When a combination of ultrasonic longitudinal waves and ultrasonic transverse waves is generated, the first piezoelectric wafer and the second piezoelectric wafer are in a parallel state. Among them, the ultrasonic longitudinal wave is coupled to the bolt 301 through the first piezoelectric wafer to generate a longitudinal wave 501; the ultrasonic transverse wave is coupled to the bolt 301 through the second piezoelectric wafer and the wedge block to generate a transverse wave 601;

[0073] S4: The transverse wave and the longitudinal wave are reflected at the bolt end face, generating a longitudinal wave echo 502 and a transverse wave echo 602. After being received by the longitudinal and transverse wave integrated probe, the longitudinal wave echo and the transverse wave echo generate two electrical signals (electrical signal 701, electrical signal 702) through the piezoelectric sensor respectively;

[0074] S5: The two electrical signals generated by the piezoelectric sensor in S4 will be loaded into the receiving end coil at different times respectively to generate two induced pulse electromagnetic field signals. The two induced pulse electromagnetic field signals are coupled to the transmitting end receiving coil 103 and output two signals (electrical signal 801, electrical signal 802) at different times. Two signals output at different times can be detected on the transmitting end receiving coil. The two signals are received by the electrical signal detection unit 104, and the electrical signal detection unit outputs two waveforms. Analyze the two waveforms to measure the propagation time of the ultrasonic longitudinal wave and the propagation time of the ultrasonic transverse wave.

[0075] In this embodiment, when a combination of ultrasonic transverse waves and ultrasonic longitudinal waves is generated, measure the propagation time T of the ultrasonic longitudinal wave in the bolt after the bolt is subjected to axial force _L and measure the propagation time T of the ultrasonic transverse wave in the bolt after the bolt is subjected to axial force _S and measure the propagation time T of the ultrasonic longitudinal wave in the stress-free state _LO and measure the propagation time T of the ultrasonic transverse wave in the stress-free state_SO , and in combination with the longitudinal wave stress coefficient K of the bolt material _L and the shear wave stress coefficient K _S , the axial force σ of the bolt is calculated, and the calculation formula is as follows:

[0076]

[0077] Measure T under different known axial tensile force states _L and T _S , and K can be calibrated _L , K _S . The axial tensile force is measured by using commercially available products, and the present invention does not limit it

[0078] Figure 4 is a schematic diagram of the longitudinal wave probe structure of an embodiment of the present invention Figure 1 , as Figure 4 shown, this embodiment provides an ultrasonic probe structure. The ultrasonic probe is a longitudinal wave probe, and the longitudinal wave probe can transmit and receive ultrasonic waves. It includes a first piezoelectric wafer and a vertical wedge block. The first piezoelectric wafer is connected to the bolt through the vertical wedge block. At this time, the ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave.

[0079] Figure 5 is a schematic diagram of the longitudinal wave probe structure of an embodiment of the present invention Figure 2 , as Figure 5 shown, this embodiment provides an ultrasonic probe structure. The ultrasonic probe is a longitudinal wave probe, and the longitudinal wave probe can transmit and receive ultrasonic waves. It includes a first piezoelectric wafer, and the first piezoelectric wafer is directly connected to the bolt. At this time, the ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave.

[0080] Embodiment 3:

[0081] This embodiment uses Figure 1 , Figure 4 to provide a passive wireless bolt axial force measurement method, which includes the following steps:

[0082] S1: The pulse transmitting unit 101 generates one or more electrical pulse signals 401 with a pulse width of 100 us to 0.01 us and applies them to the transmitting end transmitting coil 102. The transmitting end transmitting coil generates an induced pulse electromagnetic field 402 due to the electromagnetic induction phenomenon;

[0083] S2: The induced pulse electromagnetic field is applied to the receiving end coil 201 to generate an induced electrical pulse signal 403, and the induced electrical pulse signal is applied to the piezoelectric sensor 202 to generate ultrasonic waves 404;

[0084] S3: When a single ultrasonic longitudinal wave is generated, the single ultrasonic longitudinal wave is coupled into the bolt through the first piezoelectric wafer and the vertical wedge block, and then a single longitudinal wave is generated;

[0085] When a single ultrasonic longitudinal wave is generated, the single ultrasonic longitudinal wave is coupled into the bolt through the first piezoelectric wafer and then a single longitudinal wave is generated;

[0086] S4: The longitudinal wave is reflected at the bolt end face, and only one longitudinal wave echo is generated. After the longitudinal wave echo is received by the longitudinal wave probe, a unique electrical signal is generated through the piezoelectric sensor;

[0087] S5: The electrical signal generated by the piezoelectric sensor in S4 is loaded into the receiving end coil, and then an induced pulse electromagnetic field is generated. The induced pulse electromagnetic field is coupled to the transmitting end receiving coil to generate a single signal. A single signal can be detected on the transmitting end receiving coil. The signal is received by the electrical signal detection unit, and the electrical signal detection unit outputs a waveform. By analyzing the waveform, the propagation time of the ultrasonic longitudinal wave is measured.

[0088] In this embodiment, when only one ultrasonic longitudinal wave is generated, the propagation time T′ of the ultrasonic longitudinal wave after the bolt is subjected to axial force is measured _L and the propagation time T′ of the ultrasonic longitudinal wave in the stress-free state is measured _LO and combined with the stress coefficient K′ of the longitudinal wave of the bolt material _L , the axial force μ of the bolt can be calculated. The calculation formula is as follows:

[0089]

[0090] Measure T′ under different known axial tensile force states _L and T′ _LO , and K′ can be calibrated _L . The axial tensile force is measured by using commercially available products, and the present invention does not limit it

[0091] Embodiment 4:

[0092] This embodiment uses Figure 1 , Figure 5 to form a device to provide a passive wireless bolt axial force measurement method, which includes the following steps:

[0093] S1: The pulse transmitting unit 101 generates one or more electrical pulse signals 401 with a pulse width of 100 us to 0.01 us and applies them to the transmitting end transmitting coil 102. The transmitting end transmitting coil generates an induced pulse electromagnetic field 402 due to the electromagnetic induction phenomenon;

[0094] S2: The induced pulsed electromagnetic field is applied to the receiving coil 201 to generate an induced electrical pulse signal 403, and the induced electrical pulse signal is applied to the piezoelectric sensor 202 to generate ultrasonic waves 404;

[0095] S3: When a single ultrasonic longitudinal wave is generated, the single ultrasonic longitudinal wave is coupled into the bolt through the first piezoelectric wafer to generate a single longitudinal wave;

[0096] S4: The longitudinal wave is reflected at the bolt end face, and only one longitudinal wave echo is generated. After the longitudinal wave echo is received by the longitudinal wave probe, a unique electrical signal is generated through the piezoelectric sensor;

[0097] S5: The electrical signal generated by the piezoelectric sensor in S4 is loaded into the receiving coil to generate an induced pulsed electromagnetic field. The induced pulsed electromagnetic field is coupled to the transmitting end receiving coil to generate a signal. A single signal can be detected on the transmitting end receiving coil. The single signal is received by the electrical signal detection unit, and the electrical signal detection unit outputs a waveform. By analyzing the waveform, the propagation time of the ultrasonic longitudinal wave is measured.

[0098] In this embodiment, when only one ultrasonic longitudinal wave is generated, the propagation time T′ of the ultrasonic longitudinal wave after the bolt is subjected to axial force is measured _L , and the propagation time T′ of the ultrasonic longitudinal wave in the stress-free state is measured _LO Combined with the stress coefficient K′ of the longitudinal wave of the bolt material _L , the axial force μ of the bolt can be calculated. The calculation formula is as follows:

[0099]

[0100] Measure T′ under different known axial tensile force states _L and T′ _LO , and K′ can be calibrated _L . The axial tensile force is measured using commercially available products, and the present invention does not limit it.

[0101] In Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4, since the sound velocity is affected by temperature, the present invention also uses the equipment in the existing patent (2025101162001) to detect the temperature to correct the axial force detection result of the present invention.

[0102] When a combination of shear waves and longitudinal waves exists and temperature compensation is performed, such as in Embodiment 1 and Embodiment 2, according to the temperature θ0 of the sound time in the stress-free state, the temperature θ of the sound time in the stress state, the shear wave temperature coefficient α S , the longitudinal wave temperature coefficient α L , according to GB / T43232-202, calculate the axial force σ compensation calculation formula of the bolt. The calculation formula is as follows:

[0103]

[0104] When a single longitudinal ultrasonic wave is generated and temperature compensation is present, such as in Embodiment 3 and Embodiment 4, according to the temperature θ0 of the acoustic time in the stress-free state, the temperature θ of the acoustic time in the stress state, and the longitudinal wave temperature coefficient α L , according to GB / T 43232-202, calculate the compensation calculation formula for the axial force σ of the bolt. The calculation formula is as follows:

[0105]

[0106] Those of ordinary skill in the art can understand that the drawings are only schematic diagrams of an embodiment, and the modules or processes in the drawings are not necessarily essential for implementing the present invention.

[0107] Those of ordinary skill in the art can understand that the modules in the device in the embodiment can be distributed in the device of the embodiment according to the description of the embodiment, or can be correspondingly changed and located in one or more devices different from this embodiment. The modules of the above embodiments can be combined into one module, or further split into multiple sub-modules.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A passive wireless bolt axial force measurement device, characterized in that: The invention comprises an external transmitting measuring machine, a passive wireless axial force sensor, an ultrasonic probe and a bolt, wherein: The external transmission measuring machine comprises: A pulse transmitting unit, wherein the pulse transmitting unit is capable of generating one or more electrical pulse signals with a pulse width of 100us to 0.01us; A transmitting coil at the transmitting end, the electric pulse signal generated by the pulse transmitting unit is applied to the transmitting coil at the transmitting end to generate an induced pulse electromagnetic field; A transmitting end receiving coil, wherein the transmitting end receiving coil receives the induction pulse electromagnetic field emitted by the passive wireless axial force sensor; and An electrical signal detection unit, the electrical signal detection unit receives the electrical signal transmitted by the receiving coil of the transmitting end; The transmitting end receiving coil and the transmitting end transmitting coil are the same coil or two different coils; The passive wireless axial force sensor comprises: A receiving end coil, the induced pulse electromagnetic field generated by the transmitting end transmitting coil is applied to the receiving end coil to generate an induced electrical pulse signal; and A piezoelectric sensor, wherein the induced electrical pulse signal generated by the receiving end coil is applied to the piezoelectric sensor to generate ultrasonic waves, the ultrasonic waves enter the bolt and are reflected on the bolt end surface, the reflected ultrasonic waves are applied to the piezoelectric sensor, the piezoelectric sensor outputs an electrical signal, and the electrical signal is applied to the receiving end coil; Wherein, the passive wireless axial force sensor is connected to the bolt through the ultrasonic probe.

2. The passive wireless bolt axial force measurement device according to claim 1 is characterized in that: The ultrasonic probe is an integrated transverse and longitudinal wave probe, which can transmit and receive ultrasonic waves. It includes a first piezoelectric chip, a second piezoelectric chip and a trapezoidal wedge, wherein the first piezoelectric chip and the bolt are respectively arranged on two parallel surfaces of the trapezoidal wedge, and the second piezoelectric chip is arranged on the inclined surface of the trapezoidal wedge. The ultrasonic wave generated by the piezoelectric sensor is a combination of ultrasonic longitudinal waves and ultrasonic transverse waves.

3. The passive wireless bolt axial force measurement device according to claim 1 is characterized in that: The ultrasonic probe is an integrated transverse and longitudinal wave probe, which can transmit and receive ultrasonic waves. It includes a first piezoelectric chip, a second piezoelectric chip and an inclined wedge block, wherein the first piezoelectric chip is directly connected to the bolts, and the second piezoelectric chip is connected to the bolts through the inclined wedge block. The ultrasonic wave generated by the piezoelectric sensor is a combination of ultrasonic longitudinal waves and ultrasonic transverse waves.

4. The passive wireless bolt axial force measurement device according to claim 1, characterized in that: The ultrasonic probe is a longitudinal wave probe, which can transmit and receive ultrasonic waves. The ultrasonic probe includes a first piezoelectric chip and a vertical wedge. The first piezoelectric chip is connected to the vertical wedge by bolts. The ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave.

5. The passive wireless bolt axial force measurement device according to claim 1, characterized in that: The ultrasonic probe is a longitudinal wave probe, which can transmit and receive ultrasonic waves. The ultrasonic probe includes a first piezoelectric chip, which is directly connected to a bolt. The ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave.

6. A passive wireless bolt axial force measurement method, which is performed by the passive wireless bolt axial force measurement device according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: The pulse transmitting unit generates one or more electrical pulse signals with a pulse width of 100us to 0.01us and applies them to the transmitting coil of the transmitting end. The transmitting coil of the transmitting end generates an induced pulse electromagnetic field due to electromagnetic induction phenomenon; S2: the induced pulse electromagnetic field is applied to the receiving end coil to generate an induced electrical pulse signal, and the induced electrical pulse signal is applied to the piezoelectric sensor to generate ultrasonic waves; S3: The ultrasonic wave generated by the piezoelectric sensor is a combination of ultrasonic longitudinal wave and ultrasonic shear wave. At this time, the first piezoelectric chip and the second piezoelectric chip are in a parallel state, wherein the ultrasonic longitudinal wave is coupled to the bolt through the first piezoelectric chip to generate a longitudinal wave; the ultrasonic shear wave is coupled to the bolt through the second piezoelectric chip to generate a shear wave; S4: the transverse wave and the longitudinal wave are reflected on the end face of the bolt to generate a longitudinal wave echo and a transverse wave echo. After the longitudinal wave echo and the transverse wave echo are received by the transverse and longitudinal wave integrated probe, two electrical signals are generated respectively through a piezoelectric sensor; S5: The two electrical signals are loaded into the receiving end coil at different times and then coupled to the transmitting end receiving coil. The transmitting end receiving coil can detect that two signals are output at different times. The two signals are received by the electrical signal detection unit. The electrical signal detection unit outputs two waveforms. The two waveforms are analyzed to measure the ultrasonic longitudinal wave propagation sound time and the ultrasonic shear wave propagation sound time.

7. The passive wireless bolt axial force measurement method according to claim 6 is characterized in that: When a combination of ultrasonic transverse waves and ultrasonic longitudinal waves is generated, the propagation sound time T of the ultrasonic longitudinal wave in the bolt after the bolt is subjected to axial force is measured respectively. _L , measure the propagation time of ultrasonic shear wave in the bolt after the bolt is subjected to axial force T _s , measure the propagation time of ultrasonic longitudinal waves in a stress-free state T _LO , measure the propagation time of ultrasonic shear waves in a stress-free state T _SO , combined with the longitudinal wave stress coefficient K of the bolt material _L and the shear wave stress coefficient K _S , the axial force σ of the bolt is calculated according to the following formula:

8. A passive wireless bolt axial force measurement method, which is performed by the passive wireless bolt axial force measurement device according to any one of claims 1, 4 or 5, characterized in that: The following steps are involved: S1: The pulse transmitting unit generates one or more electrical pulse signals with a pulse width of 100us to 0.01us and applies them to the transmitting coil of the transmitting end. The transmitting coil of the transmitting end generates an induced pulse electromagnetic field due to electromagnetic induction phenomenon; S2: the induced pulse electromagnetic field is applied to the receiving end coil to generate an induced electrical pulse signal, and the induced electrical pulse signal is applied to the piezoelectric sensor to generate ultrasonic waves; S3: The ultrasonic wave generated by the piezoelectric sensor is a single ultrasonic longitudinal wave, and the single ultrasonic longitudinal wave is coupled to the bolt through the first piezoelectric chip to generate a single longitudinal wave; S4: The single longitudinal wave is reflected on the end face of the bolt, generating only a single longitudinal wave echo, and the single longitudinal wave echo is received by the longitudinal wave probe and then generates a single electrical signal through the piezoelectric sensor; S5: The single electrical signal generated by the piezoelectric sensor is loaded into the receiving end coil and then coupled to the transmitting end receiving coil to generate a single signal. The single signal can be detected on the transmitting end receiving coil. The single signal is received by the electrical signal detection unit. The electrical signal detection unit outputs a waveform. The waveform is analyzed to measure the propagation sound of a single ultrasonic longitudinal wave.

9. The passive wireless bolt axial force measurement method according to claim 8, characterized in that: When a single ultrasonic longitudinal wave is generated, the propagation time T′ of the single ultrasonic longitudinal wave after the bolt is subjected to axial force is measured respectively. _L , measure the propagation time T′ of a single ultrasonic longitudinal wave in a stress-free state _LO , combined with the longitudinal wave stress coefficient K′ of the bolt material _L , the axial force μ of the bolt is calculated according to the following formula:

10. The passive wireless bolt axial force measurement method according to claim 7 or 8, characterized in that: It also includes detecting the temperature and correcting the obtained axial force detection result through the temperature detection data.

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