Bolt elongation measuring device

Abstract

The utility model belongs to the technical field of nuclear power, and particularly relates to a bolt elongation measuring device. The plurality of power-losing electromagnets in the device naturally have magnetic attraction force and can be firmly adsorbed on the bottom surface of the main bolt without additional treatment, magnetic force is uniformly applied through the plurality of magnetic attraction points, and the stability in the measurement process is ensured. In addition, damage of an individual power-losing electromagnet can less affect the service life of the whole device. The device is further provided with a modularized movable power source, energization and demagnetization can be achieved according to requirements, a battery of the movable power source can be replaced at any time, the device is less interfered by power supply factors during disassembly, the whole device can be conveniently and rapidly disassembled from the main bolts, and the detection efficiency of each main bolt is improved. Therefore, the main line construction period for overhauling the shielding main pump of the power plant can be remarkably shortened, and high economic value is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of nuclear power technology, specifically relating to a bolt elongation measuring device. Background Technology

[0002] The main bolts of the AP1000 reactor's canned motor main pump are installed in an inverted manner. When preloaded, the main bolts undergo elastic deformation (elongation). Properly controlling this elongation is crucial for ensuring the safety and reliability of the joint. Insufficient or excessive elongation will affect the joint's performance, potentially leading to leaks or other malfunctions. Therefore, ensuring the main bolt elongation is within the correct range is essential.

[0003] Traditional methods for measuring bolt elongation primarily rely on mechanical measuring tools, such as micrometers, calipers, and specially designed elongation measuring instruments. These methods measure bolt elongation through physical contact during tightening, providing intuitive and easily understandable results. Operators can directly observe the measured values. These tools are relatively economical, with low maintenance and calibration costs, and are suitable for various environmental conditions. Even under extreme conditions (such as high temperature and high humidity), effective measurements can be performed as long as the tools themselves are functioning properly. However, these methods depend heavily on the operator's extensive experience and a solid theoretical foundation, making them highly reliant on human factors and posing risks such as radiation exposure.

[0004] With advancements in technology, modern measuring tools and techniques are increasingly being applied to the measurement of bolt elongation. For example, laser ranging utilizes laser technology for non-contact measurement, reducing human error. Ultrasonic testing devices measure bolt length changes by emitting and receiving ultrasonic signals. Automated and remote monitoring systems, combining sensor technology and data processing systems, enable real-time monitoring and recording of bolt elongation, improving work efficiency and reducing the risk of worker exposure to hazardous environments. However, because the measurement accuracy of main bolts needs to reach 0.01 mm, this method cannot currently be used to measure the elongation of main bolts.

[0005] For the reasons mentioned above, it is urgent to improve the accuracy and safety of main bolt elongation measurement. Utility Model Content

[0006] To overcome the problems existing in related technologies, a bolt elongation measuring device is provided, the device comprising: a depth micrometer, a base, an outer cylinder, a spring, a measuring head, and a core rod;

[0007] The base includes a base plate, a frame, multiple de-energized electromagnets, a first connector, and a mobile power supply. The frame is fixedly connected to the base plate. A cavity is set in the middle of the frame. Multiple insertion slots are set around the cavity in the frame. A de-energized electromagnet is installed in each insertion slot. Each de-energized electromagnet is electrically connected to the first connector set on the outside of the frame through the circuit in the frame. The upper surfaces of each de-energized electromagnet are located on the same horizontal plane.

[0008] A measuring rod is mounted on the upper surface of the depth micrometer. Rotating a knob allows the measuring rod to extend and retract axially, and the extension / retraction length can be read using a scale. The base plate is fixedly connected to the upper surface of the depth micrometer, and the cavity of the base can accommodate the axial extension and retraction of the measuring rod. The lower end of the outer cylinder is fixedly connected to the upper surface of the frame, and the outer cylinder cavity is axially connected to the inner cavity. The measuring head is connected to the upper end of the outer cylinder via a spring. A core rod is located inside the outer cylinder, and its upper end passes through a spring and is fixedly connected to the lower end of the measuring head. The lower end of the core rod is opposite to the upper end of the measuring rod.

[0009] Each de-energized electromagnet possesses magnetism when not energized, attracting the bottom surface of the main bolt. This attracts the base to the bottom surface of the main bolt, causing the measuring head to abut against the bottom of the measuring hole in the main bolt. When the length of the main bolt changes, it will cause the base and outer cylinder to displace relative to the core rod, controlling the measuring rod to extend and abut against the bottom end of the core rod. The scale of the measuring rod is used to indicate the current deformation of the main bolt.

[0010] The power bank is equipped with a second connector that matches the first connector. When the first connector and the second connector are connected, the power bank can energize each de-energized electromagnet and demagnetize it, allowing the entire device to be removed from the main bolt.

[0011] In one possible implementation, the first and second connectors are magnetic connectors.

[0012] In one possible implementation, the power bank is powered by one or more batteries connected in series.

[0013] In one possible implementation, a de-energized electromagnet is detachably installed in each socket.

[0014] In one possible implementation, multiple supports are fixedly mounted on the upper surface of the base frame, and the upper surface of each support is located on the same horizontal plane as the upper surface of each de-energized electromagnet.

[0015] In one possible implementation, one or more gaskets are detachably mounted between each support and the upper surface of the frame.

[0016] In one possible implementation, the base is a columnar structure, with each de-energized electromagnet evenly distributed around the axis of the base.

[0017] In one possible implementation, a support is placed between every two de-energized electromagnets.

[0018] The beneficial effects of this disclosure are as follows: The bolt elongation measuring device provided by this disclosure utilizes multiple de-energized electromagnets that naturally possess magnetic attraction, allowing them to firmly adhere to the bottom surface of the main bolt without additional processing. The uniform application of magnetic force through multiple magnetic attraction points ensures stability during the measurement process. Furthermore, damage to individual de-energized electromagnets has minimal impact on the overall lifespan of the device. The device is also equipped with a modular, portable power supply, which can be powered on and demagnetized as needed. The battery of the portable power supply is replaceable at any time, minimizing interference from power supply factors. This facilitates quick removal of the entire device from the main bolt, improving the efficiency of testing each main bolt. Consequently, it can significantly shorten the main maintenance timeline for power plant canister pumps, demonstrating high economic value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a bolt elongation measuring device shown in an embodiment of this disclosure.

[0020] Figure 2 This is a schematic diagram of the base in a bolt elongation measuring device according to an embodiment of the present disclosure.

[0021] In the picture:

[0022] 1-Measuring head; 2-Spring; 3-Core rod; 4-Guide sleeve; 5-Outer cylinder; 6-Base; 7-Depth micrometer;

[0023] 61-Base plate; 62-Frame; 63-Power-off electromagnet; 64-Support; 65-First connector; 66-Counterhead screw;

[0024] 67-Pressure plate. Detailed Implementation

[0025] The present disclosure will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] Unless otherwise defined, the technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains; the terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the term "comprising" and any variations thereof in this disclosure are intended to cover non-exclusive inclusion. Clearly, the embodiments described in this disclosure are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0027] In this disclosure, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0028] Figure 1 This is a schematic diagram of a bolt elongation measuring device according to an embodiment of this disclosure. Figure 2 This is a schematic diagram of the base in a bolt elongation measuring device according to an embodiment of this disclosure, as shown below. Figure 1 and Figure 2 As shown, the device includes a depth micrometer 7, a base 6, an outer cylinder 5, a spring 2, a measuring head 1, and a core rod 3.

[0029] The base 6 includes a base plate 61, a frame 62, multiple de-energized electromagnets 63, a first connector 65, and a power supply. The frame 62 is fixedly connected to the base plate 61. A cavity is provided in the middle of the frame 62. Multiple insertion slots are arranged around the cavity in the frame 62. A de-energized electromagnet 63 is installed in each insertion slot. Each de-energized electromagnet 63 is electrically connected to the first connector 65 located on the outside of the frame 62 through the wiring inside the frame 62 (for example, the first connector 65 can be fixedly installed on the outside of the frame 62 by a pressure plate 67 and a countersunk screw 66). The upper surfaces of each de-energized electromagnet 63 are located on the same horizontal plane.

[0030] The depth micrometer 7 includes a measuring rod, which extends and retracts by rotating a knob. The extension and retraction length of the measuring rod can be read using a scale. The base plate 61 of the base 6 is fixedly connected to the upper end face of the measuring rod on the depth micrometer 7, and the cavity of the base 6 can accommodate the axial extension and retraction of the measuring rod. The lower end of the outer cylinder 5 is fixedly connected to the upper surface of the frame 62, and the cavity of the outer cylinder 5 is axially connected to the cavity of the frame 62. The lower end of the spring 2 is fixedly connected to the upper end of the outer cylinder 5. The lower end of the measuring head 1 is fixedly connected to the upper end of the spring 2. The core rod 3 is located inside the cavity of the outer cylinder 5, and its upper end passes through the spring 2 and is fixedly connected to the lower end of the measuring head 1; the lower end of the core rod 3 is opposite to the upper end of the measuring rod.

[0031] Each de-energized electromagnet 63 possesses magnetism when not energized, attracting the bottom surface of the main bolt. This attracts the base 6 to the bottom surface of the main bolt, causing the measuring head 1 to abut against the bottom of the measuring hole in the main bolt. When the length of the main bolt changes, it will cause the base 6 and the outer cylinder to displace relative to the core rod 3, controlling the measuring rod to extend and abut against the bottom end of the core rod. The scale of the measuring rod is used to indicate the current deformation of the main bolt.

[0032] The power supply is equipped with a second connector that matches the first connector 65. When the first connector 65 and the second connector are connected, the power supply can energize each de-energized electromagnet 63 and demagnetize it, thereby facilitating the separation of the entire device from the main bolt.

[0033] The bolt elongation measuring device disclosed herein utilizes multiple de-energized electromagnets that naturally possess magnetic attraction, allowing them to firmly adhere to the bottom surface of the main bolt without additional processing. The uniform application of magnetic force through multiple magnetic attraction points ensures stability during the measurement process. Furthermore, damage to individual de-energized electromagnets has minimal impact on the overall lifespan of the device. The device is also equipped with a modular, portable power supply, which can be powered on and demagnetized as needed. The battery of the portable power supply is replaceable at any time, minimizing power supply interference during disassembly. This facilitates rapid removal of the entire device from the main bolt, improving the efficiency of testing each main bolt. Consequently, it can significantly shorten the main maintenance timeline for power plant canned motor pumps, demonstrating high economic value.

[0034] In one possible implementation, the first and second connectors are magnetic connectors, which facilitates quick connection to a portable power supply.

[0035] In one possible implementation, the power bank is powered by multiple batteries connected in series.

[0036] In one possible implementation, a de-energized electromagnet 63 is detachably installed in each insertion slot. This modular design allows for the replacement of damaged de-energized electromagnets 63 at any time, increasing the overall lifespan of the device. Furthermore, the number of de-energized electromagnets 63 can be adjusted according to the weight of the overall device and the actual condition of the main bolt being measured, ensuring the stability of the engagement and further effectively preventing the overall device from falling.

[0037] In one possible implementation, multiple supports 64 are fixedly mounted on the upper surface of the frame 62 of the base 6. The upper surface of each support 64 is on the same horizontal plane as the upper surface of each de-energized electromagnet 63, serving to support the surface of the main bolt. One or more shims are detachably installed between each support 64 and the upper surface of the frame 62 to adjust the axial height of the upper surface of each support 64.

[0038] In one possible implementation, the base 6 is a columnar structure, with each de-energized electromagnet 63 evenly distributed around the axis of the base 6, and a support 64 is provided between every two de-energized electromagnets 63. This allows the attraction force of the base 6 to be applied more evenly.

[0039] In one possible implementation, such as Figure 1 As shown, the outer cylinder 55 includes multiple sections, which are interconnected by guide sleeves 44, thereby reducing the deformation of the outer cylinder 5 and guiding the core rod 3.

[0040] In one application example, the following steps are used to measure the main bolt:

[0041] Step 1: Insert the measuring head and outer cylinder into the measuring hole of the main bolt, and magnetically connect the upper surfaces of the multiple de-energized electromagnets to the bottom surface of the main bolt to support the entire measuring tool.

[0042] Step 2: Adjust the depth micrometer so that the measuring rod extends until the measuring head is against the bottom of the measuring hole of the main bolt. At this time, read the extension length of the measuring rod and record it as X1.

[0043] Step 3: Connect the second connector of the power bank to the first connector on the side of the base, so that the multiple de-energized electromagnets are energized and lose their magnetism, and remove the entire device from the main bolt.

[0044] Step 4: Heat and stretch the main bolt. After stretching, repeat steps 1 and 2 to read the extension length of the measuring rod, and record it as X2. The difference between X2 and X1 is taken as the elongation of the main bolt after heating and stretching.

[0045] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A bolt elongation measuring device, characterized by, The device comprises a depth micrometer, a base, an outer cylinder, a spring, a measuring head and a core rod. The base comprises a bottom plate, a frame, a plurality of de-energized electromagnets, a first connector and a mobile power supply; the frame is fixedly connected to the bottom plate, a cavity is arranged in the middle of the frame, a plurality of plug-in slots are arranged around the cavity in the frame, one de-energized electromagnet is installed in each plug-in slot, each de-energized electromagnet is electrically connected to the first connector arranged on the outer side of the frame through a line in the frame, and the upper surfaces of the de-energized electromagnets are located on the same horizontal plane. The upper end surface of the depth micrometer is provided with a measuring rod, the measuring rod is axially extended or retracted by rotating a knob, and the length of the measuring rod after extension or retraction can be read by a scale; the bottom plate of the base is fixedly connected to the upper end surface of the depth micrometer, and the cavity of the base can accommodate the axial extension or retraction of the measuring rod; the lower end of the outer cylinder is fixedly connected to the upper surface of the frame, and the cylinder cavity of the outer cylinder is axially communicated with the cavity; the measuring head is connected to the upper end of the outer cylinder through the spring; the core rod is arranged in the outer cylinder, the upper end of the core rod is fixedly connected to the lower end of the measuring head through the spring; and the lower end of the core rod is opposite to the upper end of the measuring rod. Each de-energized electromagnet has magnetism in the unpowered state, is attracted to the bottom surface of the main bolt, thereby attracting the base to the bottom surface of the main bolt, and making the measuring head abut against the inner bottom of the measuring hole of the main bolt; when the length of the main bolt changes, the base and the outer cylinder will be displaced relative to the core rod, the measuring rod is controlled to abut against the bottom end of the core rod after elongation, and the scale of the measuring rod is used to indicate the current deformation of the main bolt. The mobile power supply is provided with a second connector matched with the first connector, and when the first connector is connected to the second connector, the mobile power supply can power each de-energized electromagnet and lose magnetism, and the whole device can be detached from the main bolt.

2. The apparatus of claim 1, wherein, The first connector and the second connector are magnetic connectors.

3. The apparatus of claim 1, wherein, The mobile power supply is provided with one or more series-connected batteries.

4. The apparatus of claim 1, wherein, Each de-energized electromagnet is detachably installed in each plug-in slot.

5. The apparatus of claim 1, wherein, A plurality of supports are fixedly installed on the upper surface of the frame of the base, and the upper surfaces of the supports and the upper surfaces of the de-energized electromagnets are located on the same horizontal plane.

6. The apparatus of claim 1, wherein, One or more shims are detachably installed between each support and the upper surface of the frame.

7. The apparatus of claim 1, wherein, The base is a columnar structure, and the de-energized electromagnets are uniformly distributed around the axis of the base.

8. The apparatus of claim 7, wherein, One support is arranged between each two de-energized electromagnets.

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