Fastening tool for connecting insulating pull rod and double-thread screw

Abstract

The invention discloses a fastening tool for connecting an insulating pull rod and a double-thread screw, which is applied to the technical field of electrical equipment assembly, and is characterized in that one end of a fastening rod is provided with a fastening cavity, and the insulating pull rod is provided with a fastening block; a smaller extreme value line, a datum line and a larger extreme value line are sequentially arranged on the side wall of the fastening rod from the end close to the fastening cavity; a sleeving hole is formed in the datum plate, the datum plate is arranged on the fastening rod in a sleeving mode through the sleeving hole, and a gap is formed between the sleeving hole and the fastening rod; the datum plate is further provided with a datum plane. When the double-thread screw and the internal thread screw hole of the insulating pull rod are in a standard fastening state, the reference surface is flush with the reference line; in the fastening process, the reference plate is fixed to the set position of the end face of the solid-sealed polar pole, the fastening cavity is connected to the fastening block in a sleeving mode, the fastening rod is rotated to drive the insulation pull rod to rotate synchronously till the insulation pull rod is tightened, and the position of the reference plate falls into the area between the large extreme value line and the small extreme value line. Operation is easy and convenient, standardized fastening is achieved, and stable and reliable connection quality is ensured.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment assembly technology, and in particular to a fastening fixture for connecting an insulating tie rod and a double-ended screw. Background Technology

[0002] In the assembly of solid-sealed poles of 24kV and below, the insulating tie rod is connected to the moving conductive rod of the solid-sealed pole through a double-ended screw, directly driving the arc-extinguishing chamber to complete closing and opening. Traditional threaded connections often rely on operator experience or torque value judgment, which is easily affected by human factors. However, this connection bears both mechanical and electrical loads, and its assembly quality has a decisive impact on the overall performance of the circuit breaker.

[0003] After assembly, components such as insulating tie rods, double-ended screws, conductive blocks, and moving conductive rods may experience cumulative positive and negative deviations. This can lead to excessive deviations in the exposed length of the insulating tie rod from the mounting surface of the solid-sealed pole, resulting in the exposed threads of the insulating tie rod screw being too long or too short after the solid-sealed pole is connected to the circuit breaker mechanism. If the exposed threads are too short, sufficient engagement length cannot be guaranteed, increasing the risk of loosening during operation; if the exposed threads are too long, interference with the placement plane during the break-in test can cause the screw to bend or the threads to undergo plastic deformation.

[0004] There are clear limits on the eccentricity of the insulating tie rod for the solid-sealed pole: ≤5mm for a solid-sealed pole ≤1250A, and <2mm for a solid-sealed pole >1250A. In actual assembly, if there is a lack of centering limit, a lateral force will be generated when the torque wrench is applied, causing additional eccentricity in the tie rod. The deviation between the moving conductive rod and the axis of the mechanism drive shaft will amplify the impact force at the moment of closing, causing the bounce time to exceed the standard, or even exceed the industry standard limit. Currently, production lines generally use the torque of loosening the heat sink fastening of the 10kV solid-sealed pole to adjust the closing bounce time caused by component misalignment. However, after the heat sink screw is loosened, the pressure between the solid-sealed pole and the heat sink decreases, and the vacuum interrupter will oscillate slightly under the impact of opening and closing. The screw is subjected to lateral alternating shear, which easily leads to fatigue fracture or thread stripping, increasing the after-sales failure rate.

[0005] In conclusion, how to effectively solve the above problems is an urgent issue that needs to be addressed by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a fastening fixture for connecting an insulating tie rod and a double-ended screw. It has a reasonable structure, is easy to operate, can achieve standardized fastening, and ensures stable and reliable connection quality.

[0007] To solve the above-mentioned technical problems, the present invention provides a fastening fixture for connecting an insulating tie rod and a double-ended screw, wherein the double-ended screw is threadedly connected to the internal threaded hole of the insulating tie rod, comprising:

[0008] A fastening rod has a fastening cavity at one end, and a fastening block that mates with the fastening cavity is provided on the insulating pull rod; the side wall of the fastening rod is provided with a small extreme value line, a baseline line, and a large extreme value line in sequence from the end closest to the fastening cavity.

[0009] A reference plate is provided with a fitting hole, through which the reference plate is fitted onto the fastening rod, and there is a gap between the fitting hole and the fastening rod; the reference plate is also provided with a reference surface; when the double-ended screw and the internal threaded hole of the insulating pull rod are in the standard tightening state, the reference surface is flush with the reference line;

[0010] During the tightening process, the reference plate is fixed at a set position on the end face of the sealing pole, the tightening cavity is sleeved on the tightening block, and the insulating pull rod is rotated synchronously by rotating the tightening rod until the insulating pull rod is tightened and the height position of the reference surface falls into the area between the larger extreme value line and the smaller extreme value line, thus completing the standardized tightening.

[0011] Optionally, the insulating rod further includes a threaded rod extending to the outer end of the fastening block; the fastening rod has an axial clearance hole communicating with the fastening cavity, and the threaded rod extends into the clearance hole during the fastening process.

[0012] Optionally, the bottom wall of the fastening cavity is abutted against and positioned against the end face of the fastening block; when the top surface of the insulating pull rod is flush with the reference line, the thread engagement length of the double-ended screw and the insulating pull rod is at the nominal value; the extreme value line and the extreme value line correspond to the highest and lowest allowable positions of the top surface of the insulating pull rod in the qualified fastening state, respectively, to visually determine the fastening range.

[0013] Optionally, the fastening rod has a through hole on its side wall, and the top surface of the insulating rod protrudes from the lower edge of the through hole; a comparison plate parallel to the reference plane is fixed to the top surface of the insulating rod, and the vertical distance from the comparison plate to the reference plane is the assembly deviation value of the actual fastening length of the insulating rod relative to the standard fastening length.

[0014] Optionally, the end of the comparison plate is provided with a through groove, the axis of which is parallel to the axis of the fastening rod. A telescopic ruler is installed in the through groove, and the free end of the telescopic ruler can extend along the axis of the fastening rod and abut against the reference surface. The zero mark of the telescopic ruler is located at the free end of the comparison plate. The axial deviation of the insulating pull rod relative to the standard fastening position can be directly obtained by reading the telescopic ruler.

[0015] Optionally, a support plate parallel to and in contact with the reference surface is fixed to the free end of the telescopic ruler, and the tilt angle error is eliminated by the support plate being in contact with the reference surface.

[0016] Optionally, the support plate and the reference surface are magnetically attached together.

[0017] Optionally, the through hole extends through both sides of the fastening rod, the comparison plate spans the through hole and extends to the outside of both sides, and the telescopic ruler is provided at one or both ends of the comparison plate.

[0018] Optionally, the outer wall of the fastening rod is engraved with a straight scale with the reference line as the zero point, and each scale value directly corresponds to the axial assembly deviation of the insulating rod relative to the standard fastening position.

[0019] Optionally, the reference plate is provided with a connection hole, and the end face of the solidified pole has an insert with a threaded hole pre-embedded in it;

[0020] The fastening fixture also includes:

[0021] The bearing has an outer ring that is interference-fitted with the connecting hole, and an inner ring with a polygonal hole.

[0022] The connecting screw has a polygonal block formed at one end that is interference-fitted with the polygonal hole, and an external thread at the other end that is screwed into the threaded hole of the insert. The axis of the connecting screw coincides with the axis of the solid-sealing pole.

[0023] This invention provides a fastening fixture for connecting an insulating pull rod and a double-ended screw. The internal threaded hole of the insulating pull rod is aligned with the second screw for initial screwing. Then, the fastening cavity of the fastening rod is fitted onto the fastening block on the insulating pull rod, forming a torque transmission path. The operator rotates the fastening rod, causing the insulating pull rod to rotate synchronously, moving it axially towards the sealing pole, gradually tightening the threaded connection.

[0024] During rotation, the operator continuously observes the relative position changes of the reference surface of the reference plate and the three lines on the fastening rod. As the insulating rod is screwed in, the fastening rod moves axially relative to the reference plate, and the scale line aligned with the reference surface gradually moves closer to the reference line from its initial position. When the tightening becomes noticeable, it indicates that the threaded connection is nearing its limit. At this point, rotation should be stopped, and the final position of the reference surface should be observed. If the reference surface is exactly flush with the reference line, it represents the ideal standard tightening state; if it falls between the larger and smaller extreme values, it is still considered acceptable; if it exceeds this range, adjustments or reoperation are required until the requirements are met. The entire process requires no torque wrench or depth gauge; standardized tightening can be completed visually, greatly improving operational efficiency and consistency, ensuring that each tightening is repeatable and traceable.

[0025] Thanks to the aforementioned structure, the fastening fixture of this application maps the thread insertion amount, which is difficult to measure directly, into an easily observable scale range. It transforms the difficulty of applying force in a closed space into a conventional wrench operation at the open rod end, and converts the abstract degree of tightening into an intuitive position comparison. This lowers the operational threshold and the probability of misjudgment, achieves visualized and standardized fastening, improves production efficiency, and ensures that the exposed dimensions of the insulating pull rod are qualified after it is properly tightened. This avoids both thread deformation caused by over-tightening and the risk of loosening caused by insufficient tightening. At the same time, any axial deviation caused by the accumulation of part tolerances will be amplified in real time to the scale area for the operator to correct immediately. Therefore, centering torque loading and exposed length inspection can be achieved simultaneously in the same process, which significantly improves assembly consistency and production efficiency, reduces the failure rate of circuit breakers with closing bounce time ≥2ms caused by tightening, and reduces after-sales costs. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a fastening fixture for connecting an insulating tie rod and a double-ended screw, provided in a specific embodiment of the present invention.

[0028] Figure 2 for Figure 1 A sectional view;

[0029] Figure 3 This is a schematic diagram showing the connection between the reference plate and the connecting screw.

[0030] Figure 4 This is a schematic diagram of the fastening rod.

[0031] Figure 5 This is a schematic diagram of the comparison plate structure;

[0032] Figure 6 This is a schematic diagram of the bearing structure;

[0033] Figure 7 This is a schematic diagram of the connecting screw.

[0034] Figure 8 This is a schematic diagram showing the connection between the fastening fixture used to connect the insulating tie rod and the double-ended screw, and the insulating tie rod.

[0035] Figure 9 This is a schematic diagram showing the connection between the fastening fixture used to connect the insulating tie rod and the double-ended screw and the sealing pole.

[0036] Figure label:

[0037] 1-Inner square hole; 2-Outer square head; 3-Scale line; 4-Comparison plate; 5-Through hole; 6-Fastening cavity; 21-Fastening handle; 22-Fastening rod; 23-Connecting screw; 24-Bearing; 25-Flat washer; 26-Base plate; 41-Fixed pole post; 42-Insulator; 43-Double-ended screw; 44-Insulating pull rod; 241-Polygonal hole; 231-Polygonal block. Detailed Implementation

[0038] The core of this invention is to provide a fastening fixture for connecting an insulating tie rod and a double-ended screw. It has a reasonable structure, is easy to operate, can achieve standardized fastening, and ensures stable and reliable connection quality.

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In one specific embodiment provided by the present invention, please refer to Figures 1-9 A fastening fixture for connecting an insulating tie rod and a double-ended screw, wherein the double-ended screw 43 is threadedly connected to the internal threaded hole of the insulating tie rod 44, comprising:

[0041] The fastening rod 22 has a fastening cavity 6 at one end, and the insulating pull rod 44 has a fastening block that cooperates with the fastening cavity 6; the side wall of the fastening rod 22 is provided with a small extreme value line, a baseline line, and a large extreme value line in sequence from the end closest to the fastening cavity 6.

[0042] The reference plate 26 has a fitting hole, through which the reference plate 26 is fitted onto the fastening rod 22, and there is a gap between the fitting hole and the fastening rod 22; the reference plate 26 also has a reference surface; when the double-ended screw 43 and the internal threaded hole of the insulating pull rod 44 are in the standard fastening state, the reference surface is flush with the reference line.

[0043] During the tightening process, the reference plate 26 is fixed at the set position on the end face of the sealing pole 41, the tightening cavity 6 is sleeved on the tightening block, and the insulating pull rod 44 is driven to rotate synchronously by rotating the tightening rod 22 until the insulating pull rod 44 is tightened and the height position of the reference surface falls into the area between the larger extreme value line and the smaller extreme value line, thus completing the standardized tightening.

[0044] It should be noted that the fastening fixture provides a repeatable, verifiable, and standardized operating paradigm for connecting the insulating tie rod 44 and the double-ended screw 43, significantly improving the quality stability and operation and maintenance safety of high-voltage electrical equipment assembly.

[0045] The fastening rod 22 is a long rod-shaped component with a fastening cavity 6 at one end. This cavity 6 is used to form a sleeve fit with the fastening block on the insulating pull rod 44 to achieve torque transmission. The geometry of the fastening cavity 6 should match the shape of the fastening block. It can typically be designed as a hexagonal, square, or spline structure capable of transmitting rotational torque, ensuring that rotating the fastening rod 22 synchronously drives the insulating pull rod 44 to complete the tightening operation of the threaded connection. The depth of the fastening cavity 6 is not limited and can be slightly greater than the thickness of the fastening block to prevent the cavity 6 from detaching from the fastening block during tightening. Alternatively, the depth of the cavity 6 can be equal to the thickness of the fastening block. The bottom surface of the fastening cavity 6 does not contact the outer contour of the insulating pull rod 44 to reduce interference and ensure accurate force transmission.

[0046] Three key visual reference lines are provided on the side wall of the fastening rod 22, which, starting from the end closest to the fastening cavity 6, are: the minimum extreme value line, the baseline line, and the maximum extreme value line. The baseline line, the maximum extreme value line, and the minimum extreme value line are preferably loop lines for easy viewing from different positions. These three lines are not simple scale marks, but constitute a visual judgment range. The three lines are distributed along the axial direction of the fastening rod 22, and their relative positional relationship determines the basis for judging the standard fastening state. That is, during the fastening process, it reflects the axial displacement state of the insulating pull rod 44 relative to the end face of the sealing pole 41 in real time, thereby indirectly characterizing the tightness of the connection between the insulating pull rod 44 and the double-ended threaded connection. The other end of the fastening rod 22 is provided with an external square head 2, which can be inserted into the fastening handle 21 to fasten the double-ended screw 43. The handle of the fastening handle 21 has an arc design and also has a non-slip protective sleeve. The other end of the fastening rod 22 can also be provided with an inner square hole 1. A torque wrench can be inserted into the inner square hole 1 to check the tightening torque of the double-ended screw 43.

[0047] When installed, the reference plate 26 abuts against the end face of the solid-sealed pole column 41 and is temporarily fixed by means of the existing inserts 42 or bolts on the solid-sealed pole column 41. Thus, the end face of the solid-sealed pole column 41 is extended near the tooling scale area and becomes a reference line perpendicular to the axis of the arc extinguishing chamber. The reference plate 26 is of a plate-like structure and is provided with a sleeving hole for sleeving the reference plate 26 on the fastening rod 22, with a gap left between the two. This gap ensures that the reference plate 26 does not rotate with the fastening rod 22 during the fastening process, and the reference plate 26 remains relatively stationary axially, so it can always maintain the same spatial height. Preferably, the edge of the sleeving hole is chamfered. The reference plate 26 is also provided with a reference surface, which is of a planar structure and is used to fit with the end face of the solid-sealed pole column 41 or be fixed at a set position, serving as the spatial reference datum for the entire system. The role of the reference surface is to provide a stable and visible reference plane. By comparing the relative positions with the three lines on the fastening rod 22, it is judged whether the fastening reaches the preset standard state.

[0048] By replacing the fastening cavity 6 and the reference plate 26 with different sizes, different specifications of the combination of the insulating pull rod 44 and the double-headed screw 43 can be adapted; the relative positions of the three lines can be preset or adjusted according to different connection requirements, realizing the standardized operation of multi-type products.

[0049] Since the second screw of the double-headed screw 43 is in threaded connection with the internal thread screw hole of the insulating pull rod 44, when the insulating pull rod 44 is rotated, it will displace axially, approaching or departing from the solid-sealed pole column 41. This axial displacement directly reflects the depth of the screw thread insertion, and thus determines the pre-tightening force and the fastening state of the connection. Through pre-calibration, when the connection reaches the ideal standard fastening state, the axial position of the insulating pull rod 44 corresponds to the reference line on the fastening rod 22 being flush with the reference surface of the reference plate 26. At this time, the connection is neither too loose nor too tight and is in the best mechanical and electrical performance state.

[0050] In order to cope with the manufacturing tolerances, material deformations or operation errors that may occur in actual working conditions, a fault tolerance judgment interval is introduced in this tooling, that is, a larger extreme value line and a smaller extreme value line are respectively set on both sides of the reference line, forming an allowable range interval. If the reference surface is within this interval after fastening, it is regarded as qualified for standardized fastening. If the reference surface is lower than the smaller extreme value line, it indicates that the insulating pull rod 44 is screwed in too deep, which may cause over-tightening, thread damage or excessive force on the insulating pull rod 44; if it is higher than the larger extreme value line, it means that the screwing-in is insufficient, the connection is too loose, and there is a risk of loosening or unreliable conduction. This three-line system constitutes a simple but efficient visual tolerance zone judgment system, and quality control can be completed by naked-eye observation without additional measuring tools.

[0051] In actual operation, firstly, the first screw of the double-ended screw 43 is pre-fixed onto the moving conductive rod of the solidified pole 41 to complete the electrical circuit connection. Then, the internal threaded hole of the insulating pull rod 44 is aligned with the second screw for initial tightening. At this time, the reference plate 26 is fixed at a predetermined position on the end face of the solidified pole 41. This predetermined position can be the end face itself, or it can be ensured through auxiliary devices such as the connecting screw 23 that the reference plate 26 does not shift or rotate during tightening, maintaining its spatial stability. Next, the fastening rod 22 is fitted into the through hole on the reference plate 26, and then the fastening cavity 6 of the fastening rod 22 is fitted into the fastening block on the insulating pull rod 44, forming a torque transmission path. The operator rotates the fastening rod 22, causing the insulating pull rod 44 to rotate synchronously, moving it axially towards the solidified pole 41, gradually tightening the threaded connection.

[0052] During rotation, the operator continuously observes the relative position changes of the reference surface of the reference plate 26 and the three lines on the fastening rod 22. As the insulating pull rod 44 is continuously screwed in, the fastening rod 22 moves axially relative to the reference plate 26, and the scale line 3 aligned with the reference surface gradually moves closer to the reference line from its initial position. When the feel becomes noticeably tighter, it indicates that the threaded connection is nearing its limit. At this point, rotation should be stopped, and the final position of the reference surface should be observed. If the reference surface is flush with the reference line, it represents the ideal standard tightening state; if it falls between the larger and smaller extreme values, it is still considered acceptable; if it exceeds this range, adjustments or reoperation are required until the requirements are met. The entire process does not require a torque wrench or depth gauge; standardized tightening can be completed by visual judgment, greatly improving operational efficiency and consistency, and ensuring that each tightening is repeatable and traceable.

[0053] Thanks to the aforementioned structure, the fastening fixture of this application maps the thread insertion amount, which is difficult to measure directly, into an easily observable scale range. It transforms the difficulty of applying force in a closed space into a conventional wrench operation at the open rod end, and converts the abstract degree of fastening into an intuitive position comparison. This lowers the operational threshold and the probability of misjudgment, achieves visualized and standardized fastening, improves production efficiency, and ensures that the exposed dimensions of the insulating pull rod 44 are qualified after being fastened in place. This avoids both thread deformation caused by over-tightening and the risk of loosening caused by insufficient screwing. At the same time, any axial deviation caused by the accumulation of part tolerances will be amplified in real time to the scale area for the operator to correct immediately. Therefore, centering torque loading and exposed length inspection can be achieved simultaneously in the same process, which significantly improves assembly consistency and production efficiency, reduces the non-conformity rate of circuit breaker closing bounce time ≥2ms caused by fastening, and reduces after-sales costs.

[0054] In some embodiments, the insulating rod 44 further includes a threaded rod extending to the outer end of the fastening block; the fastening rod 22 has an axial clearance hole communicating with the fastening cavity 6, and the threaded rod extends into the clearance hole during the fastening process.

[0055] It should be noted that the insulating pull rod 44 extends coaxially from the top surface of the fastening block as a threaded rod. Its outer diameter is smaller than that of the fastening block, and the thread direction can be the same as or opposite to that of the second screw. However, the pitch and thread profile are irrelevant to the main connection and serve only as redundant features for potential subsequent locking or marking. The original fastening cavity 6 of the fastening rod 22 remains unchanged, but a clearance hole is drilled along the axis at the bottom of the cavity. The hole diameter is larger than the outer diameter of the threaded rod, and the hole depth penetrates the entire rod body or reaches a sufficient length. There is a step abrupt change between the clearance hole and the fastening cavity 6. During tightening, the stepped surface abuts against the end face of the fastening block. The axis of the clearance hole coincides with that of the fastening cavity 6 to ensure smooth insertion of the threaded rod, avoid damage to the threads, and reduce weight.

[0056] When the thread is screwed in, the insulating pull rod 44 will move axially toward the sealing post 41. If there is a protrusion on the top of the insulating pull rod 44, it may collide with the end face of the fastening rod 22, resulting in false torque or distortion of the visible scale. After the addition of the clearance hole, the threaded rod enters the hole in advance, and its axial displacement is contained by the hole wall. The end face of the fastening rod 22 and the end face of the insulating pull rod 44 always maintain the designed distance. Therefore, the amount of movement of the baseline relative to the reference surface is entirely determined by the depth of the main thread, and will not be eaten or amplified by the extra length. In short, the clearance hole isolates the axial occupation of the threaded rod, so that the amount of movement of the baseline corresponds one-to-one with the engagement length of the main thread, avoiding visual judgment reflecting the true progress of the insulating pull rod 44 and the double-ended screw 43, and ensuring clear boundaries of standardized fastening.

[0057] In some embodiments, the bottom wall of the fastening cavity 6 is pressed against the end face of the fastening block for positioning; when the top face of the insulating pull rod 44 is flush with the reference line, the thread engagement length of the double-ended screw 43 and the insulating pull rod 44 is at the nominal value; the extreme value line and the extreme value line correspond to the highest and lowest allowable positions of the top face of the insulating pull rod 44 in the qualified fastening state, respectively, to visually determine the fastening range.

[0058] It should be noted that the fastening cavity 6 is responsible for circumferentially holding the fastening block. The depth of the fastening cavity 6 is now made to match the height of the fastening block, so that the bottom plane of the cavity and the top surface of the fastening block can completely fit together. This fitting surface becomes the new axial reference; that is, once the two end faces are pressed together, the axial position of the insulating pull rod 44 relative to the fastening rod 22 is locked, and any subsequent screwing action will immediately be reflected as the displacement of the fastening rod 22 relative to the reference surface. At this time, the top surface of the insulating pull rod 44 is defined as the observed feature, which forms a direct visual comparison relationship with the three scales on the fastening rod 22. That is, the nominal exposed length corresponds to the reference line position, and the maximum and minimum allowable exposed lengths correspond to the extreme value lines for larger and smaller values, respectively. In other words, wherever the top surface goes, that's where the scale is read. If the top surface stops at the reference line, it means the exposed length is exactly the nominal value; if it stops at the middle, it means it's within the tolerance zone; if it crosses either line, it's out of tolerance. This principle transforms the abstract thread engagement length into a planar position determination, which is quick and easy to identify.

[0059] In some embodiments, the side wall of the fastening rod 22 is provided with a through hole 5, and the top surface of the insulating pull rod 44 protrudes from the lower edge of the through hole 5. A comparison plate 4 parallel to the reference plane is fixed to the top surface of the insulating pull rod 44. The vertical distance from the comparison plate 4 to the reference plane is the assembly deviation value of the actual fastening length of the insulating pull rod 44 relative to the standard fastening length.

[0060] It should be noted that a through hole 5 is provided on the side wall of the fastening rod 22. The axis of the through hole 5 is perpendicular to the axis of the fastening rod 22. The lower edge of the through hole 5 is at the same height as the top surface of the insulating pull rod 44, or the lower edge of the through hole 5 is lower than the top surface of the insulating pull rod 44, and the top surface of the insulating pull rod 44 can be exposed from the lower edge of the through hole 5. The top surface of the insulating pull rod 44 is machined into a flat measuring reference, on which a thin comparison plate 4 is mounted. The comparison plate 4 extends horizontally outward, making the height of the top surface of the insulating pull rod 44 extend to the outside of the fastening rod 22, directly facing the reference surface. The comparison plate 4 is parallel to the reference surface, and a measurable gap is formed between the comparison plate 4 and the reference surface. The vertical distance of this gap is the assembly deviation value. Zero gap indicates that it is just standard fastened, and positive gap or negative gap indicates the direction and magnitude of the deviation, respectively.

[0061] Since the reference surface has been pre-fixed at the set position on the end face of the solid-sealing pole 41, any insufficient or excessive tightening will cause the comparison plate 4 to rise and fall accordingly, and the gap size will change linearly. Thus, the gap becomes a physical ruler of the assembly deviation. The gap width is equal to the actual axial deviation, making the height comparison more intuitive and reducing the magnification or reduction of readings caused by the tilt of the viewing angle.

[0062] In some embodiments, the end of the comparison plate 4 is provided with a through groove, the axial direction of the through groove is parallel to the axial direction of the fastening rod 22, a telescopic ruler is installed in the through groove, the free end of the telescopic ruler can extend along the axial direction of the fastening rod 22 and abut against the reference surface, the zero mark of the telescopic ruler is located at the free end of the comparison plate 4, and the axial deviation of the insulating pull rod 44 relative to the standard fastening position can be directly obtained by reading the telescopic ruler.

[0063] It is important to understand that a through slot is formed at the end of the comparison plate 4 furthest from the insulating pull rod 44. The axis of the slot is parallel to the axis of the fastening rod 22, and the width of the slot is slightly greater than the thickness of the telescopic ruler. The telescopic ruler is embedded in the slot, and its housing is fixed to the slot wall. The telescopic ruler can be a measuring tape. Pulling the free end makes it make end-face contact with the reference surface. The free end can extend in both upward and downward directions along the axial direction of the fastening rod 22. The zero mark of the telescopic ruler is set at the free end, and the scale at the interface between the telescopic ruler and the comparison plate 4 is the real-time axial deviation.

[0064] To reduce the swaying and skew of the telescopic ruler, it can be made of multiple interconnected telescopic rods. The entire ruler body remains parallel to the axis of the fastening rod 22 due to the guiding effect of the through groove. The length of a single telescopic rod segment is less than the depth of the through groove, ensuring that the telescopic ruler is nestled within the through groove and does not affect the measurement of small gaps.

[0065] In some embodiments, a support plate that is parallel and in contact with a reference surface is fixed to the free end of the telescopic ruler, and the tilting error is eliminated by the support plate being in contact with the reference surface.

[0066] It needs to be explained that a support plate is fixed to the outermost end of the telescopic ruler. The fixing method can be riveting, thread locking, or integral cutting and forming. The plane of the support plate is perpendicular to the axis of the ruler body. The surface area of ​​the support plate is sufficient to cover the actual contact area between the free end and the reference surface. The thickness is included in the scale of the telescopic ruler. For example, the side of the support plate that contacts the reference surface is the zero scale position.

[0067] The support plate moves towards the reference surface along with the telescopic ruler. When the support plate presses against the reference surface, even if there is a slight non-perpendicularity in the through groove or fastening rod 22, the support plate can automatically align itself through slight oscillation, making the plate surface fit against the reference surface. At this time, the axis of the telescopic ruler is forced to coincide with the normal of the reference surface, eliminating the need for manual correction and eliminating the true axial deviation after tilting. The scale reading thus corresponds to the true axial displacement, and the tilting error is offset by the structure itself. Surface contact prevents the ruler body from slipping due to point contact, keeping the scale exposure constant, and ensuring consistent results for the same operator or different operators.

[0068] In some embodiments, the support plate is magnetically attached to the reference surface.

[0069] It should be explained that the side of the support plate facing the reference surface is made of permanent magnet material, either embedded or entirely; the reference surface itself may be made of magnetizable metals such as carbon steel or stainless steel, or have magnetically conductive sheets inlaid in local areas. The magnetic strength is limited to a weak magnetic field that can be separated by hand, facilitating tool-free disassembly. The magnetic surface and the plate surface are on the same processing reference, ensuring that the direction of the magnetic force is strictly perpendicular to the reference surface and does not generate lateral components.

[0070] When the support plate approaches the reference surface with the telescopic ruler, the magnetic force pulls the two planes together in advance. Even if there is a brief fluctuation in the axial force applied by the hand, the magnetic adsorption can still maintain a tight contact. Any lateral force that attempts to tilt the ruler is offset by the frictional resistance generated by the magnetic force. The continuous surface contact ensures that the zero scale reference line does not move up and down with the change of the operator's force.

[0071] In some embodiments, the through hole 5 passes through both sides of the fastening rod 22, the comparison plate 4 spans the through hole 5 and extends to the outside of both sides, and one or both ends of the comparison plate 4 are provided with a telescopic ruler.

[0072] It should be noted that the through hole 5 on the side wall of the fastening rod 22 is rectangular or oblong, and runs horizontally through it, so that the rod wall forms two symmetrical openings at the front and back. The middle part of the comparison plate 4 still abuts against the top surface of the insulating tie rod 44. The comparison plate 4 spans across the through hole 5, and its two ends protrude outward from the outside of the fastening rod 22. A through groove parallel to the axis of the fastening rod 22 is opened at each end, and a telescopic ruler is installed in each groove. The zero mark of both telescopic rulers is set at the free end, and both free ends can extend out and abut against the reference surface.

[0073] The telescopic rulers on both sides measure values ​​simultaneously. If a difference occurs on one side due to viewing angle or local unevenness, the readings of the two rulers can be checked immediately. The operator can determine whether there is any eccentricity or tilt by taking the readings of the two rulers at the same moment. That is, the operator looks straight ahead and reads the scales on both sides: if the two readings are the same, it means that the assembly is not misaligned; if there is a difference, it can be immediately detected and the operation can be fine-tuned until the readings of the two rulers are consistent or fall within the allowable range, eliminating parallax or estimation errors that may be caused by visual inspection on one side.

[0074] In some embodiments, the outer wall of the fastening rod 22 is engraved with a straight scale with the reference line as the zero point, and each scale value directly corresponds to the axial assembly deviation of the insulating pull rod 44 relative to the standard fastening position.

[0075] It should be noted that the outer wall of the fastening rod 22 already had a baseline and extreme deviation lines. Now, these three lines are subdivided into a series of parallel short lines, forming a straight scale band parallel to the axis of the fastening rod 22. The baseline corresponds to the zero mark, and positive and negative deviation values ​​are marked upwards or downwards sequentially. The scale spacing corresponds one-to-one with the axial displacement of the insulating pull rod 44, requiring no conversion. The scale area is directly facing the operator's viewpoint, and the scale lines 3 can be arranged around half or the full circumference, allowing the operator to quickly find the corresponding reading from either the left or right side, adapting to confined cabinet spaces.

[0076] The insulating pull rod 44 and the fastening rod 22 are pressed together by their end faces to form a single unit; when the insulating pull rod 44 is screwed in, the fastening rod 22 undergoes axial displacement relative to the end face of the sealing pole 41. The reference surface remains fixed, and the scale strip on the wall of the fastening rod 22 slides across the edge of the reference surface; the edge of the reference surface becomes a pointer, and the scale value it aligns with is the current deviation.

[0077] The above structure eliminates the need for telescopic rulers, support plates, or magnetic components; measurements can be completed using only the existing rod wall and the reference surface. The edge of the reference surface and scale line 3 are within the same field of view, allowing for a single, level view to obtain the deviation value, thus eliminating the need for comparison and conversion steps.

[0078] In some embodiments, the reference plate 26 is provided with a connection hole, and a plurality of inserts 42 with threaded holes are pre-embedded on the end face of the sealing pole 41;

[0079] Fastening fixtures also include:

[0080] Bearing 24 has an outer ring that is interference-fitted with a connecting hole, and an inner ring with a polygonal hole 241.

[0081] The connecting screw 23 has a polygonal block 231 formed at one end that is interference-fitted with the polygonal hole 241, and an external thread at the other end that is screwed into the threaded hole of the insert 42. The axis of the connecting screw 23 coincides with the axis of the solid seal post 41.

[0082] It should be noted that several inserts 42 with threaded holes are evenly distributed along the circumference of the end face of the solid-sealed pole 41. The axis of the threaded holes is coaxial with the axis of the solid-sealed pole 41, and the hole opening is flush with the end face. The outer ring of the bearing 24 is press-fitted with the connecting hole of the reference plate 26; the inner ring does not have a round hole but has a polygonal hole 241, such as a hexagonal, square or spline hole.

[0083] One end of the connecting screw 23 is machined into a polygonal block 231 that interferes with the polygonal hole 241 of the inner ring of the bearing 24, ensuring torque transmission and preventing relative rotation. The other end is externally threaded and screws into the threaded hole of the insert 42. The connecting screw 23 can be a padlock screw, with a flat washer 25 at the root of the external thread to press against the end face of the inner ring of the bearing 24 and prevent axial movement. The position and axis of the connecting hole are coaxial with the position and axis of the insert 42, ensuring that the axis of the connecting screw 23 is coaxial with the axis of the threaded hole.

[0084] The connecting screw 23 is integrally connected to the inner ring of the bearing 24 via the polygonal block 231, and the outer ring of the bearing 24 is interference-fitted to the connecting hole of the reference plate 26. The connecting screw 23 can rotate under the rotational engagement of the inner and outer rings, thereby enabling the external thread of the connecting screw 23 to be screwed into the threaded hole of the insert 42, thus achieving the connection between the reference plate 26 and the end face of the solidified pole 41.

[0085] The axis of the mounting hole of the reference plate 26 coincides with the axis of the solid-sealing pole 41. The insulating tie rod 44 is fitted into the mounting hole with a small mounting gap, so that the axis of the solid-sealing pole 41 and the axis of the insulating tie rod 44 are aligned. This, in turn, enables the double-ended screw 43 and the insulating tie rod 44 to be aligned and fastened, solving the problem of inconsistent center lines when the double-ended screw 43 and the insulating tie rod 44 are fastened at the moving end of the vacuum interrupter, and reducing the probability of the circuit breaker closing bounce time failing to meet the requirements.

[0086] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0087] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fastening fixture for connecting an insulating tie rod and a double-ended screw, wherein the double-ended screw (43) is threadedly connected to the internal threaded hole of the insulating tie rod (44), characterized in that, include: The fastening rod (22) has a fastening cavity (6) at one end, and the insulating pull rod (44) has a fastening block that cooperates with the fastening cavity (6); the side wall of the fastening rod (22) is provided with a small extreme value line, a baseline line, and a large extreme value line in sequence from the end closest to the fastening cavity (6); A reference plate (26) is provided with a fitting hole. The reference plate (26) is fitted onto the fastening rod (22) through the fitting hole, and there is a gap between the fitting hole and the fastening rod (22). The reference plate (26) is also provided with a reference surface. When the double-ended screw (43) and the internal threaded hole of the insulating pull rod (44) are in the standard fastening state, the reference surface is flush with the reference line. During the tightening process, the reference plate (26) is fixed at the set position on the end face of the sealing pole (41), the tightening cavity (6) is sleeved on the fastening block, and the insulating pull rod (44) is driven to rotate synchronously by rotating the fastening rod (22) until the insulating pull rod (44) is tightened, and the height position of the reference surface falls into the area between the larger extreme value line and the smaller extreme value line, thus completing the standardized tightening.

2. The fastening fixture according to claim 1, characterized in that, The insulating pull rod (44) also includes a threaded rod extending to the outer end of the fastening block; the fastening rod (22) has an axial clearance hole that communicates with the fastening cavity (6), and the threaded rod extends into the clearance hole during the fastening process.

3. The fastening fixture according to claim 2, characterized in that, The bottom wall of the fastening cavity (6) is pressed against the end face of the fastening block for positioning; when the top surface of the insulating pull rod (44) is flush with the reference line, the thread engagement length of the double-ended screw (43) and the insulating pull rod (44) is at the nominal value; the extreme value line and the extreme value line correspond to the highest and lowest allowable positions of the top surface of the insulating pull rod (44) under qualified fastening conditions, respectively, for visual judgment of the fastening range.

4. The fastening fixture according to claim 3, characterized in that, The fastening rod (22) has a through hole (5) on its side wall, and the top surface of the insulating rod (44) protrudes from the lower edge of the through hole (5); a comparison plate (4) parallel to the reference plane is fixed on the top surface of the insulating rod (44), and the vertical distance from the comparison plate (4) to the reference plane is the assembly deviation value of the actual fastening length of the insulating rod (44) relative to the standard fastening length.

5. The fastening fixture according to claim 4, characterized in that, The end of the comparison plate (4) is provided with a through groove, the axial direction of the through groove is parallel to the axial direction of the fastening rod (22), a telescopic ruler is installed in the through groove, the free end of the telescopic ruler can extend along the axial direction of the fastening rod (22) and abut against the reference surface, the zero mark of the telescopic ruler is located at the free end of the comparison plate (4), and the axial deviation of the insulating pull rod (44) relative to the standard fastening position can be directly obtained by reading the scale body of the telescopic ruler.

6. The fastening fixture according to claim 5, characterized in that, The free end of the telescopic ruler is fixed to a support plate that is parallel and in contact with the reference surface. The support plate is connected to the reference surface to eliminate tilting error.

7. The fastening fixture according to claim 6, characterized in that, The support plate and the reference surface are magnetically attached together.

8. The fastening fixture according to claim 5, characterized in that, The through hole (5) passes through both sides of the fastening rod (22), the comparison plate (4) spans the through hole (5) and extends to the outside of both sides, and the telescopic ruler is provided at one or both ends of the comparison plate (4).

9. The fastening fixture according to claim 3, characterized in that, The outer wall of the fastening rod (22) is engraved with a straight scale with the baseline as the zero point. Each scale value directly corresponds to the axial assembly deviation of the insulating pull rod (44) relative to the standard fastening position.

10. The fastening fixture according to claim 1, characterized in that, The reference plate (26) is provided with a connection hole, and the end face of the solid-sealing pole (41) is pre-embedded with an insert (42) with a threaded hole. The fastening fixture also includes: The bearing (24) has an outer ring that is interference-fitted with the connecting hole, and an inner ring with a polygonal hole (241). The connecting screw (23) has a polygonal block (231) formed at one end that is interference-fitted with the polygonal hole (241), and an external thread at the other end that is screwed into the threaded hole of the insert (42). The axis of the connecting screw (23) coincides with the axis of the solid-sealing pole (41).

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