Fatigue life test device for metal bellows for vacuum arc-extinguishing chamber

Abstract

The invention discloses a corrugated pipe high-speed fatigue test device with an air pressure dynamic compensation function. The end part of a supporting guide rod penetrates through a test object area and an air chamber compensation area and then is connected with a driving rod; a corrugated pipe test object is arranged in the test object area, one end of the corrugated pipe test object is fixed on the inner wall of the test object area, the other end of the corrugated pipe test object is fixed on the supporting guide rod, and the air valve is communicated with the corrugated pipe test object through a first air pipe; an expansion joint is arranged in the air chamber compensation area, one end of the expansion joint is fixed to the inner wall of the air chamber compensation area, and the other end of the expansion joint is fixed to the supporting guide rod. The contraction direction of the expansion joint is opposite to the contraction direction of the corrugated pipe test object, the expansion joint is communicated with the corrugated pipe test object through a second air pipe, and the device can improve the precision of the pure mechanical fatigue performance test of the corrugated pipe.

Description

Technical Field

[0001] This invention belongs to the technical field of mechanical performance testing equipment, and relates to a fatigue life testing device for metal bellows used in vacuum interrupters. Background Technology

[0002] Vacuum interrupters, also known as vacuum switch tubes, are core components of medium and high voltage power switches. Their core function is to achieve safe circuit interruption and current suppression through the high vacuum environment inside the tube. They are characterized by high-efficiency arc extinguishing, strong insulation performance, and reliable structure, and are widely used in power, industrial, and special environment power distribution systems.

[0003] The core component of a vacuum interrupter, the metal bellows, endures severe combined mechanical and pressure loads during the opening and closing operations of the circuit breaker. To accurately assess its service life, fatigue testing must be conducted in the laboratory. However, existing testing methods generally face a technical challenge when simulating actual operating conditions with internal and external pressure differences: as the bellows specimen undergoes axial reciprocating motion, the volume of the sealed gas chamber it connects to changes periodically. According to the gas law, this volume change inevitably leads to pressure fluctuations.

[0004] This pressure fluctuation generates an additional, displacement-dependent axial aerodynamic force, superimposed on the preset mechanical driving force. On the one hand, this additional force increases the total load that the drive system needs to overcome, resulting in unnecessary energy consumption; on the other hand, and more importantly, this unstable aerodynamic force interferes with the precise application of purely mechanical fatigue loads, potentially causing test results to deviate from reality, thus affecting the accuracy and reliability of bellows fatigue life assessment. Therefore, eliminating or effectively suppressing the influence of this additional aerodynamic force is crucial to improving the accuracy of pressurized fatigue testing. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-speed fatigue testing device for bellows with dynamic air pressure compensation, which can improve the accuracy of the pure mechanical fatigue performance test of bellows.

[0006] To achieve the above objectives, this invention discloses a high-speed fatigue testing device for bellows with dynamic air pressure compensation, comprising an air valve, a drive rod, a sample area, an air chamber compensation area, and two air pipes; the end of the support guide rod passes through the sample area and the air chamber compensation area and is connected to the drive rod. A corrugated tube sample is provided in the sample area. One end of the corrugated tube sample is fixed to the inner wall of the sample area, and the other end of the corrugated tube sample is fixed to the support guide rod. The air valve is connected to the corrugated tube sample through the first air pipe. An expansion joint is provided within the air chamber compensation area. One end of the expansion joint is fixed to the inner wall of the air chamber compensation area, and the other end is fixed to the support guide rod. The contraction direction of the expansion joint is opposite to the contraction direction of the bellows sample. The expansion joint is connected to the bellows sample through a second air pipe.

[0007] Furthermore, it also includes a workbench, on which five support partitions are arranged in sequence. The first and second support partitions form a sample area, the second and third support partitions form an air chamber compensation area, the fourth and fifth support partitions form a spring storage and reset area, and the outer side of the fifth support partition forms a crank release drive area.

[0008] Furthermore, an air pressure hood is provided between the first support partition and the second support partition. One end of the air pressure hood is connected to the side of the first support partition, and the other end of the air pressure hood is connected to the side of the second support partition. The end of the support guide rod passes through the first support partition, the second support partition, the third support partition, and the fourth support partition and is connected to the drive rod. One end of the bellows sample is fixed to the first support partition through the first bellows flange, and the other end of the bellows sample is fixed to the support guide rod through the second bellows flange.

[0009] Furthermore, both the bellows flange and the bellows sample are fitted onto the support guide rod.

[0010] Furthermore, guide sleeves are provided between the support guide rod and both the first and second support partitions.

[0011] Furthermore, within the gas chamber compensation area, the second and third support partitions are connected by several first set of fixing rods. One end of the expansion joint is fixed to the side of the third support partition through the first expansion joint flange, and the other end of the expansion joint is fixed to the support guide rod through the second expansion joint flange. The support guide rod passes through the expansion joint and the expansion joint flange.

[0012] Furthermore, within the spring storage and reset area, one end of the drive rod is connected to the end of the support guide rod via a pin, and the other end of the drive rod passes through the fourth and fifth support partitions and is connected to a connecting rod. A spring and two spring seats are sleeved on the drive rod, wherein one end of the spring is fixed to the side of the fifth support partition via the first spring seat, and the other end of the spring is connected to the second spring seat.

[0013] Furthermore, a nylon pad is provided on the side of the fourth support partition, the drive rod passes through the nylon pad, and the second spring seat is directly opposite the nylon pad.

[0014] Furthermore, the crank release drive area is equipped with a motor and a motor base. The motor is mounted on the motor base, which is fixed on the worktable. The output shaft of the motor is connected to one end of the connecting rod via the crankshaft. The other end of the connecting rod is connected to a release pin via a bearing. The release pin engages in a groove on the connecting rod.

[0015] Furthermore, the workbench is provided with a release base, and the release base is provided with a release plate. The upper surface of the release plate is an inclined surface, and the release pin is located on the release plate.

[0016] The present invention has the following beneficial effects: In the specific operation of the bellows high-speed fatigue testing device with dynamic air pressure compensation described in this invention, one end of the bellows specimen is fixed to the inner wall of the specimen area, and the other end is fixed to the support guide rod. One end of the expansion joint is fixed to the inner wall of the air chamber compensation area, and the other end is fixed to the support guide rod. The contraction direction of the expansion joint is opposite to that of the bellows specimen. When the bellows specimen is stretched, causing its internal volume to increase, the expansion joint is compressed synchronously, and its internal volume decreases. This dynamic compensation of "one increase and one decrease" greatly suppresses the change in the total volume of the entire connected air chamber, thereby significantly reducing the fluctuation of gas pressure, basically offsetting the influence of additional aerodynamic force on the drive system, ensuring the purity of the test load, and improving the accuracy of the pure mechanical fatigue performance test of the bellows.

[0017] Furthermore, when the linkage moves to the preset position, the inclined surface on the release plate will lift the release pin upward, achieving instantaneous disengagement. In practical applications, the disengagement stroke can be precisely set by adjusting the position of the release plate on the release base to adapt to different working conditions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a structural diagram of the present invention; Figure 2 This is a structural diagram of the sample region in this invention; Figure 3 This is a schematic diagram illustrating the coordinated operation of the spring-loaded reset and crank release drive areas.

[0020] Among them, 1 is the bellows sample; 2 is the bellows flange; 3 is the guide sleeve; 4 is the support guide rod; 5 is the support partition; 6 is the fixing rod; 7 is the air pressure cover; 8 is the air pipe; 9 is the air valve; 10 is the sealing ring; 11 is the pin; 12 is the expansion joint; 13 is the expansion joint flange; 14 is the spring; 15 is the spring seat; 16 is the nylon pad; 17 is the drive rod; 18 is the Teflon sliding sleeve; 19 is the positioning pin; 20 is the motor; 21 is the motor base; 22 is the crankshaft; 23 is the connecting rod; 24 is the trip pin; 25 is the trip plate; 26 is the trip base; 27 is the worktable; and 28 is the bearing. Detailed Implementation

[0021] 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, not all, of the embodiments of the present invention. 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.

[0022] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0023] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0024] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0025] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0026] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0029] Example 1 refer to Figure 1 and Figure 2 The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to the present invention includes an air valve 9, a drive rod 17, a sample area, an air chamber compensation area, and two air pipes 8; the end of the support guide rod 4 passes through the sample area and the air chamber compensation area and is connected to the drive rod 17; a bellows sample 1 is provided in the sample area, one end of the bellows sample 1 is fixed to the inner wall of the sample area, and the other end of the bellows sample 1 is fixed to the support guide rod 4, and the air valve 9 is connected to the bellows sample 1 through the first air pipe 8; an expansion joint 12 is provided in the air chamber compensation area, wherein one end of the expansion joint 12 is fixed to the inner wall of the air chamber compensation area, and the other end of the expansion joint 12 is fixed to the support guide rod 4; the contraction direction of the expansion joint 12 is opposite to the contraction direction of the bellows sample 1, and the expansion joint 12 is connected to the bellows sample 1 through the second air pipe 8.

[0030] During operation, when the bellows specimen 1 is stretched, causing its internal volume to increase, the expansion joint 12 is simultaneously compressed, causing its internal volume to decrease. This dynamic compensation of "one increase and one decrease" significantly reduces the fluctuation of gas pressure, basically offsets the influence of additional aerodynamic force on the drive system, ensures the purity of the test load, and improves the accuracy of the pure mechanical fatigue performance test of the bellows.

[0031] Example 2 To further improve this application, refer to Figure 1 and Figure 2 The high-speed fatigue testing device for bellows with dynamic air pressure compensation described in this invention includes a bellows specimen 1, a bellows flange 2, a guide sleeve 3, a support guide rod 4, a support partition 5, a fixing rod 6, an air pressure cover 7, an air pipe 8, an air valve 9, a sealing ring 10, a pin 11, an expansion joint 12, an expansion joint flange 13, a spring 14, a spring seat 15, a nylon pad 16, a drive rod 17, a Teflon sliding sleeve 18, a positioning pin 19, a motor 20, a motor base 21, a crankshaft 22, a connecting rod 23, a trip pin 24, a trip plate 25, a trip base 26, a worktable 27, and a bearing 28. Five support partitions 5 are arranged sequentially on the workbench 27. The first support partition 5 and the second support partition 5 form a sample area, the second support partition 5 and the third support partition 5 form an air chamber compensation area, the fourth support partition 5 and the fifth support partition 5 form a spring 14 storage and reset area, and the outer side of the fifth support partition 5 forms a crank release drive area.

[0032] In the sample area, a pressure hood 7 is provided between the first support partition 5 and the second support partition 5. One end of the pressure hood 7 is connected to the side of the first support partition 5, and the other end of the pressure hood 7 is connected to the side of the second support partition 5. The end of the support guide rod 4 passes through the first support partition 5, the second support partition 5, the third support partition 5, and the fourth support partition 5 and is connected to one end of the drive rod 17. A sealing ring 10 is provided between the support guide rod 4 and the first and second support partitions 5. One end of the corrugated tube sample 1 is fixed to the first support partition 5 through the first corrugated tube flange 2, and the other end of the corrugated tube sample 1 is fixed to the support guide rod 4 through the second corrugated tube flange 2. The corrugated tube flange 2 and the corrugated tube sample 1 are sleeved on the support guide rod 4. The air valve 9 is connected to the pressure hood 7 and the corrugated tube sample 1 through the first air pipe 8. In addition, guide sleeves 3 are provided between the support guide rod 4 and the first support partition 5 and the second support partition 5. The guide sleeves 3 enable the support guide rod 4 to run in a straight line and avoid radial displacement.

[0033] In the air chamber compensation area, the second support partition 5 and the third support partition 5 are connected by several first set of fixing rods 6. An expansion joint 12 is provided in the air chamber compensation area. One end of the expansion joint 12 is fixed to the side of the third support partition 5 through the first expansion joint flange 13, and the other end of the expansion joint 12 is fixed to the support guide rod 4 through the second expansion joint flange 13. The support guide rod 4 passes through the expansion joint 12 and the expansion joint flange 13. The contraction direction of the expansion joint 12 is opposite to the contraction direction of the bellows specimen 1. The expansion joint 12 is connected to the bellows specimen 1 through the second air pipe 8. When the bellows specimen 1 is stretched during operation, causing its internal volume to increase, the expansion joint 12 is compressed synchronously, and its internal volume decreases. This dynamic compensation of "one increase and one decrease" greatly suppresses the change in the total volume of the entire connected air chamber, thereby significantly reducing the fluctuation of gas pressure, basically offsetting the influence of additional aerodynamic force on the drive system, ensuring the purity of the test load, and improving the accuracy of the pure mechanical fatigue performance test of the bellows.

[0034] In the spring-loaded reset area, one end of the drive rod 17 is connected to the end of the support guide rod 4 via a pin 11. The other end of the drive rod 17 passes through the fourth and fifth support partitions 5 and is connected to the drive connecting rod 23. A spring 14 and two spring seats 15 are sleeved on the drive rod 17. One end of the spring 14 is fixed to the side of the fifth support partition 5 via the first spring seat 15, and the other end of the spring 14 is connected to the second spring seat 15. A nylon pad 16 is provided on the side of the fourth support partition 5, through which the drive rod 17 passes. The second spring seat 15 faces the nylon pad 16 for cushioning. In addition, the drive rod 17 is provided with a positioning pin 19 to constrain the drive rod 17 to only reciprocate linearly. Teflon sleeves 18 are provided between the drive rod 17 and the fourth and fifth support partitions 5 to reduce friction.

[0035] In the crank release drive area, the motor 20 is mounted on the motor base 21, the motor base 21 is fixed on the worktable 27, the output shaft of the motor 20 is connected to one end of the connecting rod 23 via the crankshaft 22, and the other end of the connecting rod 23 is connected to the release pin 24 via the bearing 28.

[0036] The workbench 27 is provided with a release base 26, and the release base 26 is provided with a release plate 25. The upper surface of the release plate 25 is an inclined surface, and the release pin 24 is located on the release plate 25.

[0037] refer to Figure 3During operation, motor 20 drives connecting rod 23 to pull to the right, and trip pin 24 engages with drive rod 17, slowly pulling it to the right while simultaneously compressing spring 14 to store energy. When connecting rod 23 reaches the preset position, the inclined surface on trip plate 25 lifts trip pin 24 upward, achieving instantaneous disengagement. The energy stored in spring 14 is released instantly, propelling the entire drive rod 17-support guide rod 4 system to move rapidly to the left, completing a high-speed stretch of the bellows sample 1. By adjusting the position of trip plate 25 on trip base 26, the disengagement stroke can be precisely set to adapt to different working conditions.

[0038] The complete working process of this invention is as follows: After setting the test pressure through the air valve 9, the motor 20 is started, and the device performs one cycle of "slow energy storage stretching - high-speed unhooking release". This cycle is repeated continuously until the preset number of times is reached or the bellows specimen 1 experiences fatigue failure, thereby completing its life assessment.

[0039] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0040] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0041] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A high-speed fatigue testing device for bellows with dynamic air pressure compensation, characterized in that, It includes a gas valve (9), a drive rod (17), a sample area, a gas chamber compensation area, and two gas pipes (8); the end of the support guide rod (4) passes through the sample area and the gas chamber compensation area and is connected to the drive rod (17); The test sample area is provided with a corrugated pipe test sample (1). One end of the corrugated pipe test sample (1) is fixed to the inner wall of the test sample area, and the other end of the corrugated pipe test sample (1) is fixed to the support guide rod (4). The air valve (9) is connected to the corrugated pipe test sample (1) through the first air pipe (8). An expansion joint (12) is provided in the air chamber compensation area. One end of the expansion joint (12) is fixed to the inner wall of the air chamber compensation area, and the other end of the expansion joint (12) is fixed to the support guide rod (4). The contraction direction of the expansion joint (12) is opposite to the contraction direction of the bellows sample (1). The expansion joint (12) is connected to the bellows sample (1) through the second air pipe (8).

2. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 1, characterized in that, It also includes a workbench (27), on which five support partitions (5) are arranged in sequence. Among them, the first support partition (5) and the second support partition (5) form a sample area, the second support partition (5) and the third support partition (5) form an air chamber compensation area, the fourth support partition (5) and the fifth support partition (5) form a spring storage and reset area; and the outer side of the fifth support partition (5) forms a crank release drive area.

3. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 2, characterized in that, A pressure hood (7) is provided between the first support partition (5) and the second support partition (5). One end of the pressure hood (7) is connected to the side of the first support partition (5), and the other end of the pressure hood (7) is connected to the side of the second support partition (5). The end of the support guide rod (4) passes through the first support partition (5), the second support partition (5), the third support partition (5), and the fourth support partition (5) and is connected to the drive rod (17). One end of the corrugated pipe sample (1) is fixed to the first support partition (5) through the first corrugated pipe flange (2), and the other end of the corrugated pipe sample (1) is fixed to the support guide rod (4) through the second corrugated pipe flange (2).

4. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 3, characterized in that, The bellows flange (2) and the bellows sample (1) are both fitted onto the support guide rod (4).

5. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 3, characterized in that, A guide sleeve (3) is provided between the support guide rod (4) and the first support partition (5) and the second support partition (5).

6. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 2, characterized in that, Within the gas chamber compensation area, the second support partition (5) and the third support partition (5) are connected by several first set of fixing rods (6). One end of the expansion joint (12) is fixed to the side of the third support partition (5) through the first expansion joint flange (13), and the other end of the expansion joint (12) is fixed to the support guide rod (4) through the second expansion joint flange (13). The support guide rod (4) passes through the expansion joint (12) and the expansion joint flange (13).

7. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 2, characterized in that, Within the spring storage and reset area, one end of the drive rod (17) is connected to the end of the support guide rod (4) via a pin (11). The other end of the drive rod (17) passes through the fourth support partition (5) and the fifth support partition (5) and is connected to a connecting rod (23). A spring (14) and two spring seats (15) are sleeved on the drive rod (17). One end of the spring (14) is fixed to the side of the fifth support partition (5) via the first spring seat (15), and the other end of the spring (14) is connected to the second spring seat (15).

8. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 7, characterized in that, A nylon pad (16) is provided on the side of the fourth support partition (5), the drive rod (17) passes through the nylon pad (16), and the second spring seat (15) is directly opposite the nylon pad (16).

9. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 7, characterized in that, The crank release drive area is provided with a motor (20) and a motor base (21). The motor (20) is mounted on the motor base (21), and the motor base (21) is fixed on the worktable (27). The output shaft of the motor (20) is connected to one end of the connecting rod (23) via the crankshaft (22). The other end of the connecting rod (23) is connected to a release pin (24) via a bearing (28). The release pin (24) is engaged in the groove on the connecting rod (23).

10. The high-speed fatigue testing device for bellows with dynamic air pressure compensation according to claim 9, characterized in that, The workbench (27) is provided with a release base (26), and the release base (26) is provided with a release plate (25). The upper surface of the release plate (25) is an inclined surface, and the release pin (24) is located on the release plate (25).

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