Electrical testing equipment

Abstract

To provide an electrical testing apparatus that maintains the airtightness of the pressure vessel while improving workability and safety when inserting and removing electrical components from the pressure vessel. [Solution] The electrical testing apparatus comprises a cylindrical pressure vessel capable of housing electrical components, a gate frame having a through hole communicating with the opening of the pressure vessel and sealed and connected to the pressure vessel, a plate switchable between a first state that blocks the through hole and a second state that opens the through hole, a plate drive unit that moves the plate forward and backward relative to the through hole, and a sealing member interposed between the plate and the gate frame. When the plate is held in the first state, pressure is applied to the pressure vessel, and the plate comes into close contact with the sealing member, keeping the pressure vessel in a sealed state.

Description

Technical Field

[0001] The present invention relates to an electrical testing apparatus used for testing electrical characteristics of electrical components.

Background Art

[0002] Generally, for electrical components (such as epoxy bushings (epoxy insulation sleeves)) used in high-voltage electrical equipment such as cable terminal connection parts, various electrical tests including commercial frequency withstand voltage tests, commercial frequency partial discharge tests, lightning impulse withstand voltage tests and the like are performed before use to confirm safety before they are put into use. If such electrical tests are performed in air, air discharge and surface flashover are likely to occur from protrusions on the voltage applying part and the test sample, corners, or attached foreign matters, so generally the test is performed with the electrical component placed inside a pressure vessel filled with insulating gas of high dielectric strength (see, for example, Patent Document 1).

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the conventional electrical testing apparatus as disclosed in Patent Document 1, electrical components are put into and taken out of the pressure vessel through an opening of the pressure vessel. The pressure vessel is sealed by attaching a cover plate to the opening with a large number of bolts. When putting electrical components into or taking them out of the pressure vessel, it is necessary to attach or remove a large number of bolts, which leads to poor workability. In addition, the cover plate is often heavy, and the attaching and detaching work relative to the pressure vessel may be dangerous.

[0005] An object of the present invention is to provide an electrical testing apparatus that can improve workability and safety when putting electrical components into and taking them out of the pressure vessel.

Means for Solving the Problem

[0006] The electrical testing apparatus according to the present invention is A cylindrical pressure vessel capable of housing electrical components, A gate frame having a through hole communicating with the opening of the pressure vessel and sealed and connected to the pressure vessel, A plate that can be switched between a first state in which the through hole is blocked and a second state in which the through hole is open, A plate drive unit that moves the plate forward and backward within the through hole, A sealing member interposed between the plate and the gate frame is provided, With the plate held in the first state, pressure is applied to the pressure vessel, causing the plate to come into close contact with the sealing member and the pressure vessel to be held in a sealed state. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve workability and safety when inserting and removing electrical components from the pressure vessel of an electrical testing apparatus. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an electrical testing apparatus according to a positional embodiment of the present invention. [Figure 2] Figures 2A and 2B are longitudinal cross-sectional views of the gate device cut along the axial direction. [Figure 3] Figure 3A is a cross-sectional view of AA in Figure 2A, and Figure 3B is a cross-sectional view of BB in Figure 2B. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] Figure 1 is a diagram showing the schematic configuration of an electrical testing apparatus 1 according to one embodiment of the present invention. Figures 2A and 2B are longitudinal cross-sectional views of the gate device 20 cut along the axial direction. Figure 3A is a cross-sectional view AA in Figure 2A, and Figure 3B is a cross-sectional view BB in Figure 2B.

[0011] The electrical testing apparatus 1 is equipment for performing electrical tests, such as commercial frequency partial discharge tests, using an electrical component W as a sample. The electrical component W used as a sample is, for example, a known bushing (sheath) equipped with a high-voltage electrode, an insulator made of epoxy resin or the like, and a mounting fitting, or a known epoxy seat equipped with an insulator made of epoxy resin or the like and a mounting fitting.

[0012] As shown in Figure 1, the electrical testing apparatus 1 comprises a pressure vessel 10 and a gate device 20. The pressure vessel 10 is a container in which the electrical component W to be used as a sample is placed. The gate device 20 is a device for opening and closing the opening 11 of the pressure vessel 10.

[0013] The pressure vessel 10 is a cylindrical container having a hollow section 13 extending in the axial direction, and is capable of withstanding high pressure (e.g., 0.2 to 0.5 MPa). One end of the pressure vessel 10 is open (open 11), and the other end is closed by a lid 12. The pressure vessel 10 is installed, for example, horizontally.

[0014] The pressure vessel 10 is equipped with a sample stage 14 on which, for example, an electrical component W can be placed. The sample stage 14 is connected to a voltage application unit 31, and a voltage can be applied to the electrical component W. The pressure vessel 10 is also connected to a gas supply unit 32, and a predetermined gas can be introduced.

[0015] The gate device 20 includes a gate frame 21, a plate 22, a plate drive unit 23, and a sealing member 24. The gate device 20 is connected to the opening 11 side of the pressure vessel 10.

[0016] The gate frame 21 has a through-hole 211. The diameter of the through-hole 211 is designed to substantially match the diameter of the opening 11 of the pressure vessel 10. The gate frame 21 is hermetically connected to the opening 11 side of the pressure vessel 10 such that the opening 11 of the pressure vessel 10 and the through-hole 211 communicate with each other. Specifically, the connection portion between the flange on the side opposite to the side where the lid 12 of the pressure vessel 10 is attached and the flange of the gate frame 21 connected to the flange is connected in an airtight or liquid-tight manner so that the insulating medium inside the pressure vessel 10 does not leak. The electrical component W is taken into and out of the pressure vessel 10 through the through-hole 211 of the gate frame 21 connected to the opening 11 of the pressure vessel 10. The axial length of the gate frame 21 is short enough not to hinder the work of taking the electrical component W into and out of the pressure vessel 10.

[0017] The gate frame 21 communicates with the through-hole 211 and has a slit 212 that allows the plate 22 to advance and retreat relative to the through-hole 211. Further, the gate frame 21 has a guide groove 213 continuous with the slit 212 at the peripheral edge of the through-hole 211. The guide groove 213 is formed in an arc shape on the peripheral surface of the through-hole 211. When the plate 22 moves, the guide groove 213 fits with the peripheral edge of the plate 22 and guides the advance and retreat of the plate 22.

[0018] The plate 22 advances and retreats relative to the through-hole 211 through the slit 212 of the gate frame 21, and opens and closes the through-hole 211. The state where the plate 22 blocks the through-hole 211 is referred to as a "first state" (see Fig. 2A), and the state where the plate 22 opens the through-hole 211 is referred to as a "second state" (see Fig. 2B). The size of the main surface of the plate 22 is larger than the diameter of the through-hole 211. Of the two main surfaces of the plate 22, the side facing the pressure vessel 10 is referred to as a "first plate surface 221", and the opposite side is referred to as a "second plate surface 222".

[0019] The planar shape of the plate 22 matches the shape of the guide groove 213 of the gate frame 21 (see Fig. 3A and Fig. 3B). In the first state, the plate 22 fits into the slit 212 and the guide groove 213.

[0020] The plate driving unit 23 is an actuator that moves the plate 22 forward and backward relative to the through-hole 211 of the gate frame 21. The plate driving unit 23 moves the plate 22 forward and backward, for example, in a direction orthogonal to the axial direction of the pressure vessel 10. In the present embodiment, the plate driving unit 23 causes the plate 22 to ascend and descend in the vertical direction with respect to the horizontally installed pressure vessel 10.

[0021] The plate driving unit 23 includes a power generating section 231 and an elevating shaft 232. The power generating section 231 converts energy into motion and transmits the motion to the elevating shaft 232. The plate 22 is attached to the lower end of the elevating shaft 232. As the elevating shaft 232 reciprocates in the vertical direction, the plate 22 ascends and descends, and the through-hole 211 of the gate frame 21 is opened and closed.

[0022] For the plate driving unit 23, for example, an air cylinder that converts energy of compressed air into linear motion can be applied. The air cylinder is relatively small and lightweight, can operate the plate 22 at high speed, and has high safety. Note that the plate driving unit 23 may be configured of a hydraulic cylinder or a drive motor, or may be configured to manually move the plate 22 forward and backward by operating a lever or a handle.

[0023] The seal member 24 is interposed between the plate 22 and the gate frame 21. For the seal member 24, for example, an O-ring, a lip seal, or a U-packing can be applied. The seal member 24 is in close contact with the plate 22 held in the first state, and can completely block the through-hole 211 (see FIG. 2A). A space closer to the pressure vessel 10 than the plate 22 in the hollow portion 13 of the pressure vessel 10 and the through-hole 211 is held in a sealed state (an airtight state in the present embodiment). The phrase "completely block the through-hole 211" means that there is no gap that allows an insulating medium to flow through the through-hole 211 by wrapping around the peripheral edge of the plate 22. The insulating medium is an insulating gas in the case of the present embodiment.

[0024] In this embodiment, the sealing member 24 is positioned on the side of the plate 22 facing the second plate surface 222 in the slit 212 and guide groove 213 of the gate frame 21. In other words, the sealing member 24 only needs to be positioned on the side of the plate 22 opposite to the pressure vessel 10, and does not need to be positioned on the same side as the pressure vessel 10.

[0025] Furthermore, the sealing member 24 only needs to be positioned so that it can be in close contact with the plate 22 under the pressure conditions during the electrical test, and may be positioned so that the sealing member 24 and the plate 22 do not rub against each other when the plate 22 moves forward and backward. In this case, deterioration of the sealing member 24 due to rubbing when the plate 22 moves forward and backward can be prevented, and durability is improved.

[0026] Alternatively, separate from the sealing member 24, a sealing member may be arranged in an annular shape on the side of the slit 212 of the gate frame 21 to seal the gap between the plate 22 and the slit 212. In this case, leakage of the insulating medium through the slit 212 can be prevented, thus preventing the sealing state (airtight state in this embodiment) of the pressure vessel 10 from being compromised.

[0027] In the electrical testing apparatus 1, when inserting or removing electrical components W into or from the pressure vessel 10, the plate 22 is held in the second state (see Figures 2B and 3B). The through-hole 211 of the gate frame 21 is opened, allowing the electrical components W to be easily inserted or removed through the through-hole 211.

[0028] In the electrical testing apparatus 1, when performing an electrical test, the plate 22 is held in a first state (see Figures 2A and 3A). In addition, insulating gas (e.g., N2 gas, dry air) is introduced from the gas supply unit 32 into the pressure vessel 10 until the pressure inside the pressure vessel 10 reaches a predetermined pressure (e.g., 0.3 MPa).

[0029] As insulating gas is introduced, the internal pressure of the pressure vessel 10 (including the space communicating with the hollow portion 13 of the pressure vessel 10) increases. The internal pressure of the pressure vessel 10 presses the plate 22 against the sealing member 24, completely sealing the through hole 211 and maintaining the test space in a sealed state (airtight state in this embodiment).

[0030] Then, a voltage is applied to the sample by the voltage application unit 31 to measure its electrical characteristics (for example, commercial frequency partial discharge voltage). By creating a high pressure inside the pressure vessel 10, the desired dielectric strength can be obtained, allowing for stable electrical testing without the occurrence of air discharge or surface flashing.

[0031] Furthermore, a plate housing section 25 is attached to the gate frame 21 in a sealed state so as to cover the slit 212. Specifically, the connection between the gate frame 21 and the plate housing section 25 is airtight or liquid-tight to prevent leakage of the internal insulating medium. The plate housing section 25 has a hollow section 251 capable of accommodating the plate 22 held in the second state. The lifting shaft 232 connected to the plate 22 passes through the shaft hole (not shown) of the plate housing section 25 and is connected to the power generating section 231.

[0032] A shaft seal 26 is interposed between the shaft hole of the plate housing 25 and the lifting shaft 232, sealing the shaft hole. Known sealing members such as gland packing, O-rings, or mechanical seals can be applied to the shaft seal 26.

[0033] During electrical testing, if the plate 22 tilts from its pressed position against the sealing member 24 under pressurized conditions, a gap may form between the slit 212 and the plate 22, causing the insulating medium to leak out and potentially compromising the airtight seal of the pressure vessel 10. In this embodiment, since the plate 22 moves within the sealed plate housing 25, even if a gap forms between the slit 212 and the plate 22, the airtight seal (in this embodiment, an airtight seal) of the pressure vessel 10 can be reliably maintained.

[0034] Thus, the electrical testing apparatus 1 according to this embodiment is equipped with the following features individually or in appropriate combinations.

[0035] In other words, the electrical testing apparatus 1 comprises a cylindrical pressure vessel 10 capable of housing electrical components W, a gate frame 21 having a through hole 211 communicating with an opening 11 of the pressure vessel 10 and sealed (airtight in this embodiment) connected to the pressure vessel 10, a plate 22 that can be switched between a first state that blocks the through hole 211 and a second state that opens the through hole 211, a plate drive unit 23 that moves the plate 22 forward and backward relative to the through hole 211, and a sealing member 24 interposed between the plate 22 and the gate frame 21. When the plate 22 is held in the first state, pressure is applied to the pressure vessel 10, and the plate 22 comes into close contact with the sealing member 24, holding the pressure vessel 10 in a sealed state (airtight in this embodiment).

[0036] According to the electrical testing apparatus 1, the electrical components W can be easily inserted and removed by moving the plate 22 forward and backward to open and close the through-hole 211, thus improving the work efficiency when inserting and removing the electrical components W. Furthermore, since there is no need to remove or attach the heavy lid when inserting and removing the electrical components W, the testing time can be significantly reduced.

[0037] Specifically, conventionally, it was necessary to suspend the heavy lid with a crane, align the bolt holes, and install and remove multiple bolts to secure the lid, paying attention to the order of operations such as performing them diagonally to ensure even tightening force, each time an electrical component W was to be inserted or removed. In this embodiment, these operations are not required, and it is only necessary to lower the plate 22 to return to the first state, thus significantly reducing the test time.

[0038] Furthermore, conventionally, when moving the heavy lid while suspending it with a crane, or when attaching or removing the lid, care had to be taken to prevent the lid from falling. In this embodiment, this work is unnecessary, thus improving safety. Also, conventionally, when attaching the heavy lid, at least two people were required. In this embodiment, since the heavy lid is not required, the work can be done by one person, significantly improving work efficiency. In addition, because the plate 22 is pressed against the sealing member 24 and tightly adheres due to the pressure applied to the pressure vessel 10, the airtightness (airtightness in this embodiment) of the pressure vessel 10 required for electrical testing is not compromised.

[0039] In the electrical testing apparatus 1, the gate frame 21 has a slit 212 that allows the plate 22 to move forward and backward within the through hole 211, and a guide groove 213 formed on the periphery of the through hole 211, continuous with the slit 212. The sealing member 24 is interposed between the second plate surface 222 of the plate 22 (the plate surface opposite to the pressure vessel 10) and the slit 212 and guide groove 213. This allows the plate 22 and the sealing member 24 to be easily brought into close contact using the pressure applied to the pressure vessel 10.

[0040] In the electrical testing apparatus 1, the plate drive unit 23 has a lifting shaft 232 (shaft member) connected to the plate 22, and the linear motion of the lifting shaft 232 moves the plate 22 forward and backward in a direction perpendicular to the axial direction of the pressure vessel 10. This makes it easy to realize a configuration in which the plate 22 moves forward and backward while maintaining the airtightness (airtightness in this embodiment) of the pressure vessel 10.

[0041] In the electrical testing apparatus 1, the plate drive unit 23 is an air cylinder. This allows the plate 22 to be easily moved forward and backward by switch operation, thereby opening and closing the through hole 211 and inserting and removing the electrical components W.

[0042] The electrical testing apparatus 1 further comprises a plate housing section 25 that is sealed and connected to the gate frame 21 so as to cover the slit 212 and capable of accommodating the plate 22 held in the second state, and a shaft seal 26 interposed between the plate housing section 25 and the lifting shaft 232 (shaft member). This ensures that even if a gap occurs between the slit 212 and 22, the sealed state (airtight state in this embodiment) of the pressure vessel 10 can be reliably maintained.

[0043] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0044] For example, in this embodiment, the pressure vessel 10 and the gate frame 21 of the gate device 20 are formed separately, but the gate frame 21 may be integrally provided with the pressure vessel 10.

[0045] For example, in the embodiment, the pressure vessel 10 is installed in a horizontal position, but the pressure vessel 10 may also be installed in a vertical position. Specifically, the pressure vessel 10 may be configured to have a cylindrical pressure vessel body and branched cylindrical parts protruding from the circumferential surface of the pressure vessel body, and a gate device 20 may be connected to the opening of the branched cylindrical part so that the pressure vessel body is in a vertical position. In this case, gate devices 20 may be provided at multiple locations on the vertically positioned pressure vessel 10, and a structure may be provided in which multiple sealing points are provided by the plate 22. Also, when changing the plate 22 from the second state to the first state, in the embodiment the plate 22 was lowered from top to bottom, but the plate 22 may also be raised from bottom to top. When the pressure vessel 10 is installed in a vertical position, by shortening the branched cylindrical part, the work of replacing the electrical components W inside the pressure vessel 10 through the through hole 211 of the gate frame 21 with the plate 22 in the second state can be performed more easily than when the pressure vessel 10 is installed in a horizontal position. Furthermore, in a pressure vessel 10 installed in a vertical position, a gate device 20 may be connected to the opening of the pressure vessel body such that the plate 22 moves horizontally.

[0046] In this embodiment, the sealing member 24 is placed on the side surface of the slit 212 and the guide groove 213. However, an annular projection may be provided near the slit 212 and the guide groove 213, protruding from the inner circumferential surface of the through hole 211, and the sealing member 24 may be placed on the side surface of the projection.

[0047] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0048] 1. Electrical testing apparatus 10 Pressure vessel 11 Aperture 13 Hollow part 20 Gate device 21 Gate Frame 22 plates 23 Plate drive unit 24 sealing member 25 Plate housing section 26 Axle seal

Claims

1. A cylindrical pressure vessel capable of housing electrical components, A gate frame having a through hole communicating with the opening of the pressure vessel and sealed and connected to the pressure vessel, A plate that can be switched between a first state in which the through hole is blocked and a second state in which the through hole is open, A plate drive unit that moves the plate forward and backward within the through hole, A sealing member interposed between the plate and the gate frame is provided, With the plate held in the first state, pressure is applied to the pressure vessel, and the plate comes into close contact with the sealing member, thereby maintaining the pressure vessel in a sealed state. Electrical testing equipment.

2. The gate frame has a slit that allows the plate to move forward and backward within the through hole, and a guide groove formed on the periphery of the through hole, continuous with the slit. The sealing member is interposed between the plate surface of the plate opposite to the pressure vessel and the slit and the guide groove. The electrical testing apparatus according to claim 1.

3. The plate drive unit has a shaft member connected to the plate, and the linear motion of the shaft member causes the plate to move back and forth in a direction perpendicular to the axial direction of the pressure vessel. The electrical testing apparatus according to claim 2.

4. The plate drive unit is an air cylinder. The electrical testing apparatus according to claim 3.

5. A plate housing section connected to the gate frame so as to cover the slit and capable of accommodating the plate held in the second state, The system includes a shaft seal interposed between the plate housing and the shaft member, The electrical testing apparatus according to claim 3.

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