Vacuum circuit breaker

Abstract

To provide a vacuum circuit breaker that can prevent damage to the manual mechanism. [Solution] A support pin 48 is fixed to a retaining frame 42 that holds the button shaft 24. In addition, an interlocking lever 46, which is connected to the button shaft 24 via a support cylinder 47, is supported by the support pin 48. This results in a simple structure in which the interlocking lever 46 is attached only to the retaining frame 42 side that holds the button shaft 24, and the interlocking lever 46 rotates smoothly around the support pin 48. As a result, excessive force is not applied to the support pin 48 when the push button 20 is operated, and the support pin 48 is less likely to be damaged.

Description

Technical Field

[0001] The present invention relates to the structure of a vacuum circuit breaker equipped with a mechanism for manually opening the circuit.

Background Art

[0002] As shown in Non-Patent Document 1 below, a circuit breaker (vacuum circuit breaker) that employs a vacuum valve to interrupt abnormal current generated during a short-circuit accident or a ground-fault accident and protects the power system is known.

Prior Art Documents

Patent Documents

[0003]

Non-Patent Document 1

[0004] The vacuum circuit breaker is housed in a cubicle installed in a distribution substation. As shown in FIG. 6, it generally consists of a main circuit section 2 that houses a vacuum valve and has a pair of main circuit conductors 1a, 1b at the rear, and an operation section 3 that houses an operating mechanism that automatically interrupts the conduction state by the vacuum valve in connection with an overcurrent relay (not shown).

[0005] The operating mechanism includes a latch mechanism section that locks and holds the open state of the vacuum valve. FIG. 7 shows the latch mechanism section B. 4 is an opening and closing shaft, and 5 is a latch lever that rotates together with the rotation of the opening and closing shaft 4. 6 is a latch roller that is rotatably attached by a bearing 8 around a roller shaft 7 fixed to the tip of the latch lever 5.

[0006] 9 shows a latch that locks and holds the latch lever 5 by placing the latch roller 6 on the upper part, and a latch part bearing 11 that enables the latch 9 to rotate around a rotation shaft 10 is attached to the lower part thereof.

[0007] Reference numeral 12 denotes a trip lever with one end fixed to a latch 9 and the other end engaged with a return spring 13. The return spring 13 is housed in a housing cylinder 15 with one end fixed to a base end 16 that moves within the housing cylinder 15, which is fixed on a mounting plate 14. The base end 16 is fixed to a shaft member 17 inside the housing cylinder 15, and one end of the shaft member 17 is attached to the trip lever 12.

[0008] 18 indicates a trip coil that, when energized, extends the movable pin 19 and pushes the trip lever 12.

[0009] As described above, the latch mechanism B is in the state shown in Figure 7, with the vacuum valve housed in the main circuit section 2 shown in Figure 6 closed. From this state, when an overcurrent relay (not shown) detects a current and current flows to the trip coil 18, the movable pin 19 of the trip coil 18 extends to the left in Figure 7, pushing the trip lever 12 against the elastic force of the return spring 13 as shown in Figure 8.

[0010] As a result, the latch 9, along with the trip lever 12, rotates counterclockwise around the rotation axis 10, causing the latch roller 6, which was locked and held on the latch 9, to detach from the latch 9 as it rotates the bearing 8, as shown in Figure 8, and reach the state shown in Figure 9.

[0011] The dropping action of the latch 9 rotates the opening / closing shaft 4 via the latch lever 5. This rotation of the opening / closing shaft 4 is transmitted to the main circuit section 2 shown in Figure 6, which instantaneously opens the vacuum valve within the main circuit section 2.

[0012] After opening the vacuum valve, the power to the trip coil 18 is released, and the movable pin 19 is retracted to the position shown in Figure 10. As a result, the trip lever 12 is pulled back by the elastic force of the return spring 13.

[0013] Figure 11 shows the manual mechanism C for manually opening the vacuum circuit breaker by manual operation of a push button 20, without energizing the trip coil 18. The push button 20 is held in place by inserting the button shaft 24 into insertion openings 22a and 23a formed in a pair of retaining pieces 22 and 23 of the retaining base 21. A return spring 25 is interposed between the push button 20 and one of the retaining pieces 22, and the operation of the push button 20 is performed by compressing the return spring 25. As a result, the button shaft 25 is pushed in the depth direction, passing through the insertion openings 22a and 23a of the pair of retaining pieces 22 and 23.

[0014] An interlocking pin 26 is mounted laterally on the button shaft 24, and the engagement grooves 27a and 28a of a pair of interlocking levers 27 and 28 are engaged with the interlocking pin 26. A hollow cylindrical connecting tube 29 is fixed to the central portion of the pair of interlocking levers 27 and 28, and a stopper pin 31, which is attached to one side of the stopper 30 that surrounds the trip lever 12, is inserted through the connecting tube 29.

[0015] When the push button 20 of the manual mechanism C is operated while the latch mechanism B is in the state shown in Figure 7, that is, with the vacuum circuit breaker closed, the button shaft 24 is pushed in the depth direction into the insertion openings 22a and 23a of the pair of retaining pieces 22 and 23. An interlocking pin 26 is fixed to the button shaft 24, and the interlocking pin 26 is engaged with the engagement grooves 27a and 28a of the pair of interlocking levers 27 and 28. As the button shaft 24 is pushed in, the interlocking levers 27 and 28 rotate around the stopper pin 31 in the direction of the arrow in Figure 11. Then, a push pin 32 fixed to one of the interlocking levers 28 pushes the trip lever 12.

[0016] At this time, the trip lever 12 moves from the state shown in Figure 7 to the state shown in Figure 12, resisting the elastic force of the return spring 13. In the state shown in Figure 12, the trip lever 12 is being pressed manually, so the movable pin 19 of the trip coil 18 is not extended.

[0017] When the trip lever 12 is pushed, the latch 9 rotates counterclockwise together with the trip lever 12, and the latch roller 6, which was locked and held on the latch 9, disengages and falls off the latch 9.

[0018] As a result, the opening / closing shaft 4 rotates counterclockwise via the latch lever 5, opening the vacuum valve in the main circuit section 2 shown in Figure 6.

[0019] When the operator releases their hand, the push button 20 returns to its original position due to the elastic force of the return spring 25, and the button shaft 24 is pulled back towards the operator. As a result, the push of the trip lever 12 by the push pin 32 is released, and the trip lever 12 returns from the position shown in Figure 12 due to the elastic force of the return spring 13. [Overview of the project] [Problems that the invention aims to solve]

[0020] Conventional manual mechanism C has a complex structure in which the interlocking levers 27 and 28 that constitute it are connected to both the button shaft 24 held by the holding base 21 and the stopper pin 31 of the stopper 30 which is not fixed to the holding base 21. Therefore, if the interlocking levers 27 and 28 do not rotate smoothly around the stopper pin 31, the force applied when manually operating the push button 20 will be excessively applied to the stopper pin 31, which could lead to damage to the stopper pin 31.

[0021] If the stopper pin 29 is damaged and tilted, the interlocking levers 27 and 28 will tilt relative to the button shaft 24, causing a malfunction in which the push button 18 will not return to its original position.

[0022] The present invention prevents the occurrence of the aforementioned problem and provides a vacuum circuit breaker in which the manual mechanism C is not damaged by the operation of the push button. [Means for solving the problem]

[0023] The invention according to claim 1 is an operating mechanism of a vacuum circuit breaker that closes and opens the fixed electrode and the movable electrode of a vacuum valve in response to an input / open command. In the operating mechanism, an opening / closing shaft lever that closes and opens the movable electrode through an insulating rod or a compression spring, an input coil that operates the opening / closing shaft lever, an opening / closing shaft that rotates the opening / closing shaft lever is fixed at one end, and a latch lever having a roller shaft pivotally attached with a latch roller rotatably at the other end, a latch that engages the latch roller and locks and holds the latch lever at the closing position, a trip lever extending from the latch, and a latch coil having a movable pin that starts when an overcurrent relay detects an abnormal current and automatically pushes the trip lever to release the engagement of the latch roller and moves the latch lever to the opening position, a linkage lever that manually pushes the trip lever, and a push button that operates the linkage lever are provided.

[0024] The invention according to claim 2 is configured such that the linkage lever according to claim 1 rotates about a support pin fixed to a holding frame that inserts and holds the button shaft of the push button, and engages an engagement groove formed at one end of the linkage lever with an interlocking pin attached to the button shaft, so as to rotate by manual operation of the push button.

[0025] The invention according to claim 3 is configured such that a guide groove is formed in a guide piece extending in the longitudinal direction of the button shaft in the holding frame according to claim 2, and a guide pin fixed to the button shaft is guided by the guide groove.

Advantages of the Invention

[0026] According to the invention of claim 1, the vacuum circuit breaker can be opened either electrically or manually.

[0027] According to the invention of claim 2, since the linkage lever operates by engaging with the interlocking pin fixed to the button shaft, the manual operation mechanism including the interlocking pin is difficult to be damaged by the operation of the push button.

[0028] According to the invention described in claim 3, since the guide pin attached to the button shaft is guided along the guide groove, the possibility of damage to the manual operation mechanism including the interlocking pin can be further reduced. [Brief explanation of the drawing]

[0029] [Figure 1] This is a front longitudinal cross-sectional view showing the vacuum valve constituting the vacuum circuit breaker of the present invention in a closed and locked state. [Figure 2] This is a front longitudinal cross-sectional view showing the vacuum valve constituting the vacuum circuit breaker of the present invention in an open state. [Figure 3] This is a front longitudinal cross-sectional view showing the vacuum valve constituting the vacuum circuit breaker of the present invention in a reclosed state. [Figure 4] A perspective view showing the manual operating mechanism that constitutes the vacuum circuit breaker of the present invention. [Figure 5] This is a magnified perspective view showing the main parts of the manual operating mechanism that constitutes the vacuum circuit breaker of the present invention. [Figure 6] This is a front view showing the external appearance of a vacuum circuit breaker. [Figure 7] This is a front view of the latch mechanism, showing the vacuum circuit breaker in a closed and locked state. [Figure 8] This is a front view showing the latch mechanism in the process of automatically opening a vacuum circuit breaker instantaneously. [Figure 9] This is a front view of the latch mechanism, showing the vacuum circuit breaker in an automatically instantaneous open state. [Figure 10] This is a front view of the latch mechanism, showing the vacuum circuit breaker in an automatically instantaneous open state. [Figure 11] This is a perspective view showing the manual operating mechanism that constitutes a conventional vacuum circuit breaker. [Figure 12] This is a front view of the latch mechanism of the vacuum circuit breaker, showing it in a manually opened state. [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described below with reference to Figures 1 to 5, 7 to 10, and 12. In Figures 1 to 5, the same parts as those described in Figure 6 will be denoted by the same reference numerals. As shown in Figure 1, the vacuum circuit breaker A of the present invention is generally composed of a main circuit section 2 equipped with a pair of main circuit conductors 1a and 1b at its rear, and an operating section 3 for closing / opening a vacuum valve 33 within the main circuit section 2.

[0031] The operating section 3 houses the latch mechanism B described in Figures 7 to 10 and 12, as well as an opening / closing shaft lever 34 that operates by the rotation of the opening / closing shaft 4 of the latch mechanism B, an operating rod 35 that operates by the movement of the opening / closing shaft lever 34, a compression spring 36, an operating lever 37, and a closing coil 38 equipped with a stroke pin 37 that pushes the opening / closing shaft lever 34 upward as shown in Figure 1 when energized, causing the opening / closing shaft lever 33 to rotate clockwise around the opening / closing shaft 4.

[0032] An insulating rod 40 is installed between the main circuit unit 2 and the operating unit 3, connecting the operating lever 37 and the movable electrode (not shown) of the vacuum valve 33. Power from the operating unit 3 moves the movable electrode of the vacuum valve 33 toward and away from a fixed electrode (not shown), thereby operating the vacuum valve 33 in the closing / opening operation.

[0033] The operation of the latch mechanism B housed in the operating unit 3 is as described in Figures 7 to 10 and 12. When the vacuum valve 33 shown in Figure 7 is in the closed state, if an abnormality occurs in the power system or the overcurrent relay detects an abnormal current, the trip coil 18 is activated and the movable pin 19 pushes the trip lever 12, as shown in Figure 8.

[0034] When the trip lever 12 is pressed, the latch 9 fixed to the trip lever 12 rotates around the rotation axis 10 due to the rotation of the latch bearing 11, causing the latch roller 6 to drop from the latch 9, and the state shown in Figure 9 is reached.

[0035] At this time, the latch lever 5 rotates the opening / closing shaft 4 counterclockwise in Figure 8. After rotating the opening / closing shaft 4 counterclockwise, the activation of the trip coil 18 is stopped and the movable pin 19 is retracted, causing the trip lever 12 to rotate clockwise around the rotation shaft 10 by the elastic force of the return spring 13, transitioning to the state shown in Figure 10.

[0036] Furthermore, as the opening / closing shaft 4 rotates counterclockwise, the opening / closing shaft lever 34 fixed to the opening / closing shaft 4 shown in Figure 1 also rotates counterclockwise, pulling down the operating rod 35 as shown in Figure 2. As a result, the left end of the operating lever 37 is pushed down by the elastic force of the compression spring 36, causing the operating lever 37 to rotate counterclockwise around the pivot shaft 41.

[0037] As a result, the right end of the operating lever 37 is pushed upward, and the movable electrode (not shown) of the vacuum valve 33 is pulled up via the insulating rod 40. This eliminates the contact between the movable electrode and the fixed electrode (opens the circuit), and the vacuum valve 33 is opened. Opening the vacuum valve 33 is used to isolate faulty systems, etc.

[0038] To close the vacuum valve 33 again, as shown in Figure 3, the stroke pin 37 is extended upward by energizing the closing coil 38, and the opening / closing shaft lever 34 is rotated clockwise around the opening / closing shaft 4.

[0039] This pushes the operating rod 35 upward, causing the operating lever 37 to rotate clockwise around the pivot shaft 41. The rotation of the operating lever 37 pushes down the movable electrode (not shown) of the vacuum valve 33 via the insulating rod 40 connected to its right end, bringing it into contact with the fixed electrode (closing the circuit). To increase the contact pressure between the fixed electrode and the movable electrode, the operating rod 34 rises further, compressing the contact spring 35.

[0040] When the vacuum valve 33 is re-closed, the extension of the stroke pin 37 of the closing coil 38 causes the opening / closing shaft lever 34 to rotate clockwise together with the opening / closing shaft 4. As a result, the latch lever 5, which is in the state shown in Figure 9, rotates clockwise, causing the latch roller 6 to contact the side of the latch 9 and move upward while rotating the bearing 8.

[0041] At this time, the latch 9 is pushed by the latch roller 6 and rotates counterclockwise around the rotation axis 10 against the elastic force of the return spring 13 via the trip lever 12. When the latch roller 6 reaches the top of the latch 9, the pushing force of the latch roller 6 on the latch 9 is released, the latch 9 rotates clockwise, and the latch roller 6 is locked and held on the latch 9.

[0042] Furthermore, the latch 9 rotates clockwise around the rotation axis 10 via the trip lever 12 and the elastic force of the return spring 13, transitioning to the state shown in Figure 7. In the embodiment shown in Figure 7, the vacuum valve 33 shown in Figure 3 is held in a chain-like manner in the closed state.

[0043] After the vacuum valve 33 is re-closed, the stroke pin 37 is retracted downward as shown in Figure 1 by stopping the energization of the closing coil 38. At this time, as shown in Figure 7, the latch roller 6 is held on the latch 9, so the opening / closing shaft 4 does not rotate, and the opening / closing shaft lever 34 shown in Figure 1 does not rotate counterclockwise in accordance with the retraction of the stroke pin 37.

[0044] Figure 4 shows the manual mechanism D for manually opening the vacuum circuit breaker 33 by operating a push button 20, without energizing the trip coil 18. The push button 20 is held in place by inserting the button shaft 24 through insertion openings 43a and 44a formed in a pair of retaining pieces 43 and 44 (see Figure 5) of the retaining frame 41. A return spring 25 is interposed between the push button 20 and one of the retaining pieces 42, and the push button 20 is operated by compressing the return spring 25. As a result, the button shaft 24 passes through the insertion openings 43a and 44a of the retaining pieces 43 and 44 and is pushed in.

[0045] Furthermore, as shown in Figure 5, an interlocking pin 45 is fixed to the button shaft 24 facing in one direction (lateral direction), and this interlocking pin 45 is engaged with an engagement groove 46a formed in a single interlocking lever 46. A hollow cylindrical support tube 47 is fixed to the central part of the interlocking lever 46, and a support pin 48 attached to one side of the retaining frame 41 is inserted through the support tube 47.

[0046] As shown in Figure 5, one of the retaining pieces 44 is provided with a guide piece 49 extending from its lower end in the longitudinal direction of the button shaft 24, and a guide groove 50 is drilled in the upper surface of the guide piece 49 in the longitudinal direction of the button shaft 24. A guide pin 51 is fixed to the button shaft 24 in the longitudinal direction, and the lower end of the guide pin 51 is slidably positioned within the guide groove 50.

[0047] Next, the operation when the vacuum circuit breaker 33 is manually opened by the manual mechanism D shown in Figures 4 and 5 will be described. When manually opening the vacuum circuit breaker 33, the operator closes the push button 20 shown in Figure 4. This pushes the button shaft 24 against the elastic force of the return spring 25, and the button shaft 24 passes through the insertion openings 43a and 44a of the pair of retaining pieces 43 and 44 of the retaining frame 41 shown in Figure 5. As the button shaft 24 passes through the insertion openings 43a and 44a, the guide pin 51 attached to the button shaft 24 moves along the guide groove 50 of the guide piece 49.

[0048] An interlocking pin 45 is fixed to the button shaft 24, and the interlocking pin 45 is engaged with the engagement groove 46a of the interlocking lever 46. Therefore, when the button shaft 24 moves in the depth direction within the insertion openings 44a and 45a, the interlocking lever 46 rotates in the direction of the arrow shown in Figure 5 around a support pin 48 fixed to one side of the retaining frame 42 by a support cylinder 47.

[0049] When the interlocking lever 46 rotates in the direction of the arrow in Figure 5, the push pin 32 attached to the interlocking lever 46 pushes the trip lever 12 against the elastic force of the return spring 13, as shown in Figure 12. As a result, the latch 9 rotates counterclockwise around the rotation axis 10 together with the trip lever 12, and the latch roller 6, which was held on the latch 9, falls off the latch 9 while rotating the bearing 8.

[0050] The dropping action of the latch 9 rotates the opening / closing shaft 4 via the latch lever 5. This rotation of the opening / closing shaft 4 is transmitted to the main circuit section 2 shown in Figure 1, causing a transition from the state shown in Figure 1 to the state shown in Figure 2, and opening the vacuum valve 33 in the main circuit section 2.

[0051] Furthermore, the push button 20 shown in Figure 4 is pushed back by the elastic force of the return spring 25 when the operator releases their hand.

[0052] Thus, according to the vacuum circuit breaker of the present invention, a support pin 48 is fixed to a retaining frame 42 that holds the button shaft 24, and an interlocking lever 46 connected to the button shaft 24 via a support cylinder 47 is supported by the support pin 48. Therefore, unlike the conventional configuration in which the interlocking levers 27 and 28 (corresponding to the interlocking lever 46) are supported by a stopper pin 31 fixed to a separate stopper 30 (corresponding to the retaining base 21, corresponding to the retaining frame 42), the interlocking lever 46 has a simple structure in which it is attached only to the retaining frame 42 side into which the button shaft 24 is inserted and held. As a result, the interlocking lever 46 can rotate smoothly around the support pin 48, and the support pin 48 is less likely to be damaged.

[0053] Furthermore, because the guide pin 51 moves along the guide groove 50 of the guide piece 49, the button shaft 24 is pushed straight in the depth direction without tilting. As a result, no unnecessary load is placed on the support pin 48 that supports the interlocking lever 46, which is connected to the button shaft 24 via the interlocking pin 45, further reducing the possibility of the support pin 48 being damaged.

[0054] As explained above, with the vacuum circuit breaker of the present invention, the manual mechanism is not damaged by the operation of the push button, so malfunctions such as the push button not returning to its original position do not occur. As a result, the interlocking lever which is linked to the button shaft does not become immobile, and the risk of the vacuum circuit breaker remaining in an unintended closed state is eliminated. [Industrial applicability]

[0055] This invention is applicable to vacuum circuit breakers equipped with a manual mechanism. [Explanation of Symbols]

[0056] 1a, 1b Main circuit conductors 2 Main circuit section 3 Control section 4 Opening / closing shaft 5. Latch lever 6 Latch rollers 7 Roller shaft 8 bearings 9 Latch 10 Rotation axis 11 Latch bearing 12 Trip lever 13 Return Spring 14 Mounting plate 15. Storage tube 16 Proximal end 17 Shaft member 18 Trip Coils 19 Movable pins 20 Push buttons 21 Holding stand 22, 23, 43, 44 Holding piece 22a, 23a Insertion port 24 button axis 25. Return spring 26 Interlocking pins 27, 28, 46 Interlocking lever 27a, 28a Engagement groove 29 Connecting tube 30 Stoppers 31 Stopper pin 32 Push pins 33. Vacuum circuit breaker 34. Opening / closing shaft lever 35 Operating Rod 36 Compression spring 37 Operating lever 38 Input coil 40 Insulating Rods 41 Spindle 42 Holding slots 45 Interlocking pins 47 Support tube 48 Support pins 49 Guide piece 50 guide grooves 51 Guide pins A Vacuum circuit breaker B, B' Latch mechanism C, D Manual mechanism section

Claims

1. A vacuum circuit breaker operating mechanism for closing and opening a fixed electrode and a movable electrode of a vacuum valve in response to an on / off command, comprising: an on / off shaft lever for closing and opening the movable electrode via an insulating rod or pressure contact spring; an on / off coil for operating the on / off shaft lever; a latch lever having an on / off shaft fixed at one end for rotating the on / off shaft lever and a roller shaft attached to the other end for rotatably pivoting a latch roller; a latch for engaging the latch roller to lock and hold the latch lever in the closed position; a trip lever extending from the latch; a latch coil equipped with a movable pin that is activated when an overcurrent relay detects an abnormal current and automatically pushes the trip lever, thereby releasing the engagement of the latch roller and moving the latch lever to the open position; an interlocking lever for manually pushing the trip lever; and a push button for operating the interlocking lever.

2. The vacuum circuit breaker according to claim 1, characterized in that the interlocking lever rotates around a support pin fixed to a retaining frame that holds the button shaft of the push button, and engages an engagement groove formed on one end of the interlocking lever with the interlocking pin attached to the button shaft, thereby allowing the push button to rotate when the push button is manually operated.

3. The vacuum circuit breaker according to claim 2, characterized in that the retaining frame is configured to have a guide groove formed in a guide piece extending in the longitudinal direction of the button shaft, and to guide a guide pin fixed to the button shaft in the guide groove.

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