Self-closing force measuring device and method for vacuum circuit breaker

Abstract

To improve the accuracy of measuring self-closing force.SOLUTION: A vacuum circuit breaker (1) includes a main circuit portion (10) having a movable contact (12) and a fixed contact (14) housed in a vacuum container (11), a movable rod (15) supporting the movable contact, and a contact pressure adjustment portion (23) connected to the movable rod and having a contact pressure spring (35). A self-closing force measuring device (100) that measures the self-closing force of the main circuit portion includes a contact pressure removing portion (101) attached to the contact pressure adjustment portion and removing the elastic force applied to the movable rod from the contact pressure spring, a receiving member (116) on which a self-closing force acts by contacting a connecting link (31) of the contact pressure adjustment portion, and a sensor (115) that measures the self-closing force acting on the receiving member.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for measuring a self-closing force of a vacuum circuit breaker having switching contacts. [Background technology]

[0002] Patent Document 1 discloses a vacuum confirmation device for confirming the degree of vacuum in a vacuum valve in a vacuum circuit breaker. The vacuum circuit breaker is equipped with a contact pressure spring that presses a movable contact against a fixed contact with a constant contact pressure in the closed position. The load measuring device constituting the vacuum confirmation device measures the load by moving the vacuum valve in the closing direction, and checks whether a decrease in the degree of vacuum has occurred in the vacuum valve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6771329 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, when the vacuum valve is moved by the load measuring device, the contact pressure spring and the release spring are in a state where they can elastically deform. Therefore, in Patent Document 1, in addition to the state of elastic deformation of the contact pressure spring changing depending on the measurement conditions, the difference between the self-closing force and the excessive release spring load relative to the self-closing force is measured, which causes problems such as low accuracy in checking the vacuum degree of the self-closing force.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a self-closing force measuring device and a self-closing force measuring method for a vacuum circuit breaker that can improve the measurement accuracy of the self-closing force. [Means for solving the problem]

[0006] One embodiment of the present invention provides a self-closing force measuring device for a vacuum circuit breaker, which is a self-closing force measuring device for a vacuum circuit breaker comprising: a vacuum valve having a movable contact and a fixed contact housed in a vacuum container, a movable side rod supporting the movable contact, a contact pressure adjustment unit connected to the movable side rod, and an operating mechanism that transmits the elastic force of a spring member via a link mechanism connected to the contact pressure adjustment unit and drives the movable contact in a direction to move it toward or away from the fixed contact, wherein the contact pressure adjustment unit has a connecting link connected to the movable side rod and a contact pressure spring that applies contact pressure to the movable contact and the fixed contact via the connecting link and the movable side rod, and is equipped with a contact pressure removal unit that is attached to the contact pressure adjustment unit and removes the elastic force applied to the movable side rod from the contact pressure spring, a receiving member on which the self-closing force acts by coming into contact with the connecting link, and a sensor that measures the self-closing force acting on the receiving member.

[0007] One embodiment of the present invention provides a method for measuring the self-closing force of a vacuum circuit breaker, which measures the self-closing force of a vacuum valve in the vacuum circuit breaker, and is characterized in that it includes a contact pressure removal step of attaching a contact pressure removal part to the contact pressure adjustment part and removing the elastic force applied to the movable side rod from the contact pressure spring, an attachment step of attaching a receiving member so that it comes into contact with the connecting link and the self-closing force acts on it, and an attachment step of attaching a sensor so that the self-closing force acting on the receiving member is applied to the receiving member, and a measurement step of measuring the self-closing force acting on the receiving member with the sensor. Effect of the Invention

[0008] According to the present invention, the elastic deformation of the pressure spring is restricted by the pressure removal portion, and the self-closing force can be measured by the sensor at a position where the elastic force of the spring member does not act. In other words, the self-closing force can be measured without being affected by the pressure spring and the spring member, and the measurement accuracy of the self-closing force can be improved. [Brief description of the drawings]

[0009] [Figure 1]1 is a schematic partial perspective view of a vacuum circuit breaker in which a self-closing force measuring device according to a first embodiment is used; [Diagram 2] FIG. 2 is a vertical cross-sectional view of FIG. [Diagram 3] 2 is an exploded vertical cross-sectional view showing a part of the self-closing force measuring device and a part of the vacuum circuit breaker. FIG. [Figure 4] 2 is a vertical cross-sectional view showing a part of the self-closing force measuring device and a part of the vacuum circuit breaker. FIG. [Diagram 5] FIG. 5A is a diagram illustrating the planar shape of a clamping member, and FIG. 5B is a diagram illustrating the planar shapes of a receiving member and a contact member. [Figure 6] 2 is a vertical cross-sectional view showing a part of the vacuum circuit breaker and the self-closing force measuring device. FIG. [Figure 7] 7 is a vertical cross-sectional view similar to FIG. 6, illustrating a state in which a self-closing force is applied. [Figure 8] 11 is a longitudinal sectional view showing a self-closing force measurement device according to a second embodiment, a part of a vacuum circuit breaker, and the self-closing force measurement device. FIG. [Figure 9] 11 is a longitudinal sectional view showing a self-closing force measurement device according to a second embodiment, a part of a vacuum circuit breaker, and the self-closing force measurement device. FIG. [Figure 10] 13 is a longitudinal sectional view showing a self-closing force measurement device according to a third embodiment, a part of a vacuum circuit breaker, and the self-closing force measurement device. FIG. [Figure 11] 13 is a longitudinal sectional view showing a self-closing force measurement device according to a third embodiment, a part of a vacuum circuit breaker, and the self-closing force measurement device. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A vacuum circuit breaker using a self-closing force measuring device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiment, and can be modified as appropriate within the scope of the present invention. In the following drawings, some components may be omitted for the sake of convenience.

[0011] The present invention is applied to, for example, a vacuum circuit breaker constituting a cubicle-type gas insulated switchgear (C-GIS, hereinafter simply referred to as "switchgear"). However, the switchgear to which the present invention is applied is not limited to this and can be modified as appropriate.

[0012] [First embodiment] Fig. 1 is a schematic partial perspective view of a vacuum circuit breaker in which a self-closing force measuring device according to a first embodiment is used. Note that the self-closing force measuring device is not shown in Fig. 1. As shown in Fig. 1, a vacuum circuit breaker 1 has a metal housing 2 which forms a sealed internal space and is filled with an insulating gas such as SF6 gas. Here, in this specification and claims, "upper", "lower", "front", "rear", "left" and "right" are based on the directions indicated by arrows in each drawing.

[0013] 1 illustrates a partition wall 2a provided along the vertical direction as part of the housing 2, with the rear of the partition wall 2a forming an inner space filled with insulating gas and the front of the partition wall 2a forming an outer space where the atmosphere is present. The housing 2 also includes a partition wall 2b extending forward from the front surface of the partition wall 2a and oriented in a direction perpendicular to the left-right direction.

[0014] Fig. 2 is a vertical cross-sectional view of Fig. 1. As shown in Fig. 2, the vacuum circuit breaker 1 includes a three-phase main circuit section 10 (vacuum valve) provided inside a housing 2. The three-phase main circuit sections 10 have roughly the same structure and are arranged side by side in a direction perpendicular to the plane of Fig. 2 (left-right direction), and Fig. 2 and Figs. 3, 4, 6, and 7 described below show a simplified illustration of one of the three-phase main circuit sections 10.

[0015] The main circuit section 10 has a vacuum vessel 11 (simply shown by a two-dot chain line in FIG. 2) consisting of an insulating cylinder made of ceramic or the like, and a movable contact 12 and a fixed contact 14 housed within the vacuum vessel 11. The movable contact 12 and the fixed contact 14 are provided so as to be capable of being connected and disconnected within the vacuum vessel 11. The movable contact 12 and the fixed contact 14 form an open / close contact.

[0016] In the main circuit section 10, the movable contact 12 and the fixed contact 14 cut off (open circuit) electricity when they are in a separated state (open contact state) as shown in Fig. 2, and conduct electricity (close circuit) when they are in contact (closed contact state, see Fig. 4). Note that Fig. 2 shows the maximum open state in which the distance between the movable contact 12 and the fixed contact 14 is the greatest. The movable contact 12 is supported by a movable side rod 15 that extends in the front-rear direction. The movable side rod 15 is made of an insulating member and is sometimes called an insulating rod. The movable side rod 15 penetrates a gas seal 16 that is attached to the front surface of the partition wall 2a of the housing 2.

[0017] The gas seal 16 comprises a disk-shaped flange portion 16a attached so that its rear surface abuts against the front surface of the partition wall 2a, and a protruding tubular portion 16b protruding forward from the front surface of the flange portion 16a. An insertion hole through which the movable-side rod 15 is inserted is formed at the central axis position extending in the front-rear direction of the flange portion 16a and the protruding tubular portion 16b, and an O-ring (not shown) that slidably abuts against the outer circumferential surface of the movable-side rod 15 is provided inside the insertion hole. The O-ring maintains airtightness between the movable-side rod 15 and the partition wall 2a, and also maintains airtightness inside and outside the partition wall 2a.

[0018] 1 and 2, the vacuum circuit breaker 1 further includes an operating mechanism 20 that drives the movable contact 12 in a contact / separation direction (front-rear direction) to contact and separate the movable contact 12 with respect to the fixed contact 14. In this embodiment, the contact / separation direction is parallel to the front-rear direction. The operating mechanism 20 includes a link mechanism 21, a breaker spring 22 (spring member) arranged with its central axis extending generally in the front-rear direction, and a contact pressure adjustment unit 23 provided between the front end side of the movable rod 15 and the link mechanism 21. The operating mechanism 20 will be described in the order of the breaker spring 22, the contact pressure adjustment unit 23, and the link mechanism 21.

[0019] The shutoff spring 22 has a rear end (one end) held by a first holder 27 and a front end (the other end) held by a second holder 28. The first holder 27 is supported on the partition wall 2a via a bracket 29. The shutoff spring 22 is formed of a tension coil spring, and by extending its length in the front-rear direction from the state shown in Fig. 1, it stores elastic force in a direction that moves the second holder 28 rearward.

[0020] The contact pressure adjustment parts 23 are provided in three locations corresponding to the three phases in the front space outside the partition wall 2a. The contact pressure adjustment parts 23 are provided along the front-rear direction so as to connect a first lever 51 (described later) of the link mechanism 21 and the movable rod 15.

[0021] The contact pressure adjustment unit 23 includes a connecting link 31 connected to the front end side of the movable rod 15 via a pin 31a. The contact pressure adjustment unit 23 also includes a contact pressure spring rod 34 connected to the front end side of the connecting link 31 and the first lever 51, a contact pressure spring 35 formed of a compression coil spring into which the contact pressure spring rod 34 is inserted, a fixed side spring retainer 36, and a movable side spring retainer 37.

[0022] The connecting link 31 includes a polygonal columnar link body 32 extending in the front-rear direction, and a pressing body 33 supported in front of the link body 32. The front end side of the link body 32 is bifurcated so as to sandwich the rear end side of the pressure spring rod 34 from the left and right (see FIG. 1).

[0023] The pressing body 33 includes a connection pin 33a provided penetrating the front end side of the link body 32 in the left-right direction, and a pair of rollers 33b (one of which is not shown in FIG. 2) rotatably supported via the connection pin 33a. The connection pin 33a is supported in a state in which it cannot move relatively to the link body 32. Therefore, the connecting link 31 including the link body 32 and the pressing body 33, the movable side rod 15, and the movable contact 12 are moved in the front-rear direction as a unit U.

[0024] The pressure spring rod 34 includes a first rod 39 that is connected to a first lever 51 (described later) of the link mechanism 21 and extends rearward, and a second rod 40 that is connected to the rear end of the first rod 39 and extends rearward. The first rod 39 and the second rod 40 are positioned coaxially so as to be parallel to each other in the front-rear direction, and are also positioned coaxially with the movable rod 15.

[0025] The first rod 39 is provided with nut members 41, 42 screwed on both the front and rear sides, and the rear nut member 42 restricts the movement of the fixed side spring retainer 36 in the front-rear direction. A nut-shaped bulge 39a is formed between the front and rear nut members 41, 42 of the first rod 39. Therefore, in the contact pressure spring rod 34, the first rod 39 has portions on both the front and rear sides of the bulge 39a that are reduced in diameter and have a recessed shape.

[0026] 3 is an exploded longitudinal sectional view of a part of the vacuum circuit breaker according to the first embodiment and a part of a self-closing force measuring device described later. As shown in FIG. 3, a male screw is formed on the rear end side of the first rod 39, while a female screw hole is formed on the front end side of the second rod 40, and the first rod 39 and the second rod 40 are screwed together. The second rod 40 is inserted into the contact pressure spring 35. The second rod 40 is also inserted into the fixed side spring retainer 36 provided on the front end (one end) side of the contact pressure spring 35, and is also inserted into the movable side spring retainer 37 provided on the rear end (other end) side of the contact pressure spring 35. Each of the spring retainers 36 and 37 receives the elastic force of the contact pressure spring 35, and the movable side spring retainer 37 is provided so as to be displaceable in the front-rear direction by the elastic force.

[0027] The pressure spring 35 is arranged so that it is compressed by a predetermined length from its natural length when the movable contact 12 is separated from the fixed contact 14 in the open state, and is further compressed from this state in the closed state to apply contact pressure between the movable contact 12 and the fixed contact 14.

[0028] A long hole 40a extending in the front-rear direction is formed on the rear end side of the second rod 40. The long hole 40a is open in the left-right direction, and a connection pin 33a of the pressing body 33 is inserted into the long hole 40a. This connects the second rod 40 and the connecting link 31 via the long hole 40a and the connection pin 33a. In addition, the connection pin 33a moves in the front-rear direction within the long hole 40a, and the long hole 40a and the connection pin 33a allow the unit U to move in the front-rear direction relative to the pressure spring rod 34.

[0029] 3, the rear surface of the movable-side spring retainer 37 is in contact with the front end of the roller 33b of the pressing body 33. As a result, the elastic force of the contact pressure spring 35 is transmitted to the roller 33b via the movable-side spring retainer 37, urging the unit U forward. The elastic force of the contact pressure spring 35 is provided so as to be applied as contact pressure between the movable contact 12 and the fixed contact 14 via the connecting link 31 and the movable-side rod 15.

[0030] Returning to Fig. 1, the link mechanism 21 includes an opening / closing shaft 50, a first lever 51, and a second lever 52. The opening / closing shaft 50 extends in the left-right direction, and both ends are rotatably supported via bearings (not shown).

[0031] The first levers 51 are provided on the front end sides of the contact pressure spring rods 34 in the three contact pressure adjustment parts 23, respectively. The first levers 51 are rotatably connected at their tip ends to the front end sides of the contact pressure spring rods 34 via pins 51a. The base end side of the first levers 51 is fixed to and supported by the opening / closing shaft 50.

[0032] The second lever 52 is provided near the right side of the first lever 51, which is central in the left-right direction, among the three first levers 51. The base end side of the second lever 52 is fixedly supported by the opening / closing shaft 50. The tip side of the second lever 52 is rotatably connected to the front end side of the second holder 28 via a pin 52a.

[0033] When the second holder 28 is moved rearward by the elastic force of the breaking spring 22 in the link mechanism 21, the first lever 51, the second lever 52 and the opening / closing shaft 50 are rotated clockwise in Fig. 2, the pressure spring rod 34 and the unit U are moved forward, and the movable contact 12 is separated from the fixed contact 14. Therefore, in the operation mechanism 20, the elastic force of the breaking spring 22 is transmitted via the link mechanism 21, and the movable contact 12 and the fixed contact 14 are opened.

[0034] Here, in the operation of the vacuum circuit breaker 1, it is recommended to carry out a periodic vacuum degree confirmation test. In this embodiment, a load called a self-closing force that tries to displace the movable contact 12 in a closing direction (rearward) is constantly acting on the main circuit section 10 due to a pressure difference with the external gas. This self-closing force acts on a unit U including the movable contact 12 and the movable side rod 15 when the movable contact 12 is in a state where it is separated from the fixed contact 14. Therefore, in this embodiment, the self-closing force acting on the unit U is measured by a self-closing force measuring device 100. The degree of vacuum in the main circuit section 10 can be confirmed by analyzing the measurement results of the self-closing force, so it is recommended to carry out a periodic measurement of the self-closing force (confirmation of the vacuum degree) in the operation of the vacuum circuit breaker 1.

[0035] Next, the self-closing force measuring device 100 used in the above vacuum circuit breaker 1 will be described with reference to Fig. 4 to Fig. 7 in addition to Fig. 3. Fig. 4 is a vertical cross-sectional view showing a part of the vacuum circuit breaker and a part of the self-closing force measuring device according to the first embodiment.

[0036] 3 and 4, the self-closing force measuring device 100 includes a contact pressure removing part 101 that is attached to the contact pressure adjusting part 23. The contact pressure removing part 101 includes a pair of clamping members 102, 103 that are arranged on both sides in the front-rear direction, which is the axial direction of the contact pressure spring 35, and a clamping force applying part 104 that applies a force to clamp the contact pressure spring 35 to the pair of clamping members 102, 103. The clamping members 102, 103 are formed in a plate shape.

[0037] Fig. 5A is a diagram for explaining the planar shape of the clamping members. As shown in Fig. 5A, when viewed from the front-rear direction, each of the clamping members 102, 103 is formed in a gate shape. More specifically, the clamping members 102, 103 are formed in a rectangular shape and have a slot-like receiving portion 106 that extends upward while opening the center of the lower end. The shape and size of the receiving portion 106 are appropriately adjusted depending on the clamping members 102, 103. Furthermore, the clamping members 102, 103 have insertion holes 107 formed near each of the four corners.

[0038] 3 and 4, the front clamping member 102 is provided so that its rear surface contacts the front surface of the fixed-side spring retainer 36 while receiving the rear nut member 42 from above in the receiving portion 106. The rear clamping member 103 is provided so that its front surface contacts the rear surface of the movable-side spring retainer 37 while receiving the second rod 40 from above in the receiving portion 106.

[0039] The clamping force applying portion 104 is configured with insertion holes 107 (two not shown in FIGS. 3 and 4) formed in four locations as described above in each of the front and rear clamping members 102, 103, and bolts 109 inserted into the insertion holes 107. Four bolts 109 (two not shown in FIGS. 3 and 4) are provided corresponding to the insertion holes 107, and are arranged to extend in parallel in the front-rear direction. The front and rear clamping members 102, 103 are connected via the four bolts 109.

[0040] The insertion hole 107 formed in the front clamping member 102 is formed with an outer diameter slightly larger than the male thread of the bolt 109, and is formed so that the bolt 109 rotates freely inside. The insertion hole 107 formed in the rear clamping member 102 is an internally threaded hole that screws into the male thread of the bolt 109, and is formed so as to screw into the bolt 109. Therefore, by rotating the head of the bolt 109 located on the front side of the front clamping member 102, the bolt 109 acts as a feed screw, and the rear clamping member 102 is displaced in the front-rear direction toward and away from the front clamping member 102.

[0041] In this way, the clamping force applying unit 104 can adjust the separation distance between the front and rear clamping members 102, 103 by rotating the bolt 109, and this adjustment can apply a clamping force to compress the contact pressure spring 35. By applying such a clamping force, the movable-side spring retainer 37 is displaced rearward and separated from the roller 33b (see FIG. 4), and the elastic force of the contact pressure spring 35 is no longer applied to the connecting link 31 and the movable-side rod 15. As a result, by attaching the contact pressure removing unit 101 to the contact pressure adjusting unit 23 and operating the clamping force applying unit 104, it becomes possible to remove the elastic force applied from the contact pressure spring 35 to the movable-side rod 15.

[0042] 6 is a vertical cross-sectional view showing a part of the vacuum circuit breaker and a self-closing force measuring device according to the first embodiment. The self-closing force measuring device 100 further includes a sensor 115, a receiving member 116, and a self-closing force transmitting part 118, which are attached to the contact pressure adjusting part 23 after the contact pressure removing part 101 is attached to the contact pressure adjusting part 23.

[0043] The sensor 115 is configured with a load cell or the like, and measures the self-closing force acting rearward. The sensor 115 is supported via a sensor support 119 attached to the first rod 39 of the contact pressure adjustment part 23.

[0044] The sensor support 119 is formed in a gate shape like the clamping members 102, 103 described above, and has a slot-shaped receiving portion 120 that extends upward with the center of the lower end open. The upper edge of the receiving portion 120 in the sensor support 119 is fitted between the bulging portion 39a of the first rod 39 and the rear nut member 42. In this state, the sensor support 119 is detachably attached to the first rod 39, with displacement in directions other than the upward direction restricted by the first rod 39 and the nut member 42.

[0045] The self-closing force transmission unit 118 includes the above-mentioned sensor support 119, a contact member 122 having a similar configuration to the receiving member 116, and a connecting member 124 that extends in the front-rear direction parallel to the movable-side rod 15 and connects the receiving member 116 and the contact member 122. The receiving member 116 and the contact member 122 are formed in a plate shape. The connecting member 124 is formed by a bolt.

[0046] Fig. 5B is a diagram for explaining the planar shapes of the receiving member and the contact member. As shown in Fig. 5B, when viewed from the front-rear direction, the receiving member 116 and the contact member 122 are formed in a gate shape similar to the clamping members 102, 103 in Fig. 5A. Thus, the receiving member 116 and the contact member 122 are formed in a square shape and have a slot-shaped receiving portion 126 that extends upward while opening the center of the lower end. The shape and size of the receiving portion 126 are adjusted as appropriate. Furthermore, the receiving member 116 and the contact member 122 have insertion holes 127 formed near each of the four corners.

[0047] 6, the receiving member 116 is provided so that the link body 32 of the connecting link 31 is received from above in the receiving portion 126 while the front surface of the receiving member 116 contacts the rear end of the roller 33b of the connecting link 31. The contact member 122 is provided so that the rear surface of the contact member 122 contacts the front end of the sensor 115 while the front nut member 41 is received from above in the receiving portion 126.

[0048] Four connecting members 124 (two not shown in FIG. 6) are provided corresponding to the insertion holes 127, and are arranged to extend parallel to each other in the front-rear direction. The receiving member 116 and the contact member 122 are connected via the four connecting members 124, and the receiving member 116, the contact member 122, and the four connecting members 124 form an integrated structure.

[0049] The insertion hole 127 formed in the contact member 122 is formed with an outer diameter slightly larger than the male thread of the connecting member 124, and is formed so that the connecting member 124 rotates freely inside. The insertion hole 127 formed in the receiving member 116 is an internally threaded hole that screws into the male thread of the connecting member 124, and is formed so as to screw into the connecting member 124. Therefore, by rotating the head of the connecting member 124 located on the front side of the contact member 122, the connecting member 124 acts as a feed screw, and the rear receiving member 116 is displaced in the front-rear direction toward and away from the contact member 122.

[0050] The distance between the receiving member 116 and the contact member 122 can be adjusted by rotating the connecting member 124, and a state can be maintained in which the rear end of the roller 33b contacts the front surface of the receiving member 116 and the front end of the sensor 115 contacts the rear surface of the contact member 122. In other words, the contact member 122 and the receiving member 116 can sandwich the structure between the sensor 115 and the roller 33b from the front-rear direction, and the self-closing force transmission unit 118 can be held around the contact pressure adjustment unit 23. Here, an adjustment unit that can adjust the distance between the receiving member 116 and the contact member 122 is configured by the connecting member 124 and the insertion hole 127 formed in the receiving member 116 and the contact member 122.

[0051] From this state, when the receiving member 116 and the contact member 122 are brought closer to each other by rotating the connecting member 124, the receiving member 116 is displaced forward as shown in Fig. 7, and the roller 33b in contact with the receiving member 116 is pushed forward and displaced. Since the roller 33b is part of the unit U on which the self-closing force acts, the self-closing force (shown by the white arrow in Fig. 7) acts on the receiving member 116.

[0052] Because receiving member 116 is integrated with connecting member 124 and contact member 122, the self-closing force acting on receiving member 116 is transmitted from connecting member 124 and contact member 122 to sensor 115 by self-closing force transmission unit 118. In sensor 115, a self-closing force (shown by a white arrow in FIG. 7) is applied from contact member 122, making it possible to measure the self-closing force acting on receiving member 116.

[0053] Next, a method for measuring the self-closing force by the main circuit unit 10 of the vacuum circuit breaker 1 will be described. Note that the measurement of the self-closing force is performed in the same manner for each of the three main circuit units 10 corresponding to the three phases, so the following describes the measurement method for one of the three main circuit units 10 arranged side by side.

[0054] First, as a preliminary preparation, the connection between a predetermined current path and the main circuit section 10 is cut off, and the movable contact 12 and the fixed contact 14 are opened and separated as shown in Fig. 2. At this time, the rotation of the opening / closing shaft 50 of the link mechanism 21 is restricted via a latch mechanism (not shown) and the displacement of the first lever 51 and the pressure spring rod 34 are also restricted. Note that, although a measurement method in the open contact state will be described below, if the rotation of the opening / closing shaft 50 and the displacement of the pressure spring rod 34 due to the force stored in a closing spring (not shown) are restricted, the measurement can also be performed in the closed contact state.

[0055] The method for measuring the self-closing force in this embodiment is carried out in the order of a contact pressure removing step, a setting step, a displacement step, and a measurement step.

[0056] In the contact pressure removing step, the clamping members 102, 103 of the contact pressure removing part 101 are arranged on both the front and rear sides of the contact pressure spring 35 as shown in Fig. 4 from the state shown in Fig. 3, and the front and rear clamping members 102, 103 are brought closer to each other by rotating the bolt 109, compressing the contact pressure spring 35. As a result, the contact pressure removing part 101 is attached to the contact pressure adjusting part 23, and the movable side spring retainer 37 is displaced rearward and separated from the roller 33b, so that the elastic force of the contact pressure spring 35 is no longer applied to the unit U including the connecting link 31 and the movable side rod 15. Therefore, the elastic force applied from the contact pressure spring 35 to the movable side rod 15 is removed.

[0057] After the contact pressure removing step is performed, the mounting step is performed. In the mounting step, as shown in FIG. 6, the sensor 115 is mounted on the first rod 39 via the sensor support 119. Around the same time, the receiving member 116 is arranged behind the roller 33b in the connecting link 31, and the contact member 122 is arranged in front of the sensor 115. Thereafter, the connecting member 124 is rotated to bring the receiving member 116 and the contact member 122 closer to each other, so that the rear end of the roller 33b contacts the front surface of the receiving member 116, and the front end of the sensor 115 contacts the rear surface of the contact member 122. In this state, the receiving member 116 is mounted so as to contact the roller 33b and exert a self-closing force, and the sensor 115 is mounted so as to exert a self-closing force acting on the receiving member 116.

[0058] After the mounting step is performed, the displacement step is performed. In the displacement step, as shown in Fig. 7, the rotation operation of the connecting member 124 is further advanced, and the receiving member 116 and the contact member 122 are brought closer to each other. As a result, the receiving member 116 is displaced forward in the direction opposite to the acting direction of the self-closing force, and the self-closing force acts on the receiving member 116 and the sensor 115. Note that if the self-closing force acts on the receiving member 116 and the sensor 115 by the mounting step, the displacement step may be omitted.

[0059] After the displacement step, the measurement step is performed. In the measurement step, the self-closing force acting on the receiving member 116 and transmitted via the self-closing force transmission unit 118 is measured by the sensor 115.

[0060] Thus, according to the first embodiment, when the self-closing force is measured by sensor 115, the elastic deformation of contact pressure spring 35 can be restricted by contact pressure remover 101. Also, since the self-closing force can be applied by contacting receiving member 116 with roller 33b of connecting link 31, the self-closing force can be measured by sensor 115 at a position where the elastic forces of opening spring 22 and closing spring (not shown) do not act. This allows the self-closing force to be measured without being affected by contact pressure spring 35, opening spring 22, or closing spring, improving the accuracy of measuring the self-closing force.

[0061] Furthermore, in the first embodiment, it is possible to avoid including link mechanism 21 in the transmission path of the self-closing force when measuring the self-closing force using sensor 115. This makes it possible to suppress transmission loss of the self-closing force due to friction of link mechanism 21, etc., and also improves the measurement accuracy of the self-closing force.

[0062] Furthermore, since the self-closing force can be measured for each of the three main circuit units 10 corresponding to the three phases, the measurement accuracy of the self-closing force can be improved compared to a method in which the three phases are measured collectively.

[0063] Also, since the autism force measurement device 100 can be attached around the contact pressure adjustment unit 23 for measurement, the autism force measurement device 100 can be made smaller, and access to the connecting member 124 and the bolt 109 can be made easier when attaching and detaching the autism force measurement device 100. Furthermore, since measurement can be performed without attaching and detaching the blocking spring 22, workability can be improved.

[0064] Furthermore, in the first embodiment, the contact pressure removal unit 101 clamps the pair of clamping members 102, 103 with the clamping force application unit 104, and also clamps the sensor 115 and the roller 33b between the receiving member 116 and the contact member 122. This allows the structure of the autism force measuring device 100 to be simplified, and allows the autism force measuring device 100 to be easily attached to and detached from the contact pressure adjustment unit 23.

[0065] Furthermore, since the distance between the receiving member 116 and the contact member 122 can be adjusted by rotating the connecting member 124, the receiving member 116 and the sensor 115 can be easily adjusted to a state in which a self-closing force acts on them by the displacement step described above.

[0066] Next, other embodiments of the present invention will be described. In the following description, the same reference numerals may be used for components that are the same as or equivalent to those in the embodiment described before the embodiment described, and the description may be omitted or simplified.

[0067] [Second embodiment] A second embodiment of the present invention will be described with reference to Figs. 8 and 9. Figs. 8 and 9 are vertical cross-sectional views showing a self-closing force measuring device according to the second embodiment, a part of a vacuum circuit breaker, and the self-closing force measuring device. Fig. 8 shows the preparation stage for measurement, and Fig. 9 shows the state during measurement. As shown in Figs. 8 and 9, in the second embodiment, the size of receiving member 116 and the installation position of sensor 115 in the first embodiment are changed, and self-closing force transmission unit 118 is omitted.

[0068] In the second embodiment of the self-closing force measuring device 100, the sensor 115 is disposed near the rear of the contact pressure adjusting section 23, and is disposed between the partition wall 2a and the receiving member 130. The receiving member 130 is provided behind the roller 33b of the connecting link 31, and is held with its rear surface in contact with the front end of the sensor 115. The vertical width of the receiving member 130 is formed to be slightly larger than the vertical width of the roller 33b.

[0069] The sensor support 133 in the second embodiment supports the rear side of the sensor 115 on its front side. The sensor support 133 is supported on the partition wall 2a via a feed screw shaft 134 and a spacer 136. A nut 137 is screwed onto the feed screw shaft 134, and the nut 137 is provided so as to contact the rear side of the sensor support 133. The rear end side of the feed screw shaft 134 is supported by a spacer 135. The sensor 115, the receiving member 130, and the sensor support 133 are arranged such that the vertical center positions of the feed screw shaft 134 and the spacer 136 are aligned.

[0070] In the above configuration, by rotating nut 137 from the state shown in Fig. 8, sensor support 133, sensor 115, and receiving member 130 are displaced forward. This displacement causes receiving member 130 to contact roller 33b, and a rearward self-closing force acts from roller 33b on receiving member 130 and sensor 115, making it possible for sensor 115 to measure the self-closing force.

[0071] According to the second embodiment, the measurement accuracy of the self-closing force can be improved, as in the first embodiment. In addition, since the sensor 115 can be disposed between the partition 2a and the receiving member 130, the self-closing force measuring device 100 can be disposed in a small space in front of the partition 2a for measurement.

[0072] [Third embodiment] A third embodiment of the present invention will be described with reference to Figs. 10 and 11. Figs. 10 and 11 are vertical cross-sectional views showing a self-closing force measuring device according to the third embodiment, a part of a vacuum circuit breaker, and the self-closing force measuring device. Fig. 10 shows the preparation stage for measurement, and Fig. 11 shows the state during measurement. As shown in Figs. 10 and 11, in the third embodiment as well, the size of receiving member 116 and the installation position of sensor 115 in the first embodiment are changed, and self-closing force transmission unit 118 is omitted.

[0073] In the third embodiment, the self-closing force measuring device 100 is formed such that the vertical width of the receiving member 140 is considerably larger than the vertical width of the roller 33b, and the screw shaft 141 is provided to penetrate the upper end side of the receiving member 140. A spacer 143 is interposed between the rear end of the screw shaft 141 and the partition wall 2a, and a nut 144 is screwed into the rear of the receiving member 140 on the screw shaft 141. By rotating the nut 144 and displacing it forward, the receiving member 140 is pressed forward, and the front surface of the receiving member 140 comes into contact with the rear end of the roller 33b. As a result, a self-closing force acts on the receiving member 140 from the rear end of the roller 33b. In addition, when the nut 144 is rotated, the rear end of the screw shaft 141 is pressed against the spacer 143. Therefore, as shown in FIG. 10, the receiving member 140 and the spacer 143 are held in a taut state by the screw shaft 141 and the nut 144.

[0074] In this state, as shown in Fig. 11, the sensor 115 is inserted and disposed between the receiving member 140 and the spacer 143. Thereafter, the nut 144 is rotated to displace it rearward and separated from the receiving member 140, whereby the receiving member 140 and the sensor 115 are sandwiched and held by the roller 33b and the spacer 143 due to the self-closing force. As a result, the sensor 115 is sandwiched and disposed between the partition wall 2a and the receiving member 140, and a rearward self-closing force acts from the roller 33b on the receiving member 140 and the sensor 115, making it possible to measure the self-closing force with the sensor 115.

[0075] According to the third embodiment, the measurement accuracy of the self-closing force can be improved, as in the first embodiment. Also, as in the second embodiment, the sensor 115 can be placed between the partition 2a and the receiving member 140, so that the self-closing force measuring device 100 can be placed in a small space in front of the partition 2a to perform the measurement.

[0076] The present invention is not limited to the above-described embodiments, and can be modified in various ways. In the above-described embodiments, the size, shape, orientation, and the like shown in the accompanying drawings are not limited to these, and can be modified as appropriate within the scope of the effects of the present invention. In addition, the present invention can be modified as appropriate without departing from the scope of the object of the present invention.

[0077] In the above embodiment, the screw structure of the bolt 109 and the connecting member 124 are used as a configuration for displacing the clamping member 102 and the receiving member 116 in the forward / rearward direction, but this is not limited to this, and for example, a linear motion mechanism such as an actuator may be used.

[0078] Furthermore, the configuration of the connecting link 31 that contacts the receiving members 116, 130, 140 is not limited to the roller 33b, and may be changed, for example, to the rear end of the link body 32, as long as a self-closing force acts on the receiving members 116, 130, 140. [Explanation of symbols]

[0079] 1: Vacuum circuit breaker 2a: Bulkhead 11: Vacuum container 12: Movable contact 14: Fixed contact 15: Movable rod 20: Operating mechanism 21: Link mechanism 22: Breaking spring (spring member) 23:Contact pressure adjustment section 31: Link 35: Pressure spring 100:Self-closing force measuring device 101:Contact pressure removal part 102: Holding member 103: Holding member 104: Clamping force applying part 115: Sensor 116: Support member 118: Self-closing force transmission unit 119: Sensor support 122: Contact member 124: Connection member (adjustment part) 127: Insertion hole (adjustment part) 130: Receiving member 140: Support member

Claims

1. a vacuum valve having a movable contact and a fixed contact housed in a vacuum vessel; A movable rod supporting the movable contact; a contact pressure adjustment part connected to the movable rod; a link mechanism connected to the contact pressure adjusting section, and an operating mechanism for driving the movable contact in a contact / separation direction relative to the fixed contact, the self-closing force measuring device measuring the self-closing force of the vacuum interrupter, the contact pressure adjustment unit includes a connecting link connected to the movable rod, and a contact pressure spring that applies contact pressure to the movable contact and the fixed contact via the connecting link and the movable rod, a contact pressure removing part that is attached to the contact pressure adjusting part and removes an elastic force applied from the contact pressure spring to the movable rod; a receiving member on which the self-closing force acts by contacting the connecting link; a sensor for measuring the self-closing force acting on the receiving member.

2. The pressure spring is a coil spring, The contact pressure remover includes a pair of clamping members disposed on both sides of the contact pressure spring in the axial direction; 2. The vacuum circuit breaker self-closing force measuring device according to claim 1, further comprising a clamping force applying portion that applies a force for clamping the contact pressure spring between the pair of clamping members.

3. a self-closing force transmission unit that transmits the self-closing force acting on the receiving member to the sensor, The self-closing force transmission unit includes a sensor support member attached to the contact pressure adjustment unit and supporting the sensor; a contact member that applies the self-closing force by contacting the sensor; 3. The device for measuring the self-closing force of a vacuum circuit breaker according to claim 1, further comprising a connecting member extending parallel to said movable rod for connecting said receiving member and said contact member.

4. 4. The self-closing force measuring device for a vacuum circuit breaker according to claim 3, wherein the self-closing force transmitting portion further includes an adjustment portion capable of adjusting a distance between the receiving member and the contact member.

5. the movable rod penetrates a partition wall that defines an internal space in the vacuum circuit breaker to be filled with an insulating gas, 3. The device for measuring the self-closing force of a vacuum circuit breaker according to claim 1, wherein the sensor is disposed between the partition wall and the receiving member.

6. a vacuum valve having a movable contact and a fixed contact housed in a vacuum vessel; A movable rod supporting the movable contact; a contact pressure adjustment part connected to the movable rod; A self-closing force measuring method for measuring a self-closing force of a vacuum interrupter, the method comprising: a link mechanism connected to the contact pressure adjusting unit, which transmits an elastic force of a spring member; and an operation mechanism for driving the movable contact in a contact / separation direction relative to the fixed contact, the method comprising the steps of: the contact pressure adjustment unit includes a connecting link connected to the movable rod, and a contact pressure spring that applies contact pressure to the movable contact and the fixed contact via the connecting link and the movable rod, a contact pressure removing step of attaching a contact pressure removing part to the contact pressure adjusting part and removing the elastic force applied from the contact pressure spring to the movable rod; a mounting step of mounting a receiving member so as to come into contact with the connecting link and act on the self-closing force, and mounting a sensor so as to apply the self-closing force acting on the receiving member; and a measuring step of measuring the self-closing force acting on the receiving member by the sensor.

7. 7. The method for measuring a self-closing force of a vacuum circuit breaker according to claim 6, further comprising a displacement step of displacing the receiving member in a direction opposite to the self-closing force after the mounting step and before the measuring step.

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