Circuit Breakers

Abstract

To suppress generation of failures caused by movement of a conductive gas from an upper part of a crossbar to a counter-contact part side of the crossbar.SOLUTION: A circuit breaker comprises: a contact part consisting of a movable contact 14 provided on a movable contactor 13 and a fixed contact 16 provided on a fixed contactor 15; a crossbar 18 lifting and lowering the movable contactor in conjunction with a handle 17; and a shielding part Sh that covers an upper part of the contact part and at least an upper part of a front face of the crossbar to suppress a conductive gas from moving from an upper part of the crossbar to a counter-contact part side the crossbar.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a circuit breaker. [Background technology]

[0002] It is known that when an overcurrent or short-circuit current flows through a circuit breaker, the opening and closing mechanism of the circuit breaker is activated, and the movable contact is separated from the fixed contact, a high-temperature arc (discharge) occurs. In the technology disclosed in Patent Document 1, an arc-extinguishing device is provided near the fixed contact to extinguish the arc. In addition, when an arc occurs, a conductive gas is generated, and the conductive gas is exhausted to the outside of the circuit breaker through a gas exhaust port. However, there is a problem in that the conductive gas is not exhausted from the gas exhaust port and affects the internal mechanism of the circuit breaker. In response to this, the technology disclosed in Patent Document 2 takes measures to suppress melting of the spring that biases the movable contact by the conductive gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-123937 A [Patent Document 2] JP 2018-006178 A

[0004] Incidentally, the technology disclosed in Patent Document 2 is capable of protecting the spring of the movable contactor that is present in the same pole as the movable contact, but is unable to prevent conductive gas from flowing into the center of the circuit breaker from above the crossbar that moves the movable contactor up and down, and is therefore unable to suppress short circuit accidents that occur between metal members arranged in different poles. Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors of the present invention have studied this issue extensively and have attempted to solve the problem. The problem to be solved by the present invention is to suppress the occurrence of problems caused by the conductive gas moving from above the crossbar to the opposite contact portion of the crossbar. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a circuit breaker comprising a contact section consisting of a movable contact provided on a movable contactor and a fixed contact provided on a fixed contactor, and a crossbar that raises and lowers the movable contactor in conjunction with a handle, the circuit breaker being characterized in having a shielding section that covers the upper part of the contact section and at least the upper part of the front surface of the crossbar and is capable of preventing conductive gas from moving from above the crossbar to the anti-contact section side of the crossbar.

[0007] In addition, it is preferable that the shielding portion and the crossbar are configured so that, when the crossbar rises, the upper end of the crossbar and the shielding portion come close to each other, thereby preventing the conductive gas from moving from above the crossbar to the anti-contact side of the crossbar.

[0008] It is also preferable that the device has a case in which the tripping coil incorporating the plunger can be attached, and that a part of the case is used as a shielding portion.

[0009] In addition, it is preferable to have a configuration in which the shielding portions provided on some of the poles are formed by assembling a member separate from the base or cover to the base, and the shielding portions provided on the other poles are formed integrally with the base or cover. Effect of the Invention

[0010] In the present invention, it is possible to suppress the occurrence of problems caused by the conductive gas moving from above the crossbar to the opposite contact portion of the crossbar. [Brief description of the drawings]

[0011] [Figure 1]FIG. 2 is a perspective view of a circuit breaker according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the circuit breaker shown in FIG. [Diagram 3] FIG. 13 is a diagram showing the state before the case constituting the shielding portion is attached to the base side. [Figure 4] 1 is a cross-sectional view of a circuit breaker in the on position, but without the cover; [Diagram 5] 1 is a cross-sectional view of a circuit breaker in the off position, but without the cover; [Figure 6] 1 is a diagram of the case, crossbar, and movable contact that make up the shielding portion, with the circuit breaker in the ON state. [Figure 7] 1 is a diagram of the case, crossbar, and movable contact that make up the shielding portion, with the circuit breaker in the OFF state. [Figure 8] FIG. 2 is a perspective view of the cover in the embodiment as seen from the back side. [Figure 9] FIG. 2 is a perspective view of a tripping device according to an embodiment. [Figure 10] FIG. 10 is an exploded perspective view of the tripping device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the invention will be described below. As can be understood from Fig. 1 to Fig. 5, the circuit breaker 1 of this embodiment includes a contact section consisting of a movable contact 14 provided on a movable contactor 13 and a fixed contact 16 provided on a fixed contactor 15, and a crossbar 18 that moves the movable contactor 13 up and down in conjunction with a handle 17. This circuit breaker 1 includes a shielding part Sh that covers the upper part of the contact section and at least the upper part of the front surface of the crossbar 18 and can suppress the conductive gas from moving from above the crossbar 18 to the anti-contact part side of the crossbar 18. This makes it possible to suppress the occurrence of malfunctions caused by the conductive gas moving from above the crossbar 18 to the anti-contact part side of the crossbar 18.

[0013] Here, the external shape of the circuit breaker 1 of the embodiment will be described. The circuit breaker 1 of the embodiment includes a base 11 and a cover 12. These are combined to form the external shape, and can be separated in the vertical direction. In addition, various members are stored in the base 11 of the embodiment.

[0014] For example, a fixed contactor 15 connected to a power supply side terminal portion 41 and a movable contactor 13 connected to a load side terminal portion 42 are housed in a base 11. The fixed contactor 15 and the movable contactor 13 are used to open and close a circuit, and when a fixed contact 16 provided on the fixed contactor 15 comes into contact with a movable contact 14 provided on the movable contactor 13, the power supply side terminal portion 41 and the load side terminal portion 42 are electrically connected, and when the fixed contact 16 and the movable contact 14 are separated, the electrical connection between the power supply side terminal portion 41 and the load side terminal portion 42 is interrupted. The movable contact 14 and the fixed contact 16 are collectively referred to as a contact portion.

[0015] The circuit breaker 1 is equipped with a handle 17 that moves the movable contactor 13, and a crossbar 18 that raises and lowers the movable contactor 13 in conjunction with the movement of the handle 17. When the handle 17 is tilted in the ON direction, the crossbar 18 moves downward, applying a downward load to the movable contactor 13 and bringing the movable contact 14 into contact with the fixed contact 16. When the handle 17 is tilted in the OFF direction, the crossbar 18 moves upward and the load on the movable contactor 13 is removed, causing the movable contact 14 to move away from the fixed contact 16. A spring 19 is provided below the movable contactor 13. This spring 19 can apply a force in a direction in which the movable contact 14 moves away from the fixed contact 16.

[0016] The circuit breaker 1 of the embodiment is provided with an overcurrent tripping device that trips the circuit breaker 1 (forcibly separates the movable contact 14 from the fixed contact 16) when an overcurrent occurs in the circuit breaker 1. The circuit breaker 1 of the embodiment has a plurality of poles, and an overcurrent tripping device is provided for each pole of the circuit breaker 1.

[0017] Incidentally, a metal member 21, which is a part of the overcurrent tripping device of the embodiment, is stored so as to partially protrude from the base 11. This metal member 21 is covered by the cover 12 and is not exposed from the circuit breaker 1, and since the cover 12 is formed with ribs 22 that separate the poles, the insulation distance is secured without any problem in the normal use state. Incidentally, in Fig. 4, Fig. 5, etc., only the substantially L-shaped metal member 21 capable of supporting the tripping coil of the overcurrent tripping device is shown.

[0018] Incidentally, when an abnormal current such as an overcurrent occurs in the circuit breaker 1, the circuit breaker 1 trips and the movable contact 14 moves in a direction away from the fixed contact 16, at which time an arc and conductive gas are generated from the contact portion. The arc is extinguished by providing an arc extinguishing device (not shown) around the power supply side terminal portion 41, while the conductive gas is extinguished by providing an exhaust port (not shown) around the power supply side terminal portion 41 so that it can be exhausted to the outside of the circuit breaker 1.

[0019] However, the conductive gas may not be discharged from the exhaust port and may flow toward the load side. If the conductive gas flows near the metal component 21 of the overcurrent tripping device, a short circuit may occur in a location where an insulation distance is maintained under normal operating conditions.

[0020] Therefore, in order to prevent the conductive gas from flowing in the direction toward the load side, the circuit breaker 1 of the embodiment is provided with a shielding portion Sh that can cover the upper part of the contact portion and the upper part of the front surface of the crossbar 18. More specifically, the shielding portion Sh and the crossbar 18 are configured such that, as the crossbar 18 rises, the upper end of the crossbar 18 and the shielding portion Sh come close to each other, thereby making it possible to suppress the conductive gas from moving from the upper part of the crossbar 18 to the anti-contact portion side of the crossbar 18.

[0021] The examples shown in Fig. 6 and Fig. 7 show the crossbar 18 before and after it is raised. Before the upper end of the crossbar 18 and the shielding part Sh approach each other, as can be seen from Fig. 6, there is a gap between the crossbar 18 and the shielding part Sh that allows the gas to pass through sufficiently. On the other hand, after the upper end of the crossbar 18 and the shielding part Sh approach each other, as can be seen from Fig. 7, the gap between the crossbar 18 and the shielding part Sh becomes narrower, making it difficult for the gas to pass through. In the embodiment, when the crossbar 18 is raised, the shielding part Sh and the front surface of the crossbar 18 block the upward and backward movement of the gas, and the conductive gas is prevented from moving from above the crossbar 18 to the opposite contact part of the crossbar 18.

[0022] The shielding part Sh may be a separate member from the cover 12 and the base 11, and may be attached to the base 11 after the contact parts are assembled. Also, as can be seen from Fig. 8, the shielding part Sh may be integral with the cover 12, and the cover 12 may be attached to the base 11 so that the shielding part Sh is positioned above the contact parts and above the front surface of the crossbar 18.

[0023] The shielding portion Sh may be newly designed and developed for the purpose of covering the upper part of the contact portion and the upper part of the front surface of the crossbar 18, or may utilize a component incorporated in the circuit breaker 1.

[0024] For example, there are earth leakage current breakers 1 that have a function of tripping when an earth leakage current occurs, and breakers that do not have a tripping function for earth leakage current. The difference between these circuit breakers 1 is whether or not they have a tripping device 50.

[0025] As can be seen from FIGS. 9 and 10, the tripping device 50 includes, for example, a tripping coil 51, a plunger 52, a display device 53, a test means 54, and a case 55, and these will now be described.

[0026] The tripping coil 51 is equipped with a plunger 52, part of which protrudes from the tripping coil 51. When a leakage current occurs, the tripping coil 51 is excited, and the plunger 52 is attracted to the tripping coil 51. The end of the protruding side of the plunger 52 is engaged with a trip lever (not shown) that trips the circuit when driven, and when the plunger 52 is attracted to the tripping coil 51 by the tripping coil 51, the trip lever is driven and the circuit can be tripped.

[0027] In the embodiment, a display device 53 is provided which moves upward in conjunction with the movement of the plunger 52 being attracted to the tripping coil 51. When the display device 53 moves upward and the upper end thereof protrudes from the surface of the cover 12, it is possible to notify the outside that a leakage current has occurred.

[0028] Moreover, the tripping device 50 of the embodiment includes a test means 54 used to check whether the tripping device 50 operates normally. In the embodiment, when a test button provided on the surface of the cover 12 is pressed, the circuit of the test means 54 is closed, so that a pseudo leakage current can be generated in the tripping coil 51, and the normal operation of the tripping device 50 can be checked.

[0029] Incidentally, the tripping device 50 of the embodiment is provided with a case 55 capable of restraining at least the tripping coil 51 equipped with the plunger 52, the display device 53, and the test device within a predetermined range. By assembling this case 55, it is possible to cover the upper part of the contact portion and the upper part of the front surface of the crossbar 18. In this manner, it is preferable to provide a case 55 capable of mounting the tripping coil 51 incorporating the plunger 52, and to make a part of the case 55 into the shielding portion Sh.

[0030] In the case of an earth leakage circuit breaker, the tripping device 50 is installed, and in this state, the case 55 of the tripping device 50 can function as the shielding part Sh. On the other hand, in the case of a circuit breaker that does not have a tripping function for earth leakage current, if the case 55 is attached, it can function as the shielding part Sh. In this case, the tripping coil 51 and the like are not installed. By using it in this manner, it is possible to standardize the components and reduce the manufacturing cost.

[0031] Incidentally, when the circuit breaker 1 has multiple poles, the shielding portions Sh provided on some of the poles are formed by assembling a member separate from the base 11 and the cover 12 to the base 11, and it is also preferable that the shielding portions Sh provided on the other poles are formed integrally with the base 11 or the cover 12.

[0032] For example, the circuit breaker 1 in the example shown in Figures 1, 2 and 8 has three poles. For the pole on the right side shown in Figure 1, the case 55 of the tripping device 50 is formed as the shielding part Sh. On the other hand, for the pole on the left side, the shielding part Sh is formed on the back surface of the case 55. Note that for the pole in the center, the mechanism including the handle 17 may be formed as the shielding part Sh.

[0033] Although the present invention has been described above by taking the embodiment as an example, the present invention is not limited to the above embodiment and can be embodied in various forms. [Explanation of symbols]

[0034] 1 Circuit Breaker 11. Base 12 Cover 13 Movable contact 14 Movable contact 15 Fixed contact 16 Fixed contacts 17 Handle 18 Crossbar 51 Tripping coil 52 Plunger 55 cases Sh shielding part

Claims

1. A circuit breaker comprising: a contact unit including a movable contact provided on a movable contactor and a fixed contact provided on a fixed contactor; and a crossbar that moves the movable contactor up and down in conjunction with a handle, a shielding portion that covers an upper portion of the contact portion and at least an upper portion of a front surface of the crossbar and is capable of suppressing the conductive gas from migrating from the upper portion of the crossbar to the opposite side of the contact portion of the crossbar; A case is provided in which a tripping coil having a built-in plunger can be attached, The case is a separate member from the base and cover that form the outer shape, A circuit breaker in which a part of the case serves as a shielding portion.

2. As the crossbar rises, the upper end of the crossbar approaches the shielding portion, 2. The circuit breaker according to claim 1, characterized in that the conductive gas can be prevented from moving from above the crossbar to the opposite contact portion of the crossbar.

3. A circuit breaker comprising a contact section consisting of a movable contact provided on a movable contactor and a fixed contact provided on a fixed contactor, and a crossbar that raises and lowers the movable contactor in conjunction with a handle, a shielding portion that covers an upper portion of the contact portion and at least an upper portion of a front surface of the crossbar and is capable of suppressing the conductive gas from moving from the upper portion of the crossbar to the opposite side of the contact portion of the crossbar; It has multiple poles, The shielding portion provided on some of the electrodes is formed by assembling a member separate from the base and the cover to the base, A circuit breaker in which the shielding portion provided on the remaining part of the poles is formed integrally with the base or the cover.

Images