Circuit breaker

Abstract

To provide a circuit breaker capable of improving assemblability of a holder unit.SOLUTION: A positioning and temporary fixing part 2223 capable of positioning a holder unit and temporarily fixing the holder unit to a bottom 2a by moving the holder unit 12 in a first linear direction toward the bottom wall of a first case side wall is provided.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] The circuit breaker is equipped with a holder unit mounted inside the main body case, which includes a movable contactor unit having a movable contact and a holder case that supports the movable contactor unit so that the movable contactor can rotate freely (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-154886 Summary of the Invention [Problem to be solved by the invention]

[0004] When assembling the circuit breaker of Patent Document 1, before fixing the holder unit to the bottom wall of the main body case, the movable contact unit is aligned so that the movable contact of the movable contactor normally comes into and out of contact with the fixed contact inside the main body case, and the aligned holder unit is temporarily fixed to the bottom wall of the case. This type of work of aligning and temporarily fixing the holder unit takes a lot of time, which causes problems in terms of workability in assembling the circuit breaker.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a circuit breaker that can improve the ease of assembly of a holder unit. [Means for solving the problem]

[0006] In order to achieve the above object, one embodiment of the circuit breaker of the present invention is a circuit breaker in which a holder unit is mounted inside a main body case consisting of a first case and a second case, the holder unit comprising a movable contactor unit and a holder case supporting the movable contactor unit so that the movable contactor can rotate freely, and the circuit breaker is provided with an alignment / temporary fixing portion that can align the holder unit and temporarily fix the holder unit to the bottom wall by moving the holder unit in a first linear direction toward the bottom wall of the first case. [Effects of the Invention]

[0007] According to the circuit breaker of the present invention, the assembly of the holder unit can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a mechanical molded case circuit breaker according to the present invention. [Figure 2] FIG. 2 is a perspective view showing a mover unit constituting the mechanical molded case circuit breaker. [Figure 3] FIG. 2 is a plan view showing a mover unit. [Figure 4] FIG. 2 is a perspective view showing a holder unit in which three-phase mover units are supported by a holder case. [Figure 5] FIG. 2 is a plan view showing a main part of the holder unit. [Figure 6] FIG. 6 is a view taken along the line IV-IV in FIG. 5. [Figure 7] FIG. 2 is a perspective view showing a main part of a holder unit. [Figure 8] FIG. 10 is a view showing a state in which the holder unit is being moved toward the bottom wall of the first case. [Figure 9] 10 is a view showing a state in which the holder unit is positioned and temporarily fixed to the bottom wall of the first case. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, it goes without saying that the drawings may include parts with different dimensional relationships and ratios.

[0010] Furthermore, the embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

[0011] FIG. 1 is a cross-sectional view showing a first embodiment of a mechanical molded case circuit breaker 1 for three-phase (R, S, T) AC connected between the power supply side and the load side of a circuit, and shows the circuit structure of one of the phases assembled in parallel in a main body case 2.

[0012] The mechanical molded case circuit breaker 1 has, inside the main body case 2, a switching mechanism 4 that opens and closes the switching contacts 3, a switching handle 5 that operates the switching mechanism 4, an overcurrent tripping device 6 that causes the switching mechanism 4 to trip when an overcurrent flows in the main circuit, and an arc extinguishing device 7.

[0013] The main body case 2 is configured by assembling a power supply side intermediate case 2b and a load side intermediate case 2c on top of a lower case 2a, and assembling a top cover 2d on top of the power supply side intermediate case 2b and the load side intermediate case 2c. Note that the first case described in the present invention corresponds to the lower case 2a, and the second case described in the present invention corresponds to the power supply side intermediate case 2b and the load side intermediate case 2c.

[0014] A power supply side main circuit terminal 8 and a load side main circuit terminal 9 are fixed to the lower case 2a. The switching contacts 3 are composed of a fixed contact 10 having a fixed contact 10a and a movable contact 11 having a movable contact 11a, and the movable contact 11 is rotatably supported by a holder unit 12. The fixed contact 10 is connected to the power supply side main circuit terminal 8, and the movable contact 11 is connected to the load side main circuit terminal 9 via the holder unit 12 and the overcurrent trip device 6.

[0015] The opening / closing mechanism 4 is composed of a toggle link mechanism (not shown) that connects the movable contact 11 and the opening / closing handle 5, and a latch mechanism that combines a latch (not shown) and a trip crossbar 13. When the trip crossbar 13 rotates counterclockwise, the opening / closing mechanism 4 trips, causing the movable contact 11 to perform an opening operation.

[0016] The overcurrent tripping device 6 is equipped with a heater 14 that heats up when an overcurrent flows between the power supply side main circuit terminal 8 and the load side main circuit terminal 9, a bimetal 15 fixed to the lower part of the heater 14, and an adjustment screw 16 that engages with the free end of the upper part of the bimetal 15 and can be moved back and forth to provide a predetermined gap between the bimetal 15 and the trip crossbar 13.

[0017] The holder unit 12 includes a movable element unit 17A (17B, 17C) shown in Figures 2 and 3, and a holder case 40 that integrates the three-phase movable element units 17A, 17B, and 17C in parallel, as shown in Figures 4(a) and (b).

[0018] The movable contact unit 17A (17B, 17C) comprises a holder base 23 having a connecting plate 20, a support portion 21 and a protrusion portion 22, a movable contact rotation axis 24 attached to the support portion 21 and supporting the movable contact 11 so that it can rotate freely, a movable contact pressure spring 25 and a pair of sliding contact pressure springs 26, 27.

[0019] In the holder base 23, a support portion 21 is formed continuously from one longitudinal end of the rectangular connecting plate 20. A through-hole 20a is formed on the other longitudinal end of the connecting plate 20. The support portion 21 is formed continuously from the other longitudinal end of the connecting plate 20 and includes a rising portion 28 that rises up and is formed continuously relative to the connecting plate 20, a pair of connecting plates 29, 30 that extend overlapping the rising portion 28, and a pair of plate-shaped sliding contacts 31, 32 that extend parallel to each other from the pair of connecting plates 29, 30 in a direction away from the rising portion 28. A shaft hole (not shown) is formed in the pair of sliding contacts 31, 32, through which the mover rotation shaft 24 passes.

[0020] 2, a protrusion 22 extending downward at a right angle to the connecting plate 20 is formed on the underside of the support portion 21. Although not shown, a protrusion 22 extending downward at a right angle to the connecting plate 20 is also formed on the underside of the linking plate 29.

[0021] The movable contact pressure spring 25 is a spring that exerts a spring restoring force on the movable contactor 11 in the closing direction, and as shown in Figure 3, is arranged so as to surround the movable contactor pivot shaft 24 outside the pair of sliding contactors 31, 32, and is equipped with a coil portion 25a that surrounds the movable contactor pivot shaft 24 on the side of one sliding contactor 31, a coil portion 25b that surrounds the movable contactor pivot shaft 24 on the side of the other sliding contactor 32, side springs 25c, 25d that extend from the coil portions 25a, 25b to both sides of the movable contactor 11, and a connecting spring 25e that connects the side springs 25c, 25d and crosses the top of the movable contactor 11.

[0022] The pair of sliding contact pressure springs 26 and 27 are arranged on the outer surfaces of the pair of sliding contacts 31 and 32 so as to surround the mover rotation shaft 24 .

[0023] Then, as shown in FIGS. 4(a) and 4(b), the holder unit 12 is assembled by attaching a long holder case 40 to the three-phase mover units 17A, 17B, and 17C arranged in parallel.

[0024] As shown in Figures 5 and 6, the holder case 40 houses the mover rotation shaft 24, sliding contacts 31 and 32, a pair of sliding contact pressure springs 26 and 27, and mover pressure spring 25 of each mover unit 17A (17B, 17C).

[0025] As shown in FIG. 5, the holder case 40 has a mover opening 41 formed along the movable range of the movable contact 11 of the mover unit 17A (17B, 17C) of each phase.

[0026] 6, both ends of the movable contact rotation shaft 24 are inserted into and supported in holder case recesses 42 formed in the inner wall of the holder case 40. The pair of sliding contact pressure springs 26, 27 are arranged in a compressed spring state inside the holder case 40, and apply spring force in a direction in which the pair of sliding contacts 31, 32 come into close surface contact with the base end of the movable contact 11.

[0027] 5 and 7, only the connecting spring 25e arranged on the upper part of the movable contactor 11 of the movable contact pressure spring 25 is exposed to the outside from the movable contact opening 41. When the movable contactor 11 performs an opening operation, the side springs 25c and 25d of the movable contact pressure spring 25 move within the internal space of the holder case 40. Therefore, the opening width H of the movable contact opening 41 shown in FIG. 7 is set to a dimension slightly larger than the width dimension of the movable contactor 11.

[0028] Next, FIGS. 8 and 9 show the operation of temporarily fixing the holder unit 12 to the lower case 2a.

[0029] As shown in Fig. 8, a bottom wall recess 43 into which the protrusion 22 of the holder unit 12 fits is formed on the bottom wall of the lower case 2a. When the holder unit 12 is moved downward relative to the lower case 2a, the protrusion 22 fits into the bottom wall recess 43, and the holder unit 12 is temporarily fixed to the lower case 2a. At the same time that the protrusion 22 fits into the bottom wall recess 43, the movable contact 10a of the movable contactor 11 of the holder unit 12 is positioned so that it can be brought into and out of contact with the fixed contact 10a of the fixed contactor 10, thereby completing the alignment of the holder unit 12. Note that the first linear direction described in the present invention corresponds to the downward direction in which the holder unit 12 moves relative to the lower case 2a, the recess described in the present invention corresponds to the bottom wall recess 43, and the protrusion described in the present invention corresponds to the protrusion 22.

[0030] As shown in FIGS. 4(a) and 4(b), the holder case 40 has the following on both longitudinal side surfaces: A gripping portion 44 that can be gripped by a chuck portion (not shown) of an automatic assembly machine is formed. When the automatic assembly machine grips the gripping portion 44 with its chuck portion, it moves the holder case 40 downward toward the bottom wall of the lower case 2a, whereby the protrusion 22 of the holder unit 12 fits into the holder case recess 42 of the lower case 2a, and automatic alignment and temporary fixation of the holder unit 12 can be performed.

[0031] In the mechanical molded case circuit breaker 1 configured as described above, when an overcurrent flows between the power-source side main circuit terminal 8 and the load side main circuit terminal 9, the bimetal 15, which is bent by the heating of the heater 14, comes into contact with the trip crossbar 13 of the switching mechanism 4, causing the trip crossbar 13 to rotate counterclockwise, and the switching mechanism 4 trips, causing the movable contact 11 to perform a current-limiting opening operation. During the current-limiting opening operation of the movable contact 11, an arc is generated between the fixed contact 10a and the movable contact 11a, and arc gas and metal deposits generated between the contacts 10a, 11a attempt to enter the inside of the holder case 40 through the movable contact opening 41. However, because the opening width of the movable contact opening 41 is set small (slightly larger than the width dimension of the movable contact 11), it is difficult for the arc gas and metal deposits to enter the inside of the holder case 40.

[0032] Furthermore, if the movable contactor 11 collides with a strong force against the inner wall 2b1 (see FIG. 1) of the power supply side intermediate case 2b when the movable contactor 11 performs a current-limiting opening operation, the impact may be transmitted to the movable contactor units 17A, 17B, 17C via the movable contactor rotating shaft 24, which may affect the sliding current flowing between the pair of sliding contactors 31 and 32 and the base end of the movable contactor 11 due to deformation of the pair of sliding contactors 31 and 32. However, even if the impact of the movable contactor 11 due to contact with the inner wall 2b1 is transmitted to the movable contactor rotating shaft 24, in this embodiment, as shown in FIG. 6, both ends of the movable contactor rotating shaft 24 are inserted into and supported in the holder case recesses 42 formed in the inner wall of the holder case 40, and therefore the impact force transmitted to the movable contactor rotating shaft 24 is absorbed by the holder case 40 via the holder case recesses 42, and therefore does not affect the pair of sliding contactors 31 and 32 and the sliding current flowing between the base end of the movable contactor 11.

[0033] Therefore, in this embodiment, when the holder unit 12 is temporarily fixed to the lower case 2a, by moving the holder unit 12 downward relative to the lower case 2a, the protrusions 22 of the holder unit 12 fit into the bottom wall recesses 43 of the lower case 2a, thereby positioning and temporarily fixing the holder unit 12. This improves the ease of assembly of the holder unit 12.

[0034] In addition, the chuck portion of the automatic moving machine grasps the gripping portion 44 of the holder unit 12, and the automatic machine moves the holder case 40 downward toward the bottom wall of the lower case 2a, thereby automatically aligning and temporarily fixing the holder unit 12, making the assembly work of the holder unit 12 even more efficient.

[0035] In addition, arc gas and metal deposits generated during the current-limiting opening operation of the movable contact 11 are less likely to enter the interior through the movable contact opening 41, the opening width of which is set narrow in the holder case 40, and contact with the movable contact pressure spring 25 and the pair of sliding contact pressure springs 26, 27 housed within the holder case 40 is prevented, thereby preventing malfunction of the rotation of the movable contact 11. [Explanation of symbols]

[0036] 1 Mechanical wiring circuit breaker 2 Main unit case 2a Lower case 2b Power supply side intermediate case 2c Load side intermediate case 2d top cover 3 Switching contacts 4 Opening and closing mechanism 5 Opening and closing handle 6. Overcurrent tripping device 7 Arc extinguishing device 8 Power supply side main circuit terminal 9 Load side main circuit terminal 10 Fixed contact 10a fixed contact 11 Movable contact 11a Movable contact 12 Holder unit 13 Trip Crossbar 14 Heater 15 Bimetal 16 Adjustment screw 17A, 17B, 17C Mover unit 20 Connection plate 20a through hole 21 Support part 22 Protrusion 23 Holder base 24 Mover rotation axis 25. Mover contact pressure spring 25a, 25b Coil section 25c, 25d side springs 25e connecting spring 26,27 Sliding contact pressure spring 28 Rising section 29, 30 connection plate 31,32 Sliding contact 40 Holder Case 41 Mover opening 42 Holder case recess 43 Bottom wall recess 44 Gripping part H: Opening width of the moving element opening

Claims

1. A circuit breaker in which a holder unit is mounted inside a main body case consisting of a first case and a second case, the holder unit including a movable contactor unit having a movable contact and a holder case supporting the movable contactor unit so that the movable contactor is rotatable, A circuit breaker characterized in that it is provided with an alignment / temporary fixing portion that can align the holder unit and temporarily fix the holder unit to the bottom wall by moving the holder unit in a first linear direction toward the bottom wall of the first case.

2. 2. The circuit breaker according to claim 1, wherein the alignment / temporary fixing portion is composed of a recess provided in a bottom wall of the first case and a protrusion provided in a part of the holder unit, which is inserted into the recess to align and temporarily fix the holder unit.

3. The mover unit comprises: a holder base fixed to the bottom wall; a pair of sliding contacts formed integrally with the holder base and arranged to sandwich both side surfaces of the base end of the movable contact; a mover rotation shaft that passes through the base end portion and the pair of sliding contacts; a pair of sliding contact pressure springs that bring the base end portion and the pair of sliding contacts into close contact with each other; a movable contact pressure spring that urges the movable contact in a closing direction, 3. The circuit breaker according to claim 2, wherein the protrusion is formed integrally with the holder base and protrudes in a direction opposite to the position where the pair of sliding contacts are formed.

4. 4. The circuit breaker according to claim 3, wherein the holder case accommodates the pair of sliding contacts, the movable contact rotating shaft, the pair of sliding contact pressure springs, and the movable contact pressure spring therein, and a movable contact opening is formed along the movable range of the movable contact, and the opening width of the movable contact opening is set to a dimension slightly larger than the width dimension of the movable contact.

5. 5. The circuit breaker according to claim 1, wherein the holder case is provided with a gripping portion that is gripped by an automatic assembly machine, and the automatic assembly machine moves the holder unit in the first linear direction, thereby aligning and temporarily fixing the holder unit using the alignment / temporary fixing portion.

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