JP4700547B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a multi-pole circuit breaker in which a movable contact of each pole is brought into and out of contact with a fixed contact in accordance with an on / off operation of a handle.

  2. Description of the Related Art Conventionally, there has been provided a multipolar circuit breaker in which a movable contact of each pole is brought into and out of contact with a fixed contact in accordance with an on / off operation of a handle (for example, see Patent Document 1). The circuit breaker disclosed in Patent Document 1 is a three-pole type, one of which (for neutral wire connection) is not linked to the handle on / off operation, and the other two voltage poles are turned on to the handle. / Can be opened and closed in conjunction with the off operation. The two voltage poles have a contact opening / closing mechanism that contacts and separates the contact part consisting of a movable contact and a fixed contact according to the handle operation. The pole handles are connected via a connecting member. The circuit breaker includes a trip mechanism that trips the contact portion by detecting an overcurrent for each voltage electrode, and an interlock mechanism that operates the trip mechanism of each electrode in an interlocked manner. Thus, in this circuit breaker, by operating the handles of the poles connected via the connecting member, the contact portions of the poles can be turned on / off in conjunction with each other. In addition, when an overcurrent flows to one of the voltage electrodes and the trip mechanism performs a trip operation, the trip mechanism of the other voltage electrodes is interlocked and the trip operation is performed by the interlock mechanism. Can be forcibly opened.

  However, in this circuit breaker, the contact opening / closing mechanism is configured by a separate mechanism for each pole and is housed in a separate case, so that the handle of each pole is connected to interlock the contact portion of each pole. An interlocking mechanism that interlocks the connecting member and the trip mechanism of each pole is required, resulting in an increase in the number of parts and an increase in cost.

Therefore, the present applicant has proposed a circuit breaker in which a plurality of contact portions are opened and closed by a single contact switching mechanism (see, for example, Japanese Patent Application No. 2005-154703). That is, a plurality of storage chambers for storing the contact portions of each pole are provided in one case, and a fixed contact and a movable contact provided with a movable contact contacting and separating from the fixed contact are stored in each storage chamber. The movable contact of each pole is held by a cross bar arranged across each storage chamber, and the movable contact of each pole is operated by operating the cross bar in accordance with the on / off operation of one handle. Driven to turn on / off the contact portion. The cross bar is provided with a contact pressure spring that applies contact pressure when the movable contact contacts the fixed contact. The crossbar is biased by the opening spring in the direction of opening the contact portion of each pole. Also, the contact opening / closing mechanism operates by using a portion that is engaged with the latch member as a fulcrum by engaging with a latch member, which will be described later, and transmits a handle on / off operation to the crossbar to connect and separate the contact portion. It has a mechanism. The latch member retains the balance of the link mechanism in a state where the force in the direction of breaking the balance of the link mechanism by the contact pressure spring and the opening spring is accumulated by being locked with the link mechanism. When the overcurrent interrupting device detects an overcurrent flowing through the contact portion, the latch member is driven to release the locking state with the link mechanism, thereby breaking the balance of the link mechanism and performing the opening operation. The contact part of each pole is forcibly opened.
JP-A-8-138517 (paragraph numbers [0012]-[0019] and FIG. 1)

  In the above-mentioned circuit breaker, since the movable contact plate of multiple poles is held in one crossbar, and the single contact opening / closing mechanism operates the crossbar according to the handle operation, the contact portion is opened and closed. The spring force of the contact pressure spring that applies contact pressure to the contact portion of each pole is applied to the crossbar, and the spring force of the open spring that biases the crossbar in the direction in which the contact portion of each pole opens is also large. There was a need to do. Therefore, in a state where the latch member and the link mechanism are locked, the force of the contact pressure spring and the opening spring applied to the latch member is increased, and the overcurrent interrupting device removes the latch member from the link mechanism when an overcurrent occurs. When performing the pulling-out operation, there is a possibility that the latch member becomes difficult to come off and the trip operation is hindered.

  The present invention has been made in view of the above problems, and an object thereof is to provide a circuit breaker that facilitates driving of a latch member for performing a trip operation when an overcurrent flows. There is.

  In order to achieve the above object, the invention of claim 1 is characterized in that a plurality of movable contacts each having a movable contact contacting and separating from the fixed contact of each pole, and a contact when each movable contact contacts each fixed contact. A crossbar that supports each movable contact while holding a contact pressure spring that applies pressure between each movable contact and operates each movable contact in conjunction with each other, and a movable contact for each pole is a fixed contact An opening spring that urges the crossbar in the direction of opening from the handle, a handle support frame that rotatably supports the handle for on / off operation between the on operation position and the off operation position, and a plurality of links A link mechanism that moves the movable contact to and away from the fixed contact according to the on / off operation of the handle by transmitting the turning operation of the handle to the crossbar, and a link mechanism using a contact pressure spring and an opening spring The forces in the direction of breaking the balance of When an overcurrent flows between the latch member that holds the link mechanism in the stacked state and the fixed contact and the movable contact, the latch member is driven to break the balance of the link mechanism and forcibly open the movable contact from the fixed contact. This is a force that is weaker than the force in the direction that breaks the balance of the link mechanism by the contact pressure spring and the opening spring, and the link mechanism is attached in the opposite direction to the force by the contact pressure spring and the opening spring. And a holding spring for biasing.

  According to a second aspect of the present invention, in the first aspect of the invention, the link mechanism includes a U-shaped link having one end connected to a handle and the other end connected to a crossbar, and the other end of the U-shaped link is a handle. A loose insertion hole that is movable between an ON operation position and an OFF operation position is formed, and a first trip link that is rotatably supported by the handle support frame and one side that rotates to the first trip link. A second trip link that is supported movably and has a locking portion that is locked to the latch member on the other side, and has an elongated hole that allows the shaft supported by the handle support frame to be loosely inserted in the intermediate portion. The other end of the U-shaped link is inserted into a connecting hole provided in the crossbar, and the connecting hole drives the crossbar by operating the handle when the handle is turned on and off. U-shaped at possible operating positions The other end of the link is positioned, and the crossbar cannot be driven to the trip position where the crossbar cannot be driven by operating the handle until the overcurrent interrupting mechanism is activated and the link mechanism is unbalanced to shift to the OFF state. It is formed in the shape which the other end side of a character-shaped link can be located.

  According to a third aspect of the present invention, in the second aspect of the present invention, the holding spring is a torsion coil spring having a rotation fulcrum of the handle as a rotation axis, and one end side of the torsion coil spring is used as the first trip link and the other end. Each side is locked to one end side of the U-shaped link.

  According to a fourth aspect of the invention, in the third aspect of the invention, the locking portion of the second trip link is not locked with the latch member in the off state, and the handle is rotated from the off operation position to the on operation position. The torsion coil spring is engaged with the latch member halfway, and the torsion coil spring generates a spring force after the engaging portion is engaged with the latch member when the handle is rotated from the off operation position to the on operation position. In addition, a clearance is provided between both ends of the torsion coil spring and the first trip link and the U-shaped link.

  By the way, if the number of poles of the circuit breaker is increased, the number of contact pressure springs increases and the spring force by the contact pressure springs increases, so the force in the direction that breaks the balance of the link mechanism by the contact pressure springs and the open springs increases. However, although it becomes difficult to drive the latch member in a direction that breaks the balance of the link mechanism, according to the invention of claim 1, the holding spring has a weak force compared to the force of the contact pressure spring and the opening spring, and the contact pressure Since the link mechanism is urged in the opposite direction to the urging force of the spring and the open spring, the force required to drive the latch member when an overcurrent flows can be reduced and the latch member can be driven easily. Therefore, the trip operation can be surely performed. In addition, since it is not necessary to weaken the spring force of the contact pressure spring or the open spring to facilitate driving of the latch member, sufficient contact pressure can be applied when the movable contact of each pole contacts the fixed contact. When the overcurrent is detected and the contact is forcibly opened, the movable contact can be quickly opened from the fixed contact, and there is no possibility of reducing the breaking performance when an overcurrent occurs.

  According to the invention of claim 2, since the other end side of the U-shaped link is located at the operating position in the connecting hole at the ON operation position and the OFF operation position of the handle, when the handle is rotated, the U-shaped link By driving the crossbar on the other end side, the movable contact can be brought into and out of contact with the fixed contact. Further, when the overcurrent interrupting device detects the overcurrent and drives the latch member, the latching portion of the second trip link is detached from the latch member, and the other end side of the U-shaped link connected to the crossbar is Since it moves to the trip position in the connection hole, the movable contact can be forcibly opened from the fixed contact by moving the crossbar in the opening direction by the spring force of the opening spring and the contact pressure spring. Thus, even though it is a multi-pole type, it is possible to perform multiple pole on / off operations and trip operations in conjunction with each other by simply connecting the crossbar to the handle via a U-shaped link. A small circuit breaker can be realized.

  According to the third aspect of the present invention, the holding spring is a torsion coil spring that is pivotally supported by the handle support frame together with the handle, one end of which is engaged with the first trip link, and the other end is engaged with one end of the U-shaped link. Therefore, the work of attaching the holding spring can be easily performed.

  Furthermore, according to the invention of claim 4, when the handle is rotated from the off-operation position to the on-operation position, the spring force by the torsion coil spring is not applied from the beginning. Can be reduced.

  Embodiments of the present invention will be described below with reference to FIGS. In the following description, unless otherwise specified, the direction of the arrow ab in FIG. 5 is the front-rear direction, the direction of the arrow cd is the left-right direction, and the direction of the arrow ef is the up-down direction.

  As shown in FIGS. 5 to 7, the circuit breaker body 1 includes a voltage electrode housing portion 6 having an upper surface opened and a neutral electrode housing portion (not shown) having an open left side arranged in the left-right direction. The body 2 provided, the upper cover 3 attached to the body 2 so as to close the opening of the voltage electrode storage part 6, and the body 2 attached so as to close the opening of the neutral electrode storage part. The horizontal cover 4 and the lower cover 5 attached to the body 2 so as to cover the notch 8 provided at the lower corner of the front portion of the body 2 are configured.

  As shown in FIG. 7, a plurality (for example, three in this embodiment) of storage chambers 9 are formed in the voltage electrode storage unit 6 side by side in the horizontal direction. The chamber 9 accommodates a power supply side terminal 20a on the front side and a load side terminal 20b on the rear side, and is electrically connected to a contact portion 30 between the terminals 20a and 20b of each pole ( (See FIG. 1). In addition, the voltage electrode storage unit 6 has a contact opening / closing mechanism 40 for opening and closing each contact unit 30 in accordance with the opening / closing operation of the handle 42, and each contact unit when an abnormal current flows through any one of the contact units 30. An overcurrent interrupting device (electromagnetic release device 50 and thermal release device 60) for forcibly opening 30 in conjunction with each other is housed. Further, as shown in FIG. 7, the power supply side terminal 20c and the load side terminal 20d are housed on both sides in the front-rear direction, and the overcurrent cutoff device is activated when an abnormal current due to a ground fault is detected. An earth leakage interrupting mechanism (not shown) for forcibly opening the contact portions on the voltage electrode side and the neutral electrode side is housed.

  Here, the configuration of the voltage electrode side stored in the voltage electrode storage unit 6 will be described with reference to FIGS. A power-side terminal 20a and a load-side terminal 20b are disposed at both ends of each storage chamber 9 in the front-rear direction. A terminal plate 29a to which one end of a bimetal 61 constituting the thermal release device 60 is fixed is electrically connected to the load-side terminal 20b, and a terminal plate 29b having a fixed contact 30a is electrically connected to the power-side terminal 20a. It is connected to the. The fixed contact 30a constitutes the contact portion 30 together with the movable contact 30b provided on the movable contact 22, and the movable contact 22 contacts and separates from the fixed contact 30a according to an opening / closing operation of a contact opening / closing mechanism 40 described later. The movable contact 22 is electrically connected to one end of a coil 51 of an electromagnetic release device 50, which will be described later, via a connecting wire 23a made of a braided wire, and the other end of the coil 51 is a connecting wire 23b made of a braided wire. To the middle part of the bimetal 61. Thus, when the contact part 30 is closed, a main electric circuit through which a current flows is formed through the path of the power supply side terminal 20a → the contact part 30 → the coil 51 → the bimetal 61 → the load side terminal 20b. Further, a portion of the terminal plate 29b below the fixed contact 30a protrudes obliquely downward, and a part of the arc traveling plate 71 made of a conductive plate is overlaid. The arc traveling plate 71 is extended to the lower side of the central piece of the U-shaped yoke 52, and the arc generated during opening is extinguished between the central piece of the yoke 52 and the arc traveling plate 71. An arc-extinguishing grid 72 is arranged for this purpose.

  The contact opening / closing mechanism 40 has a handle support frame 41 that is formed in an inverted U shape in cross section by punching and bending a sheet metal, and is disposed above the central storage chamber 9. A handle 42 is pivotally supported on the frame 41 (see FIGS. 1, 6 and 7). As shown in FIG. 9, the handle 42 is integrally provided with a substantially cylindrical rotating body 42 a and a rectangular plate-shaped protruding piece 42 b protruding from the peripheral surface of the rotating body 42 a. The handle 42 is provided in the center of the shaft hole (not shown) on the left and right side walls of the handle support frame 41 and the center of the rotating body 42a with the protruding piece 42b protruding upward from the notch 41a on the upper surface of the handle support frame 41. By passing the handle shaft 43a through the shaft hole 42c, the handle support frame 41 is pivotally supported. A connecting hole 42e is formed in the lower portion of the rotating body 42a, and one leg piece 11a of the U-shaped link 11 is inserted into the connecting hole 42e.

  As shown in FIG. 5, a handle insertion hole 3a is opened on the upper surface of the upper cover 3 attached to the opening of the voltage electrode housing portion 6, and the protruding piece 42b of the handle 42 is passed through the handle insertion hole 3a. Protruding outside. In this state, the handle 42 is rotatable around the handle shaft 43a within a range in which the protruding piece 42b can move in the handle insertion hole 3a. A cap 70 formed wider than the protruding piece 42b is attached to the protruding piece 42b protruding outside through the handle insertion hole 3a. Grooves 42d extending in the width direction are formed on both side surfaces in the thickness direction of the protruding piece 42b, and the cross-sectional shape of the tip of the protruding piece 42b is formed in a substantially T shape. On the other hand, a T-shaped mortise 70a is formed in the cap 70, and the cap 70 is coupled to the projecting piece 42b by engaging the tip of the projecting piece 42b into the mortise 70a. Yes. By attaching the cap 70 wider than the protruding piece 42b to the protruding piece 42b as described above, the operability is improved, and the handle insertion hole 3a provided for inserting the protruding piece 42b is made narrower than the cap 70. Since it can do, insulation can be improved.

  Further, as shown in FIGS. 1 and 6, a cross bar 44 that supports the upper portion of each movable contact 22 and operates each movable contact 22 in an interlocked manner is rotatably attached to the handle support frame 41. ing. The cross bar 44 is formed with a connecting piece 44e protruding rearward from a portion close to the inner side surface of the left side wall of the handle support frame 41, and the other leg of the U-shaped link 11 is connected to the connecting piece 44e. A connecting hole 44d through which the piece 11b is inserted is opened. The connecting hole 44d has a long hole shape, and its front end protrudes obliquely downward and is formed in a substantially square shape. As shown in FIGS. 1 and 2, the other leg of the U-shaped link 11 is formed. When the piece 11b is located at the rear end in the connecting hole 44d (this position is referred to as the operating position), the leg piece 11b of the U-shaped link 11 is connected to the hole edge of the connecting hole 44d according to the turning operation of the handle 42. The crossbar 44 can be rotated by pressing. Further, as shown in FIG. 3, when the leg piece 11b of the U-shaped link 11 is located at the front end in the connecting hole 44d (this position is referred to as a trip position), the crossbar 44 is turned by the turning operation of the handle 42. Since the force of the contact pressure spring 46 and the opening spring 48 is received, the cross bar 44 rotates in the opening direction. At the on operation position and the off operation position of the handle 42, the other end 11 of the U-shaped link 11 has moved to the operating position in the connecting hole 44d. When the handle 42 is rotated in this state, the rotating body 42a The rotation operation is transmitted to the cross bar 44 via the link mechanism 10 (the U-shaped link 11), and the cross bar 44 rotates.

  Each movable contactor 22 has a movable contact 30b formed by bending its lower end portion into a substantially U shape, and a spring receiving piece 22a formed by bending its upper end portion into a substantially Z shape. The spring receiving piece 22a is housed in each spring receiving recess 44a of the cross bar 44. The cross bar 44 is formed with a stopper piece 44b substantially opposite to the inner surface of each spring receiving recess 44a so as to face the inner surface of each spring receiving recess 44a. A contact pressure spring 46 made of a coil spring is housed between the piece 22a and the stopper piece 44b. Further, the cross bar 44 is provided with a fulcrum projection 44 c that abuts on a portion of each movable contact 22 between the spring receiving piece 22 a and the movable contact 30 b, and the contact pressure spring 46 serves as the upper end of the movable contact 22. By urging the portion to the left side in FIG. 1, the lower end portion of the movable contact 22, that is, the movable contact 30b is urged to the right side in the drawing. Further, the shaft 43b whose both ends are supported on the left and right side walls of the handle support frame 41 is inserted into the center hole of the opening spring 49 made of a torsion coil spring, and one end side of the opening spring 49 is connected to the handle support frame 41. While being in contact with the upper surface, the other end is in contact with the upper surface of the cross bar 44, and the open bar 49 biases the cross bar 44 in the opening direction.

  The link mechanism 10 includes a U-shaped link 11, a first trip link 12, and a second trip link 13, and transmits the rotation operation of the handle 42 to the crossbar 44. The U-shaped link 11 is formed in a substantially U-shape, and one leg piece 11a is inserted into the connecting hole 42e provided in the rotating body 42a of the handle 42, and the other leg piece 11b is inserted into the connecting hole 44d of the cross bar 44. I am letting. The first trip link 12 is formed by subjecting a sheet metal to punching and bending, and is connected to the other leg piece of the U-shaped link 11 by connecting a tip portion that is substantially Y-shaped and divided into two forks. Is formed between the pair of rotating pieces 12a whose base portion of the vertical bar portion is pivotally supported by the shaft 43b, and one side edge of the tip portion divided into two forks of the rotating pieces 12a. The connecting piece 12b to be connected is integrally provided. The second trip link 13 is formed in a shape in which side pieces protrude in one direction from both side edges of the central piece, and both side pieces have shafts 43c whose both ends are held on both side walls of the handle support frame 41. A long hole 13a is inserted through the intermediate portion in the longitudinal direction. Further, both side pieces of the second trip link 13 are pivotally supported on a shaft 13b provided on the first trip link 12 on one end side in the longitudinal direction, and a latch plate 47 (latching) described later on the other end side in the longitudinal direction. A locking recess 13c (locking portion) for locking to the locking protrusion 47b of the member is provided. In this embodiment, the handle shaft 43a pivotally supporting the handle 42 is inserted into the center hole of the holding spring 58 made of a torsion coil spring, whereby the holding spring 58 is held by the handle shaft 43a. One end side of the holding spring 58 is locked to one end side (leg piece 11 a) of the U-shaped link 11, and the other end side is locked to the connecting piece 12 b of the first trip link 12. A force acting to expand both ends of the plate acts. The spring force of the holding spring 58 is set to a force that is weaker than the force in the direction of breaking the balance of the link mechanism 10 by the contact pressure spring 46 and the opening spring 48, and the force by the contact pressure spring 46 and the opening spring 48 is set. The link mechanism 10 is urged in the opposite direction.

  Here, in the state where the locking recess 13c of the second trip link 13 is locked to the locking protrusion 47b of the latch plate 47, that is, in the state where the latch plate 47 is latched, the contact pressure spring 46 and the opening are opened. The balance of the link mechanism 10 is maintained in a state in which the force in the direction of breaking the balance of the link mechanism 10 by the pole spring 49 (actually the force obtained by reducing the spring force in the opposite direction by the holding spring 58) is accumulated. In the ON operation position and the OFF operation position, the other end side of the U-shaped link 11 is positioned in an operating position where the cross bar 44 can be driven by operating the handle 42 in the connection hole 44d. On the other hand, when the locking protrusion 47b of the latch plate 47 and the second trip link 13 are released due to the operation of the overcurrent interruption mechanism, the link mechanism 10 is unbalanced, and immediately after that, the U-shaped link 11 The other end of the cross bar 44 is moved in the connecting hole 44d to a trip position where the cross bar 44 cannot be driven by the operation of the handle 42, and then the force of the contact pressure spring 46 and the opening spring 49 causes the cross bar 44 to move in the opening direction. Rotate. When the contact is forcibly opened, the other end side of the U-shaped link 11 moves to the above-mentioned operating position in the connecting hole 44d, and then when the closing operation is performed using the handle 42, the handle 42 is turned on. Accordingly, the cross bar 44 is rotated so that the movable contact 30b comes into contact with the fixed contact 30a.

  Further, as shown in FIGS. 1 and 6, the handle support frame 41 rotatably supports three latch plates 47 arranged to face the respective bimetals 61. Each latch plate 47 is formed in a band plate shape, and a bearing portion 47a projects from an intermediate portion of the surface opposite to the bimetal 61, and is integrally formed through a connecting pin 48 that passes through a shaft hole of the bearing portion 47a. It is connected. Further, the latch plate 47 at the center is provided with a protruding protrusion 47 b that protrudes in a substantially vertical direction from an intermediate portion of the surface opposite to the bimetal 61. Each latch plate 47 is pivotally attached to the handle support frame 41 by pivotally supporting a connecting pin 48 in support grooves 41c provided on the left and right side walls of the handle support frame 41 (FIG. 6). 1), when the latch plate 47 rotates clockwise in FIG. 1 around the connecting pin 48, the locked state between the locking recess 13c and the locking protrusion 47b of the second trip link 13 is released. It has become. Note that the upper end portion of the latch plate 47 is urged toward the bimetal 61 by a return spring 59. The return spring 59 is a torsion coil spring having a shaft 43d provided in the handle support frame 41 passing through the center. One end of the return spring 59 is on the upper surface of the handle support frame 41 and the other end is on the upper portion of the latch plate 47. It is in contact.

  In a state where the locking protrusion 47 b of the latch plate 47 is locked with the locking recess 13 c of the second trip link 13, that is, in a state where the second trip link 13 is latched by the latch plate 47. Since the turning operation of the handle 42 is transmitted to the cross bar 44 via the link mechanism 10, the cross bar 44 is driven to rotate so that the contact portion 30 can be contacted and separated. On the other hand, when the latch by the latch plate 47 is released, the handle 42 is rotated to the off position by the urging force of the urging spring (not shown), and the cross bar 44 is driven to rotate, so that the contact portion 30 is opened. To do. After the latch by the latch plate 47 is released and the contact portion 30 is opened, the contact portion 30 returns to the off state shown in FIG. 2, and the contact portion 30 can be opened and closed according to the subsequent handle operation.

  Here, in the off state shown in FIG. 2, since the other end side of the U-shaped link 11 has moved to the operating position in the connecting hole 44d, the handle 42 is rotated clockwise as far as shown in FIG. Then, the rotation of the handle 42 is transmitted to the cross bar 44 via the U-shaped link 11, and the cross bar 44 is driven to rotate counterclockwise so that the movable contact 30b of the movable contact 22 contacts the fixed contact 30a. (Closed state). At this time, one leg piece 11a of the U-shaped link 11 moves over the line connecting the other leg piece 11b and the handle shaft 43a to the opposite side (the left side in FIG. 1). And the force which urges | biases the handle | steering-wheel clockwise by the spring force of the opening spring 49 generate | occur | produces, and the handle | steering-wheel 42 hold | maintains an ON position.

  Further, in the on operation position shown in FIG. 1, the other end side (leg piece 11b) of the U-shaped link 11 has moved to the operating position in the connecting hole 44d. From this state, as shown in FIG. When rotating around, the rotational movement of the handle 42 is transmitted to the cross bar 44 via the U-shaped link 11, and the cross bar 44 is driven to rotate clockwise, so that the movable contact 30b of the movable contact 22 is fixed. Dissociates from contact 30a (opened state). When the handle 42 is rotated in the off direction, if the leg piece 11a of the U-shaped link 11 moves to the opposite side (right side in FIG. 2) beyond the line segment connecting the leg piece 11b and the handle shaft 43a, Since the force that biases the handle 42 counterclockwise is generated by the spring force of the pressure spring 46 and the opening spring 49, the handle 42 is rotated in the off direction and the off position is maintained.

  As described above, the handle support frame 41, the link mechanism 10, the latch plate 47, and the like constitute the contact opening / closing mechanism 40 that opens and closes the contact portion 30 according to the opening / closing operation of the handle 42. When an abnormal current such as a short circuit current or an overload current flows through the contact portion 30, the contact portion 30 is forcibly opened by the operation of the electromagnetic release device 50 or the thermal release device 60. .

  As shown in FIG. 1, the electromagnetic release device 50 includes a yoke 52 formed of a magnetic material in a substantially U shape, and the coil 51 is housed inside the yoke 52. The coil 51 is wound around the outer periphery of a coil cylinder 53 formed in a cylindrical shape by an insulating material. One end of the coil cylinder 53 in the axial direction (left side in FIG. 1) is open, and a fixed iron core 54 is attached to the opening. A movable iron core (not shown) is housed in the coil cylinder 53 so as to be movable in the axial direction, and a return made of a coil spring is provided between the movable iron core and the fixed iron core 54. A spring 56 is interposed, and the movable iron core is biased in the right direction in the figure by receiving the spring force of the return spring 56. The movable iron core is integrally provided with a hook pin 55 on one end surface in the axial direction (surface opposite to the fixed iron core 54), and a pressing pin 57 is fixed to the other end surface. The hook pin 55 protrudes to the outside through a through-hole provided in the end surface on the other end side in the axial direction of the coil cylinder 53, and a hook head 55a having a larger diameter than that of other portions of the hook pin 55 is formed at the tip portion. Has been. The pressing pin 57 is inserted into a through hole provided in each of the fixed iron core 54 and the yoke 52 so as to protrude from the yoke 52 to the outside.

  The electromagnetic release device 50 has the above-described configuration. When the coil 51 is energized, the magnetic resistance of the magnetic path passing through the fixed iron core 54 -the yoke 52 -the movable iron core -the fixed iron core 54 is reduced. A suction force acts between the movable iron core and the fixed iron core 54, and if the passing current to the coil 51 is an excessive current as in a short circuit of the load, the spring force of the return spring 56 The movable iron core moves against the fixed iron core 54 against the above. Therefore, when the electromagnetic release device 50 performs the opening operation when operated in this way, the contact portion 30 in the closed state can be forcibly opened. It is combined as follows.

  That is, as shown in FIG. 1 and FIG. 6, the hooking hole 22b formed at the portion of the movable contact 22 between the movable contact 30b and the spring receiving piece 22a is the tip of the hooking pin 55 provided on the movable iron core. When the movable iron core is attracted so as to approach the fixed iron core 54 by the excitation of the coil 51, the hook head 55a at the tip of the hook pin 55 is locked to the peripheral portion of the hook hole 22b. The movable contact 22 is pulled in a direction to separate it from the fixed contact 30a. The hooking hole 22b is formed in a shape (a so-called daruma hole) in which a locking hole having a smaller diameter than the hooking head 55a and an introduction hole having a larger diameter than the hooking head 55a are continuous. After passing the hooking head 55a, the hooking pin 55 is introduced into the locking hole, so that the hooking head 55a is locked to the peripheral portion of the locking hole, so that the electromagnetic release device 50 can be easily attached to the movable contact 22. Can be combined. Further, the tip of the pressing pin 57 fixed to the movable iron core is positioned so as to face the lower end of the latch plate 47, and when the movable iron core is sucked and moved by the fixed iron core 54, the pressing pin 57 is latched. The lower end portion of the plate 47 is pressed to the left in FIG. 1, and the latch plate 47 is rotated clockwise in FIG. 1 around the connecting pin 48 to release the locked state with the second trip link 13. ing.

  On the other hand, the thermal release device 60 includes the bimetal 61 as described above, the lower end portion of the bimetal 61 is fixed to the terminal plate 29a, and the adjustment screw 62 inserted in the bending direction of the bimetal 61 is screwed to the upper end portion. To do. The adjustment screw 62 faces the upper end of the latch plate 47. When the bimetal 61 is bent by an excessive current flowing through the main electric circuit, the latch plate 47 is pressed by the tip of the adjustment screw 62, thereby connecting the latch plate 47 to the connecting pin. 1 is rotated clockwise in FIG. 1 to release the locked state with the second trip link 13.

  By the way, in the bimetal 61, since the degree of bending (operation sensitivity) with respect to the passing current varies depending on the variation in the material of the bimetal 61, the connection position of the connection line 23b, and the like, the operation sensitivity (that is, thermal In order to prevent variation in the current passing through the main circuit when the release device 60 operates, it is necessary to adjust the protruding amount of the adjusting screw 62 from the bimetal 61 to the latch plate 47 side. Therefore, an adjustment window 3b is formed in the upper cover 3 in the vicinity of an adjustment screw 62 screwed to the bimetal 61, and a lid 63 shown in FIG. 6 is detachably attached to the adjustment window 3b. Thus, after assembly, the lid 63 is removed, and the adjustment screw 62 is operated with the adjustment window 3b opened. Since it is not necessary to operate the adjustment screw 62 once the adjustment screw 62 has been adjusted, the adjustment window 3b is closed with the lid 63, and the adjustment screw 62 may be inadvertently operated or foreign matter such as dust may be generated. Intrusion into the body 1 is prevented.

  Further, the power supply side terminal 20a and the load side terminal 20b are each composed of a terminal fitting 27 formed by bending a conductive metal plate to have a substantially rectangular shape and a tightening screw 28 screwed into an upper piece of the terminal fitting 27. And a terminal plate 21 that contacts the lower end of the tightening screw 28. Each terminal fitting 27 is accommodated in a terminal housing chamber 32 of a horizontal cross section formed in the container 1 so as to be movable up and down. That is, the terminal storage chamber 32 is larger in height than the terminal fitting 27, and the terminal fitting 27 is prevented from rotating in the terminal storage chamber 32 and can move only in the vertical direction. A screw operation hole 33 having a diameter that prevents the head of the tightening screw 28 from passing through is formed in the upper wall of the terminal storage chamber 32. Thus, when the tip of the driver is inserted into the screw operation hole 33 and the tightening screw 28 is rotated, the terminal fitting 27 moves up and down in accordance with the rotation direction of the tightening screw 28. The distance between the lower piece and the terminal board 21 can be changed. That is, after inserting a wiring member such as an electric wire or a bus bar through a connection hole 34 penetrating through the peripheral wall of the container 1 corresponding to a portion between the lower wall of the terminal storage chamber 32 and the terminal plate 21, By rotating the tightening screw 28, the lower piece of the terminal fitting 27 is brought close to the terminal plate 21, so that the wiring member is sandwiched between the lower piece of the terminal fitting 27 and the terminal plate 21, and electrical connection with the wiring member is made. To do.

  The circuit breaker of the present embodiment has the above-described structure, and a plurality of storage chambers 9 are arranged in one direction by partitioning the inside of the voltage electrode storage portion 6 on the voltage electrode side with a partition wall. The voltage electrode side contact portion 30 and the voltage electrode side input / output terminal (the power supply side terminal 20a and the load side terminal 20b) of each electrode are stored in each storage chamber 9 through the opening on the upper surface of the voltage electrode storage unit 6 from the outside. Since the contact opening / closing device 40 and the overcurrent interrupting device are disposed so as to straddle each storage chamber 9, the assembly is performed by attaching the upper cover 3 to the opening of the voltage electrode storage portion 6. Compared to the case where the contact parts 30 and the voltage side input / output terminals (terminals 20a, 20b) are assembled in separate containers and then connected to each other, the assembly work is reduced and the assembly workability is improved. A circuit breaker can be realized. Moreover, in the body 2, the voltage electrode storage portion 6 that stores the voltage electrode side contact portions 30 of a plurality of electrodes and the neutral electrode storage portion that stores the ground electrode side contact portions are arranged side by side in the arrangement direction of the storage chambers 9. Compared to the case where the circuit on the voltage electrode side and the circuit on the ground electrode side are housed in separate containers, less material is required for manufacturing the body 2, and material costs can be reduced.

  Next, the operation of this circuit breaker will be described. FIG. 1 shows a closed state of the contact portion 30 on the voltage electrode side, and the cap 70 of the handle 42 is tilted rightward around the handle shaft 43a. At this time, the latch plate 47 is urged counterclockwise in the drawing around the connecting pin 48 by the spring force of the return spring 59, and the upper end of the latch plate 47 faces the tip of the adjustment screw 62 provided on the bimetal 61. And the latch plate 47 accumulates a force obtained by subtracting the spring force in the opposite direction by the holding spring 58 from the force in the direction of breaking the balance of the link mechanism 10 by the contact pressure spring 46 and the opening spring 49. The balance of the link mechanism 10 is maintained by locking with the second trip link 13. Further, the cross bar 44 rotates counterclockwise, and the movable contact 30b of each movable contact 22 held by the cross bar 44 is in contact with the fixed contact 30a.

  On the other hand, as shown in FIG. 2, when the cap 70 of the handle 42 is tilted to the left in the drawing around the handle shaft 43a, the contact portion 30 is in an open state. That is, by rotating the handle 42 counterclockwise around the handle shaft 43a, the rotation of the handle 42 is transmitted to the cross bar 44 via the U-shaped link 11, and the cross bar 44 is rotated clockwise in the figure. The movable contact 30b of each movable contact 22 held by the cross bar 44 is dissociated from the fixed contact 30a. That is, the contact portion 30 of each pole on the voltage electrode side is opened and closed by opening and closing the handle 42. Note that, in the off operation state, the locking protrusion 47 b of the latch plate 47 is separated from the second trip link 13. The contact portion (not shown) on the ground electrode side is also opened / closed in conjunction with the opening / closing operation of the handle 42.

  By the way, in the closed state shown in FIG. 1, when an overload state occurs and an excessive current flows through the bimetal 61 and the bimetal 61 is bent, the adjustment screw 62 screwed into the bimetal 61 as shown by a broken line in FIG. As a result, the upper end of the latch plate 47 is pressed to the right in the figure. When an excessive current flows through the coil 51 due to a short circuit on the load side and the movable iron core is attracted to the fixed iron core 54, the lower end portion of the latch plate 47 is attached to the movable iron core. Is pushed to the left in the figure. Alternatively, when a leakage occurs on the load side, the leakage breaker mechanism provided on the ground electrode side opens the contact of the ground electrode and moves the interlocking lever 80 shown in FIGS. 7 and 8 downward in FIG. Then, the upper end of the latch plate 47 is pressed to the right in FIG. In either case, the latch plate 47 rotates clockwise around the connecting pin 48 in FIG. 1, and the latched state between the latch plate 47 and the second trip link 13 is released. At this time, the balance of the link mechanism 10 is lost, and the other end of the U-shaped link 11 is located in a trip position where the crossbar 44 cannot be driven by the operation of the handle 42 in the connection hole 44d. The crossbar 44 is rotated clockwise in FIG. 1 by the force of the spring 46 and the opening spring 49, and the contact portion 30 is opened. FIG. 3 shows a state immediately after the latch plate 47 is rotated and a trip operation is performed.

  When the latch state is released by the trip operation and the contact portion 30 is opened, the handle 42 can freely rotate around the handle shaft 43a, so that the handle 42 is returned to the off position by the spring force of the biasing spring. . At this time, since both the electromagnetic release device 50 and the thermal release device 60 are restored to the original state by opening the contact portion 30, the handle 42 is operated to switch to the off state after the trip operation is performed. Then, the contact portion 30 can be closed by performing an ON operation using the handle 42 thereafter.

  As described above, in the circuit breaker of this embodiment, the single contact switching mechanism 40 can open and close the contact portions 30 having a plurality of poles. However, if the number of poles of the circuit breaker is increased, the contact pressure Since the number of springs 46 increases and the spring force by the contact pressure spring 46 increases, the force in the direction of breaking the balance of the link mechanism 10 by the contact pressure spring 46 and the opening spring 49 increases, and the link mechanism is generated when an overcurrent occurs. It becomes difficult to drive the latch plate 47 in the direction of breaking the balance of 10. On the other hand, in the present embodiment, the holding spring 58 has a weak force compared to the force generated by the contact pressure spring 46 and the opening spring 49, and the link mechanism 10 is moved in the direction opposite to the force generated by the contact pressure spring 46 and the opening spring 49. Since it is energized, the force required to drive the latch plate 47 when an overcurrent flows can be reduced and the latch plate 47 can be easily driven by the overcurrent cutoff mechanism, and the trip operation is reliably performed. Can be made. In addition, since it is not necessary to weaken the spring force of the contact pressure spring 46 or the opening spring 49 in order to facilitate the driving of the latch plate 47, sufficient contact is achieved when the movable contact 30b of each pole contacts the fixed contact 30a. In addition to being able to apply pressure, the movable contact 30b can be quickly opened from the fixed contact 30a when an overcurrent is detected and the contact portion 30 is forcibly opened, and there is a possibility that the breaking performance when an overcurrent occurs is reduced. Absent.

  FIG. 8 shows the relationship between the load applied to the latch part of the third trip link 13 and the latch plate 47 and the rotation angle of the handle 42. In FIG. 8, A is the load applied to the latch part, and A is the contact pressure spring. 46 and the load by the opening spring 49, and C show the load by only the opening spring 49, respectively. When the handle 42 is rotated from the off position (0 degree) to the on position (63 degrees), the latch plate 47 and the second trip link 13 are not locked in the range from the off position to the rotation angle of 6 degrees. In addition, since both ends of the holding spring 58 are not in contact with the U-shaped link 11 and the first trip link 12, a load is not applied to the latch portion, and a necessary force at the time of operating the handle is reduced. Thereafter, when the rotation angle of the handle 42 reaches 6 degrees, the latch plate 47 and the second trip link 13 are locked, so that the spring load of the opening spring 49 is applied to the latch portion, and as the rotation angle increases. The load applied to the latch site increases. When the rotation angle reaches 29 degrees, the movable contact 30b comes into contact with the fixed contact 30a. Therefore, when the rotation angle ranges from 29 degrees to 63 degrees, the load by the contact pressure spring 46 is applied to the latch portion. When the rotation angle becomes 29 degrees, both ends of the holding spring 58 come into contact with the U-shaped link 11 and the first trip link 12, and the force in the direction opposite to the force by the contact pressure spring 46 and the opening spring 49 is latched. Therefore, the load applied to the latch portion (A in the figure) can be reduced as compared with the force exerted by the contact pressure spring 46 and the opening spring 49 (A in the figure). Here, the both ends of the holding spring 48 and the U-shaped link 11 and the second trip link 12 are connected so that the spring force of the holding spring 48 acts after the latch plate 47 is locked to the second trip link 12. Since the clearance is provided between them, when the handle 42 is rotated from the off operation position to the on operation position, the spring force by the holding spring 48 is not applied from the beginning, and the force required to turn on the handle 42 is not necessary. Can be reduced.

  In addition, since the leg piece 11b of the U-shaped link 11 is located at the operating position in the connecting hole 44d at the ON operation position and the OFF operation position of the handle 42, the leg piece 11b of the U-shaped link 11 is turned when the handle 42 is rotated. By driving the cross bar 44, the movable contact 30b can be brought into and out of contact with the fixed contact 30a. When the overcurrent interrupting device detects the overcurrent and drives the latch plate 47, the locking recess 13c of the second trip link 13 is disengaged from the locking protrusion 47b of the latch plate 47, and the crossbar 44 is driven. Since the leg piece 11b of the U-shaped link 11 connected to is moved to the trip position in the connection hole 44d, the cross bar 44 is moved in the opening direction by the spring force of the opening spring 46 and the contact pressure spring 49, The movable contact 30b can be forcibly opened from the fixed contact 30a. Thus, even though it is a multi-pole type, a plurality of poles on / off operation and trip operation can be interlocked by simply connecting the cross bar 44 to the handle 42 via the U-shaped link 11 only. A small circuit breaker with few parts can be realized.

  Further, the holding spring 58 is pivotally supported by the handle support frame 41 together with the handle 42, and one end side is locked to the first trip link 12, and the other end side is locked to the leg piece 11 a on one end side of the U-shaped link 11. Since the torsion coil spring is used, the operation of attaching the holding spring 58 can be easily performed.

  It should be noted that a wide variety of different embodiments can be configured without departing from the spirit and scope of the present invention, and the present invention is not limited to a specific embodiment.

It is sectional drawing which shows the voltage pole of the circuit breaker of this embodiment, and is an ON state. It is sectional drawing of an OFF state same as the above. It is sectional drawing which shows the state immediately after a trip same as the above. It is sectional drawing which shows the same and is rotating the handle | steering-wheel from an OFF operation position to an ON operation position. It is an external appearance perspective view of a circuit breaker same as the above. It is an external appearance perspective view of the state which removed the upper cover of the circuit breaker same as the above. It is a top view of the state which removed the upper cover of the circuit breaker same as the above. It is a figure which shows the relationship between the rotation angle of a handle same as the above, and the spring load added to a latch member. It is a disassembled perspective view of the handle | steering_wheel used for the same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Link mechanism 11 U-shaped link 12 1st trip link 13 2nd trip link 22 Movable contact 30 Contact part 30a Fixed contact 30b Movable contact 41 Handle support frame 42 Handle 44 Crossbar 46 Contact pressure spring 47 Latch plate 49 Opening spring 58 Holding spring 50 Electromagnetic release device 60 Thermal release device

Claims (4)

  Between each movable contact, a plurality of movable contacts each having a movable contact that contacts and separates from the fixed contact of each pole, and a contact pressure spring that applies a contact pressure when each movable contact contacts each fixed contact A crossbar that supports each movable contactor while being held in contact with each other and operates each movable contactor in conjunction with each other, and an opening spring that biases the crossbar in a direction in which the movable contact of each pole opens from the fixed contact And a handle support frame that rotatably supports the handle for the on / off operation between the on operation position and the off operation position, and a plurality of links, and transmits the rotation operation of the handle to the crossbar. As a result, the link mechanism in which the movable contact is brought into contact with and separated from the fixed contact according to the on / off operation of the handle and the force in the direction that breaks the balance of the link mechanism by the contact pressure spring and the opening spring is accumulated. A rack that maintains equilibrium An overcurrent blocking mechanism that drives the latch member when the overcurrent flows between the member and the fixed contact and the movable contact to break the balance of the link mechanism and forcibly opens the movable contact from the fixed contact; And a holding spring that biases the link mechanism in a direction opposite to that of the contact pressure spring and the opening spring. A circuit breaker.   The link mechanism has a U-shaped link having one end connected to the handle and the other end connected to a crossbar, and the other end of the U-shaped link is moved between an ON operation position and an OFF operation position of the handle. A free trip hole is formed, the first trip link is rotatably supported by the handle support frame, and one side is rotatably supported by the first trip link, and the other side is A second trip link provided with a latching portion for latching with the latch member, and having a long hole in which a shaft supported by the handle support frame is loosely inserted in the middle portion, and the other end of the U-shaped link The connection hole is inserted into a connection hole provided in the crossbar, and the connection hole is connected to the operation position where the crossbar can be driven by the operation of the handle in the ON operation position and the OFF operation position of the handle. The other side is located and the front The other end of the U-shaped link is located at the trip position where the crossbar cannot be driven by the handle operation until the overcurrent interrupting mechanism is activated and the balance of the link mechanism is shifted to the OFF state. 2. The circuit breaker according to claim 1, wherein the circuit breaker is formed in such a shape as to be possible.   The holding spring is a torsion coil spring having a rotation fulcrum of the handle as a rotation axis, and one end of the torsion coil spring is locked to the first trip link and the other end is locked to one end of the U-shaped link. The circuit breaker according to claim 2, wherein the circuit breaker is provided.   The locking portion of the second trip link is not locked with the latch member in the off state, and is locked with the latch member in the middle of rotating the handle from the off operation position to the on operation position. The torsion coil spring is configured such that when the handle is rotated from the off-operation position to the on-operation position, both ends of the torsion coil spring and 4. The circuit breaker according to claim 3, wherein a clearance is provided between the trip link and the U-shaped link.

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