JP4200258B2 - Undervoltage trip device with early contact for circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an undervoltage trip device with an early contact as an accessory device (optional product) applied to a circuit breaker such as a circuit breaker.
[0002]
[Prior art]
Various circuit breakers are available as optional items for the circuit breaker mentioned above, and one of them is an undervoltage trip device with a quick contact. This undervoltage trip device is attached to the circuit breaker body and trips the circuit breaker when the main circuit voltage drops abnormally during energization. The unit case has a circuit breaker on the main circuit power supply side. An electromagnet that is excited by being connected to the electromagnet, a tripping lever that links the electromagnet and the trip mechanism of the breaker body, and a quick contact point that is coupled to the operation handle of the breaker holder through the energization circuit of the electromagnet When the main circuit contact is turned on by operating the handle after the circuit breaker is tripped, the undervoltage trip device with early contact is reset prior to closing the main circuit contact. Such a configuration is known.
[0003]
Here, before explaining the undervoltage tripping device with the early contact point contact, the outline of the configuration of the circuit breaker for the wiring breaker is shown in FIGS. In FIG. 3, 1 is a main body case of a circuit breaker, 2 is a main circuit contact breaker, 3 is a contact opening / closing mechanism for the breaker 2, 4 is an overcurrent tripping device, and 5 is a rotary mounted on the upper surface of the cover. An operation handle 6 is a gear mechanism that connects the operation handle 5 and the contact opening / closing mechanism 3 to transmit the handle operating force to the contact opening / closing mechanism.
[0004]
Here, the gear mechanism 6 includes a combination of a rotating gear 8 connected to the shaft of the operation handle 5 and a toggle gear 9 assembled to the contact opening / closing mechanism 3 as shown in FIG. When the operation handle 5 is turned from the OFF position to the ON position, the toggle link mechanism 3a of the contact opening / closing mechanism section 3 operates via the gear mechanism 6, and the main circuit of the cutoff section 2 via the opening / closing spring 3b and the opening / closing lever 3c. Close the contact. Conversely, when the operation handle 5 is turned from the ON position to the OFF position, the toggle link mechanism 3a and the opening / closing lever 3c are reversed to open the main circuit contact. When the main circuit contact is reintroduced after the trip operation is performed by the operation of the overcurrent tripping device 4, the operation handle 5 is temporarily turned from the TRIP position to the RESET position (same as the OFF position), and the contact switching mechanism 3 After resetting the latch mechanism 3d, the main circuit contact is closed by turning the operation handle to the ON position. The structure and operation of the contact switching mechanism are described in detail in Japanese Patent Application No. 11-192712 previously proposed by the same applicant as the present invention.
[0005]
Next, the conventional structure and operation of an undervoltage trip device with a quick contact point attached to the main body of the circuit breaker will be described with reference to FIGS. In the figure, an undervoltage tripping device 10 as an external accessory device is mounted on the outer surface of the circuit breaker body case 1, and the unit case 11 is inserted into an energizing circuit of an attached terminal 12, an electromagnet 13, and an electromagnet 13. In addition, a quick-release contact mechanism 14, a tripping lever 15 linking the armature 13 a of the electromagnet 13 and the latch mechanism of the circuit breaker body are provided.
[0006]
Here, the trip lever 15 has a pin 15a protruding laterally from the upper end so that it faces the shoulder of the trip plate 3e (see FIG. 7 (a)) assembled to the contact opening / closing mechanism of the circuit breaker body. In the steady state where the main circuit voltage is normal, the tripping lever 15 is pushed upward against the spring force of the return spring 15b by the attracting operation of the electromagnet 13, and the pin 15a is detached from the tripping plate 3e. The latch mechanism of the circuit breaker body is held in the engaged state. On the other hand, if the main circuit voltage drops abnormally during energization, the spring force of the return spring 15b overcomes the attractive force of the electromagnet 13 and pulls the trip lever 15 downward. As a result, the pin 15a pushes down the tripping plate 3e of the breaker body to release the latch mechanism, and trips the circuit breaker.
[0007]
The early contact mechanism 14 includes a fixed contact 14a, a movable contact 14b, and an oscillating contact holder 14c that supports the movable contact 14b. The contact holder 14c is attached to its upper end with its lower end as an axis fulcrum. The pin 14c-1 on the horizontal axis is connected to the drive lever 16 incorporated in the case of the breaker body. The contact holder 14c is biased by a return spring in a direction to open the contact (counterclockwise). The drive lever 16 is arranged on the side of the operation handle 5 against the moving path of the cam 17 connected to the operation handle, and the contact holder 14c is interposed via the cam 17 and the drive lever 16 when the handle 5 is turned on. To drive. In the figure, the operating positions corresponding to the ON and OFF of the armature 13a of the electromagnet 13, the contact holder 14c of the quick contact mechanism 14 and the drive lever 16 are drawn by solid lines.
[0008]
In such a configuration, when the main circuit contact is re-inserted after the tripping operation of the circuit breaker body, the handle 5 is manually rotated in the trip state shown in FIG. b) After once moving to the RESET position, when the operation handle 5 is rotated about 10 ° clockwise, the cam 17 rotating in conjunction with the operation handle 5 pushes the drive lever 16 and swings counterclockwise. Then, the tip of the drive lever 16 moves to the left to drive the contact holder 14c of the quick contact mechanism 14 from the OFF position to the ON position. As a result, the fixed contact 14a and the movable contact 14b of the early entry contact mechanism 14 are conducted, and the electromagnet 13 is energized. Further, when the electromagnet 13 is excited, the armature 13a performs a suction operation, pulls up the tripping lever 15, and releases the restraint of the tripping plate 3e of the circuit breaker body. As a result, the trip plate 3e is pushed up by the return spring 3f, and a standby state in which the latch claw of the latch mechanism 3e and the latch receiver are engaged with each other is brought about. Then, when the operation handle 5 is continuously rotated clockwise and moved to the ON position in FIG. 7C, the main circuit contact is closed by the operation of the contact opening / closing mechanism 3 as described in FIG.
[0009]
[Problems to be solved by the invention]
However, the following problems to be solved remain in the conventional configuration of the undervoltage trip device described above. In other words, the various external accessory devices prepared as optional circuit breakers have standardized their case external dimensions, and in addition to electromagnets, such as undervoltage trip devices with early contacts, The accessory device with the built-in contact mechanism is also required to use a case having the same external dimensions as other accessory devices that are not equipped with the early contact mechanism.
[0010]
For this reason, the undervoltage trip device with early contact is greatly limited in terms of space as compared to an exterior accessory device that is not equipped with an early contact mechanism. In addition, the quick-contact mechanism is required to secure a stroke corresponding to the contact gap between the fixed / movable contacts and the contact wipe with a margin considering the wear of the fixed / movable contacts due to its dielectric strength and functionality. The
[0011]
On the other hand, the drive lever 16 (see FIGS. 5 and 6) built in the circuit breaker body for driving the contact holder of the quick contact mechanism is also limited in its component dimensions and operation stroke due to the space of the circuit breaker case. Therefore, it is difficult to ensure a large operation stroke.
Considering the above-described conventional undervoltage trip device with a quick contact point as described above, the contact holder 14c of the quick contact point mechanism 14 is connected to the drive lever 16 on the breaker body side as described in FIGS. The stroke of the drive lever 16 interlocked with the operation handle 5 is transmitted directly to the contact holder 14c, and the contact of the quick contact mechanism 14 is turned on. Therefore, the stroke transmission ratio between the drive lever and the contact holder is 1, so that the contact opening / closing stroke of the quick contact mechanism 14 has almost no allowance, and the contact gap required for ensuring the dielectric strength and the long-term use. It is difficult to provide a sufficient design margin for contact wipes that can handle contact wear.
[0012]
The present invention has been made in view of the above points, and by adding a few parts, the operation stroke of the drive lever of the circuit breaker body can be amplified and transmitted to the contact holder of the quick-contact mechanism. An undervoltage trip device with an early contact point for a circuit breaker that has been improved so that a sufficient stroke can be secured for the contact gap and contact wipe even under the space constraints imposed as an external device attachment device. The purpose is to provide.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an undervoltage trip device used by attaching to a circuit breaker main body as an accessory device of a circuit breaker, the electromagnet and tripping device in the unit case of the device Equipped with an undervoltage trip mechanism combined with a lever, and a quick contact mechanism inserted in the electromagnet energization circuit, and the quick contact mechanism supports the movable contact on a swing contact holder, When the contact holder is connected to the drive lever linked to the operation handle of the circuit breaker body, and the reopening is performed after the trip of the circuit breaker, the early contact is turned on prior to closing the main circuit contact. ,
Stroke amplifying means for amplifying the output stroke of the drive lever and transmitting it to the contact holder is provided between the contact holder of the early contact mechanism and the drive lever on the circuit breaker body side (Claim 1). Specifically, the stroke amplification means can be realized in the following manner.
[0014]
(1) As a stroke amplifying means, an intermediate lever that swings following the stroke of the drive lever is provided, and an inclined cam is formed at the tip of the contact holder so as to face the tip pin of the intermediate lever. ), When the quick contact mechanism is driven to the closing position via the drive lever by operating the handle, the operation stroke of the drive lever is amplified by the cooperative action of the intermediate lever and the inclined cam portion formed on the contact holder. The contact holder of the incoming contact mechanism is driven to increase the contact stroke.
[0015]
(2) As a stroke amplifying means, an intermediate lever that swings following the stroke of the drive lever is provided, and an inclined cam is formed at the tip of the drive lever so as to face the tip pin of the intermediate lever. ) When the quick contact mechanism is driven to the closing position through the drive lever by operating the handle, the operation stroke of the drive lever is amplified by the cooperative action of the intermediate lever and the inclined cam portion formed on the drive lever. The contact holder of the incoming contact mechanism is driven to increase the contact stroke.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the examples shown in FIGS. In the drawings of the embodiments, members corresponding to those in FIGS. 5 to 7 are denoted by the same reference numerals and description thereof is omitted.
[Example 1]
1 (a) and 1 (b) show an embodiment corresponding to claims 1 and 2 of the present invention. In this embodiment, an intermediate lever 18 is additionally provided in the case 11 of the undervoltage trip device 10 that swings in response to the stroke operation of the drive lever 16 built in the circuit breaker body. In contrast, an inclined cam portion 14c-2 is formed on the upper surface of the contact holder 14c on the surface facing the tip pin 18a of the intermediate lever.
[0017]
Here, the intermediate lever 18 has a lower end pivotally supported by the case 11, and a horizontal axis pin 18 a attached to the tip of the lever protrudes inward of the circuit breaker case 1 to face the tip of the drive lever 16. Further, the intermediate lever 18 is set at a position where the shaft fulcrum is moved to the right end side in the case 11 as shown in the figure, and in the standby position represented by a solid line in FIG. The tip pin 18a is opposed to the drive lever 16 in an inclined posture. On the other hand, the inclined cam portion 14c-2 formed on the contact holder 14c is V-shaped, and the inclination angle of the cam surface is about 40 °. The cam portion 14c-2 is at the OFF position of the early contact mechanism shown by a solid line in the drawing. Is opposed to the tip pin 18 a of the intermediate lever 18.
[0018]
With such a configuration, the drive lever 16 is moved horizontally from the standby position as described with reference to FIGS. 5 and 6 in the process of turning the operation handle 5 from the reset position to the ON position when the circuit breaker is turned on again after the trip operation. When the stroke is operated in the direction, the intermediate lever 18 is rotated clockwise around the fulcrum, and the intermediate lever 18 is in a substantially upright posture as indicated by a dotted line at the stroke end of the drive lever 16. With this movement, the tip pin 18a moves along the movement locus P shown in FIG. When the tip pin 18a of the intermediate lever 18 moves from the left to the right along the movement locus P, the contact point between the tip pin 18a and the inclined cam portion 14c-2 of the contact holder 14c becomes a valley along the cam surface. Move from the tip to the tip (upward). Therefore, the rotation angle with the lower end of the contact holder 14c as a fulcrum increases, and the ratio of the movement stroke (horizontal direction) of the contact holder 14c to the operation stroke of the drive lever 16 is amplified to about 1.4. That is, the moving stroke of the contact holder 14c is expanded by about 1.4 times the stroke amount of the drive lever 16.
[0019]
As a result, a sufficiently large contact gap and contact wipe can be secured between the fixed contact 14a and the movable contact 14b incorporated in the quick-contact mechanism 14 even under limited space constraints. .
[Example 2]
Next, FIG. 2 shows an applied embodiment corresponding to claims 1 and 3 of the present invention. In this embodiment, an intermediate lever 18 is additionally provided in the same manner as in the first embodiment, and the cam surface protrudes from the distal end portion of the drive lever 16 so as to face the distal end pin 18a of the intermediate lever as shown in the figure. An inclined cam portion 16a whose height expands upward is formed, and the tip pin 18a of the intermediate lever 18 is in contact with the lower end of the inclined cam portion 16a at the standby position indicated by the solid line in the figure.
[0020]
From this point, when the drive lever 16 is moved in the right direction, the intermediate lever 18 is pushed by the drive lever 16 and rotates clockwise, and the contact holder 14c of the quick-contact mechanism is sandwiched between the tip pin 18a of the intermediate lever 18. Moves to the right. Further, the tip pin 18a of the intermediate lever moves along the inclined cam 16a of the drive lever 16 while moving the movement locus P along the inclined cam 16a of the drive lever 16 with this movement, and at the stroke end of the drive lever 16 indicated by the dotted line, the contact point The holder 14c is pushed further to the right by the cam height of the inclined cam portion 16a with respect to the position of the drive lever 16. In this case, when the inclination angle of the inclined cam portion 16a is set to 20 °, the ratio of the movement stroke (horizontal direction) of the contact holder 14c to the operation stroke of the drive lever 16 is amplified to about 1.4.
Thereby, the effect equivalent to Example 1 mentioned previously is acquired. In addition, Example 1 and Example 2 can also be implemented together.
[0021]
【The invention's effect】
As described above, according to the present invention, in the undervoltage trip device having a built-in early contact mechanism as an external accessory for a circuit breaker, the contact between the drive lever and the early contact mechanism built in the breaker body side. An intermediate lever tip pin is interposed between the intermediate lever and the intermediate lever, and an inclined cam is formed at the tip of the contact holder or drive lever so as to face the intermediate pin. By amplifying the stroke of the drive lever by the action and transmitting it to the contact holder of the early-breaking contact mechanism, the quick-contacting mechanism can be used in a narrow space in the case that is dimensioned as an external accessory for a circuit breaker. This ensures a sufficient stroke for contact gaps and contact wipes, and this makes it possible to provide an undervoltage trip with a quick contact that is highly reliable in terms of function and insulation. It is possible to provide a.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram of an undervoltage trip device with early contact according to Embodiment 1 of the present invention, (a) is an internal side view of the entire device in a state where it is mounted on a circuit breaker, (b) Fig. 2 (a) is an enlarged view showing the operation of the stroke amplification mechanism in Fig. 2 Fig. 2 is an explanatory diagram of the structure and operation of the stroke amplification mechanism according to Embodiment 2 of the present invention. Fig. 3 is intended for a circuit breaker for wiring. Fig. 4 is a detailed structural diagram of the contact switching mechanism in Fig. 3. Fig. 5 is a plan view of the state of use in which a circuit breaker is mounted with a conventional undervoltage trip device with an early contact. FIG. 6 is a side view showing the internal structure of the undervoltage trip device in FIG. 5. FIG. 7 is an operation explanatory diagram of the breaker body in FIG. 5 and FIG. 6 and the quick contact mechanism of the undervoltage trip device. Yes, (a) Circuit breaker body: TRIP, Early entry contact: OFF, (b) Breaker body: RESET, Early entry contact: OFF, (c) Diagram showing the operating state of breaker body: ON, early entry contact: ON
DESCRIPTION OF SYMBOLS 1 Main body case of a circuit breaker 2 Main circuit contact breaking part 3 Contact switching mechanism part 4 Overcurrent tripping device 5 Rotary operation handle 10 Undervoltage tripping device 13 Electromagnet 14 Early contact mechanism 14a Fixed contact 14b Movable contact 14c Contact Holder 14c-2 Inclined cam portion 15 Trip lever 16 Drive lever 16a Inclined cam portion 18 Intermediate lever 18a Tip pin

Claims (3)

An undervoltage trip device used by attaching to a circuit breaker body as an accessory device of a circuit breaker, an undervoltage trip mechanism combining an electromagnet and a trip lever in a unit case of the device, and the electromagnet Equipped with a quick contact mechanism inserted in the energization circuit, and the quick contact mechanism supports the movable contact with a swinging contact holder, and the drive lever interlocks with the operation handle of the circuit breaker body. In the case where the quick contact is turned on prior to closing the main circuit contact when the circuit breaker is re-connected after the trip of the circuit breaker, the contact holder of the quick contact mechanism and the breaker body side A circuit breaker comprising a stroke amplifying means for amplifying the output stroke of the drive lever and transmitting it to the contact holder Contact with undervoltage tripping device enters. 2. The undervoltage trip device according to claim 1, wherein an intermediate lever that swings in accordance with a stroke of the drive lever is provided as a stroke amplifying means, and the tip of the contact holder is opposed to the tip pin of the intermediate lever. An undervoltage trip device with an early contact point for a circuit breaker characterized by forming an inclined cam. 2. The undervoltage trip device according to claim 1, wherein an intermediate lever that swings in accordance with a stroke of the drive lever is provided as a stroke amplifying means, and at the distal end portion of the drive lever facing the distal end pin of the intermediate lever. An undervoltage trip device with an early contact point for a circuit breaker characterized by forming an inclined cam.

Images