JP2021140908A - Molded-case circuit breaker - Google Patents

Abstract

To provide a molded-case circuit breaker capable of achieving miniaturization in tripping device and reduction in handle control force.SOLUTION: A molded-case circuit breaker includes: a handle 14; a link pin 18 driven in conjunction with handle movement; and a crossbar 15 working in conjunction with the link pin. The link pin 18 has a U shape with two arms 20, 21, and a cylindrical roller 25 is rotatably provided on an arm 21 in contact with the top face 22 of the crossbar 15. Friction is reduced by the roller 25.SELECTED DRAWING: Figure 3

Description

The present invention relates to an improved molded case circuit breaker provided with a crossbar that opens and closes contacts.

As a circuit breaker for wiring, a circuit breaker having a movable contact is raised and lowered by operating a handle to turn a circuit on and off. For example, in Patent Document 1, a link pin is interposed between the handle and the crossbar, and when the handle is operated in the on direction, the link pin pushes down the crossbar and the movable contact provided on the crossbar is brought into contact with the fixed contact. The circuit breaker is listed.

In Patent Document 1, the link pin has a U-shape, the upper arm portion thereof is connected to the handle, the lower arm portion thereof is connected to the pressing member, and the crossbar is raised and lowered via the pressing member. .. However, recently, a circuit breaker for wiring has become widespread in which the pressing member is omitted for the purpose of miniaturization, etc., and the lower arm of the link pin is in direct contact with the crossbar and the latch holding the crossbar and the latch in the on position. ing.

When the lower arm portion of the link pin is brought into direct contact with the crossbar and the latch in this way, a large frictional force is generated at the contact portion between the link pin and the crossbar and the latch. As is well known, in a circuit breaker of this structure, when an overcurrent or a large current is detected, the latch holding the handle, crossbar and link pin in the on position is removed from the trigger lever. , The spring force rapidly moves the crossbar and movable contact to the trip position to break the circuit. During this trip operation, the latch rotates and the force that the link pin holds the crossbar is lost, so the lower arm of the link pin comes off the crossbar, the movable contact separates from the fixed contact, and the circuit breaks. Will be done.

At the moment of this trip operation, the lower arm of the link pin slides on the surface of the crossbar and comes off from the crossbar. However, as described above, since a large frictional force is generated at the contact portion between the link pin and the crossbar, the inclination angle of the link pin is increased in order to slide the lower arm portion of the link pin on the surface of the crossbar. As a result, it is necessary to apply a large force when operating the trigger lever, which hinders the miniaturization of the tripping mechanism including the trigger lever.

Further, even when the opening / closing operation is performed by operating the handle, the link pin operates in contact with the crossbar and the latch, so that the frictional force of the contact portion is a factor of increasing the handle operating force.

JP-A-2002-75157

Therefore, an object of the present invention is to provide a circuit breaker for wiring that can solve the above-mentioned conventional problems, reduce the size of the tripping mechanism, and reduce the operating force of the handle.

The circuit breaker for wiring of the present invention made to solve the above problems includes a handle, a link pin driven in conjunction with the operation of the handle, and a crossbar that operates in conjunction with the link pin. The pin has a U-shape having two arms, and is characterized in that a tubular roller is rotatably provided on the arm in contact with the crossbar.

The link pin has a bent portion formed at the base of two arms, a convex portion for preventing the roller from coming off is formed at the tip of the arm provided with the roller, and the roller is pulled out from the bent portion. It is preferable to hold it between the convex portion for stopping.

Since the circuit breaker for wiring of the present invention has a structure in which a tubular roller is rotatably provided on the arm portion in contact with the crossbar of the U-shaped link pin provided with two arm portions, the link pin and the crossbar are provided. It is possible to reduce the friction of the contact portion with. Therefore, the force required to operate the trigger lever is reduced, and the tripping mechanism can be miniaturized. In addition, the steering wheel operating force can be reduced.

It is a perspective view which shows the internal structure of the molded case circuit breaker of embodiment. It is a cut perspective view which shows the internal structure of the molded case circuit breaker of embodiment. It is an enlarged perspective view of a main part. It is an exploded perspective view of a link pin. It is an enlarged perspective view which shows the convex part for retaining. It is an enlarged view of a link pin. It is explanatory drawing which shows the on-off state by the handle operation. It is explanatory drawing which shows the trip state.

An embodiment of the present invention will be described below.
FIG. 1 is a perspective view showing the internal structure of the molded case circuit breaker of the embodiment, and FIG. 2 is a cut perspective view thereof. Power supply side terminals 11 and load side terminals 12 are arranged at both ends of the case 10. A handle 14 capable of tilting left and right around the handle shaft 13 is arranged on the upper part of the case 10.

As shown in FIG. 3, a crossbar 15 is arranged below the handle 14. As shown in FIG. 7, the movable contact 16 penetrates the inside of the crossbar 15, and the movable contact 16 is always repelled upward by the spring 17. For this reason, an upward elastic force also acts on the crossbar 15, but as shown in the left figure of FIG. 7, when the handle 14 is in the ON position, a link provided between the handle 14 and the crossbar 15 is provided. The pin 18 pushes down the crossbar 15 and pushes down the movable contact 16 toward the fixed contact 19 to turn on the contacts. When the handle 14 is in the OFF position, the pushing force by the link pin 18 disappears, so that the crossbar 15 and the movable contact 16 move upward by the force of the spring 17 as shown in the right figure of FIG. The contacts are opened.

The details of the link pin 18 are shown in FIGS. 3 to 6. The link pin 18 has a U-shape having two parallel arms 20 and 21, the upper arm 20 is inserted into the lower shaft hole of the handle 14, and the lower arm 21 is a crossbar 15. Is in contact with the upper surface 22 of the. The link pin 18 is formed by bending a round metal rod, and as shown in FIG. 6, bent portions 23 and 24 are formed at the bases of two upper and lower arms.

A cylindrical roller 25 is rotatably provided on the arm portion 21 in contact with the crossbar 15 of the link pin 18. As shown in FIG. 4, the roller 25 is a hollow cylinder having an inner diameter slightly larger than the outer diameter of the arm portion 21, and is inserted into the arm portion 21. Then, as shown in FIGS. 5 and 6, the tip of the arm portion 21 is inserted. A plurality of retaining protrusions 26 are formed on the surface, and the roller 25 is held between the bent portion 24 and the retaining protrusion 26. The retaining convex portion 26 can be formed by crimping the tip of the arm portion 21 using a special tool and plastically flowing the metal of the plurality of concave portions into the plurality of convex portions as shown in FIG.

The movement of the roller 25 to the left side in FIG. 6 is hindered by the left end surface of the roller 25 coming into contact with the bent portion 24. Since the contact area between the left end surface of the roller 25 and the bent portion 24 is small and the contact area is close to point contact, the rotation of the roller 25 with respect to the link pin 18 is not hindered. Further, the movement of the roller 25 to the right side in FIG. 6 is hindered by the contact with the retaining protrusion 26. The contact area between the right end surface of the roller 25 and the retaining protrusion 26 is also small, and does not hinder the rotation of the roller 25 with respect to the link pin 18. The lower arm portion 21 of the link pin 18 holding the roller 25 in this way is in contact with the upper surface 22 of the crossbar 15 via the roller 25 as shown in FIG.

As shown in the left figure of FIG. 8, the link pin 18 is not at a right angle to the upper surface 22 of the crossbar 15 in the ON state, but is in contact with the link pin 18 at a slight inclination. This is to make it easy for the link pin 18 to come off the crossbar 15 during a trip. In addition to this point, the effects of the present invention will be described below.

As shown in FIGS. 3 and 8, known tripping mechanisms such as a latch 30, a trigger lever 31, an armature 32, and a coil 33 are provided on the side of the link pin 18. The trigger lever 31 has an L-shaped cross section and is rotatably supported by a shaft 34. The tip of the trigger lever 31 is in contact with the lower end of the latch 30, and the latch 30 is in contact with the roller 25 at the lower end of the link pin 18. By inclining the link pin 18 with respect to the upper surface 22 of the crossbar 15, a force for moving the roller 25 at the lower end of the link pin 18 to the right in FIG. 8 acts in the ON state. The latch 30 and the trigger lever 31 prevent the movement. At this time, the crossbar 15 is in the pushed-down position, and the movable contact 16 is pushed down toward the fixed contact 19 to turn on the contact.

When a large current flows through the circuit in the ON state, a strong magnetic force is generated in the coil 33. Therefore, as shown in the central figure of FIG. 8, the armature 32 is attracted to the coil 33, and the upper end of the trigger lever 31 is pressed. Extrude to the left in FIG. Therefore, the trigger lever 31 swings counterclockwise around the shaft 34. As a result, the lower end of the latch 30 is disengaged from the trigger lever 31, and the roller 25 at the lower end of the link pin 18 moves to the right in FIG. When the roller 25 at the lower end of the link pin 18 is disengaged from the crossbar 15, the crossbar 15 and the movable contact 16 are rapidly moved upward by the force of the spring 17 as shown in the right figure of FIG. It becomes a state.

As described above, the force for moving the roller 25 at the lower end of the link pin 18 on the upper surface 22 of the crossbar 15 during a trip depends on the tilt angle of the link pin 18 with respect to the upper surface 22 of the crossbar 15, and the larger the tilt angle, the more. It becomes easy to come off from the crossbar 15 at the time of trip. However, when this inclination angle is increased, the pressing force against the latch 30 also becomes stronger, so that the frictional force between the latch 30 and the trigger lever 31 increases, and the rotational moment of the trigger lever 31 required for reliable tripping increases. .. As a result, the pulling mechanism such as the trigger lever 31 and the armature 32 becomes large.

On the other hand, when the inclination angle of the link pin 18 is reduced (close to a right angle), the pressing force from the link pin 18 to the latch 30 is reduced. However, despite the large current flowing and the trigger lever 31 moving, the link pin 18 does not move on the upper surface 22 of the crossbar 15 due to the frictional force between the link pin 18 and the crossbar 15, and the trip cannot be reliably performed. there is a possibility.

When the inclination angle of the link pin 18 is increased in this way, the trigger lever 31 and the armature 32 must be increased in size, and when the inclination angle is decreased, tripping becomes difficult. However, in the present invention, since the roller 25 is provided on the lower arm portion 21 of the link pin 18 and brought into contact with the upper surface 22 of the crossbar 15, the frictional resistance is reduced, and the lower end of the link pin 18 is ensured even if the inclination angle is reduced. Can be moved to. Therefore, according to the present invention, it is possible to reduce the inclination angle of the link pin 18 to reduce the pressing force from the link pin 18 to the latch 30, and to reduce the size of the pulling mechanism such as the trigger lever 31 and the armature 32. can.

Further, when the handle 14 is turned on and off, the link pin 18 swings around the lower end thereof. Therefore, if the roller 25 is provided on the lower arm 21 of the link pin 18, the friction between the link pin 18 and the latch 30 or the link pin 18 and the crossbar 15 is reduced, and the force required for the handle operation is reduced. You can also let them.

As described above, the circuit breaker for wiring of the present invention has an advantage that the tripping mechanism can be miniaturized and the handle operating force can be reduced.

10 Case 11 Power supply side terminal 12 Load side terminal 13 Handle shaft 14 Handle 15 Crossbar 16 Movable contactor 17 Spring 18 Link pin 19 Fixed contactor 20 Link pin arm 21 Link pin arm 22 Cross bar top surface 23 Bending part 24 Bending part 25 Roller 26 Convex part for preventing slipping out 30 Latch 31 Trigger lever 32 Armature 33 Coil 34 Shaft

Claims (2)

It is equipped with a steering wheel, a link pin that is driven in conjunction with the operation of the steering wheel, and a crossbar that operates in conjunction with this link pin.
The link pin is a U-shaped circuit breaker having two arms, and a tubular roller is rotatably provided on the arm in contact with the crossbar. The link pin has a bent portion formed at the base of two arms, a convex portion for retaining a retaining portion is formed at the tip of the arm portion provided with the roller, and the roller is used for bending and retaining the roller. The circuit breaker for wiring according to claim 1, wherein the circuit breaker is held between the convex portion and the convex portion.

Images