CZ20013242A3 - Current overload circuit breaker of direct current circuit - Google Patents

Abstract

The present invention relates to a direct current circuit current overload circuit breaker, particularly that of traction vehicle. Closing armature (21) of a closing electromagnet (2) is connected with a pull rod (4), preferably in insulated manner. The pull rod (4) is provided with a stop (41) communicating with a projection (31) on a movable arm (3) arranged between two leads (P1, P2). An opening spring (32) acting counter the force of the closing electromagnet (2) is arranged between a frame (1) and the movable arm (3). One of the leads (P1) is provided with an overcurrent release (5) formed by a magnetic circuit with a form (51) and an armature (52). A strip (6) is fastened in swingable manner on said pull rod (4). A detent (71) of a pawl (7), being arranged between the pull rod (4) and the strip (6), directs against the overcurrent release (5) armature (52) wherein the pawl (7) is pivoted either on the pull rod (4) or the strip (6).

Description

Circuit breaker against overload of DC current circuit

Technical field

The invention is a circuit breaker against overload of a direct current circuit, in particular a traction vehicle drive, with electromagnetic switching. The closing armature of the closing solenoid is insulatingly connected to a rod provided with a stop corresponding to a projection on a movable arm arranged between the two inlets. One of the inlets is equipped with an overcurrent release formed by a magnetic circuit with a frame and an anchor.

BACKGROUND OF THE INVENTION

A common type of contactors can also be used against current overload of a DC circuit. A conventional contactor is known whose movable arm arranged between two inlets is controlled by an electromagnet. The solenoid armature is connected to the arm stripped rod. The power of the solenoid is used both to switch on and off. Switching is usually done by the operator. By applying current to the electromagnet, its armature extends and the arm spans a pair of leads. The disconnection is similarly carried out by the return movement of the electromagnet armature also by the intervention of the operator. In the event of a current overload, an external sensor provides a pulse to disconnect. The course of this operation is lengthy due to the conversion of electric current to electromagnetic force, and undesired current overloads have a longer negative effect in the installed circuit. Also, the actual use of the electromagnetic force to deflect the moving arm by the movement of the electromagnet armature is slow. This results in a long-term effect of the arc with side effects. The power of the arc is further enhanced by the current overload, which causes the contacts to open. Of these i

For these reasons, the use of these contactors, supplemented by peripheral wiring with an external Current Overload Sensor, has not been proven.

These drawbacks have been eliminated by the current overload circuit breaker in use, the movable arm of which is arranged between the two inlets is switched on and possibly switched off by a closing solenoid, the armature of which is insulated to the rod. A trip spring is arranged between the movable arm and the frame to prevent the action of the closing solenoid. Closing the circuit, when the moving arm spans both inlets, compresses the opening spring. The rod is provided with a stop corresponding to a projection on the movable arm. The projection is generally designed as a roller with an axle mounted on a movable arm. One of the inlets is equipped with an overcurrent release formed by an electromagnetic circuit with a frame and an anchor. The anchor points towards the drawbar. In the event of a current overload, the armature of the electromagnetic circuit extends and deflects the rod, the projection of which extends beyond the stop. As a result, the force of the closing solenoid ceases to be applied to the movable arm and the movable arm is diverted from the supply by the immediate action of the opening spring and the current circuit is disconnected. A higher current overload condition is necessary to generate the necessary force to open the circuit. The armature force exerted by the electromagnet must overcome the passive resistance to prevent the detent from sliding off the projection. As a rule, in traction vehicles for which this circuit breaker is intended, the current overload must exceed 1000 A. The circuit breaker does not respond reliably to minor overloads because the anchor force is insufficient to separate the stop and the projection. Therefore, the appropriate armature force will not be applied and the movable arm will remain connected to the inlets.

SUMMARY OF THE INVENTION

The circuit breaker according to the invention is designed especially for traction vehicles. Electromagnetic switch-on consists of a closing solenoid whose anchor is insulatedly connected to the tie rod. The stop formed on the rod corresponds to a protrusion on the movable arm which is arranged between two inlets. Against the force of the closing solenoid, a shut-off spring is arranged between the frame and the movable arm. One of the inlets is equipped with an overcurrent release formed by a magnetic circuit with a frame and an anchor. There is a pivotably fixed bar on the rod that holds the projection in the rod stop. The bar and the bar are held together by a latch, the tooth of which is directed against the armature of the overcurrent release. In order to separate the latch from the rod and the bar, less over-current anchor force is required. Upon detachment of the latch, the bar is moved away from the rod and the projection is detached from the rod stop and the force of the release spring deflects the movable arm, thereby releasing the contacts. The latch can be pivotally mounted on a rod or bar.

When the closing solenoid is retracted, the pawl, when swiveled to the pull rod, engages behind the bar by the action of a spring arranged between the pawl and the pull rod. If the pawl is pivotably mounted on the bar, it will engage by the pull rod by the action of a spring arranged between the pawl and the bar.

A spring arranged between the bar and the frame contributes to the inclination of the bar to the rod as well as to keeping the rod in a horizontal position.

Description of the drawing in the drawing

An exemplary embodiment of the circuit breaker according to the invention in overall section in an embodiment with a pawl pivoted on a rod is shown in the accompanying drawing.

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Description of an exemplary embodiment

An arm 3 is movably mounted on the pin 11 in the frame 1. The arm 3 is conductively connected to the first lead P1 by means of a flexible coupling 33. At the free end, the arm 3 is provided with a contact 34 corresponding to the contact 34 'on the second lead P2. Above the contacts 34, 34 'there is an extinction chamber Z. On the arm 3 a projection 31, in this case formed by a roller, is fixed. Opposed to the projection is a stop 41 of the tie rod 4, which is connected by means of an insulator 22 to the closing armature 21 of the closing solenoid 2 fixed to the frame 1. On the tie rod 4 is a pivotably fixed bar 6 connected to the frame 1 by a spring 61. A spring 72 is arranged between the pawl 7 and the pawl 4. A first overhead current P1 is provided with an overcurrent release 5 formed by a magnetic circuit with a frame 51 and an armature 52 controlling the pivot arm 53. A tooth 71 extending from the pawl 7 is directed against the pivot arm 53. Against the action of the closing solenoid 2, a trip spring 32 is arranged between the frame 2 and the arm 3. The movement of the arm 3 as well as its position is sensed by the auxiliary contacts K.

The control solenoid 2 is supplied with current from the control station of the traction vehicle. The electromagnetic field extends the fastening armature 21, which is connected to the rod 4 via the insulator 22. By pulling the rod 4, the stop 41 3 engages the projection 31 in this case formed by a follower mounted rotatably on a pin mounted on the arm. Following engagement of the protrusion 31 by the stop 41, the contacts 34, 34 'move towards one another by moving the arm 3 while compressing the opening spring 32. In normal operation, the contacts 34, 34' are opened by retracting the closing armature 21 into the closing solenoid 2 by operator. In the event of an overload, in which an overcurrent flows from the P1 to the P2 inlet, the overcurrent protection 5 responds by pulling the armature 52 into the frame 51 and swiveling. ·

The arm 53 engages the barb 71 of the latch 7. Turning the latch 7 causes the bar 6 to slide out of the latch 7 and the projection 31 overcomes the stop 41. The return spring 32 causes the contacts 34, 34 'to be detached by the reciprocating spring. . Upon subsequent retraction of the anchor bolt 21 to the initial position by the operator or by means of auxiliary contacts K, when the circuit is open, the spring 61 causes the bar 6 to incline to the protrusion 31 which is clamped between the bar 4 and the bar 6. 4 and the strips 6 secured by the action of a spring 72 on the latch 7 which engages the end of the strips 6.

Claims (4)

PATENT CLAIMS Protecting against current overload of a DC current circuit, in particular a traction vehicle drive, with electromagnetic closing, wherein the closing armature (21) of the closing electromagnet (2) is insulated lač with a rod (4) provided with a stop (41) corresponding to the projection (31) a movable arm (3) arranged between two inlets (P1, P2), wherein a tripping spring (32) is arranged between the frame (1) and the movable arm (3) against the force of the closing electromagnet (2), one of the inlets (P1) is provided with an overcurrent release (5) formed by a magnetic circuit with a frame (51) and an anchor (52), characterized in that on the rod (4) there is a pivotably fixed bar (6), is provided and a pawl (7) whose tooth (71) faces the armature (52) of the overcurrent release (5), wherein the pawl (7) is pivotably mounted on the rod (4) or rail (6). Circuit breaker according to claim 1, characterized in that a spring (71) is arranged between the pawl (7) and the rod (4). Circuit breaker according to claim 1, characterized in that a spring (71) is arranged between the latch (7) and the bar (6). Circuit breaker according to one of claims 1, 2 or 3, characterized in that a spring (6) is provided by the strip (6) and the frame (1).