European style crane phase sequence reverse connection protection device

Abstract

The utility model discloses a European style crane phase sequence reverse connection protection device which comprises a brake power supply circuit, a double-winding motor power supply circuit and a control loop. The control loop comprises a lifting control loop and a descending control loop; the lifting control loop is connected in series with an overload switch, a lifting rotation limit switch, a heavy hammer limit switch, a relay K10 and a normally closed contact of a relay K20; the descending control loop is connected in series with a relay K20 and a normally closed contact of a relay K10; and a contact of the safety limit upper limit of the lifting rotation limit switch is connected in series with the descending control loop. The lifting limit safety protection device can effectively avoid the safety accident of top rushing when the power supply is wrongly connected, and ensures the lifting limit safety protection under the condition of not increasing the cost.

Description

Technical Field

[0001] The utility model relates to the technical field of crane control, in particular to a phase sequence reverse connection protection device for a European crane. Background Art

[0002] The lifting mechanism of European cranes is controlled by a dual-speed motor and is equipped with lifting and lowering limit switches to protect the safety of the lifting limit. However, during the initial equipment installation or electrical equipment modification, when the power is reconnected, the power phase sequence is easily connected incorrectly. If the power phase sequence is connected incorrectly, in the lifting mechanism controlled by the contactor, when the controller is operated to descend, the hook does not descend but rises instead. However, the limit point of the descent control circuit is set at the lower limit position and does not provide upper limit protection. This will cause the hook to continue to rise, resulting in a top collision or even a rope break accident. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the existing defects and provide a European crane phase sequence reverse connection protection device, which can effectively avoid the safety accidents that may occur when the power supply is connected incorrectly, ensure the lifting limit safety protection without increasing the cost, and effectively solve the problems in the background technology.

[0004] To achieve the above object, the utility model provides the following technical solution: a European crane phase sequence reverse connection protection device, characterized in that: it includes a brake power supply circuit, a double-winding motor power supply circuit and a control circuit; the control circuit includes a lifting control circuit and a lowering control circuit;

[0005] The lifting control circuit is connected in series with an overload switch, a lifting rotation limit switch, a weight limit switch, a relay K10 and a normally closed contact of a relay K20;

[0006] The descending control circuit is connected in series with a relay K20 and a normally closed contact of a relay K10;

[0007] The contact of the upper safety limit of the lifting rotation limit switch is connected in series with the descending control circuit.

[0008] Preferably, the control circuit includes a gear switching control circuit, the gear switching control circuit includes a fast gear control circuit and a slow gear control circuit, the fast gear control circuit and the slow gear control circuit are connected in parallel and then connected in series with the relay K40;

[0009] The control circuit also includes a selection switch S11 and a selection switch S12, the selection switch S11 controls the synchronous on and off of the lifting control circuit and the fast gear control circuit, and the selection switch S12 controls the synchronous on and off of the lowering control circuit and the slow gear control circuit;

[0010] The dual-winding motor power supply circuit includes a fast power supply winding and a slow power supply winding. The fast power supply winding is connected in series with the normally open contact of relay K10, and the slow power supply winding is connected in series with the normally open contact of relay K20. The branches with the same two phases in the fast power supply winding and the slow power supply winding are both connected in series with the normally open contact of relay K40.

[0011] Preferably, the control circuit includes a gear switching control circuit, the gear switching control circuit includes a fast gear control circuit and a slow gear control circuit, the fast gear control circuit and the slow gear control circuit are connected in parallel and then connected in series with the relay K40;

[0012] The control circuit also includes a selection switch S11 and a selection switch S12, the selection switch S11 controls the synchronous on and off of the lifting control circuit and the fast gear control circuit, and the selection switch S12 controls the synchronous on and off of the lowering control circuit and the slow gear control circuit;

[0013] The dual-winding motor power supply circuit includes a fast power supply winding and a slow power supply winding. The fast power supply winding is connected in series with the normally open contact of relay K10, and the slow power supply winding is connected in series with the normally open contact of relay K20. The branches with the same two phases in the fast power supply winding and the slow power supply winding are both connected in series with the normally open contact of relay K40.

[0014] Preferably, the upper safety limit position of the lifting rotation limit switch is higher than the limit position of the weight limit switch.

[0015] Compared with the prior art, the beneficial effects of the utility model are: the upper limit contact of the safety limit of the lifting rotation limit is set as the upper limit point and is connected in series with the descent control circuit. When the power supply wiring is misphased, the descent operation becomes an ascending action. When the hook rises to the upper limit position of the safety limit, the contact connected in series with the descent control circuit is disconnected, and the descent control circuit is disconnected, and the ascending action is prohibited, which plays an upper limit protection role and can effectively avoid safety accidents that may occur when the power supply is connected incorrectly, and ensure the safety protection of the lifting limit without increasing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the main circuit of the utility model;

[0017] Figure 2 This is a schematic diagram of the control circuit of the utility model.

[0018] In the figure: 1 brake power supply circuit, 2 double-winding motor power supply circuit, 3 brake control circuit, 4 lifting control circuit, 5 lowering control circuit, 6 gear switching control circuit. DETAILED DESCRIPTION

[0019] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present application for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction.

[0020] See also Figure 1-2 , the utility model provides the following technical solutions:

[0021] Embodiment 1: A European crane phase sequence reverse protection device comprises a brake power supply circuit 1, a double-winding motor power supply circuit 2 and a control circuit; the control circuit comprises a lifting control circuit 4 and a lowering control circuit 5;

[0022] The lifting control circuit 4 is connected in series with an overload switch, a lifting rotation limit switch, a weight limit switch, a relay K10 and a normally closed contact of a relay K20;

[0023] The descending control loop 5 is connected in series with the relay K20 and the normally closed contact of the relay K10;

[0024] The normally closed contact of relay K10 is connected in series in the lowering control circuit 5, and the normally closed contact of relay K20 is connected in series in the lifting control circuit to realize interlocking control, that is, when the lifting control circuit 4 is energized, the lowering control circuit 5 is de-energized, and when the lowering control circuit 5 is energized, the lifting control circuit is de-energized;

[0025] The contact of the upper limit of the safety limit of the lifting rotation limit switch is connected in series with the lowering control circuit 5;

[0026] It can be understood that the lifting rotation limit usually has four contacts, which are the safety limit upper limit, upper limit, deceleration limit and lower limit. By connecting the safety limit upper limit contact of the lifting rotation limit in series to the descending control circuit, when the power supply wiring is misphased, the descending operation becomes an ascending action. When the hook rises to the safety limit upper limit position, the contact in series with the descending control circuit is disconnected, and the descending control circuit is disconnected, and the ascending action is prohibited, which can effectively avoid the safety accident of the top rushing when the power supply is connected incorrectly;

[0027] It should be noted that the upper safety limit of the lifting rotation limit switch is higher than the limit of the weight limit switch. When ensuring normal operation, the upper safety limit will not affect the descending operation. Specifically, the lifting rotation limit model is: DXZ-4 / 3.

[0028] Embodiment 2: Different from Embodiment 1, the control circuit includes a gear shift control circuit 6, the gear shift control circuit 6 includes a fast gear control circuit and a slow gear control circuit, the fast gear control circuit and the slow gear control circuit are connected in parallel and then connected in series with a relay K40;

[0029] The control circuit also includes a selection switch S11 and a selection switch S12. The selection switch S11 controls the synchronous on and off of the lifting control circuit 4 and the fast gear control circuit, and the selection switch S12 controls the synchronous on and off of the lowering control circuit 5 and the slow gear control circuit;

[0030] The dual-winding motor power supply circuit 2 includes a fast power supply winding and a slow power supply winding. The fast power supply winding is connected in series with the normally open contact of the relay K10, and the slow power supply winding is connected in series with the normally open contact of the relay K20. The branches with the same two phases in the fast power supply winding and the slow power supply winding are both connected in series with the normally open contact of the relay K40.

[0031] When the above control method is adopted, when the selection switch S11 is closed, the lifting control circuit 4 and the fast gear control circuit are closed, the fast power supply winding of the dual-winding motor power supply circuit 2 is energized, the motor rotates rapidly, and the crane lifts rapidly; when the selection switch S12 is closed, the descending control circuit 5 and the slow gear control circuit are closed, the slow power supply winding of the dual-winding motor power supply circuit 2 is energized, the motor rotates slowly, and the crane descends slowly, realizing the rapid rising and slow descending functions of the crane.

[0032] In addition, the control circuit further includes a brake control circuit 3 , the brake control circuit 3 is connected in series with a relay K01 , and the brake power supply circuit 1 is connected in series with a normally open contact of the relay K01 .

[0033] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and it is intended to include all changes that fall within the meaning and scope of equivalent elements in the content of the present invention.

Claims

1. A European crane phase sequence reverse protection device, characterized by: It comprises a brake power supply circuit (1), a dual-winding motor power supply circuit (2) and a control circuit; the control circuit comprises a lifting control circuit (4) and a lowering control circuit (5); The lifting control circuit (4) is connected in series with an overload switch, a lifting rotation limit switch, a weight limit switch, a relay K10 and a normally closed contact of a relay K20; The descending control circuit (5) is connected in series with a relay K20 and a normally closed contact of the relay K10; The contact of the upper safety limit position of the lifting rotation limit switch is connected in series with the lowering control circuit (5).

2. A European crane phase sequence reverse connection protection device according to claim 1, characterized in that: The control circuit comprises a gear switching control circuit (6), the gear switching control circuit (6) comprises a fast gear control circuit and a slow gear control circuit, the fast gear control circuit and the slow gear control circuit are connected in parallel and then connected in series with a relay K40; The control circuit also includes a selection switch S11 and a selection switch S12, wherein the selection switch S11 controls the synchronous on and off of the lifting control circuit (4) and the fast gear control circuit, and the selection switch S12 controls the synchronous on and off of the lowering control circuit (5) and the slow gear control circuit; The dual-winding motor power supply circuit (2) comprises a fast power supply winding and a slow power supply winding, the fast power supply winding is connected in series with a normally open contact of a relay K10, the slow power supply winding is connected in series with a normally open contact of a relay K20, and branches with the same two phases in the fast power supply winding and the slow power supply winding are both connected in series with a normally open contact of a relay K40.

3. A European crane phase sequence reverse connection protection device according to claim 1, characterized in that: The control circuit also includes a brake control circuit (3), the brake control circuit (3) is connected in series with a relay K01, and the brake power supply circuit (1) is connected in series with a normally open contact of the relay K01.

4. The European crane phase sequence reverse connection protection device according to claim 1 is characterized in that: The upper safety limit position of the lifting rotation limit switch is higher than the limit position of the weight limit switch.

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