A control circuit for an electric lubrication pump of a casting crane reduction gear

Abstract

The utility model discloses a kind of control circuit of casting crane speed reducer electric lubricating pump, including lubricating motor one circuit, lubricating motor two circuit and control loop;Control loop includes spare switching control loop, lubricating pump one control loop and lubricating pump two control loop;Spare switching control loop is in series with relay K50 and switch S11;Lubricating pump one control loop is in series with relay K1, the normally closed contact of relay K2 and the normally closed contact of relay K50;Lubricating pump two control loop is in series with relay K2, the normally closed contact of relay K1 and the normally open contact of relay K50;Lubricating motor one circuit is in series with the normally open contact of relay K1, and lubricating motor two circuit is in series with the normally open contact of relay K2.The utility model considers the function of one use one spare, and can better guarantee the function integration and logic control of lubricating system, reliable and stable operation.

Description

Technical Field

[0001] This utility model relates to the field of crane control circuit technology, specifically to a control circuit for an electric lubrication pump of a casting crane reducer. Background Technology

[0002] In the steel industry, casting cranes are widely used. As companies expand their production capacity, the specifications of casting cranes are also increasing, including two-beam and four-beam casting cranes, with lifting capacities ranging from 80 tons to 500 tons. Four-beam casting cranes with a lifting capacity of 240 tons or more generally use large single-stage reducers. The gears in these reducers are quite large, and lubrication through gear splashing is insufficient. Therefore, electric lubrication pumps are installed. Considering that casting cranes cannot be stopped, two electric lubrication pumps are typically installed, one for operation and one as a backup. A common control method for the lubrication pumps is that when the lifting mechanism starts and the brake is released, the lubrication system starts simultaneously. A significant drawback of this control method is that because the lifting mechanism operates frequently and involves many inching operations, the lubrication motor operates frequently and is prone to burnout. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the existing defects and provide a control circuit for an electric lubrication pump of a casting crane reducer. It takes into account the function of one in use and one in standby, and can better ensure the functional integration and logic control of the lubrication system. It is reliable and stable in operation and can effectively solve the problems in the background technology.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a control circuit for an electric lubrication pump of a casting crane reducer, comprising a lubrication motor circuit one, a lubrication motor circuit two, and a control circuit; the control circuit includes a backup switching control circuit, a lubrication pump one control circuit, and a lubrication pump two control circuit; The backup switching control circuit is connected in series with relay K50 and switching switch S11; The control circuit of the lubrication pump is connected in series with the normally closed contacts of relays K1 and K2 and the normally closed contact of relay K50. The control circuit of the lubrication pump is connected in series with the normally closed contacts of relays K2 and K1 and the normally open contact of relay K50. The first circuit of the lubrication motor is connected in series with the normally open contact of relay K1, and the second circuit of the lubrication motor is connected in series with the normally open contact of relay K2.

[0005] Preferably, it also includes a brake power-off delay control circuit, which is connected in series with a time delay relay K40 and a lifting brake contactor contact K70, and the lubrication pump one control circuit and the lubrication pump two control circuit are connected in parallel and then connected in series with the normally open contact of the time delay relay K40.

[0006] Preferably, the power-off delay time of the time-delay relay K40 is 30 seconds.

[0007] Compared with the prior art, the beneficial effects of this utility model are: Lubrication motor one works during normal operation, and when lubrication motor one fails, it switches to lubrication motor two; S11 is a switching switch. When S11 is closed, lubrication motor two is selected to work, which takes into account the function of one in use and one in standby, and can better ensure the functional integration and logic control of the lubrication system, and the operation is reliable and stable. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the lubricating oil pump motor circuit of this utility model; Figure 2 This is a schematic diagram of the control loop circuit of this utility model.

[0009] In the diagram: 1. Lubrication motor circuit 1; 2. Lubrication motor circuit 2; 3. Backup switching control circuit; 4. Brake power-off delay control circuit; 5. Lubrication pump 1 control circuit; 6. Lubrication pump 2 control circuit. Detailed Implementation

[0010] 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", "rear", "left", "right" indicating the orientation or positional relationship, they are only corresponding to the drawings of this 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 orientation.

[0011] Please see Figure 1-2 The present invention provides the following technical solution: Example 1: A control circuit for an electric lubrication pump of a casting crane reducer, including a lubrication motor circuit 1, a lubrication motor circuit 2, and a control circuit; the control circuit includes a backup switching control circuit 3, a lubrication pump control circuit 5, and a lubrication pump control circuit 6. The backup switching control circuit 3 is connected in series with relay K50 and switching switch S11; The control circuit 5 of the lubrication pump is connected in series with the normally closed contacts of relays K1 and K2 and the normally closed contact of relay K50. The control circuit 6 of the lubrication pump 2 is connected in series with the normally closed contacts of relays K2 and K1 and the normally open contact of relay K50; The normally open contact of relay K1 is connected in series in circuit 1 of the lubrication motor, and the normally open contact of relay K2 is connected in series in circuit 2 of the lubrication motor. Understandably, during normal operation, lubrication motor one works, i.e., relay K1 is energized, and lubrication pump one works. When lubrication motor one fails, it is necessary to switch to lubrication motor two. Pressing the S11 switch energizes relay K50, and the normally closed contact of relay K50 opens, i.e., the control circuit 5 of lubrication pump one is de-energized. The normally open contact of relay K50 closes, and the control circuit 6 of lubrication pump two is energized. Relay K2 is energized, and the circuit 2 of lubrication motor two is energized, so lubrication motor two works, realizing one in use and one on standby.

[0012] Example 2: Unlike Example 1, it also includes a brake power-off delay control circuit 4. The brake power-off delay control circuit 4 is connected in series with a time delay relay K40 and a hoisting brake contactor contact K70. The lubrication pump one control circuit 5 and the lubrication pump two control circuit 6 are connected in parallel and then connected in series with the normally open contact of the time delay relay K40. When the hoisting mechanism is started, the hoisting brake is opened, the hoisting brake contactor contact K70 is energized, the time delay relay K40 is energized, and the lubrication pump works. When the hoisting stops working, the lubrication pump achieves a delayed shutdown through the delayed power-off of the time delay relay K40. Specifically, the power-off delay time of the time-delay relay K40 is 30 seconds. Adjusting the power-off delay time to 30 seconds protects both the mechanical structure of the reducer and the lubrication pump motor.

[0013] The parts of this utility model not described in detail are prior art. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that this utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and are intended to include all changes that fall within the meaning and scope of equivalents in the content of this utility model.

Claims

1. A control circuit for an electric lubrication pump in a casting crane reducer, characterized in that: It includes a lubrication motor circuit 1 (1), a lubrication motor circuit 2 (2), and a control circuit; the control circuit includes a backup switching control circuit (3), a lubrication pump 1 control circuit (5), and a lubrication pump 2 control circuit (6). The backup switching control circuit (3) is connected in series with relay K50 and switching switch S11; The lubrication pump control circuit (5) is connected in series with the normally closed contacts of relays K1 and K2 and the normally closed contact of relay K50. The lubrication pump control circuit (6) is connected in series with the normally closed contacts of relays K2 and K1 and the normally open contact of relay K50; The first circuit (1) of the lubrication motor is connected in series with the normally open contact of relay K1, and the second circuit (2) of the lubrication motor is connected in series with the normally open contact of relay K2.

2. The control circuit for the electric lubrication pump of the reducer of a casting crane according to claim 1, characterized in that: It also includes a brake power-off delay control circuit (4), which is connected in series with a time delay relay K40 and a lifting brake contactor contact K70. The lubrication pump control circuit (5) and the lubrication pump control circuit (6) are connected in parallel and then connected in series with the normally open contact of the time delay relay K40.

3. The control circuit for the electric lubrication pump of the reducer of a casting crane according to claim 2, characterized in that: The power-off delay time of the time-delay relay K40 is 30 seconds.

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