Control circuit of lubricating oil pump

Abstract

The utility model discloses a control circuit of a lubricating oil pump. The control circuit comprises a control switch QF2, a first branch circuit, a second branch circuit, a third branch circuit and a fourth branch circuit, the first branch circuit is formed by connecting a time-delay open normally-closed contact of a second time relay KT2 and a coil of a first time relay KT1 in series, and the second branch circuit is formed by connecting a time-delay closed normally-open contact of the first time relay KT1 and a coil of the second time relay KT2 in series. The third branch is formed by connecting a time-delay open normally-closed contact of a first time relay KT1 and a coil of a first contactor KM1 in series, and the fourth branch is formed by connecting a time-delay closed normally-open contact of the first time relay KT1 and a coil of a second contactor KM2 in series; and the first branch, the second branch, the third branch and the fourth branch are connected in parallel and then are connected in series with the control switch QF2 to form a closed loop.

Description

Technical field:

[0001] The utility model relates to the technical field of lubricating oil pump control, in particular to a control circuit of a lubricating oil pump. Background technology:

[0002] At present, large equipment generally uses two oil pumps to provide lubricating oil to the system. In the normal state, the two oil pumps are one on and one on standby, and each oil pump needs to be manually started. Due to the lack of timely control by the on-site personnel, the main oil pump is prone to burn out after long-term operation, and the standby oil pump is not used for a long time, causing the motor winding to become damp and the insulation to deteriorate. In the long run, this will shorten the service life of the oil pump and affect normal production. Utility model content:

[0003] The purpose of the utility model is to provide a control circuit for a lubricating oil pump.

[0004] The purpose of the present utility model is implemented by the following technical solutions: a control circuit of a lubricating oil pump, which includes a control switch QF2, a first branch, a second branch, a third branch and a fourth branch; the first branch is composed of a delayed disconnection normally closed contact of the second time relay KT2 and a first time relay KT1 coil connected in series, the second branch is composed of a delayed closing normally open contact of the first time relay KT1 and a second time relay KT2 coil connected in series, the third branch is composed of a delayed disconnection normally closed contact of the first time relay KT1 and a first contactor KM1 coil connected in series, and the fourth branch is composed of a delayed closing normally open contact of the first time relay KT1 and a second contactor KM2 coil connected in series; the first branch, the second branch, the third branch and the fourth branch are connected in parallel and then connected in series with the control switch QF2 to form a closed loop.

[0005] Preferably, in the third branch, the normally closed contact of the first thermal relay FR1 is connected in series between the delayed-off normally closed contact of the first time relay KT1 and the coil of the first contactor KM1.

[0006] Preferably, in the fourth branch, a normally closed contact of the second thermal relay FR2 is connected in series between the delayed closing normally open contact of the first time relay KT1 and the coil of the second contactor KM2.

[0007] Advantages of the utility model: The utility model controls the alternating operation of the main oil pump motor M1 and the standby oil pump motor M2 through the cooperation of the first time relay KT1, the second time relay KT2, the first contactor KM1 and the second contactor KM2, replacing the manual start and stop of the oil pump, thereby avoiding the main oil pump from burning out due to long-term operation and the standby oil pump from being unused for a long time, causing the motor winding to become damp and the insulation to deteriorate. Description of the drawings:

[0008] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creativity or labor.

[0009] Figure 1 It is a circuit diagram of the utility model.

[0010] Figure 2 It is a circuit diagram of the main circuit controlled by the utility model.

[0011] The components in the accompanying drawings are marked as follows: control switch QF2, first time relay KT1, second time relay KT2, first thermal relay FR1, second thermal relay FR2, first contactor KM1, second contactor KM2, first branch 1, second branch 2, third branch 3, fourth branch 4, main switch QF1, main oil pump motor M1, standby oil pump motor M2. Specific implementation method:

[0012] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0013] like Figure 1-Figure 2 As shown, a control circuit for a lubricating oil pump includes a control switch QF2, a first branch 1, a second branch 2, a third branch 3, and a fourth branch 4; the first branch 1 is composed of a delayed-off normally closed contact of the second time relay KT2 and a coil of the first time relay KT1 connected in series, the second branch 2 is composed of a delayed-on normally open contact of the first time relay KT1 and a coil of the second time relay KT2 connected in series, the third branch 3 is composed of a delayed-off normally closed contact of the first time relay KT1, a normally closed contact of the first thermal relay FR1, and a coil of the first contactor KM1 connected in series, and the fourth branch 4 is composed of a delayed-on normally open contact of the first time relay KT1, a normally closed contact of the second thermal relay FR2, and a coil of the second contactor KM2 connected in series; the first branch 1, the second branch 2, the third branch 3, and the fourth branch 4 are connected in parallel and then in series with the control switch QF2 to form a closed loop;

[0014] The main circuit controlled by the present utility model is an existing structure, which includes a main switch QF1, a normally open contact of a first contactor KM1, a normally open contact of a second contactor KM2, a first thermal relay FR1 coil, a second thermal relay FR2 coil, a main oil pump motor M1 and a standby oil pump motor M2; the main switch QF1 is connected in series to the three-phase power line, and the main switch QF1 is connected to the normally open contact of the first contactor KM1 and the normally open contact of the second contactor KM2 through cables; the normally open contact of the first contactor KM1 is connected in series with the coil of the first thermal relay FR1, and then connected in series to the main oil pump motor M1; the normally open contact of the second contactor KM2 is connected in series with the coil of the second thermal relay FR2, and then connected in series to the standby oil pump motor M2, forming the main circuit controlled by the present utility model.

[0015] Working process: Close the main switch QF1 and control switch QF2, the third branch 3 is energized, the coil of the first contactor KM1 is energized, the normally open contact of the first contactor KM1 in the main circuit is closed, and the main oil pump motor M1 starts to run; at the same time, the first branch 1 is energized, the coil of the first time relay KT1 is energized and timing begins;

[0016] When the coil of the first time relay KT1 reaches the set time, the delayed opening normally closed contact of the first time relay KT1 in the third branch 3 is opened, the first contactor KM1 coil loses power, the normally open contact of the closed first contactor KM1 in the main circuit is opened, and the main oil pump motor M1 stops running; at the same time, the delayed closing normally open contact of the first time relay KT1 in the fourth branch 4 is closed, the second contactor KM2 coil is energized, the normally open contact of the second contactor KM2 in the main circuit is closed, and the standby oil pump motor M2 starts running; in addition, at the same time, the delayed closing normally open contact of the first time relay KT1 in the second branch 2 is closed, and the second time relay KT2 coil is energized to start timing;

[0017] When the coil of the second time relay KT2 reaches the set time, the delayed disconnection normally closed contact of the second time relay KT2 in the first branch 1 is disconnected, the coil of the first time relay KT1 loses power, the delayed closing normally open contact of the first time relay KT1 in the fourth branch 4 is disconnected, the coil of the second contactor KM2 loses power, the normally open contact of the second contactor KM2 in the main circuit is disconnected, and the standby oil pump motor M2 stops running; at the same time, the delayed disconnection normally closed contact of the first time relay KT1 in the third branch 3 is closed, the coil of the first contactor KM1 is energized, and the normally open contact of the first contactor KM1 in the main circuit is closed. The main oil pump motor M1 starts to run; at the same time, the delayed closed normally open contact of the first time relay KT1 in the second branch 2 is disconnected, the second time relay KT2 coil loses power, the delayed opened normally closed contact of the second time relay KT2 in the first branch 1 is closed, the first branch 1 is energized again, and the first time relay KT1 coil is energized and the timing is restarted. The above process is repeated to complete the alternating operation of the main oil pump motor M1 and the standby oil pump motor M2, replacing the manual start and stop of the oil pump, avoiding the main oil pump from burning out due to long-term operation and the standby oil pump from being unused for a long time, causing the motor winding to become damp and the insulation to deteriorate.

[0018] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A control circuit for a lubricating oil pump, characterized in that: It includes a control switch QF2, a first branch, a second branch, a third branch and a fourth branch; the first branch is formed by connecting the delayed opening normally closed contact of the second time relay KT2 and the coil of the first time relay KT1 in series, the second branch is formed by connecting the delayed closing normally open contact of the first time relay KT1 and the coil of the second time relay KT2 in series, the third branch is formed by connecting the delayed opening normally closed contact of the first time relay KT1 and the coil of the first contactor KM1 in series, and the fourth branch is formed by connecting the delayed closing normally open contact of the first time relay KT1 and the coil of the second contactor KM2 in series; after the first branch, the second branch, the third branch and the fourth branch are connected in parallel, they are connected in series with the control switch QF2 to form a closed loop.

2. The control circuit of a lubricating oil pump according to claim 1, characterized in that: In the third branch, the normally closed contact of the first thermal relay FR1 is connected in series between the delayed-opening normally closed contact of the first time relay KT1 and the coil of the first contactor KM1.

3. A control circuit for a lubricating oil pump according to claim 1 or 2, characterized in that: In the fourth branch, a normally closed contact of the second thermal relay FR2 is connected in series between the delayed closing normally open contact of the first time relay KT1 and the coil of the second contactor KM2.

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