Reversible belt soft start circuit

Abstract

The utility model relates to electrical control technical field discloses a kind of reversible belt soft-start circuit. Including power supply, the coil end of based on forward contactor constitutes forward control circuit, the coil end of based on reverse contactor constitutes reverse control circuit, soft-start device and motor, still include forward time-delay relay and reverse time-delay relay, the coil end of forward time-delay relay is parallel with the coil end of forward contactor in forward control circuit, the coil end of reverse time-delay relay is parallel with the coil end of reverse contactor, the positive pole of power supply is connected with the negative pole of power supply through the parallel circuit of forward control circuit and reverse control circuit, the positive pole of power supply is connected with motor through soft-start device, the auxiliary contact of forward time-delay relay and the auxiliary contact of reverse time-delay relay are connected with the signal end of soft-start transposition. The abnormality of existing contactor has solved the problem of unable to start and interlock failure.

Description

Technical Field

[0001] This utility model relates to the field of electrical control technology, and in particular to a reversible belt soft starter circuit. Background Technology

[0002] In industries such as mining and metallurgy, reversible belt conveyors are sometimes used for material transport due to process requirements. These conveyors employ a single motor, which drives the belt to move in the same direction (forward or reverse) to meet process needs. However, some belt conveyors are quite long, with powerful motors and long power distribution distances. In such cases, soft-start mechanisms are typically used to address the difficulties of starting the conveyor over long distances. Furthermore, interlocking designs in the contactors of the belt motor control circuit are employed to prevent simultaneous forward and reverse rotation of the reversible belt motor, which could lead to transport abnormalities or even motor damage.

[0003] In the power distribution circuit of a reversible belt motor soft starter, the main contacts of the forward and reverse contactors are connected in parallel to control the coil terminals of the forward or reverse contactors to close and connect the power supply, thereby enabling the soft starter to receive power. The internal control circuit detects the external start command signal and begins to smoothly start the motor.

[0004] During actual project debugging, please refer to Figure 1 There are instances where the soft starter indicates a power supply abnormality or phase sequence abnormality, preventing normal startup. This is because when the auxiliary contacts (-KM1 terminals 23 and 24 or -KM2 terminals 23 and 24) of the forward or reverse contactor are closed, the start terminal of the soft starter's internal control circuit receives a start signal. However, the main contacts (-KM1 terminals 1 and 2 or -KM2 terminals 5 and 6) of the forward or reverse contactor are not fully closed, meaning the power supply is not yet fully connected, and the motor cannot start. In this situation, the soft starter interprets the power supply as abnormal, thus preventing normal startup. Furthermore, to prevent the motor from simultaneously reversing forward and reverse, the auxiliary contacts of the forward and reverse contactors are connected in series in the reverse and forward control circuits respectively, achieving interlocking control for forward and reverse rotation. However, since the contactor is a mechanical component, the interlocking will fail when the auxiliary contacts malfunction. Utility Model Content

[0005] This invention provides a reversible belt soft-start circuit to solve the problems of failure to start and interlock failure caused by contactor malfunctions.

[0006] To achieve the above objectives, this utility model employs the following technical solution:

[0007] This utility model provides a reversible belt soft-start circuit, including a power supply, a forward control circuit based on the coil terminal of a forward contactor, a reverse control circuit based on the coil terminal of a reverse contactor, a soft-start device, and a motor. It also includes a forward delay relay and a reverse delay relay. The coil terminal of the forward delay relay is connected in parallel with the coil terminal of the forward contactor in the forward control circuit, and the coil terminal of the reverse delay relay is connected in parallel with the coil terminal of the reverse contactor. The positive terminal of the power supply is connected to the negative terminal of the power supply through a parallel circuit formed by the forward and reverse control circuits. The positive terminal of the power supply is connected to the motor through the soft-start device. The auxiliary contacts of both the forward and reverse delay relays are connected to the signal terminal of the soft-start transposed relay.

[0008] Among them, the response time of both the forward and reverse delay relays is longer than that of the forward and reverse contactors.

[0009] Furthermore, the forward rotation control circuit includes a forward rotation switch, the coil terminal of a forward rotation time delay relay, and the coil terminal of a forward rotation contactor. The coil terminal of the forward rotation time delay relay and the coil terminal of the forward rotation contactor are connected in parallel to form a first parallel circuit, which is then connected in series with the forward rotation switch to form the forward rotation control circuit.

[0010] The reversing control circuit includes a reversing switch, the coil terminal of a reversing time delay relay, and the coil terminal of a reversing contactor. The coil terminal of the reversing time delay relay and the coil terminal of the reversing contactor are connected in parallel to form a second parallel circuit, which is connected in series with the reversing switch to form the reversing control circuit.

[0011] Furthermore, the main contacts of the forward contactor and the main contacts of the reverse contactor are connected in parallel to form a power supply circuit. The positive terminal of the power supply is connected to the power input terminal of the soft starter through the power supply circuit, and the power output terminal of the soft starter is connected to the motor.

[0012] Furthermore, the auxiliary contacts of the forward delay relay and the auxiliary contacts of the reverse delay relay are connected in parallel to form a signal circuit, and the signal output terminal of the soft start device is connected to the signal output terminal through the signal circuit.

[0013] Furthermore, the normally closed auxiliary contact of the forward contactor is located between the reverse switch and the second parallel circuit;

[0014] The normally closed auxiliary contact of the reversing contactor is located between the second parallel circuits of the forward switch.

[0015] The above design achieves an interlocking function between forward and reverse rotation.

[0016] Furthermore, both the forward switch and the reverse switch are double-contact switches, and the auxiliary contact of the forward switch is located between the main contact of the reverse switch and the second parallel circuit.

[0017] The auxiliary contact of the reversing switch is located between the main contact of the forward switch and the first parallel circuit.

[0018] The above design further enhances the basic interlocking function.

[0019] Beneficial effects:

[0020] This utility model provides a reversible belt soft starter circuit. By adding forward and reverse delay relays, the soft starter does not depend on the complete synchronization of the main and auxiliary contacts of the contactor. It is applicable to various soft starter devices and contactors, ensuring the reliability of the soft starter, avoiding occasional soft starter anomalies and failures in engineering projects, improving production stability, avoiding material loss, and thus improving the economic benefits of the factory.

[0021] By selecting forward and reverse switches with auxiliary contacts, and working together with the contactor to interlock and control the forward and reverse rotation of the reversible belt, abnormal equipment operation, or even equipment damage and safety accidents may occur due to the lack of interlock function in the event of contactor interlock failure, thus improving the safety of equipment operation. Attached Figure Description

[0022] Figure 1 This is a schematic circuit diagram of a power supply abnormality or phase sequence abnormality in the soft starter of a reversible belt motor in the background art of this utility model.

[0023] Figure 2 This is a circuit diagram of a reversible belt soft-start circuit according to the present invention. Detailed Implementation

[0024] The technical solution of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "connected" or "linked," etc., are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0026] Please see Figure 2 This application provides a reversible belt soft-start circuit, including a power supply, a forward control circuit based on the coil terminal of a forward contactor-KM1, a reverse control circuit based on the coil terminal of a reverse contactor-KM2, a soft-start device-RQ, and a motor M. It also includes a forward delay relay-KT1 and a reverse delay relay-KT2. The coil terminal of the forward delay relay-KT1 is connected in parallel with the coil terminal of the forward contactor-KM1 in the forward control circuit, and the coil terminal of the reverse delay relay-KT2 is connected in parallel with the coil terminal of the reverse contactor-KM2. The positive terminal of the power supply is connected to the negative terminal of the power supply through a parallel circuit formed by the forward and reverse control circuits. The positive terminal of the power supply is connected to the motor M through the soft-start device-RQ. The auxiliary contacts of both the forward delay relay-KT1 and the reverse delay relay-KT2 are connected to the signal terminal of the soft-start transposed circuit.

[0027] The forward rotation control circuit includes the coil terminals of the forward rotation switch-SF1, the forward rotation time delay relay-KT1, and the forward rotation contactor-KM1. The coil terminals of the forward rotation time delay relay-KT1 and the forward rotation contactor-KM1 are connected in parallel to form the first parallel circuit, and then connected in series with the forward rotation switch-SF1 to form the forward rotation control circuit.

[0028] The reversing control circuit includes a reversing switch-SF2, the coil terminal of a reversing time delay relay-KT2, and the coil terminal of a reversing contactor-KM2. The coil terminals of the reversing time delay relay-KT2 and the reversing contactor-KM2 are connected in parallel to form a second parallel circuit, which is connected in series with the reversing switch-SF2 to form the reversing control circuit.

[0029] The main contacts of the forward contactor-KM1 and the main contacts of the reverse contactor are connected in parallel to form a power supply circuit. The positive terminal of the power supply is connected to the power input terminal of the soft starter-RQ through the power supply circuit, and the power output terminal of the soft starter-RQ is connected to the motor M.

[0030] The auxiliary contacts of the forward delay relay-KT1 and the reverse delay relay-KT2 are connected in parallel to form a signal circuit. The signal output terminal of the soft starter-RQ is connected to the signal output terminal through the signal circuit.

[0031] The normally closed auxiliary contact of the forward contactor-KM1 is located between the reverse switch-SF2 and the second parallel circuit;

[0032] The normally closed auxiliary contact of the reversing contactor-KM2 is located between the second parallel circuit of the forward switch-SF1.

[0033] Both forward switch-SF1 and reverse switch-SF2 are double-contact switches. The auxiliary contact of forward switch-SF1 is located between the main contact of reverse switch-SF2 and the second parallel circuit.

[0034] The auxiliary contact of the reverse switch-SF2 is located between the main contact of the forward switch-SF1 and the first parallel circuit.

[0035] In this embodiment, in addition to the interlocking function achieved by the auxiliary terminals (terminals 11 and 12 of -KM1 and terminal 11 and 12 of -KM2) of the conventional forward contactor-KM1 and reverse contactor-KM2, the interlocking function is further enhanced by setting the forward switch-SF1 and the reverse switch-SF2 as double-contact switches and setting the normally closed auxiliary contacts on another control circuit. When the forward control circuit or the reverse control circuit is turned on, the normally closed auxiliary contacts on the other control circuit are turned off, thus further enhancing the interlocking function on the conventional interlocking circuit.

[0036] When implementing this embodiment, switch-SA is turned to "field operation mode", that is, the branch with forward switch-SF1 and reverse switch-SF2 is connected. To implement the forward control function, connect (press) terminals 13 and 14 of the forward switch-SF1 of the forward control circuit. Since the forward switch-SF1 is a double contact switch, the auxiliary contacts 11 and 12 of the forward switch-SF1 of the reverse control circuit are disconnected, realizing the interlock function.

[0037] After connection, the coils of both the forward contactor-KM1 and the forward delay relay-KT1 are energized. At this time, the main contacts 1 and 2 of the forward contactor-KM1 close. Since the response time of the forward delay relay-KT1 is longer than that of the forward contactor-KM1, the 23 and 24 terminals of the delay relay-KT1 close only after the main contacts 1 and 2 of the forward contactor-KM1 close. The forward power input port of the soft starter-RQ is then energized. After being energized, the COM port of the soft starter-RQ sends a start signal to the start terminal START, and the motor starts to start. Due to the response time design, the start signal is sent only after the soft starter-RQ is energized, so there will be no power supply abnormality.

[0038] The principle of the reverse control circuit is similar to that of the forward control circuit, and will not be elaborated here.

[0039] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A reversible belt soft-start circuit, comprising a power supply, a forward control circuit based on the coil terminals of a forward contactor (-KM1), a reverse control circuit based on the coil terminals of a reverse contactor (-KM2), a soft-start device (-RQ), and a motor (M), characterized in that, It also includes a forward delay relay (-KT1) and a reverse delay relay (-KT2). The coil terminal of the forward delay relay (-KT1) is connected in parallel with the coil terminal of the forward contactor (-KM1) in the forward control circuit. The coil terminal of the reverse delay relay (-KT2) is connected in parallel with the coil terminal of the reverse contactor (-KM2). The positive terminal of the power supply is connected to the negative terminal of the power supply through a parallel circuit formed by the forward control circuit and the reverse control circuit. The positive terminal of the power supply is connected to the motor (M) through a soft starter (-RQ). The auxiliary contacts of the forward delay relay (-KT1) and the reverse delay relay (-KT2) are both connected to the signal terminal of the soft starter.

2. The reversible belt soft-start circuit according to claim 1, characterized in that, The forward rotation control circuit includes a forward rotation switch (-SF1), the coil terminal of a forward rotation time delay relay (-KT1), and the coil terminal of a forward rotation contactor (-KM1). The coil terminal of the forward rotation time delay relay (-KT1) and the coil terminal of the forward rotation contactor (-KM1) are connected in parallel to form a first parallel circuit, and then connected in series with the forward rotation switch (-SF1) to form the forward rotation control circuit. The reversing control circuit includes a reversing switch (-SF2), the coil terminal of a reversing time delay relay (-KT2), ​​and the coil terminal of a reversing contactor (-KM2). The coil terminal of the reversing time delay relay (-KT2) and the coil terminal of the reversing contactor (-KM2) are connected in parallel to form a second parallel circuit, which is connected in series with the reversing switch (-SF2) to form the reversing control circuit.

3. The reversible belt soft-start circuit according to claim 1, characterized in that, The main contacts of the forward contactor (-KM1) and the main contacts of the reverse contactor are connected in parallel to form a power supply circuit. The positive terminal of the power supply is connected to the power input terminal of the soft starter (-RQ) through the power supply circuit, and the power output terminal of the soft starter (-RQ) is connected to the motor (M).

4. The reversible belt soft-start circuit according to claim 1, characterized in that, The auxiliary contacts of the forward delay relay (-KT1) and the reverse delay relay (-KT2) are connected in parallel to form a signal circuit, and the signal output terminal of the soft start device (-RQ) is connected to the signal output terminal through the signal circuit.

5. The reversible belt soft-start circuit according to claim 2, characterized in that, The normally closed auxiliary contact of the forward contactor (-KM1) is located between the reverse switch (-SF2) and the second parallel circuit; The normally closed auxiliary contact of the reversing contactor (-KM2) is located between the second parallel circuits of the forward switch (-SF1).

6. The reversible belt soft-start circuit according to claim 5, characterized in that, Both the forward switch (-SF1) and the reverse switch (-SF2) are double-contact switches. The auxiliary contact of the forward switch (-SF1) is located between the main contact of the reverse switch (-SF2) and the second parallel circuit. The auxiliary contact of the reversing switch (-SF2) is located between the main contact of the forward switch (-SF1) and the first parallel circuit.

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