Twin electric hoist control circuit

Abstract

The utility model provides a kind of twin electric hoist control circuit, comprising: first lifting main circuit, second lifting main circuit and control circuit;First lifting main circuit has first lifting motor and control the first ascending contactor, first descending contactor of first lifting motor positive and negative rotation;Second lifting main circuit has second lifting motor and control the second ascending contactor, second descending contactor of second lifting motor positive and negative rotation;Control circuit has lifting limit branch, 1# selection branch, 2# selection branch, ascending control branch, descending control branch;Twin electric hoist control circuit stops after the ascending or descending limit of one side lifting motor triggers during operation, the lifting motor of other side also synchronously stops and cannot ascend or descend, avoid load momentary tilt, reduce security risk.

Description

Technical Field

[0001] This utility model belongs to the field of lifting equipment technology, specifically relating to a control circuit for a twin electric hoist. Background Technology

[0002] When the lifting height of an electric hoist exceeds 30 meters and a structure such as a grab bucket needs to be suspended, adopting a twin (dual lifting point) structure is a necessary technical solution that can meet the requirements of redundancy, safety, and stability.

[0003] In existing twin electric hoists, during operation, if the limit switch on one side is triggered while the other side can still operate, the load may tilt momentarily, posing a safety hazard.

[0004] Therefore, it is necessary to design a limit interlock synchronization control circuit for twin electric hoists to reduce safety hazards and solve the current technical problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this utility model provides a control circuit for twin electric hoists that features limit interlocking synchronization and reduces safety hazards.

[0006] The technical solution of this utility model is: a control circuit for twin electric hoists, including: First lifting main circuit, second lifting main circuit and control circuit; The first lifting main circuit includes a first lifting motor and a first lifting contactor and a first lowering contactor for controlling the forward and reverse rotation of the first lifting motor; The second lifting main circuit includes a second lifting motor and a second lifting contactor and a second lowering contactor for controlling the forward and reverse rotation of the second lifting motor; The control circuit has a lifting limit branch, a #1 selection branch, a #2 selection branch, an upward control branch, and a downward control branch; The lifting limit branch includes an upper limit branch and a lower limit branch; the upper limit branch has a first upper limit switch, a second upper limit switch, and an upper limit contactor coil connected in series, with a normally closed contact of a first selector contactor connected in parallel to the first upper limit switch, and a normally closed contact of a second selector contactor connected in parallel to the second upper limit switch; the lower limit branch has a first lower limit switch, a second lower limit switch, and a lower limit contactor coil connected in series, with a normally closed contact of a first selector contactor connected in parallel to the first lower limit switch, and a normally closed contact of a second selector contactor connected in parallel to the second lower limit switch; The #1 selection branch has a coil of a first selection switch and a first selection contactor connected in series. The #2 selection branch has a second selection switch and a second selection contactor coil connected in series. The rising control branch has a rising switch connected in series with rising branch #1, and rising branch #2 is connected in parallel to rising branch #1; rising branch #1 has a normally open contact of the first selection contactor, a normally open contact of the rising limit contactor, and a coil of the first rising contactor connected in series; rising branch #2 has a normally open contact of the second selection contactor, a normally open contact of the rising limit contactor, and a coil of the second rising contactor connected in series. The descent control branch has a descent switch connected in series with descent branch #1, and descent branch #2 is connected in parallel to descent branch #1; descent branch #1 has a normally open contact of the first selection contactor, a normally open contact of the descent limit contactor, and a coil of the first descent contactor connected in series; descent branch #2 has a normally open contact of the second selection contactor, a normally open contact of the descent limit contactor, and a coil of the second descent contactor connected in series.

[0007] Furthermore, the control circuit for the twin electric hoists includes a trolley main circuit, wherein the trolley main circuit has two electric hoist trolley motors connected in parallel to the output terminal of the main contactor. The control circuit also has a power control branch, which has a start button, a stop button, a first counterweight limit switch, a second counterweight limit switch and a coil of a power contactor connected in series. The start button is connected in parallel with the normally open contact of the power contactor, the first counterweight limit switch is connected in parallel with the normally closed contact of the first rising contactor, and the second counterweight limit switch is connected in parallel with the normally closed contact of the second rising contactor. Both the first lifting main circuit and the second lifting main circuit are connected to the output terminal of the main contactor; The normally open contact of the power contactor is connected in series with the coil of the main contactor.

[0008] Furthermore, the lifting limit branch, the 1# selection branch, the 2# selection branch, the rising control branch, and the falling control branch are connected in parallel and then connected in series with the start button.

[0009] Furthermore, the first descending contactor's normally closed contact is connected in series on the 1# ascending branch; the second descending contactor's normally closed contact is connected in series on the 2# ascending branch; the first ascending contactor's normally closed contact is connected in series on the 1# descending branch; and the second ascending contactor's normally closed contact is connected in series on the 2# descending branch.

[0010] Furthermore, the first upper limit switch is connected in series with the first overload limiter and then in parallel with the normally closed contact of the first selection contactor; the second upper limit switch is connected in series with the second overload limiter and then in parallel with the normally closed contact of the second selection contactor.

[0011] Furthermore, a first thermal relay is connected to the first lifting main circuit; a second thermal relay is connected to the second lifting main circuit; the first upper limit switch is connected in series with the normally closed contact of the first overload limiter and the first thermal relay, and then connected in parallel with the normally closed contact of the first selection contactor; the second upper limit switch is connected in series with the normally closed contact of the second overload limiter and the second thermal relay, and then connected in parallel with the second selection contactor.

[0012] Furthermore, the control circuit also includes a trolley control branch, which has a left-moving branch and a right-moving branch connected in parallel; the left-moving branch has a left-moving switch, a normally closed contact of a right-moving relay, and a coil of a left-moving relay connected in series; the right-moving branch has a right-moving switch, a normally closed contact of a left-moving relay, and a coil of a right-moving relay connected in series.

[0013] Furthermore, a third thermal relay and a fourth thermal relay are respectively connected to the two electric hoist trolley motors; the left shift branch and the right shift branch are connected in parallel and then connected in series with the normally closed contact of the third thermal relay and the normally closed contact of the fourth thermal relay.

[0014] The beneficial effects of this utility model are: (1) During operation, when the lifting motor of one side stops after the limit switch of the lifting motor is triggered, the lifting motor of the other side also stops synchronously and cannot rise or fall, so as to avoid the load tilting instantly and reduce safety hazards. (2) If the first upper limit switch or the first lower limit switch of the first lifting motor is triggered to open, the corresponding upper limit branch or lower limit branch will be opened. Even if the second upper limit switch and the second lower limit switch of the second lifting motor are closed normally, the corresponding 2# upper branch or 2# lower branch will be opened synchronously. (3) If the second upper limit switch or the second lower limit switch of the second lifting motor is triggered to open, the corresponding upper limit branch or lower limit branch will be opened. Even if the first upper limit switch and the first lower limit switch of the first lifting motor are closed normally, the corresponding 1# upper branch or 1# lower branch will be opened synchronously. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the main circuit of the trolley, the power control branch, and the trolley control branch in this utility model.

[0016] Figure 2 This is the circuit diagram of the lifting and limiting branch in this utility model.

[0017] Figure 3 This is a circuit diagram of the first lifting main circuit, the second lifting main circuit, the 1# selection branch, the 2# selection branch, the rising control branch, and the falling control branch in this utility model.

[0018] Figure 4 This is one of the structural schematic diagrams of the twin electric hoists in this utility model.

[0019] Figure 5 This is the second structural schematic diagram of the twin electric hoists in this utility model. Detailed Implementation

[0020] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are not intended to limit the present invention or its application or use in any way. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention thorough and complete, and to fully express the scope of the present invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0021] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] like Figures 1 to 3As shown, a control circuit for a twin electric hoist is disclosed, comprising: a first lifting main circuit, a second lifting main circuit, and a control circuit; the first lifting main circuit includes a first lifting motor 1Ds and a first ascending contactor KM5 and a first descending contactor KM6 for controlling the forward and reverse rotation of the first lifting motor 1Ds; the second lifting main circuit includes a second lifting motor 1Df and a second ascending contactor KM9 and a second descending contactor KM10 for controlling the forward and reverse rotation of the second lifting motor 1Df; the control circuit includes a lifting limit branch, a 1# selection branch, a 2# selection branch, an ascending control branch, and a descending control branch; the lifting limit branch includes an ascending limit branch and... The lower limit branch has coils of a first upper limit switch S93s, a second upper limit switch S93f, and an upper limit contactor KM97s connected in series. A normally closed contact of a first selector contactor KM30 is connected in parallel to the first upper limit switch S93s, and a normally closed contact of a second selector contactor KM20 is connected in parallel to the second upper limit switch S93f. The lower limit branch has coils of a first lower limit switch S94s, a second lower limit switch S94f, and a lower limit contactor KM98s connected in series. A normally closed contact of a first selector contactor KM30 is connected in parallel to the first lower limit switch S94s, and a normally closed contact of a second selector contactor KM20 is connected in parallel to the second upper limit switch S93f. The 94f circuit has a normally closed contact of the second selector contactor KM20 connected in parallel; the 1# selector branch has the coils of the first selector switch S1-5 and the first selector contactor KM30 connected in series; the 2# selector branch has the coils of the second selector switch S1-6 and the second selector contactor KM20 connected in series; the rise control branch has the rise switch S1-7 connected in series with the 1# rise branch, and the 2# rise branch is connected in parallel with the 1# rise branch; the 1# rise branch has the normally open contact of the first selector contactor KM30, the normally open contact of the rise limit contactor KM97s, and the coil of the first rise contactor KM5 connected in series; the 2# rise branch has the coils of the second selector contactor S1-6 and the second selector contactor KM20 connected in series... The normally open contact of the second selector contactor KM20, the normally open contact of the rise limit contactor KM97s, and the coil of the second rise contactor KM9; the descent control branch has a descent switch S1-8 connected in series with the 1# descent branch, and the 2# descent branch is connected in parallel on the 1# descent branch; the 1# descent branch has a normally open contact of the first selector contactor KM30, a normally open contact of the descent limit contactor KM98s, and the coil of the first descent contactor KM6 connected in series; the 2# descent branch has a normally open contact of the second selector contactor KM20, a normally open contact of the descent limit contactor KM98s, and the coil of the second descent contactor KM10 connected in series.

[0023] In the above embodiment, when the first lifting motor 1Ds and the second lifting motor 1Df start simultaneously, the normally closed contacts of the first selection contactor KM30 and the second selection contactor KM20 are both in the open state; if the first upper limit switch S93s or the first lower limit switch S94s of the first lifting motor 1Ds is triggered to open, the corresponding upper limit branch or lower limit branch will be disconnected, and even if the second upper limit switch S93f and the second lower limit switch S94f of the second lifting motor 1Df are normally closed, the corresponding #2 upper branch or #2 lower branch will be simultaneously disconnected; If the second upper limit switch S93f or the second lower limit switch S94f of the second lifting motor 1Df is triggered and disconnected, the corresponding upper limit branch or lower limit branch will be disconnected. Even if the first upper limit switch S93s and the first lower limit switch S94s of the first lifting motor 1Ds are normally closed, the corresponding 1# upper branch or 1# lower branch will be disconnected simultaneously. During the operation of the twin electric hoists, if the upper or lower limit of one side of the lifting motor is triggered and stops, the lifting motor on the other side will also stop simultaneously and cannot rise or fall, thus avoiding instantaneous tilting of the load and reducing safety hazards.

[0024] In some embodiments, the control circuit for the twin electric hoists includes a trolley main circuit, which has two electric hoist trolley motors connected in parallel to the output terminal of the main contactor K0; the control circuit also has a power control branch, which has a start button S1-1, a stop button S1-2, a first counterweight limit switch S91s, a second counterweight limit switch S91f, and the coil of the power contactor K00 connected in series. The normally open contact of the power contactor K00 is connected in parallel to the start button S1-1, the normally closed contact of the first lifting contactor KM5 is connected in parallel to the first counterweight limit switch S91s, and the normally closed contact of the second lifting contactor KM9 is connected in parallel to the second counterweight limit switch S91f; both the first lifting main circuit and the second lifting main circuit are connected to the main contactor K0. The output terminal of contactor K0 is connected; the normally open contact of power contactor K00 is connected in series with the coil of main contactor K0; when the start button S1-1 is pressed, the coil of power contactor K00 is energized, and the normally closed contact of power contactor K00 is simultaneously energized, and the power control branch is connected and self-locked. When the first hammer limit switch S91s or the second hammer limit switch S91f is triggered to open; if the descent control branch is connected, the normally closed contact of the first ascending contactor KM5 remains closed, and the power control branch is still conducting, which can control the lifting motor to descend; if the ascending control branch is connected, the normally closed contact of the first ascending contactor KM5 opens, the power control branch is disconnected, and the lifting motor cannot be controlled to ascend; thus, the hammer limit switch and the power control branch are interlocked to prevent overshooting.

[0025] In some embodiments, the lifting limit branch, the 1# selection branch, the 2# selection branch, the rising control branch, and the falling control branch are connected in parallel and then connected in series with the start button S1-1. The start button S1-1 controls the on / off state of the lifting limit branch, the 1# selection branch, the 2# selection branch, the rising control branch, and the falling control branch.

[0026] In some embodiments, the power control branch is powered by a transformer T, the input terminal of which is connected to two phase lines; the normally open contact of the power contactor K00 and the coil of the main contactor K0 are connected in series between the input terminals of the transformer T; the transformer T is a 380V to 36V transformer.

[0027] In some embodiments, the normally closed contact of the first descending contactor KM6 is connected in series on the 1# ascending branch; the normally closed contact of the second descending contactor KM10 is connected in series on the 2# ascending branch; the normally closed contact of the first ascending contactor KM5 is connected in series on the 1# descending branch; and the normally closed contact of the second ascending contactor KM9 is connected in series on the 2# descending branch; thereby realizing the interlocking control of the ascending and reversing directions of the first lifting motor 1Ds and the second lifting motor 1Df.

[0028] In some embodiments, the first upper limit switch S93s is connected in series with the first overload limiter F70s and then in parallel with the normally closed contact of the first selector contactor KM30; the second upper limit switch S93f is connected in series with the second overload limiter F70f and then in parallel with the normally closed contact of the second selector contactor KM20; when the first overload limiter F70s and the second overload limiter F70f are activated and disconnected, the first lifting motor 1Ds and the second lifting motor 1Df can be controlled to descend but not ascend, effectively improving the safety of the electric hoist.

[0029] In some embodiments, a first thermal relay FRS1 is connected to the first lifting main circuit; a second thermal relay FRS2 is connected to the second lifting main circuit; a first upper limit switch S93s is connected in series with the normally closed contact of the first overload limiter F70s and the first thermal relay FRS1, and then in parallel with the normally closed contact of the first selection contactor KM30; a second upper limit switch S93f is connected in series with the normally closed contact of the second overload limiter F70f and the second thermal relay FRS2, and then in parallel with the second selection contactor KM20; when any one of the first overload limiter F70s, the first thermal relay FRS1, the second overload limiter F70f, and the second thermal relay FRS2 is activated and disconnected, the first lifting motor 1Ds and the second lifting motor 1Df can be controlled to descend but not ascend, effectively improving the safety of the electric hoist.

[0030] In some embodiments, the control circuit further includes a trolley control branch, which has a left-moving branch and a right-moving branch connected in parallel; the left-moving branch has a left-moving switch S1-3, a normally closed contact of a right-moving relay KM2, and a coil of a left-moving relay KM1 connected in series; the right-moving branch has a right-moving switch S1-4, a normally closed contact of a left-moving relay KM1, and a coil of a right-moving relay KM2 connected in series; thereby realizing the forward and reverse interlock control of the two electric hoist trolley motors.

[0031] In some embodiments, a third thermal relay FRx1 and a fourth thermal relay FRx2 are respectively connected to the two electric hoist trolley motors; the left shift branch and the right shift branch are connected in parallel and then connected in series with the normally closed contact of the third thermal relay FRx1 and the normally closed contact of the fourth thermal relay FRx2; when either the normally closed contact of the third thermal relay FRx1 or the fourth thermal relay FRx2 is activated, the trolley control branch can be disconnected, and the electric hoist trolley cannot be controlled to move; wherein the two electric hoist trolley motors are the first electric hoist trolley motor 1Dx and the second electric hoist trolley motor 2Dx.

[0032] The various embodiments of this utility model have now been described in detail. To avoid obscuring the concept of this utility model, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0033] The embodiments described above only illustrate some implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A control circuit for twin electric hoists, characterized in that, include: First lifting main circuit, second lifting main circuit and control circuit; The first lifting main circuit includes a first lifting motor and a first lifting contactor and a first lowering contactor for controlling the forward and reverse rotation of the first lifting motor; The second lifting main circuit includes a second lifting motor and a second lifting contactor and a second lowering contactor for controlling the forward and reverse rotation of the second lifting motor; The control circuit has a lifting limit branch, a #1 selection branch, a #2 selection branch, an upward control branch, and a downward control branch; The lifting limit branch includes an upper limit branch and a lower limit branch; the upper limit branch has a first upper limit switch, a second upper limit switch, and an upper limit contactor coil connected in series, with a normally closed contact of a first selector contactor connected in parallel to the first upper limit switch, and a normally closed contact of a second selector contactor connected in parallel to the second upper limit switch; the lower limit branch has a first lower limit switch, a second lower limit switch, and a lower limit contactor coil connected in series, with a normally closed contact of a first selector contactor connected in parallel to the first lower limit switch, and a normally closed contact of a second selector contactor connected in parallel to the second lower limit switch; The #1 selection branch has a coil of a first selection switch and a first selection contactor connected in series. The #2 selection branch has a second selection switch and a second selection contactor coil connected in series. The rising control branch has a rising switch connected in series with rising branch #1, and rising branch #2 is connected in parallel to rising branch #1; rising branch #1 has a normally open contact of the first selection contactor, a normally open contact of the rising limit contactor, and a coil of the first rising contactor connected in series; rising branch #2 has a normally open contact of the second selection contactor, a normally open contact of the rising limit contactor, and a coil of the second rising contactor connected in series. The descent control branch has a descent switch connected in series with descent branch #1, and descent branch #2 is connected in parallel to descent branch #1; descent branch #1 has a normally open contact of the first selection contactor, a normally open contact of the descent limit contactor, and a coil of the first descent contactor connected in series; descent branch #2 has a normally open contact of the second selection contactor, a normally open contact of the descent limit contactor, and a coil of the second descent contactor connected in series.

2. The control circuit for the twin electric hoists according to claim 1, characterized in that: The system includes a trolley main circuit, which has two electric hoist trolley motors connected in parallel to the output of the main contactor; the control circuit also includes a power control branch, which has a start button, a stop button, a first counterweight limit switch, a second counterweight limit switch, and a power contactor coil connected in series. The start button has a normally open contact of the power contactor connected in parallel, the first counterweight limit switch has a normally closed contact of the first lifting contactor connected in parallel, and the second counterweight limit switch has a normally closed contact of the second lifting contactor connected in parallel; both the first and second lifting main circuits are connected to the output of the main contactor; the normally open contact of the power contactor is connected in series with the coil of the main contactor.

3. The control circuit for the twin electric hoists according to claim 2, characterized in that: The lifting limit branch, selection branch #1, selection branch #2, lifting control branch, and lowering control branch are connected in parallel and then connected in series with the start button.

4. The control circuit for the twin electric hoists according to claim 1, characterized in that: The first descending contactor is connected in series with a normally closed contact in the first descending contactor on the first descending branch; the second descending contactor is connected in series with a normally closed contact in the second descending branch; the first descending contactor is connected in series with a normally closed contact in the first descending branch; the second descending contactor is connected in series with a normally closed contact in the second descending branch.

5. The control circuit for the twin electric hoists according to claim 1, characterized in that: The first upper limit switch is connected in series with the first overload limiter and then in parallel with the normally closed contact of the first selector contactor; the second upper limit switch is connected in series with the second overload limiter and then in parallel with the normally closed contact of the second selector contactor.

6. The control circuit for the twin electric hoists according to claim 1, characterized in that: A first thermal relay is connected to the first lifting main circuit; a second thermal relay is connected to the second lifting main circuit; the first upper limit switch is connected in series with the normally closed contact of the first overload limiter and the first thermal relay, and then connected in parallel with the normally closed contact of the first selection contactor; the second upper limit switch is connected in series with the normally closed contact of the second overload limiter and the second thermal relay, and then connected in parallel with the second selection contactor.

7. The control circuit for the twin electric hoists according to claim 2, characterized in that: The control circuit also includes a trolley control branch, which has a left-moving branch and a right-moving branch connected in parallel; the left-moving branch has a left-moving switch, a normally closed contact of a right-moving relay, and a coil of a left-moving relay connected in series; the right-moving branch has a right-moving switch, a normally closed contact of a left-moving relay, and a coil of a right-moving relay connected in series.

8. The control circuit for the twin electric hoists according to claim 7, characterized in that: The two electric hoist trolley motors are respectively connected to a third thermal relay and a fourth thermal relay; the left shift branch and the right shift branch are connected in parallel and then connected in series with the normally closed contact of the third thermal relay and the normally closed contact of the fourth thermal relay.

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