CN217417957U - Lifting weight limiting safety protection circuit - Google Patents

Abstract

A lifting heavy hammer limiting safety protection circuit comprises a heavy hammer limiting loop, a heavy hammer resetting loop, a main contactor loop, a lifting mechanism ascending loop and an ascending instruction induction loop which are sequentially connected in parallel, wherein the heavy hammer limiting loop is formed by connecting limiting relays and limiting switches in series, and the heavy hammer resetting loop is formed by connecting resetting relays and resetting switches in series; the main contactor loop is formed by connecting a main contactor, a main contactor control unit and a switch unit in series, wherein the switch unit is formed by connecting a first normally open contact of a limiting relay and a normally open contact of a reset relay in parallel; the lifting loop of the lifting mechanism is formed by connecting a mechanism lifting contactor, a lifting control unit and a second normally open contact of a limiting relay in series; the ascending instruction induction loop can induce the operation action of an ascending instruction of the hoisting mechanism; the circuit can ensure the safe operation of the crane.

Description

Lifting weight limiting safety protection circuit

Technical Field

The utility model belongs to the technical field of crane operation protection technique and specifically relates to a play to rise spacing safety protection circuit of weight.

Background

As is known, the weight limiting circuit of a crane has the function that when a hoisted heavy object touches a weight limiting contactor, the coil of the weight limiting contactor loses power, so that a hoisting mechanism circuit and a main contactor circuit of the crane are disconnected, and the hoisting mechanism and a whole vehicle running mechanism cannot work; conventionally, a heavy hammer reset loop is arranged, a crown block operator presses a heavy hammer bypass button in the heavy hammer reset loop and starts a main contactor loop, and a heavy hammer limit loop is switched on again, so that a hoisting mechanism can normally work and operate, however, a hoisted heavy object is still at the heavy hammer limit contactor, namely the heavy object is at the highest point of the hoisting, and at the moment, if the crown block operator operates by mistake to cause the hoisting mechanism to ascend, an accident that the heavy object rushes to the top is caused;

therefore, in view of the above, there is a need in the market for a protection circuit that can ensure safe operation of a crane.

Disclosure of Invention

In order to overcome the not enough in the background art, the utility model discloses a play to rise spacing safety protection circuit of weight.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a lifting weight limiting safety protection circuit is characterized in that: the system comprises a heavy hammer limit circuit, a heavy hammer reset circuit, a main contactor circuit, a lifting mechanism ascending circuit and an ascending instruction induction circuit which are sequentially connected in parallel, wherein the heavy hammer limit circuit is formed by connecting a limit relay and a limit switch in series, and the heavy hammer reset circuit is formed by connecting a reset relay and a reset switch in series; the main contactor loop is formed by connecting a main contactor, a main contactor control unit and a switch unit in series, wherein the switch unit is formed by connecting a first normally open contact of a limiting relay and a first normally open contact of a reset relay in parallel; the lifting loop of the lifting mechanism is formed by connecting a mechanism lifting contactor, a lifting control unit and a second normally open contact of a limiting relay in series; the ascending instruction induction loop can induce the operation action of the ascending instruction of the hoisting mechanism.

Preferably, the ascending instruction induction loop is formed by connecting an induction unit and an instruction feedback relay in series.

Preferably, a misoperation prompting loop is arranged outside the lifting loop of the lifting mechanism in parallel, and the misoperation prompting loop is formed by connecting a normally closed contact of a limit relay, a second normally open contact of a reset relay, a normally open contact of an instruction feedback relay in series and a buzzer.

Due to the adoption of the technical scheme, the utility model discloses following beneficial effect has:

the utility model discloses a lifting weight limiting safety protection circuit, which can ensure that a lifting mechanism can not execute the lifting action but the descending action can be normally carried out when the heavy object is still hung at the highest point through a second normally open contact of a limiting relay;

in addition, the misoperation prompting loop can give out a sound through the buzzer for warning when the lifting mechanism lifting button is still pressed after the limit switch is triggered.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure: 1. a heavy hammer limit loop; 101. a limit relay; 102. a limit switch; 2. a weight reset loop; 201. resetting the relay; 202. a reset switch; 3. a main contactor loop; 301. a main contactor; 302. a main contactor control unit; 303. a switch unit; 4. a lifting mechanism lifting loop; 401. raising the contactor; 402. a rise control unit; 5. an ascending command induction loop; 501. a command feedback relay; 502. A sensing unit; 6. a misoperation prompting loop; 601. a buzzer.

Detailed Description

In the following description, the technical solution of the present invention will be described with reference to the accompanying drawings in the embodiment of the present invention, it should be understood that, if there are the indicated positions or positional relationships such as "upper", "lower", "front", "rear", "left", "right", etc., it only corresponds to the drawings of the present invention, and for convenience of description, it is not intended to indicate or imply that the indicated device or element must have a specific position:

the safety protection circuit for limiting the lifting weight described in fig. 1 includes a weight limiting circuit 1, a weight resetting circuit 2, a main contactor circuit 3, a lifting mechanism ascending circuit 4 and an ascending instruction induction circuit 5, which are sequentially connected in parallel, wherein the weight limiting circuit 1 is formed by connecting a limiting relay 101 and a limiting switch 102 in series, and the weight resetting circuit 2 is formed by connecting a resetting relay 201 and a resetting switch 202 in series; when the heavy object lifted by the lifting mechanism rises to the highest point, the limit switch 102 is touched, so that the limit switch 102 is switched off;

the main contactor loop 3 is formed by serially connecting a main contactor 301, a main contactor control unit 302 and a switch unit 303, wherein the main contactor 301 is used for controlling an operation motor of the crane, and the switch unit 303 is formed by connecting a first normally open contact of a limit relay 101 and a first normally open contact of a reset relay 201 in parallel; the operation of the main contactor control unit 302 can be cut off and restored through the switch unit 303, wherein the reason for cutting off the main contactor control unit 302 is that after the limit switch 102 is turned off, the limit relay 101 loses power, the first normally open contact of the limit relay 101 is cut off at the moment, meanwhile, the reset switch 202 is not pressed, the weight reset circuit 2 is still in a cut-off state, the first normally open contact of the reset relay 201 is also in a cut-off state, so that the cut-off of the main contactor circuit is caused, and the main contactor control unit 302 is cut off; the reason why the main contactor control unit 302 is recovered is that after the reset switch 202 is pressed, the reset relay 201 is powered on, and the first normally open contact of the reset relay 201 is closed, so that the main contactor control unit 302 is recovered to operate;

the lifting mechanism ascending loop 4 is formed by connecting a mechanism ascending contactor 401, an ascending control unit 402 and a second normally open contact of the limit relay 101 in series, wherein the mechanism ascending contactor 401 is used for controlling the working of a lifting mechanism running motor of the crane, and the ascending control unit 402 is used for controlling the forward and reverse rotation of the lifting mechanism running motor; through the second normally open contact of the limit relay 101, when the heavy object is still hung at the highest point, the lifting mechanism cannot execute lifting action;

the ascending instruction induction loop 5 can induce the operation action of the ascending instruction of the hoisting mechanism; in addition, the ascending instruction induction loop 5 is formed by connecting an induction unit 502 and an instruction feedback relay 501 in series, namely after the ascending instruction of the hoisting mechanism is input, the induction unit 502 is powered on, and then the instruction feedback relay 501 is powered on;

according to the requirement, the lifting mechanism lifting loop 4 is externally connected in parallel with a misoperation prompting loop 6, the misoperation prompting loop 6 is composed of a normally closed contact of a limit relay 101, a second normally open contact of a reset relay 201, a normally open contact of an instruction feedback relay 501 and a buzzer 601, when the limit relay 101 loses power after being triggered by a limit switch 102, the reset relay 201 is powered on after a reset switch 202 is pressed down, and the instruction feedback relay 501 is powered on after a lifting instruction of the lifting mechanism is input, the normally closed contact of the limit relay 101, the second normally open contact of the reset relay 201 and the normally open contact of the instruction feedback relay 501 are all in a closed state, the buzzer 601 is powered on and generates sound, which indicates that a lifted heavy object is located at the moment, a descending operation loop of the lifting mechanism is also conducted, but an operator presses a button for lifting the lifting mechanism by mistake, finally, the warning effect is achieved.

The details of the present invention not described in detail are prior art, and it will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof; the present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not to be construed as limiting the claim concerned.

Claims (3)

1. A lifting weight limiting safety protection circuit is characterized in that: the automatic lifting mechanism comprises a heavy hammer limit loop (1), a heavy hammer reset loop (2), a total contactor loop (3), a lifting mechanism ascending loop (4) and an ascending instruction induction loop (5) which are sequentially connected in parallel, wherein the heavy hammer limit loop (1) is formed by connecting a limit relay (101) and a limit switch (102) in series, and the heavy hammer reset loop (2) is formed by connecting a reset relay (201) and a reset switch (202) in series; the main contactor loop (3) is formed by connecting a main contactor (301), a main contactor control unit (302) and a switch unit (303) in series, wherein the switch unit (303) is formed by connecting a first normally open contact of a limiting relay (101) and a first normally open contact of a reset relay (201) in parallel; the lifting mechanism lifting loop (4) is formed by connecting a mechanism lifting contactor (401), a lifting control unit (402) and a second normally open contact of the limit relay (101) in series; the ascending instruction induction loop (5) can induce the operation action of the ascending instruction of the hoisting mechanism.

2. The safety protection circuit for limiting the lifting weight as claimed in claim 1, wherein: the ascending instruction induction loop (5) is formed by connecting an instruction feedback relay (501) and an induction unit (502) in series.

3. The lifting weight limit safety protection circuit of claim 2, wherein: and a misoperation prompt loop (6) is arranged outside the lifting mechanism lifting loop (4) in parallel, and the misoperation prompt loop (6) is formed by connecting a normally closed contact of a limiting relay (101), a second normally open contact of a reset relay (201), a normally open contact of an instruction feedback relay (501) in series and a buzzer (601).

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