CN202322055U - Variable frequency control system for crane lifting mechanism - Google Patents

Abstract

The utility model discloses a variable frequency control system for a crane lifting mechanism. The key point is that the control system comprises a weighing and transmitting device, a processor and an electronic change-over switch; the weighing and transmitting device is used for weighing an article to be lifted by the weighing device and inputting a weight signal to the processor; the processor is used for performing judgment treatment and transmitting the judgment result to the electronic change-over switch; and the electronic change-over switch controls a frequency converter to enter a constant-torque variable-frequency speed-adjusting mode or a constant-powder variable-frequency speed-adjusting mode. The variable frequency control system has a simple structure. Based on the original technology, the weighing and transmitting device, the processor and the electronic change-over switch are provided and the traditional artificial judgment is converted into automatic judgment of the processor, so the artificial judgment process is reduced, the work efficiency is improved, and the labor cost is reduced.

Description

A kind of crane hoisting mechanism frequency-changing control system

Technical field

The utility model relates to a kind of hoisting crane, relates in particular to the control system of lifting mechanism on the hoisting crane.

Background technology

Hoisting crane is in daily applying working condition; Usually the lifting mechanism that requires hoisting crane obtains at a high speed to improve the work efficiency of hoisting crane when empty hook or during underloading; Accuracy of positioning adopts low speed with obtaining accurately for safe in utilization in when heavy duty lifting; This just needs large-scale speed ratio; Except adopting the mechanical gear shift governor can obtain the required speed ratio, frequency control also can reach above-mentioned requirements: promptly adopt permanent torque frequency control below the power frequency 50Hz during heavy-duty low-speed, adopt the above constant power frequency-variable speed-regulating of 50Hz when empty hook or underloading high speed.When obtaining identical speed and speed adjustable range, the use power that can reduce motor is with cost-cutting like this.The control characteristics of permanent torque are under different rotating speed; The resistive torque substantially constant of load is that the size and the rotating speed of load resistive torque is irrelevant; The control characteristics of permanent power are under different rotating speed, and the power substantially constant of load is that the size of bearing power and the height of rotating speed have nothing to do.Frequency converter is under the diverse master mode state when adopting the constant torque load frequency control and adopting the constant power load frequency control; Conversion between these two kinds of Different control patterns needs an external signal to be input in the frequency converter, and frequency converter judges that after obtaining signal carrying out speed control by constant torque control still is to carry out speed control by constant power control.Usual way is for being provided with a signal button switch in the present signal inputting method on the control desk of hoisting crane; When lifting mechanism promotes; At first adopt the electronic scale weighing need promote the weight of object, then artificially rule of thumb, manually press the button switch after; Frequency converter is identified as heavy-duty low-speed and carries out permanent torque control, otherwise is permanent power control.

Switching mode needs the staff to handle like this, and work efficiency is lower.

The utility model purpose

The purpose of the utility model provides a kind of crane hoisting mechanism frequency-changing control system of the mode of operation that can automatically switch.

To achieve these goals, adopt following technical scheme: a kind of crane hoisting mechanism frequency-changing control system is characterized in that: said control system comprises weighing sending set, treater and electronic commutator;

Weighing sending set wherein uses the meausring apparatus weighing need promote the weight of article, and with the weight signal input processor;

Treater carries out judgment processing after receiving weight signal, judged result is passed to electronics transform switch;

Electronic commutator, the control frequency converter gets into permanent torque frequency control pattern or constant power frequency-variable speed-regulating pattern.

The utility model is simple in structure, on the basis of original technology, through increasing meausring apparatus sending set, treater and electronic commutator; Conventional artificial is judged that changing treater into judges automatically; Reduce the process of artificial judgment, increased work efficiency, reduced labour cost.

Description of drawings

Fig. 1 is the electrical schematic diagram of the utility model.

The specific embodiment

Below in conjunction with accompanying drawing and specific embodiment the utility model is done and to be further described.

As shown in Figure 1, a kind of crane hoisting mechanism frequency-changing control system comprises

The weighing sending set, the weighing of use meausring apparatus need promote the weight of article, and with the weight signal input processor;

Treater carries out judgment processing after receiving weight signal, judged result is passed to electronics transform switch;

Electronic commutator, the control frequency converter gets into permanent torque frequency control pattern or constant power frequency-variable speed-regulating pattern.

Treater also can input to frequency converter with weight signal carrying out the master mode judgement according to weight signal when, frequency converter is selected different hoisting speeies according to different weight.

Manual pushbutton input before the utility model has been cancelled is no longer judged hoisting weight through artificial, but is differentiated automatically through the output signal of weighing sending set, has improved work efficiency.

Claims (1)

1. crane hoisting mechanism frequency-changing control system, it is characterized in that: said control system comprises weighing sending set, treater and electronic commutator;

Weighing sending set wherein uses the meausring apparatus weighing need promote the weight of article, and with the weight signal input processor;

Treater carries out judgment processing after receiving weight signal, judged result is passed to electronics transform switch;

Electronic commutator, the control frequency converter gets into permanent torque frequency control pattern or constant power frequency-variable speed-regulating pattern.

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